| /* |
| * 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. |
| */ |
| |
| #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/dmaengine.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/of_gpio.h> |
| #include <linux/spi/spi.h> |
| #include <linux/spi/spi_bitbang.h> |
| #include <linux/slab.h> |
| |
| #include <linux/platform_data/spi-davinci.h> |
| |
| #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) |
| #define SPIDAT1_WDEL BIT(10) |
| |
| /* 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 |
| |
| #define DMA_MIN_BYTES 16 |
| |
| /* 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; |
| int rcount; |
| int wcount; |
| |
| struct dma_chan *dma_rx; |
| struct dma_chan *dma_tx; |
| |
| 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; |
| |
| u8 prescaler_limit; |
| }; |
| |
| 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; |
| struct davinci_spi_config *spicfg = spi->controller_data; |
| u8 chip_sel = spi->chip_select; |
| u16 spidat1 = CS_DEFAULT; |
| |
| dspi = spi_master_get_devdata(spi->master); |
| pdata = &dspi->pdata; |
| |
| /* program delay transfers if tx_delay is non zero */ |
| if (spicfg && spicfg->wdelay) |
| spidat1 |= SPIDAT1_WDEL; |
| |
| /* |
| * Board specific chip select logic decides the polarity and cs |
| * line for the controller |
| */ |
| if (spi->cs_gpio >= 0) { |
| if (value == BITBANG_CS_ACTIVE) |
| gpio_set_value(spi->cs_gpio, spi->mode & SPI_CS_HIGH); |
| else |
| gpio_set_value(spi->cs_gpio, |
| !(spi->mode & SPI_CS_HIGH)); |
| } 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 value 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; |
| |
| /* Subtract 1 to match what will be programmed into SPI register. */ |
| ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1; |
| |
| if (ret < dspi->prescaler_limit || ret > 255) |
| return -EINVAL; |
| |
| return ret; |
| } |
| |
| /** |
| * 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; |
| int prescale; |
| |
| dspi = spi_master_get_devdata(spi->master); |
| spicfg = 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) { |
| 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 { |
| dspi->get_rx = davinci_spi_rx_buf_u16; |
| dspi->get_tx = davinci_spi_tx_buf_u16; |
| dspi->bytes_per_word[spi->chip_select] = 2; |
| } |
| |
| 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; |
| |
| /* |
| * Assume wdelay is used only on SPI peripherals that has this field |
| * in SPIFMTn register and when it's configured from board file or DT. |
| */ |
| if (spicfg->wdelay) |
| spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) |
| & SPIFMT_WDELAY_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; |
| |
| 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; |
| } |
| |
| static int davinci_spi_of_setup(struct spi_device *spi) |
| { |
| struct davinci_spi_config *spicfg = spi->controller_data; |
| struct device_node *np = spi->dev.of_node; |
| struct davinci_spi *dspi = spi_master_get_devdata(spi->master); |
| u32 prop; |
| |
| if (spicfg == NULL && np) { |
| spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL); |
| if (!spicfg) |
| return -ENOMEM; |
| *spicfg = davinci_spi_default_cfg; |
| /* override with dt configured values */ |
| if (!of_property_read_u32(np, "ti,spi-wdelay", &prop)) |
| spicfg->wdelay = (u8)prop; |
| spi->controller_data = spicfg; |
| |
| if (dspi->dma_rx && dspi->dma_tx) |
| spicfg->io_type = SPI_IO_TYPE_DMA; |
| } |
| |
