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author | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2012-07-25 18:41:10 +0000 |
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committer | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2012-07-25 18:41:10 +0000 |
commit | cf48e3c73f884d28b715db676a6777c32af702dc (patch) | |
tree | e1361e761b01704d1ad41b9f89c9501a42610b4a /nuttx/drivers/input/pga11x.c | |
parent | ca8620083e4f2c28d7b65d97880a42d1d68d1700 (diff) | |
download | px4-firmware-cf48e3c73f884d28b715db676a6777c32af702dc.tar.gz px4-firmware-cf48e3c73f884d28b715db676a6777c32af702dc.tar.bz2 px4-firmware-cf48e3c73f884d28b715db676a6777c32af702dc.zip |
Add support for the TI PGA11x amplifier/multiplexer
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4977 7fd9a85b-ad96-42d3-883c-3090e2eb8679
Diffstat (limited to 'nuttx/drivers/input/pga11x.c')
-rw-r--r-- | nuttx/drivers/input/pga11x.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/nuttx/drivers/input/pga11x.c b/nuttx/drivers/input/pga11x.c new file mode 100644 index 000000000..e2edb4f3d --- /dev/null +++ b/nuttx/drivers/input/pga11x.c @@ -0,0 +1,580 @@ +/**************************************************************************** + * drivers/input/pga11x.c + * + * Copyright (C) 2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * References: + * "PGA112, PGA113, PGA116, PGA117: Zerø-Drift PROGRAMMABLE GAIN AMPLIFIER + * with MUX", SBOS424B, March 2008, Revised September 2008, Texas + * Instruments Incorporated" + * + * 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/input/pga11x.h> + +#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_PGA11X) + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ +/* The PGA112/PGA113 have a three-wire SPI digital interface; the + * PGA116/PGA117 have a four-wire SPI digital interface. The PGA116/117 also + * have daisy-chain capability (The PGA112/PGA113 can be used as the last device + * in a daisy-chain as shown if write-only communication is acceptable). + */ + +/* PGA11x commands (PGA112/PGA113) */ + +#define PGA11X_CMD_READ 0x6a00 +#define PGA11X_CMD_WRITE 0x2a00 +#define PGA11X_CMA_NOOP 0x0000 +#define PGA11X_CMA_SDN_DIS 0xe100 +#define PGA11X_CMA_SDN_EN 0xe1f1 + +/* SPI Daisy-Chain Commands (PGA116/PGA117) */ + +#define PGA11X_DCCMD_SELECTOR 0x8000 +#define PGA11X_DCCMD_NOOP (PGA11X_DCCMD_SELECTOR | PGA11X_CMA_NOOP) +#define PGA11X_DCCMA_SDN_DIS (PGA11X_DCCMD_SELECTOR | PGA11X_CMA_SDN_DIS) +#define PGA11X_DCCMA_SDN_EN (PGA11X_DCCMD_SELECTOR | PGA11X_CMA_SDN_EN) +#define PGA11X_DCCMD_READ (PGA11X_DCCMD_SELECTOR | PGA11X_CMD_READ) +#define PGA11X_DCCMD_WRITE (PGA11X_DCCMD_SELECTOR | PGA11X_CMD_WRITE) + +/* Write command Gain Selection Bits (PGA112/PGA113) + * + * the PGA112 and PGA116 provide binary gain selections (1, 2, 4, 8, 16, 32, + * 64, 128); the PGA113 and PGA117 provide scope gain selections (1, 2, 5, 10, + * 20, 50, 100, 200). + */ + +#define PGA11X_GAIN_SHIFT (4) /* Bits 4-7: Gain Selection Bits */ +#define PGA11X_GAIN_MASK (15 << PGA11X_GAIN_SHIFT) + +/* Write command Mux Channel Selection Bits + * + * The PGA112/PGA113 have a two-channel input MUX; the PGA116/PGA117 have a + * 10-channel input MUX. + */ + +#define PGA11X_CHAN_SHIFT (0) /* Bits 0-3: Channel Selection Bits */ +#define PGA11X_CHAN_MASK (15 << PGA11X_CHAN_SHIFT) + +/* Other definitions ********************************************************/ + +#define SPI_DUMMY 0xff + +/* Debug ****************************************************************************/ +/* Check if (non-standard) SPI debug is enabled */ + +#ifndef CONFIG_DEBUG +# undef CONFIG_DEBUG_VERBOSE +# undef CONFIG_DEBUG_SPI +#endif + +#ifdef CONFIG_DEBUG_SPI +# define spidbg lldbg +# ifdef CONFIG_DEBUG_VERBOSE +# define spivdbg lldbg +# else +# define spivdbg(x...) +# endif +#else +# define