diff options
Diffstat (limited to 'drivers/spi/davinci_spi.c')
| -rw-r--r-- | drivers/spi/davinci_spi.c | 1255 |
1 files changed, 1255 insertions, 0 deletions
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c new file mode 100644 index 0000000..225ab60 --- /dev/null +++ b/drivers/spi/davinci_spi.c @@ -0,0 +1,1255 @@ +/* + * Copyright (C) 2009 Texas Instruments. + * + * 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 <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 SPI_BUFSIZ (SMP_CACHE_BYTES + 1) +#define DAVINCI_DMA_DATA_TYPE_S8 0x01 +#define DAVINCI_DMA_DATA_TYPE_S16 0x02 +#define DAVINCI_DMA_DATA_TYPE_S32 0x04 + +#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_CHARLEN_MASK 0x0000001Fu + +/* SPIGCR1 */ +#define SPIGCR1_SPIENA_MASK 0x01000000u + +/* 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 SPIPC0_EN1FUN_MASK BIT(1) +#define SPIPC0_EN0FUN_MASK BIT(0) + +#define SPIINT_MASKALL 0x0101035F +#define SPI_INTLVL_1 0x000001FFu +#define SPI_INTLVL_0 0x00000000u + +/* SPIDAT1 */ +#define SPIDAT1_CSHOLD_SHIFT 28 +#define SPIDAT1_CSNR_SHIFT 16 +#define SPIGCR1_CLKMOD_MASK BIT(1) +#define SPIGCR1_MASTER_MASK BIT(0) +#define SPIGCR1_LOOPBACK_MASK BIT(16) + +/* SPIBUF */ +#define SPIBUF_TXFULL_MASK BIT(29) +#define SPIBUF_RXEMPTY_MASK BIT(31) + +/* 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_RX_INTR_MASK BIT(8) +#define SPIFLG_TX_INTR_MASK BIT(9) +#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24) +#define SPIFLG_MASK (SPIFLG_DLEN_ERR_MASK \ + | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \ + | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \ + | SPIFLG_OVRRUN_MASK | SPIFLG_RX_INTR_MASK \ + | SPIFLG_TX_INTR_MASK \ + | SPIFLG_BUF_INIT_ACTIVE_MASK) + +#define SPIINT_DLEN_ERR_INTR BIT(0) +#define SPIINT_TIMEOUT_INTR BIT(1) +#define SPIINT_PARERR_INTR BIT(2) +#define SPIINT_DESYNC_INTR BIT(3) +#define SPIINT_BITERR_INTR BIT(4) +#define SPIINT_OVRRUN_INTR BIT(6) +#define SPIINT_RX_INTR BIT(8) +#define SPIINT_TX_INTR BIT(9) +#define SPIINT_DMA_REQ_EN BIT(16) +#define SPIINT_ENABLE_HIGHZ BIT(24) + +#define SPI_T2CDELAY_SHIFT 16 +#define SPI_C2TDELAY_SHIFT 24 + +/* SPI Controller registers */ +#define SPIGCR0 0x00 +#define SPIGCR1 0x04 +#define SPIINT 0x08 +#define SPILVL 0x0c +#define SPIFLG 0x10 +#define SPIPC0 0x14 +#define SPIPC1 0x18 +#define SPIPC2 0x1c +#define SPIPC3 0x20 +#define SPIPC4 0x24 +#define SPIPC5 0x28 +#define SPIPC6 0x2c +#define SPIPC7 0x30 +#define SPIPC8 0x34 +#define SPIDAT0 0x38 +#define SPIDAT1 0x3c +#define SPIBUF 0x40 +#define SPIEMU 0x44 +#define SPIDELAY 0x48 +#define SPIDEF 0x4c +#define SPIFMT0 0x50 +#define SPIFMT1 0x54 +#define SPIFMT2 0x58 +#define SPIFMT3 0x5c +#define TGINTVEC0 0x60 +#define TGINTVEC1 0x64 + +struct davinci_spi_slave { + u32 cmd_to_write; + u32 clk_ctrl_to_write; + u32 bytes_per_word; + u8 active_cs; +}; + +/* We have 2 DMA channels per CS, one for RX and one for TX */ +struct davinci_spi_dma { + int dma_tx_channel; + int dma_rx_channel; + int dma_tx_sync_dev; + int dma_rx_sync_dev; + enum dma_event_q eventq; + + struct completion dma_tx_completion; + struct completion dma_rx_completion; +}; + +/* 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; + size_t region_size; + u32 irq; + struct completion done; + + const void *tx; + void *rx; + u8 *tmp_buf; + int count; + struct davinci_spi_dma *dma_channels; + struct davinci_spi_platform_data *pdata; + + void (*get_rx)(u32 rx_data, struct davinci_spi *); + u32 (*get_tx)(struct davinci_spi *); + + struct davinci_spi_slave