| 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; |
| struct spi_master *master = spi->master; |
| struct device_node *np = spi->dev.of_node; |
| bool internal_cs = true; |
| |
| dspi = spi_master_get_devdata(spi->master); |
| pdata = &dspi->pdata; |
| |
| if (!(spi->mode & SPI_NO_CS)) { |
| if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { |
| retval = gpio_direction_output( |
| spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); |
| internal_cs = false; |
| } else if (pdata->chip_sel && |
| spi->chip_select < pdata->num_chipselect && |
| pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) { |
| spi->cs_gpio = pdata->chip_sel[spi->chip_select]; |
| retval = gpio_direction_output( |
| spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); |
| internal_cs = false; |
| } |
| |
| if (retval) { |
| dev_err(&spi->dev, "GPIO %d setup failed (%d)\n", |
| spi->cs_gpio, retval); |
| return retval; |
| } |
| |
| if (internal_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 davinci_spi_of_setup(spi); |
| } |
| |
| static void davinci_spi_cleanup(struct spi_device *spi) |
| { |
| struct davinci_spi_config *spicfg = spi->controller_data; |
| |
| spi->controller_data = NULL; |
| if (spi->dev.of_node) |
| kfree(spicfg); |
| } |
| |
| static bool davinci_spi_can_dma(struct spi_master *master, |
| struct spi_device *spi, |
| struct spi_transfer *xfer) |
| { |
| struct davinci_spi_config *spicfg = spi->controller_data; |
| bool can_dma = false; |
| |
| if (spicfg) |
| can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) && |
| (xfer->len >= DMA_MIN_BYTES) && |
| !is_vmalloc_addr(xfer->rx_buf) && |
| !is_vmalloc_addr(xfer->tx_buf); |
| |
| return can_dma; |
| } |
| |
| 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_err(sdev, "SPI Time-out Error\n"); |
| return -ETIMEDOUT; |
| } |
| if (int_status & SPIFLG_DESYNC_MASK) { |
| dev_err(sdev, "SPI Desynchronization Error\n"); |
| return -EIO; |
| } |
| if (int_status & SPIFLG_BITERR_MASK) { |
| dev_err(sdev, "SPI Bit error\n"); |
| return -EIO; |
| } |
| |
| if (dspi->version == SPI_VERSION_2) { |
| if (int_status & SPIFLG_DLEN_ERR_MASK) { |
| dev_err(sdev, "SPI Data Length Error\n"); |
| return -EIO; |
| } |
| if (int_status & SPIFLG_PARERR_MASK) { |
| dev_err(sdev, "SPI Parity Error\n"); |
| return -EIO; |
| } |
| if (int_status & SPIFLG_OVRRUN_MASK) { |
| dev_err(sdev, "SPI Data Overrun error\n"); |
| return -EIO; |
| } |
| if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) { |
| dev_err(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_rx_callback(void *data) |
| { |
| struct davinci_spi *dspi = (struct davinci_spi *)data; |
| |
| dspi->rcount = 0; |
| |
| if (!dspi->wcount && !dspi->rcount) |
| complete(&dspi->done); |
| } |
| |
| static void davinci_spi_dma_tx_callback(void *data) |
| { |
| struct davinci_spi *dspi = (struct davinci_spi *)data; |
| |
| dspi->wcount = 0; |
| |
| if (!dspi->wcount && !dspi->rcount) |
| 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 = -ENOMEM; |
| u32 tx_data, spidat1; |
| u32 errors = 0; |
| struct davinci_spi_config *spicfg; |
| struct davinci_spi_platform_data *pdata; |
| unsigned uninitialized_var(rx_buf_count); |
| |
| 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; |
| |
| /* 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); |
| |
| reinit_completion(&dspi->done); |
| |
| if (!davinci_spi_can_dma(spi->master, spi, t)) { |
| if (spicfg->io_type != SPI_IO_TYPE_POLL) |
