/**************************************************************************** * config/mcu123-lpc214x/src/up_spi.c * * Copyright (C) 2008-2009 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. * ****************************************************************************/ /**************************************************************************** * One the mcu123.com lpc214x board, the MMC slot is connect via SPI with the * following SPI mode pinout: * * 1 CS: Chip select (low) - SSEL1 5 SCLK: Clock - SCK1 * 2 DI: Data input - MOSI1 6 Vss2: Supply Voltage- GRND * 3 Vss: Supply Voltage - GRND 7 DO: Data Output - MISO1 * 4 Vdd: Power Supply - Vcc 8 - N/C * * The LPC214x supports one SPI port (SPI0) and one SSP port (SPI1). SPI1 * is used to interface with the MMC connect * * SCK1 - pin 47, P0.17/CAP1.2/SCK1/MAT1.2 * MISO1 - pin 53, P0.18/CAP1.3/MISO1/MAT1.3 * MOSI1 - pin 54, P0.19/MAT1.2/MOSI1/CAP1.2 * SSEL1 - pin 55, P0.20/MAT1.3/SSEL1/EINT3 * * SPI0 is available on the mcu123.com board (pins 27, 29, 30, and 31). * Pin 27 is dedicated to a chip select, pins 30 and 31 connect to keys, nd * pin 29 is unconnected. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "up_internal.h" #include "up_arch.h" #include "chip.h" #include "lpc214x_power.h" #include "lpc214x_pinsel.h" #include "lpc214x_spi.h" /**************************************************************************** * Definitions ****************************************************************************/ /* Enables debug output from this file (needs CONFIG_DEBUG too) */ #undef SPI_DEBUG /* Define to enable debug */ #undef SPI_VERBOSE /* Define to enable verbose debug */ #ifdef SPI_DEBUG # define spidbg lldbg # ifdef SPI_VERBOSE # define spivdbg lldbg # else # define spivdbg(x...) # endif #else # undef SPI_VERBOSE # define spidbg(x...) # define spivdbg(x...) #endif /* Clocking */ #define LPC214X_CCLKFREQ (LPC214X_FOSC*LPC214X_PLL_M) #define LPC214X_PCLKFREQ (LPC214X_CCLKFREQ/LPC214X_APB_DIV) /* Use either FIO or legacy GPIO */ #ifdef CONFIG_LPC214x_FIO # define CS_SET_REGISTER (LPC214X_FIO0_BASE+LPC214X_FIO_SET_OFFSET) # define CS_CLR_REGISTER (LPC214X_FIO0_BASE+LPC214X_FIO_CLR_OFFSET) # define CS_DIR_REGISTER (LPC214X_FIO0_BASE+LPC214X_FIO_DIR_OFFSET) #else # define CS_SET_REGISTER (LPC214X_GPIO0_BASE+LPC214X_GPIO_SET_OFFSET) # define CS_CLR_REGISTER (LPC214X_GPIO0_BASE+LPC214X_GPIO_CLR_OFFSET) # define CS_DIR_REGISTER (LPC214X_GPIO0_BASE+LPC214X_GPIO_DIR_OFFSET) #endif /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static void spi_select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, boolean selected); static uint32 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency); static ubyte spi_status(FAR struct spi_dev_s *dev, enum spi_dev_e devid); static uint16 spi_send(FAR struct spi_dev_s *dev, uint16 ch); static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer, size_t nwords); static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer, size_t nwords); /**************************************************************************** * Private Data ****************************************************************************/ static const struct spi_ops_s g_spiops = { .select = spi_select, .setfrequency = spi_setfrequency, .status = spi_status, .send = spi_send, .sndblock = spi_sndblock, .recvblock = spi_recvblock, }; static struct spi_dev_s g_spidev = { &g_spiops }; /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: spi_select * * Description: * Enable/disable the SPI slave select. The implementation of this method * must include handshaking: If a device is selected, it must hold off * all other attempts to select the device until the device is deselecte. * * Input Parameters: * dev - Device-specific state data * devid - Identifies the device to select * selected - TRUE: slave selected, FALSE: slave de-selected * * Returned Value: * None * ****************************************************************************/ static void spi_select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, boolean selected) { uint32 bit = 1 << 20; if (selected) { /* Enable slave select (low enables) */ spidbg("CD asserted\n"); putreg32(bit, CS_CLR_REGISTER); } else { /* Disable