diff options
author | Gregory Nutt <gnutt@nuttx.org> | 2014-05-14 07:48:47 -0600 |
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committer | Gregory Nutt <gnutt@nuttx.org> | 2014-05-14 07:48:47 -0600 |
commit | 5f9e14d7e3426a42783d6e034f86a559d39a2e9c (patch) | |
tree | f5b8cad2bdda7c2ba3b586d04e7ec69f04d86cd8 | |
parent | 6f0e0c034f607591fc16b79c802e3e93cefc7950 (diff) | |
download | nuttx-5f9e14d7e3426a42783d6e034f86a559d39a2e9c.tar.gz nuttx-5f9e14d7e3426a42783d6e034f86a559d39a2e9c.tar.bz2 nuttx-5f9e14d7e3426a42783d6e034f86a559d39a2e9c.zip |
Add an alternate STM32 I2C driver that works around errata in the F103 chip (and maybe others). From Patrizio Simona
-rw-r--r-- | nuttx/arch/arm/include/sam34/chip.h | 8 | ||||
-rw-r--r-- | nuttx/arch/arm/src/stm32/Kconfig | 11 | ||||
-rw-r--r-- | nuttx/arch/arm/src/stm32/Make.defs | 4 | ||||
-rwxr-xr-x | nuttx/arch/arm/src/stm32/stm32_i2c_alt.c | 2650 |
4 files changed, 2669 insertions, 4 deletions
diff --git a/nuttx/arch/arm/include/sam34/chip.h b/nuttx/arch/arm/include/sam34/chip.h index fbb6690a3..b702e9c64 100644 --- a/nuttx/arch/arm/include/sam34/chip.h +++ b/nuttx/arch/arm/include/sam34/chip.h @@ -831,10 +831,10 @@ * bits[7:4] of each field, bits[3:0] read as zero and ignore writes. */ -#define NVIC_SYSH_PRIORITY_MIN 0xf0 /* All bits[7:4] set is minimum priority */ -#define NVIC_SYSH_PRIORITY_DEFAULT 0x80 /* Midpoint is the default */ -#define NVIC_SYSH_PRIORITY_MAX 0x00 /* Zero is maximum priority */ -#define NVIC_SYSH_PRIORITY_STEP 0x10 /* Four bits of interrupt priority used */ +#define NVIC_SYSH_PRIORITY_MIN 0xf0 /* All bits[7:4] set is minimum priority */ +#define NVIC_SYSH_PRIORITY_DEFAULT 0x80 /* Midpoint is the default */ +#define NVIC_SYSH_PRIORITY_MAX 0x00 /* Zero is maximum priority */ +#define NVIC_SYSH_PRIORITY_STEP 0x10 /* Four bits of interrupt priority used */ /* If CONFIG_ARMV7M_USEBASEPRI is selected, then interrupts will be disabled * by setting the BASEPRI register to NVIC_SYSH_DISABLE_PRIORITY so that most diff --git a/nuttx/arch/arm/src/stm32/Kconfig b/nuttx/arch/arm/src/stm32/Kconfig index 8ea719c82..ba9c4ec65 100644 --- a/nuttx/arch/arm/src/stm32/Kconfig +++ b/nuttx/arch/arm/src/stm32/Kconfig @@ -3052,6 +3052,17 @@ endmenu menu "I2C Configuration" depends on STM32_I2C +config STM32_I2C_ALT + bool "Alternate I2C implementation" + default n if !STM32_PERFORMANCELINE + default y if STM32_PERFORMANCELINE + ---help--- + This selection enables an alternative I2C driver. This alternate + driver implements some rather complex workarounds for errata against + the STM32 F103 "Performance Line". This selection is an option + because: (1) It has not yet been fully verified and (2) It is not + certain that he scope of this workaround is needed only for the F103. + config STM32_I2C_DYNTIMEO bool "Use dynamic timeouts" default n diff --git a/nuttx/arch/arm/src/stm32/Make.defs b/nuttx/arch/arm/src/stm32/Make.defs index 68a856c78..4b15941a3 100644 --- a/nuttx/arch/arm/src/stm32/Make.defs +++ b/nuttx/arch/arm/src/stm32/Make.defs @@ -105,11 +105,15 @@ ifeq ($(CONFIG_NUTTX_KERNEL),y) CHIP_CSRCS += stm32_userspace.c stm32_mpuinit.c endif +ifeq ($(CONFIG_STM32_I2C_ALT),y) +CHIP_CSRCS += stm32_i2c_alt.c +else ifeq ($(CONFIG_STM32_STM32F30XX),y) CHIP_CSRCS += stm32f30xxx_i2c.c else CHIP_CSRCS += stm32_i2c.c endif +endif ifeq ($(CONFIG_USBDEV),y) ifeq ($(CONFIG_STM32_USB),y) diff --git a/nuttx/arch/arm/src/stm32/stm32_i2c_alt.c b/nuttx/arch/arm/src/stm32/stm32_i2c_alt.c new file mode 100755 index 000000000..8445279dc --- /dev/null +++ b/nuttx/arch/arm/src/stm32/stm32_i2c_alt.c @@ -0,0 +1,2650 @@ +/************************************************************************************ + * arch/arm/src/stm32/stm32_i2c_alt.c + * STM32 I2C Hardware Layer - Device Driver + * + * Copyright (C) 2011 Uros Platise. All rights reserved. + * Author: Uros Platise <uros.platise@isotel.eu> + * + * With extensions, modifications by: + * + * Copyright (C) 2011-2014 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Copyright( C) 2014 Patrizio Simona. All rights reserved. + * Author: Patrizio Simona <psimona@ethz.ch> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ************************************************************************************/ + +/* Supports: + * - Master operation, 100 kHz (standard) and 400 kHz (full speed) + * - Multiple instances (shared bus) + * - Interrupt based operation + * + * Structure naming: + * - Device: structure as defined by the nuttx/i2c/i2c.h + * - Instance: represents each individual access to the I2C driver, obtained by + * the i2c_init(); it extends the Device structure from the nuttx/i2c/i2c.h; + * Instance points to OPS, to common I2C Hardware private data and contains + * its own private data, as frequency, address, mode of operation (in the future) + * - Private: Private data of an I2C Hardware + * + * TODO + * - Setup and test polled operation (CONFIG_I2C_POLLED) + * - Check for all possible deadlocks (as BUSY='1' I2C needs to be reset in HW using the I2C_CR1_SWRST) + * - SMBus support (hardware layer timings are already supported) and add SMBA gpio pin + * - Slave support with multiple addresses (on multiple instances): + * - 2 x 7-bit address or + * - 1 x 10 bit addresses + 1 x 7 bit address (?) + * - plus the broadcast address (general call) + * - Multi-master support + * - DMA (to get rid of too many CPU wake-ups and interventions) + * - Be ready for IPMI + * - Write trace events to keep track of ISR flow + */ + +/************************************************************************************ + * Included Files + ************************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <stdbool.h> +#include <semaphore.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/arch.h> +#include <nuttx/irq.h> +#include <nuttx/i2c.h> +#include <nuttx/kmalloc.h> +#include <nuttx/clock.h> + +#include <arch/board/board.h> + +#include "up_arch.h" + +#include "stm32_rcc.h" +#include "stm32_i2c.h" +#include "stm32_waste.h" + +/* At least one I2C peripheral must be enabled */ + +#if defined(CONFIG_STM32_I2C1) || defined(CONFIG_STM32_I2C2) || \ + defined(CONFIG_STM32_I2C3) + +/* This implementation is for the STM32 F1, F2, and F4 only */ +/* Experimentally enabled for STM32L15XX */ + +#if defined(CONFIG_STM32_STM32L15XX) || defined(CONFIG_STM32_STM32F10XX) || \ + defined(CONFIG_STM32_STM32F20XX) || defined(CONFIG_STM32_STM32F40XX) + +/************************************************************************************ + * Pre-processor Definitions + ************************************************************************************/ +/* Configuration ********************************************************************/ +/* CONFIG_I2C_POLLED may be set so that I2C interrupts will not be used. Instead, + * CPU-intensive polling will be used. + */ + +/* Interrupt wait timeout in seconds and milliseconds */ + +#if !defined(CONFIG_STM32_I2CTIMEOSEC) && !defined(CONFIG_STM32_I2CTIMEOMS) +# define CONFIG_STM32_I2CTIMEOSEC 0 +# define CONFIG_STM32_I2CTIMEOMS 500 /* Default is 500 milliseconds */ +#elif !defined(CONFIG_STM32_I2CTIMEOSEC) +# define CONFIG_STM32_I2CTIMEOSEC 0 /* User provided milliseconds */ +#elif !defined(CONFIG_STM32_I2CTIMEOMS) +# define CONFIG_STM32_I2CTIMEOMS 0 /* User provided seconds */ +#endif + +/* Interrupt wait time timeout in system timer ticks */ + +#ifndef CONFIG_STM32_I2CTIMEOTICKS +# define CONFIG_STM32_I2CTIMEOTICKS \ + (SEC2TICK(CONFIG_STM32_I2CTIMEOSEC) + MSEC2TICK(CONFIG_STM32_I2CTIMEOMS)) +#endif + +#ifndef CONFIG_STM32_I2C_DYNTIMEO_STARTSTOP +# define CONFIG_STM32_I2C_DYNTIMEO_STARTSTOP TICK2USEC(CONFIG_STM32_I2CTIMEOTICKS) +#endif + +/* On the STM32F103ZE, there is an internal conflict between I2C1 and FSMC. In that + * case, it is necessary to disable FSMC before each I2C1 access and re-enable FSMC + * when the I2C access completes. + */ + +#undef I2C1_FSMC_CONFLICT +#if defined(CONFIG_STM32_STM32F10XX) && defined(CONFIG_STM32_FSMC) && defined(CONFIG_STM32_I2C1) +# define I2C1_FSMC_CONFLICT +#endif + +/* Macros to convert a I2C pin to a GPIO output */ + +#if defined(CONFIG_STM32_STM32L15XX) +# define I2C_OUTPUT (GPIO_OUTPUT | GPIO_OUTPUT_SET | GPIO_OPENDRAIN | \ + GPIO_SPEED_40MHz) +#elif defined(CONFIG_STM32_STM32F10XX) +# define I2C_OUTPUT (GPIO_OUTPUT | GPIO_OUTPUT_SET | GPIO_CNF_OUTOD | \ + GPIO_MODE_50MHz) +#elif defined(CONFIG_STM32_STM32F20XX) || defined(CONFIG_STM32_STM32F40XX) +# define I2C_OUTPUT (GPIO_OUTPUT | GPIO_FLOAT | GPIO_OPENDRAIN |\ + GPIO_SPEED_50MHz | GPIO_OUTPUT_SET) +#endif + +#define MKI2C_OUTPUT(p)(((p) & (GPIO_PORT_MASK | GPIO_PIN_MASK)) | I2C_OUTPUT) + +/* Debug ****************************************************************************/ +/* CONFIG_DEBUG_I2C + CONFIG_DEBUG enables general I2C debug output. */ + +#ifdef CONFIG_DEBUG_I2C +# define i2cdbg dbg +# define i2cvdbg vdbg +#else +# define i2cdbg(x...) +# define i2cvdbg(x...) +#endif + +/* I2C event trace logic. NOTE: trace uses the internal, non-standard, low-level + * debug interface syslog() but does not require that any other debug + * is enabled. + */ + +#ifndef CONFIG_I2C_TRACE +# define stm32_i2c_tracereset(p) +# define stm32_i2c_tracenew(p,s) +# define stm32_i2c_traceevent(p,e,a) +# define stm32_i2c_tracedump(p) +#endif + +#ifndef CONFIG_I2C_NTRACE +# define CONFIG_I2C_NTRACE 32 +#endif + +/************************************************************************************ + * Private Types + ************************************************************************************/ +/* Interrupt state */ + +enum stm32_intstate_e +{ + INTSTATE_IDLE = 0, /* No I2C activity */ + INTSTATE_WAITING, /* Waiting for completion of interrupt activity */ + INTSTATE_DONE, /* Interrupt activity complete */ +}; + +/* Trace events */ + +#ifdef