| set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); |
| /* start the transfer */ |
| dspi->wcount--; |
| tx_data = dspi->get_tx(dspi); |
| spidat1 &= 0xFFFF0000; |
| spidat1 |= tx_data & 0xFFFF; |
| iowrite32(spidat1, dspi->base + SPIDAT1); |
| } else { |
| struct dma_slave_config dma_rx_conf = { |
| .direction = DMA_DEV_TO_MEM, |
| .src_addr = (unsigned long)dspi->pbase + SPIBUF, |
| .src_addr_width = data_type, |
| .src_maxburst = 1, |
| }; |
| struct dma_slave_config dma_tx_conf = { |
| .direction = DMA_MEM_TO_DEV, |
| .dst_addr = (unsigned long)dspi->pbase + SPIDAT1, |
| .dst_addr_width = data_type, |
| .dst_maxburst = 1, |
| }; |
| struct dma_async_tx_descriptor *rxdesc; |
| struct dma_async_tx_descriptor *txdesc; |
| |
| dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf); |
| dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf); |
| |
| rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx, |
| t->rx_sg.sgl, t->rx_sg.nents, DMA_DEV_TO_MEM, |
| DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| if (!rxdesc) |
| goto err_desc; |
| |
| if (!t->tx_buf) { |
| /* To avoid errors when doing rx-only transfers with |
| * many SG entries (> 20), use the rx buffer as the |
| * dummy tx buffer so that dma reloads are done at the |
| * same time for rx and tx. |
| */ |
| t->tx_sg.sgl = t->rx_sg.sgl; |
| t->tx_sg.nents = t->rx_sg.nents; |
| } |
| |
| txdesc = dmaengine_prep_slave_sg(dspi->dma_tx, |
| t->tx_sg.sgl, t->tx_sg.nents, DMA_MEM_TO_DEV, |
| DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
| if (!txdesc) |
| goto err_desc; |
| |
| rxdesc->callback = davinci_spi_dma_rx_callback; |
| rxdesc->callback_param = (void *)dspi; |
| txdesc->callback = davinci_spi_dma_tx_callback; |
| txdesc->callback_param = (void *)dspi; |
| |
| if (pdata->cshold_bug) |
| iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2); |
| |
| dmaengine_submit(rxdesc); |
| dmaengine_submit(txdesc); |
| |
| dma_async_issue_pending(dspi->dma_rx); |
| dma_async_issue_pending(dspi->dma_tx); |
| |
| set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); |
| } |
| |
| /* Wait for the transfer to complete */ |
| if (spicfg->io_type != SPI_IO_TYPE_POLL) { |
| if (wait_for_completion_timeout(&dspi->done, HZ) == 0) |
| errors = SPIFLG_TIMEOUT_MASK; |
| } 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 (davinci_spi_can_dma(spi->master, spi, t)) |
| 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(&spi->dev, "SPI data transfer error\n"); |
| return -EIO; |
| } |
| |
| return t->len; |
| |
| err_desc: |
| return ret; |
| } |
| |
| /** |
| * dummy_thread_fn - dummy thread function |
| * @irq: IRQ number for this SPI Master |
| * @context_data: structure for SPI Master controller davinci_spi |
| * |
| * This is to satisfy the request_threaded_irq() API so that the irq |
| * handler is called in interrupt context. |
| */ |
| static irqreturn_t dummy_thread_fn(s32 irq, void *data) |
| { |
| return IRQ_HANDLED; |
| } |
| |
| /** |
| * 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) |
| { |
| struct device *sdev = dspi->bitbang.master->dev.parent; |
| |
| dspi->dma_rx = dma_request_chan(sdev, "rx"); |
| if (IS_ERR(dspi->dma_rx)) |
| return PTR_ERR(dspi->dma_rx); |
| |
| dspi->dma_tx = dma_request_chan(sdev, "tx"); |
| if (IS_ERR(dspi->dma_tx)) { |
| dma_release_channel(dspi->dma_rx); |
| return PTR_ERR(dspi->dma_tx); |
| } |
| |
| return 0; |
| } |
| |