slave[SPI_MAX_CHIPSELECT]; +}; + +static unsigned use_dma; + +static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi) +{ + u8 *rx = davinci_spi->rx; + + *rx++ = (u8)data; + davinci_spi->rx = rx; +} + +static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *davinci_spi) +{ + u16 *rx = davinci_spi->rx; + + *rx++ = (u16)data; + davinci_spi->rx = rx; +} + +static u32 davinci_spi_tx_buf_u8(struct davinci_spi *davinci_spi) +{ + u32 data; + const u8 *tx = davinci_spi->tx; + + data = *tx++; + davinci_spi->tx = tx; + return data; +} + +static u32 davinci_spi_tx_buf_u16(struct davinci_spi *davinci_spi) +{ + u32 data; + const u16 *tx = davinci_spi->tx; + + data = *tx++; + davinci_spi->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); +} + +static inline void set_fmt_bits(void __iomem *addr, u32 bits, int cs_num) +{ + set_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits); +} + +static inline void clear_fmt_bits(void __iomem *addr, u32 bits, int cs_num) +{ + clear_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits); +} + +static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable) +{ + struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master); + + if (enable) + set_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN); + else + clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN); +} + +/* + * Interface to control the chip select signal + */ +static void davinci_spi_chipselect(struct spi_device *spi, int value) +{ + struct davinci_spi *davinci_spi; + struct davinci_spi_platform_data *pdata; + u32 data1_reg_val = 0; + + davinci_spi = spi_master_get_devdata(spi->master); + pdata = davinci_spi->pdata; + + /* + * Board specific chip select logic decides the polarity and cs + * line for the controller + */ + if (value == BITBANG_CS_INACTIVE) { + set_io_bits(davinci_spi->base + SPIDEF, CS_DEFAULT); + + data1_reg_val |= CS_DEFAULT << SPIDAT1_CSNR_SHIFT; + iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); + + while ((ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_RXEMPTY_MASK) == 0) + cpu_relax(); + } +} + +/** + * 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 *davinci_spi; + struct davinci_spi_platform_data *pdata; + u8 bits_per_word = 0; + u32 hz = 0, prescale; + + davinci_spi = spi_master_get_devdata(spi->master); + pdata = davinci_spi->pdata; + + 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) { + davinci_spi->get_rx = davinci_spi_rx_buf_u8; + davinci_spi->get_tx = davinci_spi_tx_buf_u8; + davinci_spi->slave[spi->chip_select].bytes_per_word = 1; + } else if (bits_per_word <= 16 && bits_per_word >= 2) { + davinci_spi->get_rx = davinci_spi_rx_buf_u16; + davinci_spi->get_tx = davinci_spi_tx_buf_u16; + davinci_spi->slave[spi->chip_select].bytes_per_word = 2; + } else + return -EINVAL; + + if (!hz) + hz = spi->max_speed_hz; + + clear_fmt_bits(davinci_spi->base, SPIFMT_CHARLEN_MASK, + spi->chip_select); + set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f, + spi->chip_select); + + prescale = ((clk_get_rate(davinci_spi->clk) / hz) - 1) & 0xff; + + clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select); + set_fmt_bits(davinci_spi->base, prescale << 8, spi->chip_select); + + return 0; +} + +static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data) +{ + struct spi_device *spi = (struct spi_device *)data; + struct davinci_spi *davinci_spi; + struct davinci_spi_dma *davinci_spi_dma; + struct davinci_spi_platform_data *pdata; + + davinci_spi = spi_master_get_devdata(spi->master); + davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]); + pdata = davinci_spi->pdata; + + if (ch_status == DMA_COMPLETE) + edma_stop(davinci_spi_dma->dma_rx_channel); + else + edma_clean_channel(davinci_spi_dma->dma_rx_channel); + + complete(&davinci_spi_dma->dma_rx_completion); + /* We must disable the DMA RX request */ + davinci_spi_set_dma_req(spi, 0); +} + +static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data) +{ + struct spi_device *spi = (struct spi_device *)data; + struct davinci_spi *davinci_spi; + struct davinci_spi_dma *davinci_spi_dma; + struct davinci_spi_platform_data *pdata; + + davinci_spi = spi_master_get_devdata(spi->master); + davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]); + pdata = davinci_spi->pdata; + + if (ch_status == DMA_COMPLETE) + edma_stop(davinci_spi_dma->dma_tx_channel); + else + edma_clean_channel(davinci_spi_dma->dma_tx_channel); + + complete(&davinci_spi_dma->dma_tx_completion); + /* We must disable the DMA TX request */ + davinci_spi_set_dma_req(spi, 0); +} + +static int davinci_spi_request_dma(struct spi_device *spi) +{ + struct davinci_spi *davinci_spi; + struct davinci_spi_dma *davinci_spi_dma; + struct davinci_spi_platform_data *pdata; + struct device *sdev; + int r; + + davinci_spi = spi_master_get_devdata(spi->master); + davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select]; + pdata = davinci_spi->pdata; + sdev = davinci_spi->bitbang.master->dev.parent; + + r = edma_alloc_channel(davinci_spi_dma->dma_rx_sync_dev, + davinci_spi_dma_rx_callback, spi, + davinci_spi_dma->eventq); + if (r < 0) { + dev_dbg(sdev, "Unable to request DMA channel for SPI RX\n"); + return -EAGAIN; + } + davinci_spi_dma->dma_rx_channel = r; + r = edma_alloc_channel(davinci_spi_dma->dma_tx_sync_dev, + davinci_spi_dma_tx_callback, spi, + davinci_spi_dma->eventq); + if (r < 0) { + edma_free_channel(davinci_spi_dma->dma_rx_channel); + davinci_spi_dma->dma_rx_channel = -1; + dev_dbg(sdev, "Unable to request DMA channel for SPI TX\n"); + return -EAGAIN; + } + davinci_spi_dma->dma_tx_channel = r; + + 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; + struct davinci_spi *davinci_spi; + struct davinci_spi_dma *davinci_spi_dma; + struct device *sdev; + + davinci_spi = spi_master_get_devdata(spi->master); + sdev = davinci_spi->bitbang.master->dev.parent; + + /* if bits per word length is zero then set it default 8 */ + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + davinci_spi->slave[spi->chip_select].cmd_to_write = 0; + + if (use_dma && davinci_spi->dma_channels) { + davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select]; + + if ((davinci_spi_dma->dma_rx_channel == -1) + || (davinci_spi_dma->dma_tx_channel == -1)) { + retval = davinci_spi_request_dma(spi); + if (retval < 0) + return retval; + } + } + + /* + * SPI in DaVinci and DA8xx operate between + * 600 KHz and 50 MHz + */ + if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000) { + dev_dbg(sdev, "Operating frequency is not in acceptable " + "range\n"); + return -EINVAL; + } + + /* + * Set up SPIFMTn register, unique to this chipselect. + * + * NOTE: we could do all of these with one write. Also, some + * of the "version 2" features are found in chips that don't + * support all of them... + */ + if (spi->mode & SPI_LSB_FIRST) + set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK, + spi->chip_select); + + if (spi->mode & SPI_CPOL) + set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK, + spi->chip_select); + + if (!