CONFIG_I2C_TRACE +static const uint32_t I2CEVENT_NONE = 0, /* No events have occurred with this status */ +static const uint32_t I2CEVENT_STATE_ERROR = 1000, /* No correct state detected, diver cannot handle state */ +static const uint32_t I2CEVENT_ISR_SHUTDOWN = 1001, /* ISR gets shutdown */ +static const uint32_t I2CEVENT_ISR_EMPTY_CALL = 1002, /* ISR gets called but no I2C logic comes into play */ +static const uint32_t I2CEVENT_MSG_HANDLING = 1003, /* Message Handling 1/1: advances the msg processing param = msgc*/ +static const uint32_t I2CEVENT_POLL_DEV_NOT_RDY = 1004, /* During polled operation if device is not ready yet */ +static const uint32_t I2CEVENT_ISR_CALL = 1111, /* ISR called*/ + +static const uint32_t I2CEVENT_SENDADDR = 5, /* Start/Master bit set and address sent, param = priv->msgv->addr(EV5 in reference manual) */ +static const uint32_t I2CEVENT_ADDR_HDL_READ_1 = 51, /* Read of length 1 address handling, param = 0 */ +static const uint32_t I2CEVENT_ADDR_HDL_READ_2 = 52, /* Read of length 2 address handling, param = 0 */ +static const uint32_t I2CEVENT_EMPTY_MSG = 5000, /* Empty message detected, param=0 */ + +static const uint32_t I2CEVENT_ADDRESS_ACKED = 6, /* Address has been ACKed(i.e. it's a valid address) param = address */ +static const uint32_t I2CEVENT_ADDRESS_ACKED_READ_1 = 63, /* Event when reading single byte just after address is beeing ACKed, param = 0 */ +static const uint32_t I2CEVENT_ADDRESS_ACKED_READ_2 = 61, /* Event when reading two bytes just after address is beeing ACKed, param = 0 */ +static const uint32_t I2CEVENT_ADDRESS_ACKED_WRITE = 681, /* Address has been ACKed(i.e. it's a valid address) in write mode and byte has been written */ +static const uint32_t I2CEVENT_ADDRESS_NACKED = 6000, /* Address has been NACKed(i.e. it's an invalid address) param = address */ + +static const uint32_t I2CEVENT_READ = 7, /* RxNE = 1 therefore can be read, param = dcnt */ +static const uint32_t I2CEVENT_READ_3 = 72, /* EV7_2 reference manual, reading byte N-2 and N-1 when N >=3 */ +static const uint32_t I2CEVENT_READ_2 = 73, /* EV7_3 reference manual, reading byte 1 and 2 when N == 2 */ +static const uint32_t I2CEVENT_READ_SR_EMPTY = 79, /* DR is full but SR is empty, does not read DR and waits for SR to fill in next ISR */ +static const uint32_t I2CEVENT_READ_LAST_BYTE = 72, /* EV7_2 reference manual last two bytes are in SR and DR */ +static const uint32_t I2CEVENT_READ_ERROR = 7000, /* read mode error */ + +static const uint32_t I2CEVENT_WRITE_TO_DR = 8, /* EV8 reference manual, writing into the data register param = byte to send */ +static const uint32_t I2CEVENT_WRITE_STOP = 82, /* EV8_2 reference manual, set stop bit after write is finished */ +static const uint32_t I2CEVENT_WRITE_RESTART = 83, /* Re-send start bit as next packet is a read */ +static const uint32_t I2CEVENT_WRITE_NO_RESTART = 84, /* don't restart as packet flag says so */ +static const uint32_t I2CEVENT_WRITE_ERROR = 8000, /* Error in write mode, param = 0 */ +static const uint32_t I2CEVENT_WRITE_FLAG_ERROR = 8001; /* Next message has unrecognized flag, param = priv->msgv->flags */ +#endif /* CONFIG_I2C_TRACE */ + +/* Trace data */ + +struct stm32_trace_s +{ + uint32_t status; /* I2C 32-bit SR2|SR1 status */ + uint32_t count; /* Interrupt count when status change */ + uint32_t event; /* Last event that occurred with this status */ + uint32_t parm; /* Parameter associated with the event */ + uint32_t time; /* First of event or first status */ +}; + +/* I2C Device hardware configuration */ + +struct stm32_i2c_config_s +{ + uint32_t base; /* I2C base address */ + uint32_t clk_bit; /* Clock enable bit */ + uint32_t reset_bit; /* Reset bit */ + uint32_t scl_pin; /* GPIO configuration for SCL as SCL */ + uint32_t sda_pin; /* GPIO configuration for SDA as SDA */ +#ifndef CONFIG_I2C_POLLED + int (*isr)(int, void *); /* Interrupt handler */ + uint32_t ev_irq; /* Event IRQ */ + uint32_t er_irq; /* Error IRQ */ +#endif +}; + +/* I2C Device Private Data */ + +struct stm32_i2c_priv_s +{ + const struct stm32_i2c_config_s *config; /* Port configuration */ + int refs; /* Referernce count */ + sem_t sem_excl; /* Mutual exclusion semaphore */ +#ifndef CONFIG_I2C_POLLED + sem_t sem_isr; /* Interrupt wait semaphore */ +#endif + volatile uint8_t intstate; /* Interrupt handshake (see enum stm32_intstate_e) */ + + uint8_t msgc; /* Message count */ + struct i2c_msg_s *msgv; /* Message list */ + uint8_t *ptr; /* Current message buffer */ + int dcnt; /* Current message length */ + uint16_t flags; /* Current message flags */ + bool check_addr_ACK; /* Flag to signal if on next interrupt address has ACKed */ + uint8_t total_msg_len; /* Flag to signal a short read sequence */ + + /* I2C trace support */ + +#ifdef CONFIG_I2C_TRACE + int tndx; /* Trace array index */ + uint32_t start_time; /* Time when the trace was started */ + + /* The actual trace data */ + + struct stm32_trace_s trace[CONFIG_I2C_NTRACE]; +#endif + + uint32_t status; /* End of transfer SR2|SR1 status */ +}; + +/* I2C Device, Instance */ + +struct stm32_i2c_inst_s +{ + struct i2c_ops_s *ops; /* Standard I2C operations */ + struct stm32_i2c_priv_s *priv; /* Common driver private data structure */ + + uint32_t frequency; /* Frequency used in this instantiation */ + int address; /* Address used in this instantiation */ + uint16_t flags; /* Flags used in this instantiation */ +}; + +/************************************************************************************ + * Private Function Prototypes + ************************************************************************************/ + +static inline uint16_t stm32_i2c_getreg(FAR struct stm32_i2c_priv_s *priv, + uint8_t offset); +static inline void stm32_i2c_putreg(FAR struct stm32_i2c_priv_s *priv, uint8_t offset, + uint16_t value); +static inline void stm32_i2c_modifyreg(FAR struct stm32_i2c_priv_s *priv, + uint8_t offset, uint16_t clearbits, + uint16_t setbits); +static inline void stm32_i2c_sem_wait(FAR struct i2c_dev_s *dev); + +#ifdef CONFIG_STM32_I2C_DYNTIMEO +static useconds_t stm32_i2c_tousecs(int msgc, FAR struct i2c_msg_s *msgs); +#endif /* CONFIG_STM32_I2C_DYNTIMEO */ + +static inline int stm32_i2c_sem_waitdone(FAR struct stm32_i2c_priv_s *priv); +static inline void stm32_i2c_sem_waitstop(FAR struct stm32_i2c_priv_s *priv); +static inline void stm32_i2c_sem_post(FAR struct i2c_dev_s *dev); +static inline void stm32_i2c_sem_init(FAR struct i2c_dev_s *dev); +static inline void stm32_i2c_sem_destroy(FAR struct i2c_dev_s *dev); + +#ifdef CONFIG_I2C_TRACE +static void stm32_i2c_tracereset(FAR struct stm32_i2c_priv_s *priv); +static void stm32_i2c_tracenew(FAR struct stm32_i2c_priv_s *priv, uint32_t status); +static void stm32_i2c_traceevent(FAR struct stm32_i2c_priv_s *priv, + uint32_t event, uint32_t parm); +static void stm32_i2c_tracedump(FAR struct stm32_i2c_priv_s *priv); +#endif /* CONFIG_I2C_TRACE */ + +static void stm32_i2c_setclock(FAR struct stm32_i2c_priv_s *priv, + uint32_t frequency); +static inline void stm32_i2c_sendstart(FAR struct stm32_i2c_priv_s *priv); +static inline void stm32_i2c_clrstart(FAR struct stm32_i2c_priv_s *priv); +static inline void stm32_i2c_sendstop(FAR struct stm32_i2c_priv_s *priv); +static inline uint32_t stm32_i2c_getstatus(FAR struct stm32_i2c_priv_s *priv); + +#ifdef I2C1_FSMC_CONFLICT +static inline uint32_t stm32_i2c_disablefsmc(FAR struct stm32_i2c_priv_s *priv); +static inline void stm32_i2c_enablefsmc(uint32_t ahbenr); +#endif /* I2C1_FSMC_CONFLICT */ + +static int stm32_i2c_isr(struct stm32_i2c_priv_s * priv); + +#ifndef CONFIG_I2C_POLLED +#ifdef CONFIG_STM32_I2C1 +static int stm32_i2c1_isr(int irq, void *context); +#endif +#ifdef CONFIG_STM32_I2C2 +static int stm32_i2c2_isr(int irq, void *context); +#endif +#ifdef CONFIG_STM32_I2C3 +static int stm32_i2c3_isr(int irq, void *context); +#endif +#endif /* !CONFIG_I2C_POLLED */ + +static int stm32_i2c_init(FAR struct stm32_i2c_priv_s *priv); +static int stm32_i2c_deinit(FAR struct stm32_i2c_priv_s *priv); +static uint32_t stm32_i2c_setfrequency(FAR struct i2c_dev_s *dev, + uint32_t frequency); +static int stm32_i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits); +static int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, + int count); +static int stm32_i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, + int buflen); +static int stm32_i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen); + +#ifdef CONFIG_I2C_WRITEREAD +static int stm32_i2c_writeread(FAR struct i2c_dev_s *dev, + const uint8_t *wbuffer, int wbuflen, + uint8_t *buffer, int buflen); +#endif /* CONFIG_I2C_WRITEREAD */ + +#ifdef CONFIG_I2C_TRANSFER +static int stm32_i2c_transfer(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, + int count); +#endif /* CONFIG_I2C_TRANSFER */ + +/************************************************************************************ + * Private Data + ************************************************************************************/ + +#ifdef CONFIG_STM32_I2C1 +static const struct stm32_i2c_config_s stm32_i2c1_config = +{ + .base = STM32_I2C1_BASE, + .clk_bit = RCC_APB1ENR_I2C1EN, + .reset_bit = RCC_APB1RSTR_I2C1RST, + .scl_pin = GPIO_I2C1_SCL, + .sda_pin = GPIO_I2C1_SDA, +#ifndef CONFIG_I2C_POLLED + .isr = stm32_i2c1_isr, + .ev_irq = STM32_IRQ_I2C1EV, + .er_irq = STM32_IRQ_I2C1ER +#endif +}; + +struct stm32_i2c_priv_s stm32_i2c1_priv = +{ + .config = &stm32_i2c1_config, + .refs = 0, + .intstate = INTSTATE_IDLE, + .msgc = 0, + .msgv = NULL, + .ptr = NULL, + .dcnt = 0, + .flags = 0, + .status = 0 +}; +#endif + +#ifdef CONFIG_STM32_I2C2 +static const struct stm32_i2c_config_s stm32_i2c2_config = +{ + .base = STM32_I2C2_BASE, + .clk_bit = RCC_APB1ENR_I2C2EN, + .reset_bit = RCC_APB1RSTR_I2C2RST, + .scl_pin = GPIO_I2C2_SCL, + .sda_pin = GPIO_I2C2_SDA, +#ifndef CONFIG_I2C_POLLED + .isr = stm32_i2c2_isr, + .ev_irq = STM32_IRQ_I2C2EV, + .er_irq = STM32_IRQ_I2C2ER +#endif +}; + +struct stm32_i2c_priv_s stm32_i2c2_priv = +{ + .config = &stm32_i2c2_config, + .refs = 0, + .intstate = INTSTATE_IDLE, + .msgc = 0, + .msgv = NULL, + .ptr = NULL, + .dcnt = 0, + .flags = 0, + .status = 0 +}; +#endif + +#ifdef CONFIG_STM32_I2C3 +static const struct stm32_i2c_config_s stm32_i2c3_config = +{ + .base = STM32_I2C3_BASE, + .clk_bit = RCC_APB1ENR_I2C3EN, + .reset_bit = RCC_APB1RSTR_I2C3RST, + .scl_pin = GPIO_I2C3_SCL, + .sda_pin = GPIO_I2C3_SDA, +#ifndef CONFIG_I2C_POLLED + .isr = stm32_i2c3_isr, + .ev_irq = STM32_IRQ_I2C3EV, + .er_irq = STM32_IRQ_I2C3ER +#endif +}; + +struct stm32_i2c_priv_s stm32_i2c3_priv = +{ + .config = &stm32_i2c3_config, + .refs = 0, + .intstate = INTSTATE_IDLE, + .msgc = 0, + .msgv = NULL, + .ptr = NULL, + .dcnt = 0, + .flags = 0, + .status = 0 +}; +#endif + +/* Device Structures, Instantiation */ + +struct i2c_ops_s stm32_i2c_ops = +{ + .setfrequency = stm32_i2c_setfrequency, + .setaddress = stm32_i2c_setaddress, + .write = stm32_i2c_write, + .read = stm32_i2c_read +#ifdef CONFIG_I2C_WRITEREAD + , .writeread = stm32_i2c_writeread +#endif +#ifdef CONFIG_I2C_TRANSFER + , .transfer = stm32_i2c_transfer +#endif +#ifdef CONFIG_I2C_SLAVE + , .setownaddress = stm32_i2c_setownaddress, + .registercallback = stm32_i2c_registercallback +#endif +}; + +/************************************************************************************ + * Private Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: stm32_i2c_getreg + * + * Description: + * Get a 16-bit register value by offset + * + ************************************************************************************/ + +static inline uint16_t stm32_i2c_getreg(FAR struct stm32_i2c_priv_s *priv, + uint8_t offset) +{ + return getreg16(priv->config->base + offset); +} + +/************************************************************************************ + * Name: stm32_i2c_putreg + * + * Description: + * Put a 16-bit register value by offset + * + ************************************************************************************/ + +static inline void stm32_i2c_putreg(FAR struct stm32_i2c_priv_s *priv, uint8_t offset, + uint16_t value) +{ + putreg16(value, priv->config->base + offset); +} + +/************************************************************************************ + * Name: stm32_i2c_modifyreg + * + * Description: + * Modify a 16-bit register value by offset + * + ************************************************************************************/ + +static inline void stm32_i2c_modifyreg(FAR struct stm32_i2c_priv_s *priv, + uint8_t offset, uint16_t clearbits, + uint16_t setbits) +{ + modifyreg16(priv->config->base + offset, clearbits, setbits); +} + +/************************************************************************************ + * Name: stm32_i2c_sem_wait + * + * Description: + * Take the exclusive access, waiting as necessary + * + ************************************************************************************/ + +static inline void stm32_i2c_sem_wait(FAR struct i2c_dev_s *dev) +{ + while (sem_wait(&((struct stm32_i2c_inst_s *)dev)->priv->sem_excl) != 0) + { + ASSERT(errno == EINTR); + } +} + +/************************************************************************************ + * Name: stm32_i2c_tousecs + * + * Description: + * Return a micro-second delay based on the number of bytes left to be processed. + * + ************************************************************************************/ + +#ifdef CONFIG_STM32_I2C_DYNTIMEO +static useconds_t stm32_i2c_tousecs(int msgc, FAR struct i2c_msg_s *msgs) +{ + size_t bytecount = 0; + int i; + + /* Count the number of bytes left to process */ + + for (i = 0; i < msgc; i++) + { + bytecount += msgs[i].length; + } + + /* Then return a number of microseconds based on a user provided scaling + * factor. + */ + + return (useconds_t)(CONFIG_STM32_I2C_DYNTIMEO_USECPERBYTE * bytecount); +} +#endif + +/************************************************************************************ + * Name: stm32_i2c_sem_waitdone + * + * Description: + * Wait for a transfer to complete + * + ************************************************************************************/ + +#ifndef CONFIG_I2C_POLLED +static int stm32_i2c_sem_waitdone(FAR struct stm32_i2c_priv_s *priv) +{ + struct timespec abstime; + irqstate_t flags; + uint32_t regval; + int ret; + + flags = irqsave(); + + /* Enable I2C interrupts */ + + regval = stm32_i2c_getreg(priv, STM32_I2C_CR2_OFFSET); + regval |= (I2C_CR2_ITERREN | I2C_CR2_ITEVFEN); + stm32_i2c_putreg(priv, STM32_I2C_CR2_OFFSET, regval); + + /* Signal the interrupt handler that we are waiting. NOTE: Interrupts + * are currently disabled but will be temporarily re-enabled below when + * sem_timedwait() sleeps. + */ + + priv->intstate = INTSTATE_WAITING; + do + { + /* Get the current time */ + + (void)clock_gettime(CLOCK_REALTIME, &abstime); + + /* Calculate a time in the future */ + +#if CONFIG_STM32_I2CTIMEOSEC > 0 + abstime.tv_sec += CONFIG_STM32_I2CTIMEOSEC; +#endif + + /* Add a value proportional to the number of bytes in the transfer */ + +#ifdef CONFIG_STM32_I2C_DYNTIMEO + abstime.tv_nsec += 1000 * stm32_i2c_tousecs(priv->msgc, priv->msgv); + if (abstime.tv_nsec > 1000 * 1000 * 1000) + { + abstime.tv_sec++; + abstime.tv_nsec -= 1000 * 1000 * 1000; + } + +#elif CONFIG_STM32_I2CTIMEOMS > 0 + abstime.tv_nsec += CONFIG_STM32_I2CTIMEOMS * 1000 * 1000; + if (abstime.tv_nsec > 1000 * 1000 * 1000) + { + abstime.tv_sec++; + abstime.tv_nsec -= 1000 * 1000 * 1000; + } +#endif + /* Wait until either the transfer is complete or the timeout expires */ + + ret = sem_timedwait(&priv->sem_isr, &abstime); + if (ret != OK && errno != EINTR) + { + /* Break out of the loop on irrecoverable errors. This would + * include timeouts and mystery errors reported by sem_timedwait. + * NOTE that we try again if we are awakened by a signal (EINTR). + */ + + break; + } + } + + /* Loop until the interrupt level transfer is complete. */ + + while (priv->intstate != INTSTATE_DONE); + + /* Set the interrupt state back to IDLE */ + + priv->intstate = INTSTATE_IDLE; + + /* Disable I2C interrupts */ + + regval = stm32_i2c_getreg(priv, STM32_I2C_CR2_OFFSET); + regval &= ~I2C_CR2_ALLINTS; + stm32_i2c_putreg(priv, STM32_I2C_CR2_OFFSET, regval); + + irqrestore(flags); + return ret; +} +#else +static int stm32_i2c_sem_waitdone(FAR struct stm32_i2c_priv_s *priv) +{ + uint32_t timeout; + uint32_t start; + uint32_t elapsed; + int ret; + + /* Get the timeout value */ + +#ifdef CONFIG_STM32_I2C_DYNTIMEO + timeout = USEC2TICK(stm32_i2c_tousecs(priv->msgc, priv->msgv)); +#else + timeout = CONFIG_STM32_I2CTIMEOTICKS; +#endif + + /* Signal the interrupt handler that we are waiting. NOTE: Interrupts + * are currently disabled but will be temporarily re-enabled below when + * sem_timedwait() sleeps. + */ + + priv->intstate = INTSTATE_WAITING; + start = clock_systimer(); + + do + { + /* Poll by simply calling the timer interrupt handler until it + * reports that it is done. + */ + + stm32_i2c_isr(priv); + + /* Calculate the elapsed time */ + + elapsed = clock_systimer() - start; + } + + /* Loop until the transfer is complete. */ + + while (priv->intstate != INTSTATE_DONE && elapsed < timeout); + + i2cvdbg("intstate: %d elapsed: %d threshold: %d status: %08x\n", + priv->intstate, elapsed, timeout, priv->status); + + /* Set the interrupt state back to IDLE */ + + ret = priv->intstate == INTSTATE_DONE ? OK : -ETIMEDOUT; + priv->intstate = INTSTATE_IDLE; + return ret; +} +#endif + +/************************************************************************************ + * Name: stm32_i2c_sem_waitstop + * + * Description: + * Wait for a STOP to complete + * + ************************************************************************************/ + +static inline void stm32_i2c_sem_waitstop(FAR struct stm32_i2c_priv_s *priv) +{ + uint32_t start; + uint32_t elapsed; + uint32_t timeout; + uint32_t cr1; + uint32_t sr1; + + /* Select a timeout */ + +#ifdef CONFIG_STM32_I2C_DYNTIMEO + timeout = USEC2TICK(CONFIG_STM32_I2C_DYNTIMEO_STARTSTOP); +#else + timeout = CONFIG_STM32_I2CTIMEOTICKS; +#endif + + /* Wait as stop might still be in progress; but stop might also + * be set because of a timeout error: "The [STOP] bit is set and + * cleared by software, cleared by hardware when a Stop condition is + * detected, set by hardware when a timeout error is detected." + */ + + start = clock_systimer(); + do + { + /* Check for STOP condition */ + + cr1 = stm32_i2c_getreg(priv, STM32_I2C_CR1_OFFSET); + if ((cr1 & I2C_CR1_STOP) == 0) + { + return; + } + + /* Check for timeout error */ + + sr1 = stm32_i2c_getreg(priv, STM32_I2C_SR1_OFFSET); + if ((sr1 & I2C_SR1_TIMEOUT) != 0) + { + return; + } + + /* Calculate the elapsed time */ + + elapsed = clock_systimer() - start; + } + + /* Loop until the stop is complete or a timeout occurs. */ + + while (elapsed < timeout); + + /* If we get here then a timeout occurred with the STOP condition + * still pending. + */ + + i2cvdbg("Timeout with CR1: %04x SR1: %04x\n", cr1, sr1); +} + +/************************************************************************************ + * Name: stm32_i2c_sem_post + * + * Description: + * Release the mutual exclusion semaphore + * + ************************************************************************************/ + +static inline void stm32_i2c_sem_post(FAR struct i2c_dev_s *dev) +{ + sem_post(&((struct stm32_i2c_inst_s *)dev)->priv->sem_excl); +} + +/************************************************************************************ + * Name: stm32_i2c_sem_init + * + * Description: + * Initialize semaphores + * + ************************************************************************************/ + +static inline void stm32_i2c_sem_init(FAR struct i2c_dev_s *dev) +{ + sem_init(&((struct stm32_i2c_inst_s *)dev)->priv->sem_excl, 0, 1); +#ifndef CONFIG_I2C_POLLED + sem_init(&((struct stm32_i2c_inst_s *)dev)->priv->sem_isr, 0, 0); +#endif +} + +/************************************************************************************ + * Name: stm32_i2c_sem_destroy + * + * Description: + * Destroy semaphores. + * + ************************************************************************************/ + +static inline void stm32_i2c_sem_destroy(FAR struct i2c_dev_s *dev) +{ + sem_destroy(&((struct stm32_i2c_inst_s *)dev)->priv->sem_excl); +#ifndef CONFIG_I2C_POLLED + sem_destroy(&((struct stm32_i2c_inst_s *)dev)->priv->sem_isr); +#endif +} + +/************************************************************************************ + * Name: stm32_i2c_trace* + * + * Description: + * I2C trace instrumentation + * + ************************************************************************************/ + +#ifdef CONFIG_I2C_TRACE +static void stm32_i2c_traceclear(FAR struct stm32_i2c_priv_s *priv) +{ + struct stm32_trace_s *trace = &priv->trace[priv->tndx]; + + trace->status = 0; /* I2C 32-bit SR2|SR1 status */ + trace->count = 0; /* Interrupt count when status change */ + trace->event = I2CEVENT_NONE; /* Last event that occurred with this status */ + trace->parm = 0; /* Parameter associated with the event */ + trace->time = 0; /* Time of first status or event */ +} + +static void stm32_i2c_tracereset(FAR struct stm32_i2c_priv_s *priv) +{ + /* Reset the trace info for a new data collection */ + + priv->tndx = 0; + priv->start_time = clock_systimer(); + stm32_i2c_traceclear(priv); +} + +static void stm32_i2c_tracenew(FAR struct stm32_i2c_priv_s *priv, uint32_t status) +{ + struct stm32_trace_s *trace = &priv->trace[priv->tndx]; + + /* Is the current entry uninitialized? Has the status changed? */ + + if (trace->count == 0 || status != trace->status) + { + /* Yes.. Was it the status changed? */ + + if (trace->count != 0) + { + /* Yes.. bump up the trace index (unless we are out of trace entries) */ + + if (priv->tndx >= (CONFIG_I2C_NTRACE-1)) + { + i2cdbg("Trace table overflow\n"); + return; + } + + priv->tndx++; + trace = &priv->trace[priv->tndx]; + } + + /* Initialize the new trace entry */ + + stm32_i2c_traceclear(priv); + trace->status = status; + trace->count = 1; + trace->time = clock_systimer(); + } + else + { + /* Just increment the count of times that we have seen this status */ + + trace->count++; + } +} + +static void stm32_i2c_traceevent(FAR struct stm32_i2c_priv_s *priv, + uint32_t event, uint32_t parm) +{ + struct stm32_trace_s *trace; + + if (event != I2CEVENT_NONE || event != I2CEVENT_POLL_DEV_NOT_RDY) + { + trace = &priv->trace[priv->tndx]; + + /* Initialize the new trace entry */ + + trace->event = event; + trace->parm = parm; + + /* Bump up the trace index (unless we are out of trace entries) */ + + if (priv->tndx >= (CONFIG_I2C_NTRACE-1)) + { + i2cdbg("Trace table overflow\n"); + return; + } + + priv->tndx++; + stm32_i2c_traceclear(priv); + } +} + +static void stm32_i2c_tracedump(FAR struct stm32_i2c_priv_s *priv) +{ + struct stm32_trace_s *trace; + int i; + + syslog("Elapsed time: %d\n", clock_systimer() - priv->start_time); + for (i = 0; i <= priv->tndx; i++) + { + trace = &priv->trace[i]; + syslog("%2d. STATUS: %08x COUNT: %4d EVENT: %4d PARM: %08x TIME: %d\n", + i+1, trace->status, trace->count, trace->event, trace->parm, + trace->time - priv->start_time); + } +} +#endif /* CONFIG_I2C_TRACE */ + +/************************************************************************************ + * Name: stm32_i2c_setclock + * + * Description: + * Set the I2C clock + * + ************************************************************************************/ + +static void stm32_i2c_setclock(FAR struct stm32_i2c_priv_s *priv, uint32_t frequency) +{ + uint16_t cr1; + uint16_t ccr; + uint16_t trise; + uint16_t freqmhz; + uint16_t speed; + + /* Disable the selected I2C peripheral to configure TRISE */ + + cr1 = stm32_i2c_getreg(priv, STM32_I2C_CR1_OFFSET); + stm32_i2c_putreg(priv, STM32_I2C_CR1_OFFSET, cr1 & ~I2C_CR1_PE); + + /* Update timing and control registers */ + + freqmhz = (uint16_t)(STM32_PCLK1_FREQUENCY / 1000000); + ccr = 0; + + /* Configure speed in standard mode */ + + if (frequency <= 100000) + { + /* Standard mode speed calculation */ + + speed = (uint16_t)(STM32_PCLK1_FREQUENCY / (frequency << 1)); + + /* The CCR fault must be >= 4 */ + + if (speed < 4) + { + /* Set the minimum allowed value */ + + speed = 4; + } + + ccr |= speed; + + /* Set Maximum Rise Time for standard mode */ + + trise = freqmhz + 1; + } + + /* Configure speed in fast mode */ + + else /* (frequency <= 400000) */ + { + /* Fast mode speed calculation with Tlow/Thigh = 16/9 */ + +#ifdef CONFIG_STM32_I2C_DUTY16_9 + speed = (uint16_t)(STM32_PCLK1_FREQUENCY / (frequency * 25)); + + /* Set DUTY and fast speed bits */ + + ccr |= (I2C_CCR_DUTY|I2C_CCR_FS); +#else + /* Fast mode speed calculation with Tlow/Thigh = 2 */ + + speed = (uint16_t)(STM32_PCLK1_FREQUENCY / (frequency * 3)); + + /* Set fast speed bit */ + + ccr |= I2C_CCR_FS; +#endif + + /* Verify that the CCR speed value is nonzero */ + + if (speed < 1) + { + /* Set the minimum allowed value */ + + speed = 1; + } + + ccr |= speed; + + /* Set Maximum Rise Time for fast mode */ + + trise = (uint16_t)(((freqmhz * 300) / 1000) + 1); + } + + /* Write the new values of the CCR and TRISE registers */ + + stm32_i2c_putreg(priv, STM32_I2C_CCR_OFFSET, ccr); + stm32_i2c_putreg(priv, STM32_I2C_TRISE_OFFSET, trise); + + /* Bit 14 of OAR1 must be configured and kept at 1 */ + + stm32_i2c_putreg(priv, STM32_I2C_OAR1_OFFSET, I2C_OAR1_ONE); + + /* Re-enable the peripheral (or not) */ + + stm32_i2c_putreg(priv, STM32_I2C_CR1_OFFSET, cr1); +} + +/************************************************************************************ + * Name: stm32_i2c_sendstart + * + * Description: + * Send the START conditions/force Master mode + * + ************************************************************************************/ + +static inline void stm32_i2c_sendstart(FAR struct stm32_i2c_priv_s *priv) +{ + /* Disable ACK on receive by default and generate START */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, I2C_CR1_START); +} + +/************************************************************************************ + * Name: stm32_i2c_clrstart + * + * Description: + * Clear the STOP, START or PEC condition on certain error recovery steps. + * + ************************************************************************************/ + +static inline void stm32_i2c_clrstart(FAR struct stm32_i2c_priv_s *priv) +{ + /* "Note: When the STOP, START or PEC bit is set, the software must + * not perform any write access to I2C_CR1 before this bit is + * cleared by hardware. Otherwise there is a risk of setting a + * second STOP, START or PEC request." + * + * "The [STOP] bit is set and cleared by software, cleared by hardware + * when a Stop condition is detected, set by hardware when a timeout + * error is detected. + * + * "This [START] bit is set and cleared by software and cleared by hardware + * when start is sent or PE=0." The bit must be cleared by software if the + * START is never sent. + * + * "This [PEC] bit is set and cleared by software, and cleared by hardware + * when PEC is transferred or by a START or Stop condition or when PE=0." + */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, + I2C_CR1_START|I2C_CR1_STOP|I2C_CR1_PEC, 0); +} + +/************************************************************************************ + * Name: stm32_i2c_sendstop + * + * Description: + * Send the STOP conditions + * + ************************************************************************************/ + +static inline void stm32_i2c_sendstop(FAR struct stm32_i2c_priv_s *priv) +{ + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, I2C_CR1_STOP); +} + +/************************************************************************************ + * Name: stm32_i2c_getstatus + * + * Description: + * Get 32-bit status (SR1 and SR2 combined) + * + ************************************************************************************/ + +static inline uint32_t stm32_i2c_getstatus(FAR struct stm32_i2c_priv_s *priv) +{ + uint32_t status = stm32_i2c_getreg(priv, STM32_I2C_SR1_OFFSET); + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + return status; +} + +/************************************************************************************ + * Name: stm32_i2c_disablefsmc + * + * Description: + * FSMC must be disable while accessing I2C1 because it uses a common resource + * (LBAR) + * + * NOTE: This is an issue with the STM32F103ZE, but may not be an issue with other + * STM32s. You may need to experiment + * + ************************************************************************************/ + +#ifdef I2C1_FSMC_CONFLICT +static inline uint32_t stm32_i2c_disablefsmc(FAR struct stm32_i2c_priv_s *priv) +{ + uint32_t ret = 0; + uint32_t regval; + + /* Is this I2C1 */ + +#if defined(CONFIG_STM32_I2C2) || defined(CONFIG_STM32_I2C3) + if (priv->config->base == STM32_I2C1_BASE) +#endif + { + /* Disable FSMC unconditionally */ + + ret = getreg32(STM32_RCC_AHBENR); + regval = ret & ~RCC_AHBENR_FSMCEN; + putreg32(regval, STM32_RCC_AHBENR); + } + + return ret; +} + +/************************************************************************************ + * Name: stm32_i2c_enablefsmc + * + * Description: + * Re-enabled the FSMC + * + ************************************************************************************/ + +static inline void stm32_i2c_enablefsmc(uint32_t ahbenr) +{ + uint32_t