| #if defined(CONFIG_OF) |
| |
| /* OF SPI data structure */ |
| struct davinci_spi_of_data { |
| u8 version; |
| u8 prescaler_limit; |
| }; |
| |
| static const struct davinci_spi_of_data dm6441_spi_data = { |
| .version = SPI_VERSION_1, |
| .prescaler_limit = 2, |
| }; |
| |
| static const struct davinci_spi_of_data da830_spi_data = { |
| .version = SPI_VERSION_2, |
| .prescaler_limit = 2, |
| }; |
| |
| static const struct davinci_spi_of_data keystone_spi_data = { |
| .version = SPI_VERSION_1, |
| .prescaler_limit = 0, |
| }; |
| |
| static const struct of_device_id davinci_spi_of_match[] = { |
| { |
| .compatible = "ti,dm6441-spi", |
| .data = &dm6441_spi_data, |
| }, |
| { |
| .compatible = "ti,da830-spi", |
| .data = &da830_spi_data, |
| }, |
| { |
| .compatible = "ti,keystone-spi", |
| .data = &keystone_spi_data, |
| }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(of, davinci_spi_of_match); |
| |
| /** |
| * spi_davinci_get_pdata - Get platform data from DTS binding |
| * @pdev: ptr to platform data |
| * @dspi: ptr to driver data |
| * |
| * Parses and populates pdata in dspi from device tree bindings. |
| * |
| * NOTE: Not all platform data params are supported currently. |
| */ |
| static int spi_davinci_get_pdata(struct platform_device *pdev, |
| struct davinci_spi *dspi) |
| { |
| struct device_node *node = pdev->dev.of_node; |
| struct davinci_spi_of_data *spi_data; |
| struct davinci_spi_platform_data *pdata; |
| unsigned int num_cs, intr_line = 0; |
| const struct of_device_id *match; |
| |
| pdata = &dspi->pdata; |
| |
| match = of_match_device(davinci_spi_of_match, &pdev->dev); |
| if (!match) |
| return -ENODEV; |
| |
| spi_data = (struct davinci_spi_of_data *)match->data; |
| |
| pdata->version = spi_data->version; |
| pdata->prescaler_limit = spi_data->prescaler_limit; |
| /* |
| * default num_cs is 1 and all chipsel are internal to the chip |
| * indicated by chip_sel being NULL or cs_gpios being NULL or |
| * set to -ENOENT. num-cs includes internal as well as gpios. |
| * indicated by chip_sel being NULL. GPIO based CS is not |
| * supported yet in DT bindings. |
| */ |
| num_cs = 1; |
| of_property_read_u32(node, "num-cs", &num_cs); |
| pdata->num_chipselect = num_cs; |
| of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line); |
| pdata->intr_line = intr_line; |
| return 0; |
| } |
| #else |
| static int spi_davinci_get_pdata(struct platform_device *pdev, |
| struct davinci_spi *dspi) |
| { |
| return -ENODEV; |
| } |
| #endif |
| |
| /** |
| * 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; |
| int ret = 0; |
| u32 spipc0; |
| |
| master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi)); |
| if (master == NULL) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| platform_set_drvdata(pdev, master); |
| |
| dspi = spi_master_get_devdata(master); |
| |
| if (dev_get_platdata(&pdev->dev)) { |
| pdata = dev_get_platdata(&pdev->dev); |
| dspi->pdata = *pdata; |
| } else { |
| /* update dspi pdata with that from the DT */ |
| ret = spi_davinci_get_pdata(pdev, dspi); |
| if (ret < 0) |
| goto free_master; |
| } |
| |
| /* pdata in dspi is now updated and point pdata to that */ |
| pdata = &dspi->pdata; |
| |
| dspi->bytes_per_word = devm_kzalloc(&pdev->dev, |
| sizeof(*dspi->bytes_per_word) * |
| pdata->num_chipselect, GFP_KERNEL); |
| if (dspi->bytes_per_word == NULL) { |
| ret = -ENOMEM; |
| goto free_master; |
| } |
| |
