/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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_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 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; #define SPI_TMP_BUFSZ (SMP_CACHE_BYTES + 1) u8 rx_tmp_buf[SPI_TMP_BUFSZ]; int rcount; int wcount; 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 *); u8 bytes_per_word[SPI_MAX_CHIPSELECT]; }; static struct davinci_spi_config davinci_spi_default_cfg; static unsigned use_dma; static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi) { if (davinci_spi->rx) { 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) { if (davinci_spi->rx) { 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 = 0; if (davinci_spi->tx) { 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 = 0; if (davinci_spi->tx) { 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 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; u8 chip_sel = spi->chip_select; u16 spidat1_cfg = CS_DEFAULT; bool gpio_chipsel = false; davinci_spi = spi_master_get_devdata(spi->master); pdata = davinci_spi->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_cfg |= SPIDAT1_CSHOLD_MASK; spidat1_cfg &= ~(0x1 << chip_sel); } iowrite16(spidat1_cfg, davinci_spi->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 *davinci_spi, u32 max_speed_hz) { int ret; ret = DIV_ROUND_UP(clk_get_rate(davinci_spi->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 *davinci_spi; struct davinci_spi_config *spicfg; u8 bits_per_word = 0; u32 hz = 0, spifmt = 0, prescale = 0; davinci_spi = 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) { davinci_spi->get_rx = davinci_spi_rx_buf_u8; davinci_spi->get_tx = davinci_spi_tx_buf_u8; davinci_spi->bytes_per_word[spi->chip_select] = 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->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(davinci_spi, 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 (davinci_spi->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, davinci_spi->base + SPIDELAY); } iowrite32(spifmt, davinci_spi->base + SPIFMT0); 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; davinci_spi = spi_master_get_devdata(spi->master); davinci_spi_dma = &davinci_spi->dma_channels; 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; davinci_spi = spi_master_get_devdata(spi->master); davinci_spi_dma = &davinci_spi->dma_channels; 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 device *sdev; int r; davinci_spi = spi_master_get_devdata(spi->master); davinci_spi_dma = &davinci_spi->dma_channels; 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 = 0; 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); pdata = davinci_spi->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(davinci_spi->base + SPIPC0, 1 << spi->chip_select); } if (spi->mode & SPI_READY) set_io_bits(davinci_spi->base + SPIPC0, SPIPC0_SPIENA_MASK); 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); if (use_dma) { davinci_spi_dma = &davinci_spi->dma_channels; if ((davinci_spi_dma->dma_rx_channel == -1) || (davinci_spi_dma->dma_tx_channel == -1)) retval = davinci_spi_request_dma(spi); } return retval; } static void davinci_spi_cleanup(struct spi_device *spi) { if (use_dma) { struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master); struct davinci_spi_dma *davinci_spi_dma = &davinci_spi->dma_channels; 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_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_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 * @davinci_spi: 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 *davinci_spi) { u32 buf, status, errors = 0, data1_reg_val; buf = ioread32(davinci_spi->base + SPIBUF); if (davinci_spi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) { davinci_spi->get_rx(buf & 0xFFFF, davinci_spi); davinci_spi->rcount--; } status = ioread32(davinci_spi->base + SPIFLG); if (unlikely(status & SPIFLG_ERROR_MASK)) { errors = status & SPIFLG_ERROR_MASK; goto out; } if (davinci_spi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) { data1_reg_val = ioread32(davinci_spi->base + SPIDAT1); davinci_spi->wcount--; data1_reg_val &= ~0xFFFF; data1_reg_val |= 0xFFFF & davinci_spi->get_tx(davinci_spi); iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); } out: return errors; } /** * 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 ret; u32 tx_data, data1_reg_val; u32 errors = 0; struct davinci_spi_config *spicfg; struct davinci_spi_platform_data *pdata; davinci_spi = spi_master_get_devdata(spi->master); pdata = davinci_spi->pdata; spicfg = (struct davinci_spi_config *)spi->controller_data; if (!spicfg) spicfg = &davinci_spi_default_cfg; davinci_spi->tx = t->tx_buf; davinci_spi->rx = t->rx_buf; davinci_spi->wcount = t->len / davinci_spi->bytes_per_word[spi->chip_select]; davinci_spi->rcount = davinci_spi->wcount; data1_reg_val = ioread32(davinci_spi->base + SPIDAT1); /* Enable SPI */ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); if (spicfg->io_type == SPI_IO_TYPE_INTR) { set_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKINT); INIT_COMPLETION(davinci_spi->done); } /* start the transfer */ davinci_spi->wcount--; tx_data = davinci_spi->get_tx(davinci_spi); data1_reg_val &= 0xFFFF0000; data1_reg_val |= tx_data & 0xFFFF; iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1); /* Wait for the transfer to complete */ if (spicfg->io_type == SPI_IO_TYPE_INTR) { wait_for_completion_interruptible(&(davinci_spi->done)); } else { while (davinci_spi->rcount > 0 || davinci_spi->wcount > 0) { errors = davinci_spi_process_events(davinci_spi); if (errors) break; cpu_relax(); } } clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL); /* * Check for bit error, desync error,parity error,timeout error and * receive overflow errors */ if (errors) { ret = davinci_spi_check_error(davinci_spi, errors); WARN(!ret, "%s: error reported but no error found!\n", dev_name(&spi->dev)); return ret; } 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 *context_data) { struct davinci_spi *davinci_spi = context_data; int status; status = davinci_spi_process_events(davinci_spi); if (unlikely(status != 0)) clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKINT); if ((!davinci_spi->rcount && !davinci_spi->wcount) || status) complete(&davinci_spi->done); return IRQ_HANDLED; } 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; unsigned rx_buf_count; struct davinci_spi_dma *davinci_spi_dma; int data_type, ret; unsigned long tx_reg, rx_reg; struct davinci_spi_platform_data *pdata; void *rx_buf; 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; 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 */ data_type = davinci_spi->bytes_per_word[spi->chip_select]; init_completion(&davinci_spi_dma->dma_rx_completion); init_completion(&davinci_spi_dma->dma_tx_completion); count = t->len / data_type; /* the number of elements */ /* disable all interrupts for dma transfers */ clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL); /* Enable SPI */ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); /* * 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, 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; } } edma_set_transfer_params(davinci_spi_dma->dma_tx_channel, data_type, 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_buf ? t->tx_dma : tx_reg, INCR, W8BIT); edma_set_src_index(davinci_spi_dma->dma_tx_channel, t->tx_buf ? data_type : 0, 0); edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0); /* * 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 = count; } else { rx_buf = davinci_spi->rx_tmp_buf; rx_buf_count = sizeof(davinci_spi->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, 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, t->rx_buf ? data_type : 0, 0); if (pdata->cshold_bug) { u16 spidat1 = ioread16(davinci_spi->base + SPIDAT1 + 2); iowrite16(spidat1, davinci_spi->base + SPIDAT1 + 2); } edma_start(davinci_spi_dma->dma_rx_channel); edma_start(davinci_spi_dma->dma_tx_channel); davinci_spi_set_dma_req(spi, 1); wait_for_completion_interruptible(&davinci_spi_dma->dma_tx_completion); wait_for_completion_interruptible(&davinci_spi_dma->dma_rx_completion); if (t->tx_buf) dma_unmap_single(NULL, t->tx_dma, count, DMA_TO_DEVICE); dma_unmap_single(NULL, t->rx_dma, rx_buf_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; return t->len; } /** * 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; 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); 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 = 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, 0, dev_name(&pdev->dev), davinci_spi); if (ret) goto unmap_io; davinci_spi->bitbang.master = spi_master_get(master); if (davinci_spi->bitbang.master == NULL) { ret = -ENODEV; goto irq_free; } 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.dma_rx_channel = -1; davinci_spi->dma_channels.dma_rx_sync_dev = dma_rx_chan; davinci_spi->dma_channels.dma_tx_channel = -1; davinci_spi->dma_channels.dma_tx_sync_dev = dma_tx_chan; davinci_spi->dma_channels.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); /* 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, davinci_spi->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); } } /* 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); if (pdata->intr_line) iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL); else iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL); iowrite32(CS_DEFAULT, davinci_spi->base + SPIDEF); /* master mode default */ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK); ret = spi_bitbang_start(&davinci_spi->bitbang); if (ret) goto free_clk; dev_info(&pdev->dev, "Controller at 0x%p\n", davinci_spi->base); return ret; free_clk: clk_disable(davinci_spi->clk); clk_put(davinci_spi->clk); put_master: spi_master_put(master); 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); 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");