regval; + + /* Enable AHB clocking to the FSMC only if it was previously enabled. */ + + if ((ahbenr & RCC_AHBENR_FSMCEN) != 0) + { + regval = getreg32(STM32_RCC_AHBENR); + regval |= RCC_AHBENR_FSMCEN; + putreg32(regval, STM32_RCC_AHBENR); + } +} +#else +# define stm32_i2c_disablefsmc(priv) (0) +# define stm32_i2c_enablefsmc(ahbenr) +#endif /* I2C1_FSMC_CONFLICT */ + +/************************************************************************************ + * Name: stm32_i2c_isr + * + * Description: + * Common interrupt service routine (ISR) that handles I2C protocol logic. + * + * This ISR is activated and deactivated by stm32_i2c_waitdone(). Interrupt fires + * on(both ITEVFEN and ITBUFEN are set): + * + * - Start bit + * - Address sent + * - 10-bit header sent + * - Data byte transfer finished + * - Receive buffer not empty + * - Transmit buffer empty + * + * Input Parameters: + * priv - The private struct of the I2C driver. + * + * Returned Value: + * + ************************************************************************************/ + +static int stm32_i2c_isr(struct stm32_i2c_priv_s *priv) +{ + uint32_t status; + + i2cvdbg("I2C ISR called\n"); + + /* Get state of the I2C controller (register SR1 only) + * + * Get control register SR1 only as reading both SR1 and SR2 clears the ADDR + * flag(possibly others) causing the hardware to advance to the next state + * without the proper action being taken. + */ + + status = stm32_i2c_getreg(priv, STM32_I2C_SR1_OFFSET); + + /* Update private version of the state */ + + priv->status = status; + + /* Check if this is a new transmission so to set up the + * trace table accordingly. + */ + + stm32_i2c_tracenew(priv, status); + stm32_i2c_traceevent(priv, I2CEVENT_ISR_CALL, 0); + + /* Messages handling (1/2) + * + * Message handling should only operate when a message has been completely + * sent and after the ISR had the chance to run to set bits after the last + * written/read byte, i.e. priv->dcnt == -1. This is also the case in when + * the ISR is called for the first time. This can seen in stm32_i2c_process() + * before entering the stm32_i2c_sem_waitdone() waiting process. + * + * Message handling should only operate when: + * - A message has been completely sent and there are still messages + * to send(i.e. msgc > 0). + * - After the ISR had the chance to run to set start bit or termination + * flags after the last written/read byte(after last byte dcnt=0, msg + * handling dcnt = -1). + * + * When the ISR is called for the first time the same conditions hold. + * This can seen in stm32_i2c_process() before entering the + * stm32_i2c_sem_waitdone() waiting process. + */ + + if (priv->dcnt == -1 && priv->msgc > 0) + { + i2cvdbg("Switch to new message\n"); + + /* Get current message to process data and copy to private structure */ + + priv->ptr = priv->msgv->buffer; /* Copy buffer to private struct */ + priv->dcnt = priv->msgv->length; /* Set counter of current msg length */ + priv->total_msg_len = priv->msgv->length; /* Set total msg length */ + priv->flags = priv->msgv->flags; /* Copy flags to private struct */ + + i2cvdbg("Current flags %i\n", priv->flags); + + /* Decrease counter to indicate the number of messages left to process */ + + priv->msgc--; + + /* Decrease message pointer. If last message set next message vector to null */ + + if (priv->msgc == 0) + { + priv->msgv == NULL; + + /* Good practice + done by last implementation when messages are finished + * (compatibility) + */ + } + else + { + /* If not last message increment to next message to process */ + + priv->msgv++; + } + + /* Trace event */ + + stm32_i2c_traceevent(priv, I2CEVENT_MSG_HANDLING, priv->msgc); + } + + /* Note the event where we are on the last message and after the last + * byte is handled at the bottom of this function, as it terminates + * the repeated calls to the ISR. + */ + + /* I2C protocol logic + * + * I2C protocol logic follows. It's organized in an if else chain such that + * only one mode of operation is executed every time the ISR is called. + */ + + /* Address Handling + * + * Check if a start bit was set and transmit address with proper format. + * + * Note: + * On first call the start bit has been set by stm32_i2c_waitdone() + * Otherwise it will be set from this ISR. + * + * Remember that after a start bit an address has always to be sent. + */ + + if ((status & I2C_SR1_SB) != 0) + { + /* Start bit is set */ + + i2cvdbg("Entering address handling, status = %i\n", status); + + /* Check for empty message (for robustness) */ + + if (priv->dcnt > 0) + { + /* When reading messages of length 1 or 2 actions have to be taken + * during this event. The following block handles that. + */ + + if (priv->total_msg_len == 1 && (priv->flags & I2C_M_READ)) + { + i2cvdbg("short read N=1: setting NACK\n"); + + /* Set POS bit to zero (can be up from a previous 2 byte receive) */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_POS, 0); + + /* Immediately set NACK */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, 0); + stm32_i2c_traceevent(priv, I2CEVENT_ADDR_HDL_READ_1, 0); + } + else if (priv->total_msg_len == 2 && (priv->flags & I2C_M_READ)) + { + i2cvdbg("short read N=2: setting POS and ACK bits\n"); + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, 0, I2C_CR1_POS); + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, 0, I2C_CR1_ACK); + stm32_i2c_traceevent(priv, I2CEVENT_ADDR_HDL_READ_2, 0); + } + else + { + /* Enable ACK after address byte */ + + i2cvdbg("setting ACK\n"); + + /* Set POS bit to zero (can be up from a previous 2 byte receive) */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_POS, 0); + + /* ACK is the expected answer for N>=3 reads and writes */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, 0, I2C_CR1_ACK); + } + + /* Send address byte with correct 8th bit set(for writing or reading) + * Transmission happens after having written to the data register + * STM32_I2C_DR + */ + + stm32_i2c_putreg(priv, STM32_I2C_DR_OFFSET, + (priv->flags & I2C_M_TEN) ? + 0 :((priv->msgv->addr << 1) | (priv->flags & I2C_M_READ))); + + i2cvdbg("Address sent. Addr=%#02x Write/Read bit=%i\n", + priv->msgv->addr, (priv->flags & I2C_M_READ)); + + /* Flag that address has just been sent */ + + priv->check_addr_ACK = true; + + stm32_i2c_traceevent(priv, I2CEVENT_SENDADDR, priv->msgv->addr); + } + else + { + /* TODO: untested!! */ + + i2cdbg(" An empty message has been detected, ignoring and passing to next message.\n"); + + /* Trace event */ + + stm32_i2c_traceevent(priv, I2CEVENT_EMPTY_MSG, 0); + + /* Set condition to activate msg handling */ + + priv->dcnt = -1; + + /* Restart ISR by setting an interrupt buffer bit */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR2_OFFSET, 0, I2C_CR2_ITBUFEN); + } + } + + /* Address cleared event + * + * Check if the address cleared, i.e. the driver found a valid address. + * If a NACK was received the address is invalid, if an ACK was + * received the address is valid and transmission can continue. + */ + + /* Check for NACK after an address*/ + +#ifndef CONFIG_I2C_POLLED + /* When polling the i2c ISR it's not possible to determine when + * an address has been ACKed(i.e. the address is valid). + * + * The mechanism to deal a NACKed address is to wait for the I2C + * call to timeout (value defined in defconfig by one of the + * following: CONFIG_STM32_I2C_DYNTIMEO, CONFIG_STM32_I2CTIMEOSEC, + * CONFIG_STM32_I2CTIMEOMS, CONFIG_STM32_I2CTIMEOTICKS). + * + * To be safe in the case of a timeout/NACKed address a stop bit + * is set on the bus to clear it. In POLLED operation it's done + * stm32_i2c_process() after the call to stm32_i2c_sem_waitdone(). + * + * In ISR driven operation the stop bit in case of a NACKed address + * is set in the ISR itself. + * + * Note: this commentary is found in both places. + */ + + else if ((status & I2C_SR1_ADDR) == 0 && priv->check_addr_ACK) + { + i2cvdbg("Invalid Address. Setting stop bit and clearing message\n"); + i2cvdbg("status %i\n", status); + + /* Set condition to terminate msg chain transmission as address is invalid. */ + + priv->dcnt = -1; + priv->msgc = 0; + + i2cvdbg("dcnt %i , msgc %i\n", priv->dcnt, priv->msgc); + + /* Reset flag to check for valid address */ + + priv->check_addr_ACK = false; + + /* Send stop bit to clear bus */ + + stm32_i2c_sendstop(priv); + + /* Trace event */ + + stm32_i2c_traceevent(priv, I2CEVENT_ADDRESS_NACKED, priv->msgv->addr); + } +#endif + + /* ACK in read mode, ACK in write mode is handled separately */ + + else if ((priv->flags & I2C_M_READ) != 0 && (status & I2C_SR1_ADDR) != 0 && + priv->check_addr_ACK) + { + /* Reset check addr flag as we are handling this event */ + + priv->check_addr_ACK = false; + + /* Clear ADDR flag by reading SR2 and adding it to status */ + + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + + /* Note: + * + * When reading a single byte the stop condition has to be set + * immediately after clearing the state flags, which happens + * when reading SR2(as SR1 has already been read). + * + * Similarly when reading 2 bytes the NACK bit has to be set as just + * after the clearing of the address. + */ + + if (priv->dcnt == 1 && priv->total_msg_len == 1) + { + /* this should only happen when receiving a message of length 1 */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR2_OFFSET, 0, I2C_CR2_ITBUFEN); + stm32_i2c_sendstop(priv); + + i2cvdbg("Address ACKed beginning data reception\n"); + i2cvdbg("short read N=1: programming stop bit\n"); + priv->dcnt--; + + /* Trace */ + + stm32_i2c_traceevent(priv, I2CEVENT_ADDRESS_ACKED_READ_1, 0); + } + else if (priv->dcnt == 2 && priv->total_msg_len == 2) + { + /* This should only happen when receiving a message of length 2 + * Set NACK + */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, 