slave select (low enables) */ spidbg("CD de-asserted\n"); putreg32(bit, CS_SET_REGISTER); /* Wait for the TX FIFO not full indication */ while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF)); putreg16(0xff, LPC214X_SPI1_DR); /* Wait until TX FIFO and TX shift buffer are empty */ while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_BSY); /* Wait until RX FIFO is not empty */ while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE)); /* Then read and discard bytes until the RX FIFO is empty */ do { (void)getreg16(LPC214X_SPI1_DR); } while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE); } } /**************************************************************************** * Name: spi_setfrequency * * Description: * Set the SPI frequency. * * Input Parameters: * dev - Device-specific state data * frequency - The SPI frequency requested * * Returned Value: * Returns the actual frequency selected * ****************************************************************************/ static uint32 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency) { uint32 divisor = LPC214X_PCLKFREQ / frequency; if (divisor < 2) { divisor = 2; } else if (divisor > 254) { divisor = 254; } divisor = (divisor + 1) & ~1; putreg8(divisor, LPC214X_SPI1_CPSR); spidbg("Frequency %d->%d\n", frequency, LPC214X_PCLKFREQ / divisor); return LPC214X_PCLKFREQ / divisor; } /**************************************************************************** * Name: spi_status * * Description: * Get SPI/MMC status * * Input Parameters: * dev - Device-specific state data * devid - Identifies the device to report status on * * Returned Value: * Returns a bitset of status values (see SPI_STATUS_* defines * ****************************************************************************/ static ubyte spi_status(FAR struct spi_dev_s *dev, enum spi_dev_e devid) { /* I don't think there is anyway to determine these things on the mcu123.com * board. */ spidbg("Return SPI_STATUS_PRESENT\n"); return SPI_STATUS_PRESENT; } /**************************************************************************** * Name: spi_send * * Description: * Exchange one word on SPI * * Input Parameters: * dev - Device-specific state data * wd - The word to send. the size of the data is determined by the * number of bits selected for the SPI interface. * * Returned Value: * response * ****************************************************************************/ static uint16 spi_send(FAR struct spi_dev_s *dev, uint16 wd) { register uint16 regval; /* Wait while the TX FIFO is full */ while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF)); /* Write the byte to the TX FIFO */ putreg16((ubyte)wd, LPC214X_SPI1_DR); /* Wait for the RX FIFO not empty */ while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE)); /* Get the value from the RX FIFO and return it */ regval = getreg16(LPC214X_SPI1_DR); spidbg("%04x->%04x\n", wd, regval); return regval; } /************************************************************************* * Name: spi_sndblock * * Description: * Send a block of data on SPI * * Input Parameters: * dev - Device-specific state data * buffer - A pointer to the buffer of data to be sent * nwords - the length of data to send from the buffer in number of words. * The wordsize is determined by the number of bits-per-word * selected for the SPI interface. If nbits <= 8, the data is * packed into ubytes; if nbits >8, the data is packed into uint16's * * Returned Value: * None * ****************************************************************************/ static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer, size_t nwords) { FAR const ubyte *ptr = (FAR const ubyte *)buffer; ubyte sr; /* Loop while thre are bytes remaining to be sent */ spidbg("nwords: %d\n", nwords); while (nwords > 0) { /* While the TX FIFO is not full and there are bytes left to send */ while ((getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF) && nwords) { /* Send the data */ putreg16((uint16)*ptr, LPC214X_SPI1_DR); ptr++; nwords--; } } /* Then discard all card responses until the RX & TX FIFOs are emptied. */ spidbg("discarding\n"); do { /* Is there anything in the RX fifo? */ sr = getreg8(LPC214X_SPI1_SR); if ((sr & LPC214X_SPI1SR_RNE) != 0) { /* Yes.. Read and discard */ (void)getreg16(LPC214X_SPI1_DR); } /* There is a race condition where TFE may go TRUE just before * RNE goes true and this loop terminates prematurely. The nasty little * delay in the following solves that (it could probably be tuned * to improve performance). */ else if ((sr & LPC214X_SPI1SR_TFE) != 0) { up_udelay(100); sr = getreg8(LPC214X_SPI1_SR); } } while ((sr & LPC214X_SPI1SR_RNE) != 0 || (sr & LPC214X_SPI1SR_TFE) == 0); } /**************************************************************************** * Name: spi_recvblock * * Description: * Revice a block of data from SPI * * Input Parameters: * dev - Device-specific state data * buffer - A pointer to the buffer in which to recieve data * nwords - the length of data that can be received in the buffer in number * of words. The wordsize is determined by the number of bits-per-word * selected for the SPI interface. If nbits <= 8, the data is * packed into ubytes; if nbits >8, the data is packed into uint16's * * Returned Value: * None * ****************************************************************************/ static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer, size_t nwords) { FAR ubyte *ptr = (FAR ubyte*)buffer; uint32 rxpending = 0; /* While there is remaining to be sent (and no synchronization error has occurred) */ spidbg("nwords: %d\n", nwords); while (nwords || rxpending) { /* Fill the transmit FIFO with 0xff... * Write 0xff to the data register while (1) the TX FIFO is * not full, (2) we have not exceeded the depth of the TX FIFO, * and (3) there are more bytes to be sent. */ spivdbg("TX: rxpending: %d nwords: %d\n", rxpending, nwords); while ((getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF) && (rxpending < LPC214X_SPI1_FIFOSZ) && nwords) { putreg16(0xff, LPC214X_SPI1_DR); nwords--; rxpending++; } /* Now, read the RX data from the RX FIFO while the RX FIFO is not empty */ spivdbg("RX: rxpending: %d\n", rxpending); while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE) { *ptr++ = (ubyte)getreg16(LPC214X_SPI1_DR); rxpending--; } } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: up_spiinitialize * * Description: * Initialize the selected SPI port * * Input Parameter: * Port number (for hardware that has mutiple SPI interfaces) * * Returned Value: * Valid SPI device structre reference on succcess; a NULL on failure * ****************************************************************************/ FAR struct spi_dev_s *up_spiinitialize(int port) { uint32 regval32; ubyte regval8; int i; /* Only the SPI1 interface is supported */ #ifdef CONFIG_DEBUG if (port != 1) { return NULL; } #endif /* Configure multiplexed pins as connected on the mcu123.com board: * * PINSEL1 P0.17/CAP1.2/SCK1/MAT1.2 Bits 2-3=10 for SCK1 * PINSEL1 P0.18/CAP1.3/MISO1/MAT1.3 Bits 4-5=10 for MISO1 * PINSEL1 P0.19/MAT1.2/MOSI1/CAP1.2 Bits 6-7=10 for MOSI1 * PINSEL1 P0.20/MAT1.3/SSEL1/EINT3 Bits 8-9=10 for P0.20 (we'll control it via GPIO or FIO) */ regval32 = getreg32(LPC214X_PINSEL1); regval32 &= ~(LPC214X_PINSEL1_P017_MASK|LPC214X_PINSEL1_P018_MASK| LPC214X_PINSEL1_P019_MASK|LPC214X_PINSEL1_P020_MASK); regval32 |= (LPC214X_PINSEL1_P017_SCK1|LPC214X_PINSEL1_P018_MISO1| LPC214X_PINSEL1_P019_MOSI1|LPC214X_PINSEL1_P020_GPIO); putreg32(regval32, LPC214X_PINSEL1); /* Disable chip select using P0.20 (SSEL1) (low enables) */ regval32 = 1 << 20; putreg32(regval32, CS_SET_REGISTER); regval32 |= getreg32(CS_DIR_REGISTER); putreg32(regval32, CS_DIR_REGISTER); /* Enable peripheral clocking to SPI1 */ regval32 = getreg32(LPC214X_PCON_PCONP); regval32 |= LPC214X_PCONP_PCSPI1; putreg32(regval32, LPC214X_PCON_PCONP); /* Configure 8-bit SPI mode */ putreg16(LPC214X_SPI1CR0_DSS8BIT|LPC214X_SPI1CR0_FRFSPI, LPC214X_SPI1_CR0); /* Disable the SSP and all interrupts (we'll poll for all data) */ putreg8(0, LPC214X_SPI1_CR1); putreg8(0, LPC214X_SPI1_IMSC); /* Set the initial clock frequency for indentification mode < 400kHz */ spi_setfrequency(NULL, 400000); /* Enable the SPI */ regval8 = getreg8(LPC214X_SPI1_CR1); putreg8(regval8 | LPC214X_SPI1CR1_SSE, LPC214X_SPI1_CR1); for (i = 0; i < 8; i++) { (void)getreg16(LPC214X_SPI1_DR); } return &g_spidev; }