diff options
Diffstat (limited to 'drivers/spi/spi-davinci.c')
| -rw-r--r-- | drivers/spi/spi-davinci.c | 1030 |
1 files changed, 1030 insertions, 0 deletions
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c new file mode 100644 index 00000000000..1f0ed8005c9 --- /dev/null +++ b/drivers/spi/spi-davinci.c @@ -0,0 +1,1030 @@ +/* + * Copyright (C) 2009 Texas Instruments. + * Copyright (C) 2010 EF Johnson Technologies + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/dma-mapping.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/slab.h> + +#include <mach/spi.h> +#include <mach/edma.h> + +#define SPI_NO_RESOURCE ((resource_size_t)-1) + +#define SPI_MAX_CHIPSELECT 2 + +#define CS_DEFAULT 0xFF + +#define SPIFMT_PHASE_MASK BIT(16) +#define SPIFMT_POLARITY_MASK BIT(17) +#define SPIFMT_DISTIMER_MASK BIT(18) +#define SPIFMT_SHIFTDIR_MASK BIT(20) +#define SPIFMT_WAITENA_MASK BIT(21) +#define SPIFMT_PARITYENA_MASK BIT(22) +#define SPIFMT_ODD_PARITY_MASK BIT(23) +#define SPIFMT_WDELAY_MASK 0x3f000000u +#define SPIFMT_WDELAY_SHIFT 24 +#define SPIFMT_PRESCALE_SHIFT 8 + +/* SPIPC0 */ +#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */ +#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */ +#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */ +#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */ + +#define SPIINT_MASKALL 0x0101035F +#define SPIINT_MASKINT 0x0000015F +#define SPI_INTLVL_1 0x000001FF +#define SPI_INTLVL_0 0x00000000 + +/* SPIDAT1 (upper 16 bit defines) */ +#define SPIDAT1_CSHOLD_MASK BIT(12) + +/* SPIGCR1 */ +#define SPIGCR1_CLKMOD_MASK BIT(1) +#define SPIGCR1_MASTER_MASK BIT(0) +#define SPIGCR1_POWERDOWN_MASK BIT(8) +#define SPIGCR1_LOOPBACK_MASK BIT(16) +#define SPIGCR1_SPIENA_MASK BIT(24) + +/* SPIBUF */ +#define SPIBUF_TXFULL_MASK BIT(29) +#define SPIBUF_RXEMPTY_MASK BIT(31) + +/* SPIDELAY */ +#define SPIDELAY_C2TDELAY_SHIFT 24 +#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT) +#define SPIDELAY_T2CDELAY_SHIFT 16 +#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT) +#define SPIDELAY_T2EDELAY_SHIFT 8 +#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT) +#define SPIDELAY_C2EDELAY_SHIFT 0 +#define SPIDELAY_C2EDELAY_MASK 0xFF + +/* Error Masks */ +#define SPIFLG_DLEN_ERR_MASK BIT(0) +#define SPIFLG_TIMEOUT_MASK BIT(1) +#define SPIFLG_PARERR_MASK BIT(2) +#define SPIFLG_DESYNC_MASK BIT(3) +#define SPIFLG_BITERR_MASK BIT(4) +#define SPIFLG_OVRRUN_MASK BIT(6) +#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24) +#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \ + | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \ + | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \ + | SPIFLG_OVRRUN_MASK) + +#define SPIINT_DMA_REQ_EN BIT(16) + +/* SPI Controller registers */ +#define SPIGCR0 0x00 +#define SPIGCR1 0x04 +#define SPIINT 0x08 +#define SPILVL 0x0c +#define SPIFLG 0x10 +#define SPIPC0 0x14 +#define SPIDAT1 0x3c +#define SPIBUF 0x40 +#define SPIDELAY 0x48 +#define SPIDEF 0x4c +#define SPIFMT0 0x50 + +/* We have 2 DMA channels per CS, one for RX and one for TX */ +struct davinci_spi_dma { + int tx_channel; + int rx_channel; + int dummy_param_slot; + enum dma_event_q eventq; +}; + +/* SPI Controller driver's private data. */ +struct davinci_spi { + struct spi_bitbang bitbang; + struct clk *clk; + + u8 version; + resource_size_t pbase; + void __iomem *base; + u32 irq; + struct completion done; + + const void *tx; + void *rx; +#define SPI_TMP_BUFSZ (SMP_CACHE_BYTES + 1) + u8 rx_tmp_buf[SPI_TMP_BUFSZ]; + int rcount; + int wcount; + struct davinci_spi_dma dma; + struct davinci_spi_platform_data *pdata; + + void (*get_rx)(u32 rx_data, struct davinci_spi *); + u32 (*get_tx)(struct davinci_spi *); + + u8 bytes_per_word[SPI_MAX_CHIPSELECT]; +}; + +static struct davinci_spi_config