| r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (r == NULL) { |
| ret = -ENOENT; |
| goto free_master; |
| } |
| |
| dspi->pbase = r->start; |
| |
| dspi->base = devm_ioremap_resource(&pdev->dev, r); |
| if (IS_ERR(dspi->base)) { |
| ret = PTR_ERR(dspi->base); |
| goto free_master; |
| } |
| |
| init_completion(&dspi->done); |
| |
| ret = platform_get_irq(pdev, 0); |
| if (ret == 0) |
| ret = -EINVAL; |
| if (ret < 0) |
| goto free_master; |
| dspi->irq = ret; |
| |
| ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq, |
| dummy_thread_fn, 0, dev_name(&pdev->dev), dspi); |
| if (ret) |
| goto free_master; |
| |
| dspi->bitbang.master = master; |
| |
| dspi->clk = devm_clk_get(&pdev->dev, NULL); |
| if (IS_ERR(dspi->clk)) { |
| ret = -ENODEV; |
| goto free_master; |
| } |
| ret = clk_prepare_enable(dspi->clk); |
| if (ret) |
| goto free_master; |
| |
| master->dev.of_node = pdev->dev.of_node; |
| master->bus_num = pdev->id; |
| master->num_chipselect = pdata->num_chipselect; |
| master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); |
| master->flags = SPI_MASTER_MUST_RX; |
| master->setup = davinci_spi_setup; |
| master->cleanup = davinci_spi_cleanup; |
| master->can_dma = davinci_spi_can_dma; |
| |
| dspi->bitbang.chipselect = davinci_spi_chipselect; |
| dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; |
| dspi->prescaler_limit = pdata->prescaler_limit; |
| 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; |
| |
| if (pdev->dev.of_node) { |
| int i; |
| |
| for (i = 0; i < pdata->num_chipselect; i++) { |
| int cs_gpio = of_get_named_gpio(pdev->dev.of_node, |
| "cs-gpios", i); |
| |
| if (cs_gpio == -EPROBE_DEFER) { |
| ret = cs_gpio; |
| goto free_clk; |
| } |
| |
| if (gpio_is_valid(cs_gpio)) { |
| ret = devm_gpio_request(&pdev->dev, cs_gpio, |
| dev_name(&pdev->dev)); |
| if (ret) |
| goto free_clk; |
| } |
| } |
| } |
| |
| dspi->bitbang.txrx_bufs = davinci_spi_bufs; |
| |
| ret = davinci_spi_request_dma(dspi); |
| if (ret == -EPROBE_DEFER) { |
| goto free_clk; |
| } else if (ret) { |
| dev_info(&pdev->dev, "DMA is not supported (%d)\n", ret); |
| dspi->dma_rx = NULL; |
| dspi->dma_tx = NULL; |
| } |
| |
| dspi->get_rx = davinci_spi_rx_buf_u8; |
| dspi->get_tx = davinci_spi_tx_buf_u8; |
| |
| /* 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); |
| |
| 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: |
| if (dspi->dma_rx) { |
| dma_release_channel(dspi->dma_rx); |
| dma_release_channel(dspi->dma_tx); |
| } |
| free_clk: |
| clk_disable_unprepare(dspi->clk); |
| free_master: |
| spi_master_put(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 davinci_spi_remove(struct platform_device *pdev) |
| { |
| struct davinci_spi *dspi; |
| struct spi_master *master; |
| |
| master = platform_get_drvdata(pdev); |
| dspi = spi_master_get_devdata(master); |
| |
| spi_bitbang_stop(&dspi->bitbang); |
| |
| clk_disable_unprepare(dspi->clk); |
| spi_master_put(master); |
| |
| if (dspi->dma_rx) { |
| dma_release_channel(dspi->dma_rx); |
| dma_release_channel(dspi->dma_tx); |
| } |
| |
| return 0; |
| } |
| |
| static struct platform_driver davinci_spi_driver = { |
| .driver = { |
| .name = "spi_davinci", |
| .of_match_table = of_match_ptr(davinci_spi_of_match), |
| }, |
| .probe = davinci_spi_probe, |
| .remove = davinci_spi_remove, |
| }; |
| module_platform_driver(davinci_spi_driver); |
| |
| MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver"); |
| MODULE_LICENSE("GPL"); |