(spi->mode & SPI_CPHA)) + set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK, + spi->chip_select); + + /* + * 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 (davinci_spi->version == SPI_VERSION_2) { + clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK, + spi->chip_select); + set_fmt_bits(davinci_spi->base, + (davinci_spi->pdata->wdelay + << SPIFMT_WDELAY_SHIFT) + & SPIFMT_WDELAY_MASK, + spi->chip_select); + + if (davinci_spi->pdata->odd_parity) + set_fmt_bits(davinci_spi->base, + SPIFMT_ODD_PARITY_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, + SPIFMT_ODD_PARITY_MASK, + spi->chip_select); + + if (davinci_spi->pdata->parity_enable) + set_fmt_bits(davinci_spi->base, + SPIFMT_PARITYENA_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, + SPIFMT_PARITYENA_MASK, + spi->chip_select); + + if (davinci_spi->pdata->wait_enable) + set_fmt_bits(davinci_spi->base, + SPIFMT_WAITENA_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, + SPIFMT_WAITENA_MASK, + spi->chip_select); + + if (davinci_spi->pdata->timer_disable) + set_fmt_bits(davinci_spi->base, + SPIFMT_DISTIMER_MASK, + spi->chip_select); + else + clear_fmt_bits(davinci_spi->base, + SPIFMT_DISTIMER_MASK, + spi->chip_select); + } + + retval = davinci_spi_setup_transfer(spi, NULL); + + return retval; +} + +static void davinci_spi_cleanup(struct spi_device *spi) +{ + struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master); + struct davinci_spi_dma *davinci_spi_dma; + + davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select]; + + if (use_dma && davinci_spi->dma_channels) { + davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select]; + + if ((davinci_spi_dma->dma_rx_channel != -1) + && (davinci_spi_dma->dma_tx_channel != -1)) { + edma_free_channel(davinci_spi_dma->dma_tx_channel); + edma_free_channel(davinci_spi_dma->dma_rx_channel); + } + } +} + +static int davinci_spi_bufs_prep(struct spi_device *spi, + struct davinci_spi *davinci_spi) +{ + int op_mode = 0; + + /* + * REVISIT unless devices disagree about SPI_LOOP or + * SPI_READY (SPI_NO_CS only allows one device!), this + * should not need to be done before each message... + * optimize for both flags staying cleared. + */ + + op_mode = SPIPC0_DIFUN_MASK + | SPIPC0_DOFUN_MASK + | SPIPC0_CLKFUN_MASK; + if (!(spi->mode & SPI_NO_CS)) + op_mode |= 1 << spi->chip_select; + if (spi->mode & SPI_READY) + op_mode |= SPIPC0_SPIENA_MASK; + + iowrite32(op_mode, davinci_spi->base + SPIPC0); + + if (spi->mode & SPI_LOOP) + set_io_bits(davinci_spi->base + SPIGCR1, + SPIGCR1_LOOPBACK_MASK); + else + clear_io_bits(davinci_spi->base + SPIGCR1, + SPIGCR1_LOOPBACK_MASK); + + return 0; +} + +static int davinci_spi_check_error(struct davinci_spi *davinci_spi, + int int_status) +{ + struct device *sdev = davinci_spi->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 (davinci_spi->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_TX_INTR_MASK) { + dev_dbg(sdev, "SPI TX intr bit set\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_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_pio(struct spi_device *spi, struct spi_transfer *t) +{ + struct davinci_spi *davinci_spi; + int int_status, count, ret; + u8 conv, tmp; + u32 tx_data, data1_reg_val; + u32 buf_val, flg_val; + struct davinci_spi_platform_data *pdata; + + davinci_spi = spi_master_get_devdata(spi->master); + pdata = davinci_spi->pdata; + + davinci_spi->tx = t->tx_buf; + davinci_spi->rx = t->rx_buf; + + /* convert len to words based on bits_per_word */ + conv = davinci_spi->slave[spi->chip_select].bytes_per_word; + davinci_spi->count = t->len / conv; + + INIT_COMPLETION(davinci_spi->done); + + ret = davinci_spi_bufs_prep(spi, davinci_spi); + if (ret) + return ret; + + /* Enable SPI */ + set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + + iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) | + (pdata->t2cdelay << SPI_T2CDELAY_SHIFT), + davinci_spi->base + SPIDELAY); + + count = davinci_spi->count; + data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT; + tmp = ~(0x1 << spi->chip_select); + + clear_io_bits(davinci_spi->base + SPIDEF, ~tmp); + + data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT; + + while ((ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_RXEMPTY_MASK) == 0) + cpu_relax(); + + /* Determine the command to execute READ or WRITE */ + if (t->tx_buf) { + clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL); + + while (1) { + tx_data = davinci_spi->get_tx(davinci_spi); + + data1_reg_val &= ~(0xFFFF); + data1_reg_val |= (0xFFFF & tx_data); + + buf_val = ioread32(davinci_spi->base + SPIBUF); + if ((buf_val & SPIBUF_TXFULL_MASK) == 0) { + iowrite32(data1_reg_val, + davinci_spi->base + SPIDAT1); + + count--; + } + while (ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_RXEMPTY_MASK) + cpu_relax(); + + /* getting the returned byte */ + if (t->rx_buf) { + buf_val = ioread32(davinci_spi->base + SPIBUF); + davinci_spi->get_rx(buf_val, davinci_spi); + } + if (count <= 0) + break; + } + } else { + if (pdata->poll_mode) { + while (1) { + /* keeps the serial clock going */ + if ((ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_TXFULL_MASK) == 0) + iowrite32(data1_reg_val, + davinci_spi->base + SPIDAT1); + + while (ioread32(davinci_spi->base + SPIBUF) & + SPIBUF_RXEMPTY_MASK) + cpu_relax(); + + flg_val = ioread32(davinci_spi->base + SPIFLG); + buf_val = ioread32(davinci_spi->base + SPIBUF); + + davinci_spi->get_rx(buf_val, davinci_spi); + + count--; + if (count <= 0) + break; + } + } else { /* Receive in Interrupt mode */ + int i; + + for (i = 0; i < davinci_spi->count; i++) { + set_io_bits(davinci_spi->base + SPIINT, + SPIINT_BITERR_INTR + | SPIINT_OVRRUN_INTR + | SPIINT_RX_INTR); + + iowrite32(data1_reg_val, + davinci_spi->base + SPIDAT1); + + while (ioread32(davinci_spi->base + SPIINT) & + SPIINT_RX_INTR) + cpu_relax(); + } + iowrite32((data1_reg_val & 0x0ffcffff), + davinci_spi->base + SPIDAT1); + } + } + + /* + * Check for bit error, desync error,parity error,timeout error and + * receive overflow errors + */ + int_status = ioread32(davinci_spi->base + SPIFLG); + + ret = davinci_spi_check_error(davinci_spi, int_status); + if (ret != 0) + return ret; + + /* SPI Framework maintains the count only in bytes so convert back */ + davinci_spi->count *= conv; + + return t->len; +} + +#define DAVINCI_DMA_DATA_TYPE_S8 0x01 +#define DAVINCI_DMA_DATA_TYPE_S16 0x02 +#define DAVINCI_DMA_DATA_TYPE_S32 0x04 + +static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) +{ + struct davinci_spi *davinci_spi; + int int_status = 0; + int count, temp_count; + u8 conv = 1; + u8 tmp; + u32 data1_reg_val; + struct davinci_spi_dma *davinci_spi_dma; + int word_len, data_type, ret; + unsigned long tx_reg, rx_reg; + struct davinci_spi_platform_data *pdata; + struct device *sdev; + + davinci_spi = spi_master_get_devdata(spi->master); + pdata = davinci_spi->pdata; + sdev = davinci_spi->bitbang.master->dev.parent; + + davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select]; + + tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1; + rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF; + + davinci_spi->tx = t->tx_buf; + davinci_spi->rx = t->rx_buf; + + /* convert len to words based on bits_per_word */ + conv = davinci_spi->slave[spi->chip_select].bytes_per_word; + davinci_spi->count = t->len / conv; + + INIT_COMPLETION(davinci_spi->done); + + init_completion(&davinci_spi_dma->dma_rx_completion); + init_completion(&davinci_spi_dma->dma_tx_completion); + + word_len = conv * 8; + + if (word_len <= 8) + data_type = DAVINCI_DMA_DATA_TYPE_S8; + else if (word_len <= 16) + data_type = DAVINCI_DMA_DATA_TYPE_S16; + else if (word_len <= 32) + data_type = DAVINCI_DMA_DATA_TYPE_S32; + else + return -EINVAL; + + ret = davinci_spi_bufs_prep(spi, davinci_spi); + if (ret) + return ret; + + /* Put delay val if required */ + iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) | + (pdata->t2cdelay << SPI_T2CDELAY_SHIFT), + davinci_spi->base + SPIDELAY); + + count = davinci_spi->count; /* the number of elements */ + data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT; + + /* CS default = 0xFF */ + tmp = ~(0x1 << spi->chip_select); + + clear_io_bits(davinci_spi->base + SPIDEF, ~tmp); + + data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT; + + /* disable all interrupts for dma transfers */ + clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL); + /* Disable SPI to write configuration bits in SPIDAT */ + clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); + /* Enable SPI */ + set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + + while ((ioread32(davinci_spi->base + SPIBUF) + & SPIBUF_RXEMPTY_MASK) == 0) + cpu_relax(); + + + if (t->tx_buf) { + t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count, + DMA_TO_DEVICE); + if (dma_mapping_error(&spi->dev, t->tx_dma)) { + dev_dbg(sdev, "Unable to DMA map a %d bytes" + " TX buffer\n", count); + return -ENOMEM; + } + temp_count = count; + } else { + /* We need TX clocking for RX transaction */ + t->tx_dma = dma_map_single(&spi->dev, + (void *)davinci_spi->tmp_buf, count + 1, + DMA_TO_DEVICE); + if (dma_mapping_error(&spi->dev, t->tx_dma)) { + dev_dbg(sdev, "Unable to DMA map a %d bytes" + " TX tmp buffer\n", count); + return -ENOMEM; + } + temp_count = count + 1; + } + + edma_set_transfer_params(davinci_spi_dma->dma_tx_channel, + data_type, temp_count, 1, 0, ASYNC); + edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT); + edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT); + edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0); + edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0); + + if (t->rx_buf) { + /* initiate transaction */ + iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); + + t->rx_dma = dma_map_single(&spi->dev, (void *)t->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", + count); + if (t->tx_buf != NULL) + dma_unmap_single(NULL, t->tx_dma, + count, DMA_TO_DEVICE); + return -ENOMEM; + } + edma_set_transfer_params(davinci_spi_dma->dma_rx_channel, + data_type, count, 1, 0, ASYNC); + edma_set_src(davinci_spi_dma->dma_rx_channel, + rx_reg, INCR, W8BIT); + edma_set_dest(davinci_spi_dma->dma_rx_channel, + t->rx_dma, INCR, W8BIT); + edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0); + edma_set_dest_index(davinci_spi_dma->dma_rx_channel, + data_type, 0); + } + + if ((t->tx_buf) || (t->rx_buf)) + edma_start(davinci_spi_dma->dma_tx_channel); + + if (t->rx_buf) + edma_start(davinci_spi_dma->dma_rx_channel); + + if ((t->rx_buf) || (t->tx_buf)) + davinci_spi_set_dma_req(spi, 1); + + if (t->tx_buf) + wait_for_completion_interruptible( + &davinci_spi_dma->dma_tx_completion); + + if (t->rx_buf) + wait_for_completion_interruptible( + &davinci_spi_dma->dma_rx_completion); + + dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE); + + if (t->rx_buf) + dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE); + + /* + * Check for bit error, desync error,parity error,timeout error and + * receive overflow errors + */ + int_status = ioread32(davinci_spi->base + SPIFLG); + + ret = davinci_spi_check_error(davinci_spi, int_status); + if (ret != 0) + return ret; + + /* SPI Framework maintains the count only in bytes so convert back */ + davinci_spi->count *= conv; + + return t->len; +} + +/** + * davinci_spi_irq - IRQ handler for DaVinci SPI + * @irq: IRQ number for this SPI Master + * @context_data: structure for SPI Master controller davinci_spi + */ +static irqreturn_t davinci_spi_irq(s32 irq, void *context_data) +{ + struct davinci_spi *davinci_spi = context_data; + u32 int_status, rx_data = 0; + irqreturn_t ret = IRQ_NONE; + + int_status = ioread32(davinci_spi->base + SPIFLG); + + while ((int_status & SPIFLG_RX_INTR_MASK)) { + if (likely(int_status & SPIFLG_RX_INTR_MASK)) { + ret = IRQ_HANDLED; + + rx_data = ioread32(davinci_spi->base + SPIBUF); + davinci_spi->get_rx(rx_data, davinci_spi); + + /* Disable Receive Interrupt */ + iowrite32(~(SPIINT_RX_INTR | SPIINT_TX_INTR), + davinci_spi->base + SPIINT); + } else + (void)davinci_spi_check_error(davinci_spi, int_status); + + int_status = ioread32(davinci_spi->base + SPIFLG); + } + + return ret; +} + +/** + * davinci_spi_probe - probe function for SPI Master Controller + * @pdev: platform_device structure which contains plateform specific data + */ +static int davinci_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct davinci_spi *davinci_spi; + 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; + resource_size_t dma_eventq = SPI_NO_RESOURCE; + int i = 0, ret = 0; + + 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); + + davinci_spi = spi_master_get_devdata(master); + if (davinci_spi == NULL) { + ret = -ENOENT; + goto free_master; + } + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + ret = -ENOENT; + goto free_master; + } + + davinci_spi->pbase = r->start; + davinci_spi->region_size = resource_size(r); + davinci_spi->pdata = pdata; + + mem = request_mem_region(r->start, davinci_spi->region_size, + pdev->name); + if (mem == NULL) { + ret = -EBUSY; + goto free_master; + } + + davinci_spi->base = (struct davinci_spi_reg __iomem *) + ioremap(r->start, davinci_spi->region_size); + if (davinci_spi->base == NULL) { + ret = -ENOMEM; + goto release_region; + } + + davinci_spi->irq = platform_get_irq(pdev, 0); + if (davinci_spi->irq <= 0) { + ret = -EINVAL; + goto unmap_io; + } + + ret = request_irq(davinci_spi->irq, davinci_spi_irq, IRQF_DISABLED, + dev_name(&pdev->dev), davinci_spi); + if (ret) + goto unmap_io; + + /* Allocate tmp_buf for tx_buf */ + davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL); + if (davinci_spi->tmp_buf == NULL) { + ret = -ENOMEM; + goto irq_free; + } + + davinci_spi->bitbang.master = spi_master_get(master); + if (davinci_spi->bitbang.master == NULL) { + ret = -ENODEV; + goto free_tmp_buf; + } + + davinci_spi->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(davinci_spi->clk)) { + ret = -ENODEV; + goto put_master; + } + clk_enable(davinci_spi->clk); + + + master->bus_num = pdev->id; + master->num_chipselect = pdata->num_chipselect; + master->setup = davinci_spi_setup; + master->cleanup = davinci_spi_cleanup; + + davinci_spi->bitbang.chipselect = davinci_spi_chipselect; + davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer; + + davinci_spi->version = pdata->version; + use_dma = pdata->use_dma; + + davinci_spi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP; + if (davinci_spi->version == SPI_VERSION_2) + davinci_spi->bitbang.flags |= SPI_READY; + + if (use_dma) { + 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; + r = platform_get_resource(pdev, IORESOURCE_DMA, 2); + if (r) + dma_eventq = r->start; + } + + if (!use_dma || + dma_rx_chan == SPI_NO_RESOURCE || + dma_tx_chan == SPI_NO_RESOURCE || + dma_eventq == SPI_NO_RESOURCE) { + davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio; + use_dma = 0; + } else { + davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_dma; + davinci_spi->dma_channels = kzalloc(master->num_chipselect + * sizeof(struct davinci_spi_dma), GFP_KERNEL); + if (davinci_spi->dma_channels == NULL) { + ret = -ENOMEM; + goto free_clk; + } + + for (i = 0; i < master->num_chipselect; i++) { + davinci_spi->dma_channels[i].dma_rx_channel = -1; + davinci_spi->dma_channels[i].dma_rx_sync_dev = + dma_rx_chan; + davinci_spi->dma_channels[i].dma_tx_channel = -1; + davinci_spi->dma_channels[i].dma_tx_sync_dev = + dma_tx_chan; + davinci_spi->dma_channels[i].eventq = dma_eventq; + } + dev_info(&pdev->dev, "DaVinci SPI driver in EDMA mode\n" + "Using RX channel = %d , TX channel = %d and " + "event queue = %d", dma_rx_chan, dma_tx_chan, + dma_eventq); + } + + davinci_spi->get_rx = davinci_spi_rx_buf_u8; + davinci_spi->get_tx = davinci_spi_tx_buf_u8; + + init_completion(&davinci_spi->done); + + /* Reset In/OUT SPI module */ + iowrite32(0, davinci_spi->base + SPIGCR0); + udelay(100); + iowrite32(1, davinci_spi->base + SPIGCR0); + + /* Clock internal */ + if (davinci_spi->pdata->clk_internal) + set_io_bits(davinci_spi->base + SPIGCR1, + SPIGCR1_CLKMOD_MASK); + else + clear_io_bits(davinci_spi->base + SPIGCR1, + SPIGCR1_CLKMOD_MASK); + + /* master mode default */ + set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK); + + if (davinci_spi->pdata->intr_level) + iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL); + else + iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL); + + ret = spi_bitbang_start(&davinci_spi->bitbang); + if (ret) + goto free_clk; + + dev_info(&pdev->dev, "Controller at 0x%p \n", davinci_spi->base); + + if (!pdata->poll_mode) + dev_info(&pdev->dev, "Operating in interrupt mode" + " using IRQ %d\n", davinci_spi->irq); + + return ret; + +free_clk: + clk_disable(davinci_spi->clk); + clk_put(davinci_spi->clk); +put_master: + spi_master_put(master); +free_tmp_buf: + kfree(davinci_spi->tmp_buf); +irq_free: + free_irq(davinci_spi->irq, davinci_spi); +unmap_io: + iounmap(davinci_spi->base); +release_region: + release_mem_region(davinci_spi->pbase, davinci_spi->region_size); +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 *davinci_spi; + struct spi_master *master; + + master = dev_get_drvdata(&pdev->dev); + davinci_spi = spi_master_get_devdata(master); + + spi_bitbang_stop(&davinci_spi->bitbang); + + clk_disable(davinci_spi->clk); + clk_put(davinci_spi->clk); + spi_master_put(master); + kfree(davinci_spi->tmp_buf); + free_irq(davinci_spi->irq, davinci_spi); + iounmap(davinci_spi->base); + release_mem_region(davinci_spi->pbase, davinci_spi->region_size); + + return 0; +} + +static struct platform_driver davinci_spi_driver = { + .driver.name = "spi_davinci", + .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"); |