davinci_spi_default_cfg; + +static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi) +{ + if (dspi->rx) { + u8 *rx = dspi->rx; + *rx++ = (u8)data; + dspi->rx = rx; + } +} + +static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi) +{ + if (dspi->rx) { + u16 *rx = dspi->rx; + *rx++ = (u16)data; + dspi->rx = rx; + } +} + +static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi) +{ + u32 data = 0; + if (dspi->tx) { + const u8 *tx = dspi->tx; + data = *tx++; + dspi->tx = tx; + } + return data; +} + +static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi) +{ + u32 data = 0; + if (dspi->tx) { + const u16 *tx = dspi->tx; + data = *tx++; + dspi->tx = tx; + } + return data; +} + +static inline void set_io_bits(void __iomem *addr, u32 bits) +{ + u32 v = ioread32(addr); + + v |= bits; + iowrite32(v, addr); +} + +static inline void clear_io_bits(void __iomem *addr, u32 bits) +{ + u32 v = ioread32(addr); + + v &= ~bits; + iowrite32(v, addr); +} + +/* + * Interface to control the chip select signal + */ +static void davinci_spi_chipselect(struct spi_device *spi, int value) +{ + struct davinci_spi *dspi; + struct davinci_spi_platform_data *pdata; + u8 chip_sel = spi->chip_select; + u16 spidat1 = CS_DEFAULT; + bool gpio_chipsel = false; + + dspi = spi_master_get_devdata(spi->master); + pdata = dspi->pdata; + + if (pdata->chip_sel && chip_sel < pdata->num_chipselect && + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) + gpio_chipsel = true; + + /* + * Board specific chip select logic decides the polarity and cs + * line for the controller + */ + if (gpio_chipsel) { + if (value == BITBANG_CS_ACTIVE) + gpio_set_value(pdata->chip_sel[chip_sel], 0); + else + gpio_set_value(pdata->chip_sel[chip_sel], 1); + } else { + if (value == BITBANG_CS_ACTIVE) { + spidat1 |= SPIDAT1_CSHOLD_MASK; + spidat1 &= ~(0x1 << chip_sel); + } + + iowrite16(spidat1, dspi->base + SPIDAT1 + 2); + } +} + +/** + * davinci_spi_get_prescale - Calculates the correct prescale value + * @maxspeed_hz: the maximum rate the SPI clock can run at + * + * This function calculates the prescale value that generates a clock rate + * less than or equal to the specified maximum. + * + * Returns: calculated prescale - 1 for easy programming into SPI registers + * or negative error number if valid prescalar cannot be updated. + */ +static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, + u32 max_speed_hz) +{ + int ret; + + ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz); + + if (ret < 3 || ret > 256) + return -EINVAL; + + return ret - 1; +} + +/** + * davinci_spi_setup_transfer - This functions will determine transfer method + * @spi: spi device on which data transfer to be done + * @t: spi transfer in which transfer info is filled + * + * This function determines data transfer method (8/16/32 bit transfer). + * It will also set the SPI Clock Control register according to + * SPI slave device freq. + */ +static int davinci_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + + struct davinci_spi *dspi; + struct davinci_spi_config *spicfg; + u8 bits_per_word = 0; + u32 hz = 0, spifmt = 0, prescale = 0; + + dspi = spi_master_get_devdata(spi->master); + spicfg = (struct davinci_spi_config *)spi->controller_data; + if (!spicfg) + spicfg = &davinci_spi_default_cfg; + + if (t) { + bits_per_word = t->bits_per_word; + hz = t->speed_hz; + } + + /* if bits_per_word is not set then set it default */ + if (!bits_per_word) + bits_per_word = spi->bits_per_word; + + /* + * Assign function pointer to appropriate transfer method + * 8bit, 16bit or 32bit transfer + */ + if (bits_per_word <= 8 && bits_per_word >= 2) { + dspi->get_rx = davinci_spi_rx_buf_u8; + dspi->get_tx = davinci_spi_tx_buf_u8; + dspi->bytes_per_word[spi->chip_select] = 1; + } else if (bits_per_word <= 16 && bits_per_word >= 2) { + dspi->get_rx = davinci_spi_rx_buf_u16; + dspi->get_tx = davinci_spi_tx_buf_u16; + dspi->bytes_per_word[spi->chip_select] = 2; + } else + return -EINVAL; + + if (!hz) + hz = spi->max_speed_hz; + + /* Set up SPIFMTn register, unique to this chipselect. */ + + prescale = davinci_spi_get_prescale(dspi, hz); + if (prescale < 0) + return prescale; + + spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f); + + if (spi->mode & SPI_LSB_FIRST) + spifmt |= SPIFMT_SHIFTDIR_MASK; + + if (spi->mode & SPI_CPOL) + spifmt |= SPIFMT_POLARITY_MASK; + + if (!