spidbg(x...) +# define spivdbg(x...) +#endif + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: pga11x_configure + * + * Description: + * Configure the SPI bus as needed for the PGA11x device. + * + * Returned Value: + * None + * + ****************************************************************************/ + +static void pga11x_configure(FAR struct spi_dev_s *spi) +{ + spivdbg("MODE: %d BITS: 8 Frequency: %d\n", + CONFIG_PGA11X_SPIMODE, CONFIG_PGA11X_SPIFREQUENCY); + + /* Call the setfrequency, setbits, and setmode methods to make sure that + * the SPI is properly configured for the device. + */ + + SPI_SETMODE(spi, CONFIG_PGA11X_SPIMODE); + SPI_SETBITS(spi, 8); + (void)SPI_SETFREQUENCY(spi, CONFIG_PGA11X_SPIFREQUENCY); +} + +/**************************************************************************** + * Name: pga11x_lock + * + * Description: + * Lock the SPI bus and configure it as needed for the PGA11x device. + * + * Returned Value: + * None + * + ****************************************************************************/ + +#ifndef CONFIG_SPI_OWNBUS +static void pga11x_lock(FAR struct spi_dev_s *spi) +{ + spivdbg("Locking\n"); + + /* On SPI busses where there are multiple devices, it will be necessary to + * lock SPI to have exclusive access to the busses for a sequence of + * transfers. The bus should be locked before the chip is selected. + * + * This is a blocking call and will not return until we have exclusiv access to + * the SPI buss. We will retain that exclusive access until the bus is unlocked. + */ + + SPI_LOCK(spi, true); + + /* After locking the SPI bus, the we also need call the setfrequency, setbits, and + * setmode methods to make sure that the SPI is properly configured for the device. + * If the SPI buss is being shared, then it may have been left in an incompatible + * state. + */ + + pga11x_configure(spi); +} +#else +# define pga11x_lock(spi) +#endif + +/**************************************************************************** + * Name: pga11x_unlock + * + * Description: + * Lock the SPI bus and configure it as needed for the PGA11x device. + * + * Returned Value: + * None + * + ****************************************************************************/ + +#ifndef CONFIG_SPI_OWNBUS +static inline void pga11x_unlock(FAR struct spi_dev_s *spi) +{ + spivdbg("Unlocking\n"); + + SPI_LOCK(spi, false); +} +#else +# define pga11x_unlock(spi) +#endif + +/**************************************************************************** + * Name: pga11x_send16 + * + * Description: + * Send 16 bits of data, ignoring any returned data + * + * Input Parameters: + * spi - PGA11X driver instance + * word - The data to send + * + * Returned Value: + * None + * + * Assumptions: + * The bus is locked and the device is selected + * + ****************************************************************************/ + +static void pga11x_send16(FAR struct spi_dev_s *spi, uint16_t word) +{ + spivdbg("Send %04x\n", word); + + /* The logical interface is 16-bits wide. However, this driver uses a + * 8-bit configuration for greaer portability. + * + * Send the MS byte first. Then the LS byte. + */ + + SPI_SEND(spi, word >> 8); + SPI_SEND(spi, word & 0xff); +} + +/**************************************************************************** + * Name: pga11x_recv16 + * + * Description: + * Receive 16 bits of data. + * + * Input Parameters: + * spi - PGA11X driver instance + * + * Returned Value: + * The received 16-bit value + * + * Assumptions: + * The bus is locked and the device is selected + * + ****************************************************************************/ + +static uint16_t pga11x_recv16(FAR struct spi_dev_s *spi) +{ + uint8_t msb; + uint8_t lsb; + + /* The logical interface is 16-bits wide. However, this driver uses a + * 8-bit configuration for greaer