0); + + i2cvdbg("Address ACKed beginning data reception\n"); + i2cvdbg("short read N=2: programming NACK\n"); + + /* Trace */ + + stm32_i2c_traceevent(priv, I2CEVENT_ADDRESS_ACKED_READ_2, 0); + } + else + { + i2cvdbg("Address ACKed beginning data reception\n"); + + /* Trace */ + + stm32_i2c_traceevent(priv, I2CEVENT_ADDRESS_ACKED, 0); + } + } + + /* Write mode + * + * Handles all write related I2C protocol logic. Also handles the + * ACK event after clearing the ADDR flag as the write has to + * begin immediately after. + */ + + else if ((priv->flags & (I2C_M_READ)) == 0 && + (status & (I2C_SR1_ADDR | I2C_SR1_TXE)) != 0) + { + /* The has cleared(ADDR is set, ACK was received after the address) + * or the transmit buffer is empty flag has been set(TxE) then we can + * transmit the next byte. + */ + + i2cvdbg("Entering write mode dcnt = %i msgc = %i\n", + priv->dcnt, priv->msgc); + + /* Clear ADDR flag by reading SR2 and adding it to status */ + + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + + /* Address has cleared so don't check on next call */ + + priv->check_addr_ACK = false; + + /* Check if we have transmitted the whole message or we are after + * the last byte where the stop condition or else(according to the + * msg flags) has to be set. + */ + + if (priv->dcnt >= 1) + { + /* Transmitting message. Send byte == write data into write register */ + + stm32_i2c_putreg(priv, STM32_I2C_DR_OFFSET, *priv->ptr++); + + /* Decrease current message length */ + + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_TO_DR, priv->dcnt); + priv->dcnt--; + + } + else if (priv->dcnt == 0) + { + /* After last byte, check what to do based on next message flags */ + + if (priv->msgc == 0) + { + /* If last message send stop bit */ + + stm32_i2c_sendstop(priv); + i2cvdbg("Stop sent dcnt = %i msgc = %i\n", priv->dcnt, priv->msgc); + + /* Decrease counter to get to next message */ + + priv->dcnt--; + i2cvdbg("dcnt %i\n", priv->dcnt); + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_STOP, priv->dcnt); + } + + /* If there is a next message with no flags or the read flag + * a restart sequence has to be sent. + * Note msgv already points to the next message. + */ + + else if (priv->msgc > 0 && + (priv->msgv->flags == 0 || (priv->msgv[0].flags & I2C_M_READ) != 0)) + { + stm32_i2c_sendstart(priv); + + i2cvdbg("Restart detected!\n"); + i2cvdbg("Nextflag %i\n", priv->msgv[0].flags); + + /* Decrease counter to get to next message */ + + priv->dcnt--; + i2cvdbg("dcnt %i\n", priv->dcnt); + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_RESTART, priv->dcnt); + } + + /* If there is a next message with the NO_RESTART flag + * do nothing. + */ + + else if (priv->msgc > 0 && ((priv->msgv->flags & I2C_M_NORESTART) != 0)) + { + /* Set condition to get to next message */ + + priv->dcnt =- 1; + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_NO_RESTART, priv->dcnt); + } + else + { + i2cdbg("Write mode: next message has an unrecognized flag.\n"); + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_FLAG_ERROR, priv->msgv->flags); + } + + } + else + { + i2cdbg("Write mode error.\n"); + stm32_i2c_traceevent(priv, I2CEVENT_WRITE_ERROR, 0); + } + } + + /* Read mode + * + * Handles all read related I2C protocol logic. + * + * * * * * * * WARNING STM32F1xx HARDWARE ERRATA * * * * * * * + * source: https://github.com/hikob/openlab/blob/master/drivers/stm32/i2c.c + * + * RXNE-only events should not be handled since it sometimes + * fails. Only BTF & RXNE events should be handled (with the + * consequence of slowing down the transfer). + * + * It seems that when a RXNE interrupt is handled 'around' + * the end of the next byte reception, the DR register read + * is ignored by the i2c controller: it does not flush the + * DR with next byte + * + * Thus we read twice the same byte and we read effectively + * read one byte less than expected from the i2c slave point + * of view. + * + * Example: + * + we want to receive 6 bytes (B1 to B6) + * + the problem appear when reading B3 + * -> we read B1 B2 B3 B3 B4 B5(B3 twice) + * -> the i2c transfer was B1 B2 B3 B4 B5(B6 is not sent) + */ + + else if ((priv->flags & (I2C_M_READ)) != 0 && (status & I2C_SR1_RXNE) != 0) + { + /* When read flag is set and the receive buffer is not empty + *(RXNE is set) then the driver can read from the data register. + */ + + i2cvdbg("Entering read mode dcnt = %i msgc = %i, status %i\n", + priv->dcnt, priv->msgc, status); + + /* Implementation of method 2 for receiving data following + * the stm32f1xx reference manual. + */ + + /* Case total message length = 1 */ + + if (priv->dcnt == 0 && priv->total_msg_len == 1) + { + i2cvdbg("short read N=1: Read data from data register(DR)\n"); + + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + priv->dcnt--; + stm32_i2c_traceevent(priv, I2CEVENT_READ, 0); + } + + /* Case total message length = 2 */ + + else if (priv->dcnt == 2 && priv->total_msg_len == 2 && !(status & I2C_SR1_BTF)) + { + i2cvdbg("short read N=2: DR full, SR empty. Waiting for more bytes.\n"); + stm32_i2c_traceevent(priv, I2CEVENT_READ_SR_EMPTY, 0); + } + else if (priv->dcnt == 2 && priv->total_msg_len == 2 && (status & I2C_SR1_BTF)) + { + i2cvdbg("short read N=2: DR and SR full setting stop bit and reading twice\n"); + + stm32_i2c_sendstop(priv); + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + priv->dcnt--; + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + priv->dcnt--; + + /* Stop request already programmed so set dcnt for next message */ + + priv->dcnt--; + + /* Set trace */ + + stm32_i2c_traceevent(priv, I2CEVENT_READ_2, 0); + } + + /* Case total message length >= 3 */ + + else if (priv->total_msg_len >= 3 && !(status & I2C_SR1_BTF)) + { + /* If the shift register is still empty (i.e. BTF is low) + * then do nothing and wait for it to fill in the next ISR. + *(should not happen in ISR mode, but if using polled mode + * this should be able to handle it). + */ + + i2cvdbg("DR full, SR empty. Waiting for more bytes.\n"); + stm32_i2c_traceevent(priv, I2CEVENT_READ_SR_EMPTY, 0); + } + else if (priv->dcnt >= 4 && priv->total_msg_len >= 3 && (status & I2C_SR1_BTF)) + { + /* Read data from data register(DR). Note this clears the + * RXNE(receive buffer not empty) flag. + */ + + i2cvdbg("Read data from data register(DR)\n"); + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + + /* Decrease current message length */ + + priv->dcnt--; + stm32_i2c_traceevent(priv, I2CEVENT_READ, 0); + } + else if (priv->dcnt == 3 && (status & I2C_SR1_BTF) && priv->total_msg_len >= 3) + { + /* This means that we are reading dcnt 3 and there is already dcnt 2 in + * the shift register. + * This coincides with EV7_2 in the reference manual. + */ + + i2cvdbg("Program NACK\n"); + i2cvdbg("Read data from data register(DR) dcnt=3\n"); + + stm32_i2c_traceevent(priv, I2CEVENT_READ_3, priv->dcnt); + + /* Program NACK */ + + stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, 0); + + /* Read dcnt = 3, to ensure a BTF event after having recieved + * in the shift register. + */ + + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + + /* Decrease current message length */ + + priv->dcnt--; + } + else if (priv->dcnt == 2 && (status & I2C_SR1_BTF) && priv->total_msg_len >= 3) + { + i2cvdbg("Program stop\n"); + i2cvdbg("Read data from data register(DR) dcnt=2\n"); + i2cvdbg("Read data from data register(SR) dcnt=1\n"); + i2cvdbg("Setting condition to stop ISR dcnt = -1\n"); + + stm32_i2c_traceevent(priv, I2CEVENT_READ_3, priv->dcnt); + + /* Program stop */ + + stm32_i2c_sendstop(priv); + + /* read dcnt = 2 */ + + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + + /* read last byte dcnt=1 */ + + *priv->ptr++ = stm32_i2c_getreg(priv, STM32_I2C_DR_OFFSET); + + /* Stop already sent will not get another interrupt set + * condition to stop ISR + */ + + priv->dcnt = -1; + } + + /* Error handling for read mode */ + + else + { + i2cdbg("I2C read mode no correct state detected\n"); + i2cdbg(" state %i, dcnt=%i\n", status, priv->dcnt); + + /* set condition to terminate ISR and wake waiting thread */ + + priv->dcnt = -1; + priv->msgc = 0; + stm32_i2c_traceevent(priv, I2CEVENT_READ_ERROR, 0); + } + + /* Read rest of the state */ + + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + } + + /* Empty call handler + * + * Case to handle an empty call to the ISR where it only has to + * Shutdown + */ + + else if (priv->dcnt == -1 && priv->msgc == 0) + { + /* Read rest of the state */ + + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + i2cdbg("Empty call to ISR: Stopping ISR\n"); + stm32_i2c_traceevent(priv, I2CEVENT_ISR_EMPTY_CALL, 0); + } + + /* Error handler + * + * Gets triggered if the driver does not recognize a situation(state) + * it can deal with. + * This should not happen in interrupt based operation(i.e. when + * CONFIG_I2C_POLLED is not set in the defconfig file). + * During polled operation(i.e. CONFIG_I2C_POLLED=y in defconfig) + * this case should do nothing but tracing the event that the + * device wasn't ready yet. + */ + + else + { +#ifdef CONFIG_I2C_POLLED + stm32_i2c_traceevent(priv, I2CEVENT_POLL_DEV_NOT_RDY, 0); +#else + /* Read rest of the state */ + + status |= (stm32_i2c_getreg(priv, STM32_I2C_SR2_OFFSET) << 16); + + i2cdbg(" No correct state detected(start bit, read or write) \n"); + i2cdbg(" state %i\n", status); + + /* set condition to terminate ISR and wake waiting thread */ + + priv->dcnt = -1; + priv->msgc = 0; + stm32_i2c_traceevent(priv, I2CEVENT_STATE_ERROR, 0); +#endif + } + + /* Messages handling(2/2) + * + * Transmission of the whole message chain has been completed. We have to + * terminate the ISR and wake up stm32_i2c_process() that is waiting for + * the ISR cycle to handle the sending/receiving of the messages. + */ + + if (priv->dcnt == -1 && priv->msgc == 0) + { + uint32_t regval; + + i2cvdbg("Shutting down I2C ISR\n"); + + stm32_i2c_traceevent(priv, I2CEVENT_ISR_SHUTDOWN, 0); +#ifdef CONFIG_I2C_POLLED + priv->intstate = INTSTATE_DONE; +#else + /* clear all interrupts */ + + regval = stm32_i2c_getreg(priv, STM32_I2C_CR2_OFFSET); + regval &= ~I2C_CR2_ALLINTS; + stm32_i2c_putreg(priv, STM32_I2C_CR2_OFFSET, regval); + + /* Is there a thread waiting for this event(there should be) */ + + if (priv->intstate == INTSTATE_WAITING) + { + /* Yes.. inform the thread that the transfer is complete + * and wake it up. + */ + + sem_post(&priv->sem_isr); + priv->intstate = INTSTATE_DONE; + } +#endif + } + + return OK; +} + +/************************************************************************************ + * Name: stm32_i2c1_isr + * + * Description: + * I2C1 interrupt service routine + * + ************************************************************************************/ + +#ifndef CONFIG_I2C_POLLED +#ifdef CONFIG_STM32_I2C1 +static int stm32_i2c1_isr(int irq, void *context) +{ + return stm32_i2c_isr(&stm32_i2c1_priv); +} +#endif + +/************************************************************************************ + * Name: stm32_i2c2_isr + * + * Description: + * I2C2 interrupt service routine + * + ************************************************************************************/ + +#ifdef CONFIG_STM32_I2C2 +static int stm32_i2c2_isr(int irq, void *context) +{ + return stm32_i2c_isr(&stm32_i2c2_priv); +} +#endif + +/************************************************************************************ + * Name: stm32_i2c3_isr + * + * Description: + * I2C2 interrupt service routine + * + ************************************************************************************/ + +#ifdef CONFIG_STM32_I2C3 +static int stm32_i2c3_isr(int irq, void *context) +{ + return stm32_i2c_isr(&stm32_i2c3_priv); +} +#endif +#endif + +/************************************************************************************ + * Private Initialization and Deinitialization + ************************************************************************************/ + +/************************************************************************************ + * Name: stm32_i2c_init + * + * Description: + * Setup the I2C hardware, ready for operation with defaults + * + ************************************************************************************/ + +static int stm32_i2c_init(FAR struct stm32_i2c_priv_s *priv) +{ + /* Power-up and configure GPIOs */ + + /* Enable power and reset the peripheral */ + + modifyreg32(STM32_RCC_APB1ENR, 0, priv->config->clk_bit); + modifyreg32(STM32_RCC_APB1RSTR, 0, priv->config->reset_bit); + modifyreg32(STM32_RCC_APB1RSTR, priv->config->reset_bit, 0); + + /* Configure pins */ + + if (stm32_configgpio(priv->config->scl_pin) < 0) + { + return ERROR; + } + + if (stm32_configgpio(priv->config->sda_pin) < 0) + { + stm32_unconfiggpio(priv->config->scl_pin); + return ERROR; + } + + /* Attach ISRs */ + +#ifndef CONFIG_I2C_POLLED + irq_attach(priv->config->ev_irq, priv->config->isr); + irq_attach(priv->config->er_irq, priv->config->isr); + up_enable_irq(priv->config->ev_irq); + up_enable_irq(priv->config->er_irq); +#endif + + /* Set peripheral frequency, where it must be at least 2 MHz for 100 kHz + * or 4 MHz for 400 kHz. This also disables all I2C interrupts. + */ + + stm32_i2c_putreg(priv, STM32_I2C_CR2_OFFSET, (STM32_PCLK1_FREQUENCY / 1000000)); + stm32_i2c_setclock(priv, 100000); + + /* Enable I2C */ + + stm32_i2c_putreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_PE); + return OK; +} + +/************************************************************************************ + * Name: stm32_i2c_deinit + * + * Description: + * Shutdown the I2C hardware + * + ************************************************************************************/ + +static int stm32_i2c_deinit(FAR struct stm32_i2c_priv_s *priv) +{ + /* Disable I2C */ + + stm32_i2c_putreg(priv, STM32_I2C_CR1_OFFSET, 0); + + /* Unconfigure GPIO pins */ + + stm32_unconfiggpio(priv->config->scl_pin); + stm32_unconfiggpio(priv->config->sda_pin); + + /* Disable and detach interrupts */ + +#ifndef CONFIG_I2C_POLLED + up_disable_irq(priv->config->ev_irq); + up_disable_irq(priv->config->er_irq); + irq_detach(priv->config->ev_irq); + irq_detach(priv->config->er_irq); +#endif + + /* Disable clocking */ + + modifyreg32(STM32_RCC_APB1ENR, priv->config->clk_bit, 0); + return OK; +} + +/************************************************************************************ + * Device Driver Operations + ************************************************************************************/ + +/************************************************************************************ + * Name: stm32_i2c_setfrequency + * + * Description: + * Set the I2C frequency + * + ************************************************************************************/ + +static uint32_t stm32_i2c_setfrequency(FAR struct i2c_dev_s *dev, uint32_t frequency) +{ + stm32_i2c_sem_wait(dev); + +#if STM32_PCLK1_FREQUENCY < 4000000 + ((struct stm32_i2c_inst_s *)dev)->frequency = 100000; +#else + ((struct stm32_i2c_inst_s *)dev)->frequency = frequency; +#endif + + stm32_i2c_sem_post(dev); + return ((struct stm32_i2c_inst_s *)dev)->frequency; +} + +/************************************************************************************ + * Name: stm32_i2c_setaddress + * + * Description: + * Set the I2C slave address + * + ************************************************************************************/ + +static int stm32_i2c_setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits) +{ + stm32_i2c_sem_wait(dev); + + ((struct stm32_i2c_inst_s *)dev)->address = addr; + ((struct stm32_i2c_inst_s *)dev)->flags = (nbits == 10) ? I2C_M_TEN : 0; + + stm32_i2c_sem_post(dev); + return OK; +} + +/************************************************************************************ + * Name: stm32_i2c_process + * + * Description: + * Common I2C transfer logic + * + ************************************************************************************/ + +static int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, + int count) +{ + struct stm32_i2c_inst_s *inst = (struct stm32_i2c_inst_s *)dev; + FAR struct stm32_i2c_priv_s *priv = inst->priv; + uint32_t status = 0; + uint32_t ahbenr; + int errval = 0; + + ASSERT(count); + + /* Disable FSMC that shares a pin with I2C1 (LBAR) */ + + ahbenr = stm32_i2c_disablefsmc(priv); + + /* Wait for any STOP in progress. NOTE: If we have to disable the FSMC + * then we cannot do this at the top of the loop, unfortunately. The STOP + * will not complete normally if the FSMC is enabled. + */ + +#ifndef I2C1_FSMC_CONFLICT + stm32_i2c_sem_waitstop(priv); +#endif + + /* Clear any pending error interrupts */ + + stm32_i2c_putreg(priv, STM32_I2C_SR1_OFFSET, 0); + + /* "Note: When the STOP, START or PEC bit is set, the software must + * not perform any write access to I2C_CR1 before this bit is + * cleared by hardware. Otherwise there is a risk of setting a + * second STOP, START or PEC request." However, if the bits are + * not cleared by hardware, then we will have to do that from hardware. + */ + + stm32_i2c_clrstart(priv); + + /* Old transfers are done + * + * Reset ptr and dcnt to ensure an unexpected data interrupt doesn't + * overwrite stale data. + */ + + priv->dcnt = 0; + priv->ptr = NULL; + + priv->msgv = msgs; + priv->msgc = count; + + /* Reset I2C trace logic */ + + stm32_i2c_tracereset(priv); + + /* Set I2C clock frequency (on change it toggles I2C_CR1_PE !) */ + + stm32_i2c_setclock(priv, inst->frequency); + + /* Trigger start condition, then the process moves into the ISR. I2C + * interrupts will be enabled within stm32_i2c_waitdone(). + * + * Initialize current message length counter to zero. This is needed to + * process the first message(first priv->msgv entry) correctly. + */ + + priv->dcnt = -1; + priv->status = 0; + stm32_i2c_sendstart(priv); + + /* Wait for an ISR, if there was a timeout, fetch latest status to get + * the BUSY flag. + */ + + if (stm32_i2c_sem_waitdone(priv) < 0) + { + status = stm32_i2c_getstatus(priv); + errval = ETIMEDOUT; + + i2cdbg("Timed out: CR1: 0x%04x status: 0x%08x\n", + stm32_i2c_getreg(priv, STM32_I2C_CR1_OFFSET), status); + + /* "Note: When the STOP, START or PEC bit is set, the software must + * not perform any write access to I2C_CR1 before this bit is + * cleared by hardware. Otherwise there is a risk of setting a + * second STOP, START or PEC request." + */ + + stm32_i2c_clrstart(priv); + +#ifdef CONFIG_I2C_POLLED + /* When polling the i2c ISR it's not possible to determine when + * an address has been ACKed(i.e. the address is valid). + * + * The mechanism to deal a NACKed address is to wait for the I2C + * call to timeout(value defined in defconfig by one of the + * following: CONFIG_STM32_I2C_DYNTIMEO, CONFIG_STM32_I2CTIMEOSEC, + * CONFIG_STM32_I2CTIMEOMS, CONFIG_STM32_I2CTIMEOTICKS). + * + * To be safe in the case of a timeout/NACKed address a stop bit + * is set on the bus to clear it. In POLLED operation it's done + * stm32_i2c_process() after the call to stm32_i2c_sem_waitdone(). + * + * In ISR driven operation the stop bit in case of a NACKed address + * is set in the ISR itself. + * + * Note: this commentary is found in both places. + * + */ + i2cdbg("Check if the address was valid\n"); + stm32_i2c_sendstop(priv); +#endif + /* Clear busy flag in case of timeout */ + + status = priv->status & 0xffff; + } + else + { + /* clear SR2 (BUSY flag) as we've done successfully */ + + status = priv->status & 0xffff; + } + + /* Check for error status conditions */ + + if ((status & I2C_SR1_ERRORMASK) != 0) + { + /* I2C_SR1_ERRORMASK is the 'OR' of the following individual bits: */ + + if (status & I2C_SR1_BERR) + { + /* Bus Error */ + + errval = EIO; + } + else if (status & I2C_SR1_ARLO) + { + /* Arbitration Lost (master mode) */ + + errval = EAGAIN; + } + else if (status & I2C_SR1_AF) + { + /* Acknowledge Failure */ + + errval = ENXIO; + } + else if (status & I2C_SR1_OVR) + { + /* Overrun/Underrun */ + + errval = EIO; + } + else if (status & I2C_SR1_PECERR) + { + /* PEC Error in reception */ + + errval = EPROTO; + } + else if (status & I2C_SR1_TIMEOUT) + { + /* Timeout or Tlow Error */ + + errval = ETIME; + } + + /* This is not an error and should never happen since SMBus is not enabled */ + + else /* if (status & I2C_SR1_SMBALERT) */ + { + /* SMBus alert is an optional signal with an interrupt line for devices + * that want to trade their ability to master for a pin. + */ + + errval = EINTR; + } + } + + /* This is not an error, but should not happen. The BUSY signal can hang, + * however, if there are unhealthy devices on the bus that need to be reset. + * NOTE: We will only see this busy indication if stm32_i2c_sem_waitdone() + * fails above; Otherwise it is cleared. + */ + + else if ((status & (I2C_SR2_BUSY << 16)) != 0) + { + /* I2C Bus is for some reason busy */ + + errval = EBUSY; + } + + /* Dump the trace result */ + + stm32_i2c_tracedump(priv); + + /* Wait for any STOP in progress. NOTE: If we have to disable the FSMC + * then we cannot do this at the top of the loop, unfortunately. The STOP + * will not complete normally if the FSMC is enabled. + */ + +#ifdef I2C1_FSMC_CONFLICT + stm32_i2c_sem_waitstop(priv); +#endif + + /* Re-enable the FSMC */ + + stm32_i2c_enablefsmc(ahbenr); + stm32_i2c_sem_post(dev); + + /* Ensure that any ISR happening after we finish can't overwrite any user data */ + + priv->dcnt = 0; + priv->ptr = NULL; + + return -errval; +} + +/************************************************************************************ + * Name: stm32_i2c_write + * + * Description: + * Write I2C data + * + ************************************************************************************/ + +static int stm32_i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen) +{ + stm32_i2c_sem_wait(dev); /* ensure that address or flags don't change meanwhile */ + + struct i2c_msg_s msgv = + { + .addr = ((struct stm32_i2c_inst_s *)dev)->address, + .flags = ((struct stm32_i2c_inst_s *)dev)->flags, + .buffer = (uint8_t *)buffer, + .length = buflen + }; + + return stm32_i2c_process(dev, &msgv, 1); +} + +/************************************************************************************ + * Name: stm32_i2c_read + * + * Description: + * Read I2C data + * + ************************************************************************************/ + +int stm32_i2c_read(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen) +{ + stm32_i2c_sem_wait(dev); /* ensure that address or flags don't change meanwhile */ + + struct i2c_msg_s msgv = + { + .addr = ((struct stm32_i2c_inst_s *)dev)->address, + .flags = ((struct stm32_i2c_inst_s *)dev)->flags | I2C_M_READ, + .buffer = buffer, + .length = buflen + }; + + return stm32_i2c_process(dev, &msgv, 1); +} + +/************************************************************************************ + * Name: stm32_i2c_writeread + * + * Description: + * Read then write I2C data + * + ************************************************************************************/ + +#ifdef CONFIG_I2C_WRITEREAD +static int stm32_i2c_writeread(FAR struct i2c_dev_s *dev, + const uint8_t *wbuffer, int wbuflen, + uint8_t *buffer, int buflen) +{ + stm32_i2c_sem_wait(dev); /* Ensure that address or flags don't change meanwhile */ + + struct i2c_msg_s msgv[2] = + { + { + .addr = ((struct stm32_i2c_inst_s *)dev)->address, + .flags = ((struct stm32_i2c_inst_s *)dev)->flags, + .buffer = (uint8_t *)wbuffer, /* This is really ugly, sorry const ... */ + .length = wbuflen + }, + { + .addr = ((struct stm32_i2c_inst_s *)dev)->address, + .flags = ((struct stm32_i2c_inst_s *)dev)->flags | ((buflen>0) ? I2C_M_READ : I2C_M_NORESTART), + .buffer = buffer, + .length = (buflen>0) ? buflen : -buflen + } + }; + + return stm32_i2c_process(dev, msgv, 2); +} +#endif + +/************************************************************************************ + * Name: stm32_i2c_transfer + * + * Description: + * Generic I2C transfer function + * + ************************************************************************************/ + +#ifdef CONFIG_I2C_TRANSFER +static int stm32_i2c_transfer(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, + int count) +{ + stm32_i2c_sem_wait(dev); /* Ensure that address or flags don't change meanwhile */ + return stm32_i2c_process(dev, msgs, count); +} +#endif + +/************************************************************************************ + * Public Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: up_i2cinitialize + * + * Description: + * Initialize one I2C bus + * + ************************************************************************************/ + +FAR struct i2c_dev_s *up_i2cinitialize(int port) +{ + struct stm32_i2c_priv_s * priv = NULL; /* Private data of device with multiple instances */ + struct stm32_i2c_inst_s * inst = NULL; /* Device, single instance */ + int irqs; + +#if STM32_PCLK1_FREQUENCY < 4000000 +# warning STM32_I2C_INIT: Peripheral clock must be at least 4 MHz to support 400 kHz operation. +#endif + +#if STM32_PCLK1_FREQUENCY < 2000000 +# warning STM32_I2C_INIT: Peripheral clock must be at least 2 MHz to support 100 kHz operation. + return NULL; +#endif + + /* Get I2C private structure */ + + switch (port) + { +#ifdef CONFIG_STM32_I2C1 + case 1: + priv = (struct stm32_i2c_priv_s *)&stm32_i2c1_priv; + break; +#endif +#ifdef CONFIG_STM32_I2C2 + case 2: + priv = (struct stm32_i2c_priv_s *)&stm32_i2c2_priv; + break; +#endif +#ifdef CONFIG_STM32_I2C3 + case 3: + priv = (struct stm32_i2c_priv_s *)&stm32_i2c3_priv; + break; +#endif + default: + return NULL; + } + + /* Allocate instance */ + + if (!(inst = kmalloc(sizeof(struct stm32_i2c_inst_s)))) + { + return NULL; + } + + /* Initialize instance */ + + inst->ops = &stm32_i2c_ops; + inst->priv = priv; + inst->frequency = 100000; + inst->address = 0; + inst->flags = 0; + + /* Initialize private data for the first time, increment reference count, + * power-up hardware and configure GPIOs. + */ + + irqs = irqsave(); + + if ((volatile int)priv->refs++ == 0) + { + stm32_i2c_sem_init((struct i2c_dev_s *)inst); + stm32_i2c_init(priv); + } + + irqrestore(irqs); + return (struct i2c_dev_s *)inst; +} + +/************************************************************************************ + * Name: up_i2cuninitialize + * + * Description: + * Uninitialize an I2C bus + * + ************************************************************************************/ + +int up_i2cuninitialize(FAR struct i2c_dev_s * dev) +{ + int irqs; + + ASSERT(dev); + + /* Decrement reference count and check for underflow */ + + if (((struct stm32_i2c_inst_s *)dev)->priv->refs == 0) + { + return ERROR; + } + + irqs = irqsave(); + + if (--((struct stm32_i2c_inst_s *)dev)->priv->refs) + { + irqrestore(irqs); + kfree(dev); + return OK; + } + + irqrestore(irqs); + + /* Disable power and other HW resource (GPIO's) */ + + stm32_i2c_deinit(((struct stm32_i2c_inst_s *)dev)->priv); + + /* Release unused resources */ + + stm32_i2c_sem_destroy((struct i2c_dev_s *)dev); + + kfree(dev); + return OK; +} + +/************************************************************************************ + * Name: up_i2creset + * + * Description: + * Reset an I2C bus + * + ************************************************************************************/ + +#ifdef CONFIG_I2C_RESET +int up_i2creset(FAR struct i2c_dev_s * dev) +{ + struct stm32_i2c_priv_s * priv; + unsigned int clock_count; + unsigned int stretch_count; + uint32_t scl_gpio; + uint32_t sda_gpio; + int ret = ERROR; + + ASSERT(dev); + + /* Get I2C private structure */ + + priv = ((struct stm32_i2c_inst_s *)dev)->priv; + + /* Our caller must own a ref */ + + ASSERT(priv->refs > 0); + + /* Lock out other clients */ + + stm32_i2c_sem_wait(dev); + + /* De-init the port */ + + stm32_i2c_deinit(priv); + + /* Use GPIO configuration to un-wedge the bus */ + + scl_gpio = MKI2C_OUTPUT(priv->config->scl_pin); + sda_gpio = MKI2C_OUTPUT(priv->config->sda_pin); + + /* Let SDA go high */ + + stm32_gpiowrite(sda_gpio, 1); + + /* Clock the bus until any slaves currently driving it let it go. */ + + clock_count = 0; + while (!stm32_gpioread(sda_gpio)) + { + /* Give up if we have tried too hard */ + + if (clock_count++ > 10) + { + goto out; + } + + /* Sniff to make sure that clock stretching has finished. + * + * If the bus never relaxes, the reset has failed. + */ + + stretch_count = 0; + while (!stm32_gpioread(scl_gpio)) + { + /* Give up if we have tried too hard */ + + if (stretch_count++ > 10) + { + goto out; + } + + up_udelay(10); + } + + /* Drive SCL low */ + + stm32_gpiowrite(scl_gpio, 0); + up_udelay(10); + + /* Drive SCL high again */ + + stm32_gpiowrite(scl_gpio, 1); + up_udelay(10); + } + + /* Generate a start followed by a stop to reset slave + * state machines. + */ + + stm32_gpiowrite(sda_gpio, 0); + up_udelay(10); + stm32_gpiowrite(scl_gpio, 0); + up_udelay(10); + stm32_gpiowrite(scl_gpio, 1); + up_udelay(10); + stm32_gpiowrite(sda_gpio, 1); + up_udelay(10); + + /* Revert the GPIO configuration. */ + + stm32_unconfiggpio(sda_gpio); + stm32_unconfiggpio(scl_gpio); + + /* Re-init the port */ + + stm32_i2c_init(priv); + ret = OK; + +out: + + /* Release the port for re-use by other clients */ + + stm32_i2c_sem_post(dev); + return ret; +} +#endif /* CONFIG_I2C_RESET */ + +#endif /* CONFIG_STM32_STM32F10XX || CONFIG_STM32_STM32F20XX || CONFIG_STM32_STM32F40XX */ +#endif /* CONFIG_STM32_I2C1 || CONFIG_STM32_I2C2 || CONFIG_STM32_I2C3 */ |