(spi->mode & SPI_CPHA)) + spifmt |= SPIFMT_PHASE_MASK; + + /* + * Version 1 hardware supports two basic SPI modes: + * - Standard SPI mode uses 4 pins, with chipselect + * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS) + * (distinct from SPI_3WIRE, with just one data wire; + * or similar variants without MOSI or without MISO) + * + * Version 2 hardware supports an optional handshaking signal, + * so it can support two more modes: + * - 5 pin SPI variant is standard SPI plus SPI_READY + * - 4 pin with enable is (SPI_READY | SPI_NO_CS) + */ + + if (dspi->version == SPI_VERSION_2) { + + u32 delay = 0; + + spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) + & SPIFMT_WDELAY_MASK); + + if (spicfg->odd_parity) + spifmt |= SPIFMT_ODD_PARITY_MASK; + + if (spicfg->parity_enable) + spifmt |= SPIFMT_PARITYENA_MASK; + + if (spicfg->timer_disable) { + spifmt |= SPIFMT_DISTIMER_MASK; + } else { + delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT) + & SPIDELAY_C2TDELAY_MASK; + delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT) + & SPIDELAY_T2CDELAY_MASK; + } + + if (spi->mode & SPI_READY) { + spifmt |= SPIFMT_WAITENA_MASK; + delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT) + & SPIDELAY_T2EDELAY_MASK; + delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT) + & SPIDELAY_C2EDELAY_MASK; + } + + iowrite32(delay, dspi->base + SPIDELAY); + } + + iowrite32(spifmt, dspi->base + SPIFMT0); + + return 0; +} + +/** + * davinci_spi_setup - This functions will set default transfer method + * @spi: spi device on which data transfer to be done + * + * This functions sets the default transfer method. + */ +static int davinci_spi_setup(struct spi_device *spi) +{ + int retval = 0; + struct davinci_spi *dspi; + struct davinci_spi_platform_data *pdata; + + dspi = spi_master_get_devdata(spi->master); + pdata = dspi->pdata; + + /* if bits per word length is zero then set it default 8 */ + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + if (!(spi->mode & SPI_NO_CS)) { + if ((pdata->chip_sel == NULL) || + (pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS)) + set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); + + } + + if (spi->mode & SPI_READY) + set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK); + + if (spi->mode & SPI_LOOP) + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); + else + clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); + + return retval; +} + +static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) +{ + struct device *sdev = dspi->bitbang.master->dev.parent; + + if (int_status & SPIFLG_TIMEOUT_MASK) { + dev_dbg(sdev, "SPI Time-out Error\n"); + return -ETIMEDOUT; + } + if (int_status & SPIFLG_DESYNC_MASK) { + dev_dbg(sdev, "SPI Desynchronization Error\n"); + return -EIO; + } + if (int_status & SPIFLG_BITERR_MASK) { + dev_dbg(sdev, "SPI Bit error\n"); + return -EIO; + } + + if (dspi->version == SPI_VERSION_2) { + if (int_status & SPIFLG_DLEN_ERR_MASK) { + dev_dbg(sdev, "SPI Data Length Error\n"); + return -EIO; + } + if (int_status & SPIFLG_PARERR_MASK) { + dev_dbg(sdev, "SPI Parity Error\n"); + return -EIO; + } + if (int_status & SPIFLG_OVRRUN_MASK) { + dev_dbg(sdev, "SPI Data Overrun error\n"); + return -EIO; + } + if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) { + dev_dbg(sdev, "SPI Buffer Init