portability. + * + * Send a dummy byte and receive MS byte first. Then the LS byte. + */ + + msb = SPI_SEND(spi, SPI_DUMMY); + lsb = SPI_SEND(spi, SPI_DUMMY); + spivdbg("Received %02x %02x\n", msb, lsb); + + return ((uint16_t)msb << 8) | (uint16_t)lsb; +} + +/**************************************************************************** + * Name: pga11x_write + * + * Description: + * Send a 16-bit command. + * + * Input Parameters: + * spi - PGA11X driver instance + * + * Returned Value: + * The received 16-bit value + * + * Assumptions: + * The device is NOT selected and the NOT bus is locked. + * + ****************************************************************************/ + +#ifndef CONFIG_PGA11X_DAISYCHAIN +static void pga11x_write(FAR struct spi_dev_s *spi, uint16_t cmd) +{ + spivdbg("cmd %04x\n", cmd); + + /* Lock, select, send the 16-bit command, de-select, and un-lock. */ + + pga11x_lock(spi); + SPI_SELECT(spi, SPIDEV_MUX, true); + pga11x_send16(spi, cmd); + SPI_SELECT(spi, SPIDEV_MUX, false); + pga11x_unlock(spi); +} +#else +{ + spivdbg("cmd %04x\n", cmd); + + /* Lock, select, send the 16-bit command, the 16-bit daisy-chain command, + * de-select, and un-lock. + */ + + pga11x_lock(spi); + SPI_SELECT(spi, SPIDEV_MUX, true); + pga11x_send16(spi, cmd); + pga11x_send16(spi, cmd | PGA11X_DCCMD_SELECTOR); + SPI_SELECT(spi, SPIDEV_MUX, false); + pga11x_unlock(spi); +} +#endif + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: pga11x_initialize + * + * Description: + * Initialize the PGA117 amplifier/multiplexer. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * + * Returned Value: + * On success, a non-NULL opaque handle is returned; a NULL is returned + * on any failure. This handle may be used with the other PGA117 interface + * functions to control the multiplexer + * + ****************************************************************************/ + +PGA11X_HANDLE pga11x_initialize(FAR struct spi_dev_s *spi) +{ + spivdbg("Entry\n"); + + /* Configure the SPI us for the device. Do this now only if the PGA11X is + * the only device on the bus. + */ + +#ifdef CONFIG_SPI_OWNBUS + pga11x_configure(spi); +#endif + + /* No other special state is required, just return the SPI driver instance + * as the handle. This gives us a place to extend functionality in the + * future if neccessary. + */ + + return (PGA11X_HANDLE)spi; +} + +/**************************************************************************** + * Name: pga11x_select + * + * Description: + * Select an input channel and gain. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * channel - See the PGA11X_CHAN_* definitions above + * gain - See the PGA11X_GAIN_* definitions above + * + * Returned Value: + * Zero on sucess; a negated errno value on failure. + * + ****************************************************************************/ + +int pga11x_select(PGA11X_HANDLE handle, uint8_t channel, uint8_t gain) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + uint16_t cmd; + + spivdbg("channel: %d gain: %d\n"); + DEBUGASSERT(handle); + + /* Format the command */ + + cmd = PGA11X_CMD_WRITE | + (channel << PGA11X_CHAN_SHIFT) | + (gain << PGA11X_GAIN_SHIFT); + + /* Lock the bus and send the command */ + + pga11x_write(spi, cmd); + return OK; +} + +/**************************************************************************** + * Name: pga11x_read + * + * Description: + * Read from the PGA117 amplifier/multiplexer. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * + * Returned Value: + * 16-bit value read from the device (32-bits in daisy chain mode) + * + ****************************************************************************/ + +#ifdef CONFIG_PGA11X_DAISYCHAIN +uint32_t pga11x_read(PGA11X_HANDLE handle) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + uint16_t msvalue; + uint16_t lsvalue; + + spivdbg("Entry\n"); + DEBUGASSERT(handle); + + /* Lock the bus and read the configuration */ + + pga11x_lock(spi); + + /* Select, send the 16-bit command, the 16-bit daisy-chain command, and + * then de-select the part. I do not know if de-selection between word + * transfers is required. However, it is shown in the timing diagrams + * for the part. + */ + + SPI_SELECT(spi, SPIDEV_MUX, true); + pga11x_send16(spi, PGA11X_CMD_READ); + pga11x_send16(spi, PGA11X_DCCMD_READ); + SPI_SELECT(spi, SPIDEV_MUX, false); + + /* Re-select, get the returned values, de-select, and unlock */ + + SPI_SELECT(spi, SPIDEV_MUX, true); + msvalue = pga11x_recv16(spi); + mssvalue = pga11x_recv16(spi); + SPI_SELECT(spi, SPIDEV_MUX, false); + pga11x_unlock(spi); + + spivdbg("Returning %04x %04x\n", msvalue, lsvalue); + return (uint32_t)msvalue << 16 | (uint32_t)lsvalue; +} +#else +uint16_t pga11x_read(PGA11X_HANDLE handle) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + uint16_t value; + + spivdbg("Entry\n"); + DEBUGASSERT(handle); + + /* Lock the bus and read the configuration */ + + pga11x_lock(spi); + + /* Select, send the 16-bit PGA11X_CMD_READ command, and de-select. I do + * not know if de-selection between word transfers is required. However, + * it is shown in the timing diagrams for the part. + */ + + SPI_SELECT(spi, SPIDEV_MUX, true); + pga11x_send16(spi, PGA11X_CMD_READ); + SPI_SELECT(spi, SPIDEV_MUX, false); + + /* Re-select, get the returned value, de-select, and unlock */ + + SPI_SELECT(spi, SPIDEV_MUX, true); + value = pga11x_recv16(spi); + SPI_SELECT(spi, SPIDEV_MUX, false); + pga11x_unlock(spi); + + spivdbg("Returning: %04x\n", value); + return value; +} +#endif + +/**************************************************************************** + * Name: pga11x_noop + * + * Description: + * Perform PGA11x no-operation. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * + * Returned Value: + * Zero on sucess; a negated errno value on failure. + * + ****************************************************************************/ + +int pga11x_noop(PGA11X_HANDLE handle) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + + spivdbg("Entry\n"); + DEBUGASSERT(handle); + + /* Lock the bus and send the NOOP command */ + + pga11x_write(spi, PGA11X_CMA_NOOP); + return OK; +} + +/**************************************************************************** + * Name: pga11x_shutdown + * + * Description: + * Put the PGA11x in shutdown down mode. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * + * Returned Value: + * Zero on sucess; a negated errno value on failure. + * + ****************************************************************************/ + +int pga11x_shutdown(PGA11X_HANDLE handle) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + + spivdbg("Entry\n"); + DEBUGASSERT(handle); + + /* Lock the bus and enter shutdown mode by issuing an SDN_EN command */ + + pga11x_write(spi, PGA11X_CMA_SDN_EN); + return OK; +} + +/**************************************************************************** + * Name: pga11x_enable + * + * Description: + * Take the PGA11x out of shutdown down mode. + * + * Input Parameters: + * spi - An SPI "bottom half" device driver instance + * + * Returned Value: + * Zero on sucess; a negated errno value on failure. + * + ****************************************************************************/ + +int pga11x_enable(PGA11X_HANDLE handle) +{ + FAR struct spi_dev_s *spi = (FAR struct spi_dev_s *)handle; + + spivdbg("Entry\n"); + DEBUGASSERT(handle); + + /* Lock the bus and send the shutdown disable command. Shutdown mode is + * cleared (returned to the last valid write configuration) by the SDN_DIS + * command or by any valid Write command + */ + + pga11x_write(spi, PGA11X_CMA_SDN_DIS); + return OK; +} + +#endif /* CONFIG_INPUT && CONFIG_INPUT_PGA11X */ + |