Active\n"); + return -EBUSY; + } + } + + return 0; +} + +/** + * davinci_spi_process_events - check for and handle any SPI controller events + * @dspi: the controller data + * + * This function will check the SPIFLG register and handle any events that are + * detected there + */ +static int davinci_spi_process_events(struct davinci_spi *dspi) +{ + u32 buf, status, errors = 0, spidat1; + + buf = ioread32(dspi->base + SPIBUF); + + if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) { + dspi->get_rx(buf & 0xFFFF, dspi); + dspi->rcount--; + } + + status = ioread32(dspi->base + SPIFLG); + + if (unlikely(status & SPIFLG_ERROR_MASK)) { + errors = status & SPIFLG_ERROR_MASK; + goto out; + } + + if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) { + spidat1 = ioread32(dspi->base + SPIDAT1); + dspi->wcount--; + spidat1 &= ~0xFFFF; + spidat1 |= 0xFFFF & dspi->get_tx(dspi); + iowrite32(spidat1, dspi->base + SPIDAT1); + } + +out: + return errors; +} + +static void davinci_spi_dma_callback(unsigned lch, u16 status, void *data) +{ + struct davinci_spi *dspi = data; + struct davinci_spi_dma *dma = &dspi->dma; + + edma_stop(lch); + + if (status == DMA_COMPLETE) { + if (lch == dma->rx_channel) + dspi->rcount = 0; + if (lch == dma->tx_channel) + dspi->wcount = 0; + } + + if ((!dspi->wcount && !dspi->rcount) || (status != DMA_COMPLETE)) + complete(&dspi->done); +} + +/** + * davinci_spi_bufs - functions which will handle transfer data + * @spi: spi device on which data transfer to be done + * @t: spi transfer in which transfer info is filled + * + * This function will put data to be transferred into data register + * of SPI controller and then wait until the completion will be marked + * by the IRQ Handler. + */ +static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) +{ + struct davinci_spi *dspi; + int data_type, ret; + u32 tx_data, spidat1; + u32 errors = 0; + struct davinci_spi_config *spicfg; + struct davinci_spi_platform_data *pdata; + unsigned uninitialized_var(rx_buf_count); + struct device *sdev; + + dspi = spi_master_get_devdata(spi->master); + pdata = dspi->pdata; + spicfg = (struct davinci_spi_config *)spi->controller_data; + if (!spicfg) + spicfg = &davinci_spi_default_cfg; + sdev = dspi->bitbang.master->dev.parent; + + /* convert len to words based on bits_per_word */ + data_type = dspi->bytes_per_word[spi->chip_select]; + + dspi->tx = t->tx_buf; + dspi->rx = t->rx_buf; + dspi->wcount = t->len / data_type; + dspi->rcount = dspi->wcount; + + spidat1 = ioread32(dspi->base + SPIDAT1); + + clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + + INIT_COMPLETION(dspi->done); + + if (spicfg->io_type == SPI_IO_TYPE_INTR) + set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); + + if (spicfg->io_type != SPI_IO_TYPE_DMA) { + /* start the transfer */ + dspi->wcount--; + tx_data = dspi->get_tx(dspi); + spidat1 &= 0xFFFF0000; + spidat1 |= tx_data & 0xFFFF; + iowrite32(spidat1, dspi->base + SPIDAT1); + } else { + struct davinci_spi_dma *dma; + unsigned long tx_reg, rx_reg; + struct edmacc_param param; + void *rx_buf; + int b, c; + + dma = &dspi->dma; + + tx_reg = (unsigned long)dspi->pbase + SPIDAT1; + rx_reg = (unsigned long)dspi->pbase + SPIBUF; + + /* + * Transmit DMA setup + * + * If there is transmit data, map the transmit buffer, set it + * as the source of data and set the source B index to data + * size. If there is no transmit data, set the transmit register + * as the source of data, and set the source B index to zero. + * + * The destination is always the transmit register itself. And + * the destination never increments. + */ + + if (t->tx_buf) { + t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, + t->len, DMA_TO_DEVICE); + if (dma_mapping_error(&spi->dev, t->tx_dma)) { + dev_dbg(sdev, "Unable to DMA map %d bytes" + "TX buffer\n", t->len); + return -ENOMEM; + } + } + + /* + * If number of words is greater than 65535, then we need + * to configure a 3 dimension transfer. Use the BCNTRLD + * feature to allow for transfers that aren't even multiples + * of 65535 (or any other possible b size) by first transferring + * the remainder amount then grabbing the next N blocks of + * 65535 words. + */ + + c = dspi->wcount / (SZ_64K - 1); /* N 65535 Blocks */ + b = dspi->wcount - c * (SZ_64K - 1); /* Remainder */ + if (b) + c++; + else + b = SZ_64K - 1; + + param.opt = TCINTEN | EDMA_TCC(dma->tx_channel); + param.src = t->tx_buf ? t->tx_dma : tx_reg; + param.a_b_cnt = b << 16 | data_type; + param.dst = tx_reg; + param.src_dst_bidx = t->tx_buf ? data_type : 0; + param.link_bcntrld = 0xffffffff; + param.src_dst_cidx = t->tx_buf ? data_type : 0; + param.ccnt = c; + edma_write_slot(dma->tx_channel, ¶m); + edma_link(dma->tx_channel, dma->dummy_param_slot); + + /* + * Receive DMA setup + * + * If there is receive buffer, use it to receive data. If there + * is none provided, use a temporary receive buffer. Set the + * destination B index to 0 so effectively only one byte is used + * in the temporary buffer (address does not increment). + * + * The source of receive data is the receive data register. The + * source address never increments. + */ + + if (t->rx_buf) { + rx_buf = t->rx_buf; + rx_buf_count = t->len; + } else { + rx_buf = dspi->rx_tmp_buf; + rx_buf_count = sizeof(dspi->rx_tmp_buf); + } + + t->rx_dma = dma_map_single(&spi->dev, rx_buf, rx_buf_count, + DMA_FROM_DEVICE); + if (dma_mapping_error(&spi->dev, t->rx_dma)) { + dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n", + rx_buf_count); + if (t->tx_buf) + dma_unmap_single(NULL, t->tx_dma, t->len, + DMA_TO_DEVICE); + return -ENOMEM; + } + + param.opt = TCINTEN | EDMA_TCC(dma->rx_channel); + param.src = rx_reg; + param.a_b_cnt = b << 16 | data_type; + param.dst = t->rx_dma; + param.src_dst_bidx = (t->rx_buf ? data_type : 0) << 16; + param.link_bcntrld = 0xffffffff; + param.src_dst_cidx = (t->rx_buf ? data_type : 0) << 16; + param.ccnt = c; + edma_write_slot(dma->rx_channel, ¶m); + + if (pdata->cshold_bug) + iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2); + + edma_start(dma->rx_channel); + edma_start(dma->tx_channel); + set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); + } + + /* Wait for the transfer to complete */ + if (spicfg->io_type != SPI_IO_TYPE_POLL) { + wait_for_completion_interruptible(&(dspi->done)); + } else { + while (dspi->rcount > 0 || dspi->wcount > 0) { + errors = davinci_spi_process_events(dspi); + if (errors) + break; + cpu_relax(); + } + } + + clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL); + if (spicfg->io_type == SPI_IO_TYPE_DMA) { + + if (t->tx_buf) + dma_unmap_single(NULL, t->tx_dma, t->len, + DMA_TO_DEVICE); + + dma_unmap_single(NULL, t->rx_dma, rx_buf_count, + DMA_FROM_DEVICE); + + clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); + } + + clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); + + /* + * Check for bit error, desync error,parity error,timeout error and + * receive overflow errors + */ + if (errors) { + ret = davinci_spi_check_error(dspi, errors); + WARN(!ret, "%s: error reported but no error found!\n", + dev_name(&spi->dev)); + return ret; + } + + if (dspi->rcount != 0 || dspi->wcount != 0) { + dev_err(sdev, "SPI data transfer error\n"); + return -EIO; + } + + return t->len; +} + +/** + * davinci_spi_irq - Interrupt handler for SPI Master Controller + * @irq: IRQ number for this SPI Master + * @context_data: structure for SPI Master controller davinci_spi + * + * ISR will determine that interrupt arrives either for READ or WRITE command. + * According to command it will do the appropriate action. It will check + * transfer length and if it is not zero then dispatch transfer command again. + * If transfer length is zero then it will indicate the COMPLETION so that + * davinci_spi_bufs function can go ahead. + */ +static irqreturn_t davinci_spi_irq(s32 irq, void *data) +{ + struct davinci_spi *dspi = data; + int status; + + status = davinci_spi_process_events(dspi); + if (unlikely(status != 0)) + clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); + + if ((!dspi->rcount && !dspi->wcount) || status) + complete(&dspi->done); + + return IRQ_HANDLED; +} + +static int davinci_spi_request_dma(struct davinci_spi *dspi) +{ + int r; + struct davinci_spi_dma *dma = &dspi->dma; + + r = edma_alloc_channel(dma->rx_channel, davinci_spi_dma_callback, dspi, + dma->eventq); + if (r < 0) { + pr_err("Unable to request DMA channel for SPI RX\n"); + r = -EAGAIN; + goto rx_dma_failed; + } + + r = edma_alloc_channel(dma->tx_channel, davinci_spi_dma_callback, dspi, + dma->eventq); + if (r < 0) { + pr_err("Unable to request DMA channel for SPI TX\n"); + r = -EAGAIN; + goto tx_dma_failed; + } + + r = edma_alloc_slot(EDMA_CTLR(dma->tx_channel), EDMA_SLOT_ANY); + if (r < 0) { + pr_err("Unable to request SPI TX DMA param slot\n"); + r = -EAGAIN; + goto param_failed; + } + dma->dummy_param_slot = r; + edma_link(dma->dummy_param_slot, dma->dummy_param_slot); + + return 0; +param_failed: + edma_free_channel(dma->tx_channel); +tx_dma_failed: + edma_free_channel(dma->rx_channel); +rx_dma_failed: + return r; +} + +/** + * davinci_spi_probe - probe function for SPI Master Controller + * @pdev: platform_device structure which contains plateform specific data + * + * According to Linux Device Model this function will be invoked by Linux + * with platform_device struct which contains the device specific info. + * This function will map the SPI controller's memory, register IRQ, + * Reset SPI controller and setting its registers to default value. + * It will invoke spi_bitbang_start to create work queue so that client driver + * can register transfer method to work queue. + */ +static int davinci_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct davinci_spi *dspi; + struct davinci_spi_platform_data *pdata; + struct resource *r, *mem; + resource_size_t dma_rx_chan = SPI_NO_RESOURCE; + resource_size_t dma_tx_chan = SPI_NO_RESOURCE; + int i = 0, ret = 0; + u32 spipc0; + + pdata = pdev->dev.platform_data; + if (pdata == NULL) { + ret = -ENODEV; + goto err; + } + + master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi)); + if (master == NULL) { + ret = -ENOMEM; + goto err; + } + + dev_set_drvdata(&pdev->dev, master); + + dspi = spi_master_get_devdata(master); + if (dspi == NULL) { + ret = -ENOENT; + goto free_master; + } + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + ret = -ENOENT; + goto free_master; + } + + dspi->pbase = r->start; + dspi->pdata = pdata; + + mem = request_mem_region(r->start, resource_size(r), pdev->name); + if (mem == NULL) { + ret = -EBUSY; + goto free_master; + } + + dspi->base = ioremap(r->start, resource_size(r)); + if (dspi->base == NULL) { + ret = -ENOMEM; + goto release_region; + } + + dspi->irq = platform_get_irq(pdev, 0); + if (dspi->irq <= 0) { + ret = -EINVAL; + goto unmap_io; + } + + ret = request_irq(dspi->irq, davinci_spi_irq, 0, dev_name(&pdev->dev), + dspi); + if (ret) + goto unmap_io; + + dspi->bitbang.master = spi_master_get(master); + if (dspi->bitbang.master == NULL) { + ret = -ENODEV; + goto irq_free; + } + + dspi->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(dspi->clk)) { + ret = -ENODEV; + goto put_master; + } + clk_enable(dspi->clk); + + master->bus_num = pdev->id; + master->num_chipselect = pdata->num_chipselect; + master->setup = davinci_spi_setup; + + dspi->bitbang.chipselect = davinci_spi_chipselect; + dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; + + dspi->version = pdata->version; + + dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP; + if (dspi->version == SPI_VERSION_2) + dspi->bitbang.flags |= SPI_READY; + + r = platform_get_resource(pdev, IORESOURCE_DMA, 0); + if (r) + dma_rx_chan = r->start; + r = platform_get_resource(pdev, IORESOURCE_DMA, 1); + if (r) + dma_tx_chan = r->start; + + dspi->bitbang.txrx_bufs = davinci_spi_bufs; + if (dma_rx_chan != SPI_NO_RESOURCE && + dma_tx_chan != SPI_NO_RESOURCE) { + dspi->dma.rx_channel = dma_rx_chan; + dspi->dma.tx_channel = dma_tx_chan; + dspi->dma.eventq = pdata->dma_event_q; + + ret = davinci_spi_request_dma(dspi); + if (ret) + goto free_clk; + + dev_info(&pdev->dev, "DMA: supported\n"); + dev_info(&pdev->dev, "DMA: RX channel: %d, TX channel: %d, " + "event queue: %d\n", dma_rx_chan, dma_tx_chan, + pdata->dma_event_q); + } + + dspi->get_rx = davinci_spi_rx_buf_u8; + dspi->get_tx = davinci_spi_tx_buf_u8; + + init_completion(&dspi->done); + + /* Reset In/OUT SPI module */ + iowrite32(0, dspi->base + SPIGCR0); + udelay(100); + iowrite32(1, dspi->base + SPIGCR0); + + /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */ + spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK; + iowrite32(spipc0, dspi->base + SPIPC0); + + /* initialize chip selects */ + if (pdata->chip_sel) { + for (i = 0; i < pdata->num_chipselect; i++) { + if (pdata->chip_sel[i] != SPI_INTERN_CS) + gpio_direction_output(pdata->chip_sel[i], 1); + } + } + + if (pdata->intr_line) + iowrite32(SPI_INTLVL_1, dspi->base + SPILVL); + else + iowrite32(SPI_INTLVL_0, dspi->base + SPILVL); + + iowrite32(CS_DEFAULT, dspi->base + SPIDEF); + + /* master mode default */ + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK); + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK); + set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); + + ret = spi_bitbang_start(&dspi->bitbang); + if (ret) + goto free_dma; + + dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base); + + return ret; + +free_dma: + edma_free_channel(dspi->dma.tx_channel); + edma_free_channel(dspi->dma.rx_channel); + edma_free_slot(dspi->dma.dummy_param_slot); +free_clk: + clk_disable(dspi->clk); + clk_put(dspi->clk); +put_master: + spi_master_put(master); +irq_free: + free_irq(dspi->irq, dspi); +unmap_io: + iounmap(dspi->base); +release_region: + release_mem_region(dspi->pbase, resource_size(r)); +free_master: + kfree(master); +err: + return ret; +} + +/** + * davinci_spi_remove - remove function for SPI Master Controller + * @pdev: platform_device structure which contains plateform specific data + * + * This function will do the reverse action of davinci_spi_probe function + * It will free the IRQ and SPI controller's memory region. + * It will also call spi_bitbang_stop to destroy the work queue which was + * created by spi_bitbang_start. + */ +static int __exit davinci_spi_remove(struct platform_device *pdev) +{ + struct davinci_spi *dspi; + struct spi_master *master; + struct resource *r; + + master = dev_get_drvdata(&pdev->dev); + dspi = spi_master_get_devdata(master); + + spi_bitbang_stop(&dspi->bitbang); + + clk_disable(dspi->clk); + clk_put(dspi->clk); + spi_master_put(master); + free_irq(dspi->irq, dspi); + iounmap(dspi->base); + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(dspi->pbase, resource_size(r)); + + return 0; +} + +static struct platform_driver davinci_spi_driver = { + .driver = { + .name = "spi_davinci", + .owner = THIS_MODULE, + }, + .remove = __exit_p(davinci_spi_remove), +}; + +static int __init davinci_spi_init(void) +{ + return platform_driver_probe(&davinci_spi_driver, davinci_spi_probe); +} +module_init(davinci_spi_init); + +static void __exit davinci_spi_exit(void) +{ + platform_driver_unregister(&davinci_spi_driver); +} +module_exit(davinci_spi_exit); + +MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver"); +MODULE_LICENSE("GPL"); |