diff options
Diffstat (limited to 'drivers/spi/spi-s3c64xx.c')
| -rw-r--r-- | drivers/spi/spi-s3c64xx.c | 1245 |
1 files changed, 1245 insertions, 0 deletions
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c new file mode 100644 index 000000000000..595dacc7645f --- /dev/null +++ b/drivers/spi/spi-s3c64xx.c @@ -0,0 +1,1245 @@ +/* + * Copyright (C) 2009 Samsung Electronics Ltd. + * Jaswinder Singh <jassi.brar@samsung.com> + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/workqueue.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/dma-mapping.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> + +#include <mach/dma.h> +#include <plat/s3c64xx-spi.h> + +/* Registers and bit-fields */ + +#define S3C64XX_SPI_CH_CFG 0x00 +#define S3C64XX_SPI_CLK_CFG 0x04 +#define S3C64XX_SPI_MODE_CFG 0x08 +#define S3C64XX_SPI_SLAVE_SEL 0x0C +#define S3C64XX_SPI_INT_EN 0x10 +#define S3C64XX_SPI_STATUS 0x14 +#define S3C64XX_SPI_TX_DATA 0x18 +#define S3C64XX_SPI_RX_DATA 0x1C +#define S3C64XX_SPI_PACKET_CNT 0x20 +#define S3C64XX_SPI_PENDING_CLR 0x24 +#define S3C64XX_SPI_SWAP_CFG 0x28 +#define S3C64XX_SPI_FB_CLK 0x2C + +#define S3C64XX_SPI_CH_HS_EN (1<<6) /* High Speed Enable */ +#define S3C64XX_SPI_CH_SW_RST (1<<5) +#define S3C64XX_SPI_CH_SLAVE (1<<4) +#define S3C64XX_SPI_CPOL_L (1<<3) +#define S3C64XX_SPI_CPHA_B (1<<2) +#define S3C64XX_SPI_CH_RXCH_ON (1<<1) +#define S3C64XX_SPI_CH_TXCH_ON (1<<0) + +#define S3C64XX_SPI_CLKSEL_SRCMSK (3<<9) +#define S3C64XX_SPI_CLKSEL_SRCSHFT 9 +#define S3C64XX_SPI_ENCLK_ENABLE (1<<8) +#define S3C64XX_SPI_PSR_MASK 0xff + +#define S3C64XX_SPI_MODE_CH_TSZ_BYTE (0<<29) +#define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD (1<<29) +#define S3C64XX_SPI_MODE_CH_TSZ_WORD (2<<29) +#define S3C64XX_SPI_MODE_CH_TSZ_MASK (3<<29) +#define S3C64XX_SPI_MODE_BUS_TSZ_BYTE (0<<17) +#define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17) +#define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17) +#define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17) +#define S3C64XX_SPI_MODE_RXDMA_ON (1<<2) +#define S3C64XX_SPI_MODE_TXDMA_ON (1<<1) +#define S3C64XX_SPI_MODE_4BURST (1<<0) + +#define S3C64XX_SPI_SLAVE_AUTO (1<<1) +#define S3C64XX_SPI_SLAVE_SIG_INACT (1<<0) + +#define S3C64XX_SPI_ACT(c) writel(0, (c)->regs + S3C64XX_SPI_SLAVE_SEL) + +#define S3C64XX_SPI_DEACT(c) writel(S3C64XX_SPI_SLAVE_SIG_INACT, \ + (c)->regs + S3C64XX_SPI_SLAVE_SEL) + +#define S3C64XX_SPI_INT_TRAILING_EN (1<<6) +#define S3C64XX_SPI_INT_RX_OVERRUN_EN (1<<5) +#define S3C64XX_SPI_INT_RX_UNDERRUN_EN (1<<4) +#define S3C64XX_SPI_INT_TX_OVERRUN_EN (1<<3) +#define S3C64XX_SPI_INT_TX_UNDERRUN_EN (1<<2) +#define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1) +#define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0) + +#define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5) +#define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4) +#define S3C64XX_SPI_ST_TX_OVERRUN_ERR (1<<3) +#define S3C64XX_SPI_ST_TX_UNDERRUN_ERR (1<<2) +#define S3C64XX_SPI_ST_RX_FIFORDY (1<<1) +#define S3C64XX_SPI_ST_TX_FIFORDY (1<<0) + +#define S3C64XX_SPI_PACKET_CNT_EN (1<<16) + +#define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4) +#define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3) +#define S3C64XX_SPI_PND_RX_UNDERRUN_CLR (1<<2) +#define S3C64XX_SPI_PND_RX_OVERRUN_CLR (1<<1) +#define S3C64XX_SPI_PND_TRAILING_CLR (1<<0) + +#define S3C64XX_SPI_SWAP_RX_HALF_WORD (1<<7) +#define S3C64XX_SPI_SWAP_RX_BYTE (1<<6) +#define S3C64XX_SPI_SWAP_RX_BIT (1<<5) +#define S3C64XX_SPI_SWAP_RX_EN (1<<4) +#define S3C64XX_SPI_SWAP_TX_HALF_WORD (1<<3) +#define S3C64XX_SPI_SWAP_TX_BYTE (1<<2) +#define S3C64XX_SPI_SWAP_TX_BIT (1<<1) +#define S3C64XX_SPI_SWAP_TX_EN (1<<0) + +#define S3C64XX_SPI_FBCLK_MSK (3<<0) + +#define S3C64XX_SPI_ST_TRLCNTZ(v, i) ((((v) >> (i)->rx_lvl_offset) & \ + (((i)->fifo_lvl_mask + 1))) \ + ? 1 : 0) + +#define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & (1 << (i)->tx_st_done)) ? 1 : 0) +#define TX_FIFO_LVL(v, i) (((v) >> 6) & (i)->fifo_lvl_mask) +#define RX_FIFO_LVL(v, i) (((v) >> (i)->rx_lvl_offset) & (i)->fifo_lvl_mask) + +#define S3C64XX_SPI_MAX_TRAILCNT 0x3ff +#define S3C64XX_SPI_TRAILCNT_OFF 19 + +#define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT + +#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) + +#define SUSPND (1<<0) +#define SPIBUSY (1<<1) +#define RXBUSY (1<<2) +#define TXBUSY (1<<3) + +/** + * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver. + * @clk: Pointer to the spi clock. + * @src_clk: Pointer to the clock used to generate SPI signals. + * @master: Pointer to the SPI Protocol master. + * @workqueue: Work queue for the SPI xfer requests. + * @cntrlr_info: Platform specific data for the controller this driver manages. + * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint. + * @work: Work + * @queue: To log SPI xfer requests. + * @lock: Controller specific lock. + * @state: Set of FLAGS to indicate status. + * @rx_dmach: Controller's DMA channel for Rx. + * @tx_dmach: Controller's DMA channel for Tx. + * @sfr_start: BUS address of SPI controller regs. + * @regs: Pointer to ioremap'ed controller registers. + * @xfer_completion: To indicate completion of xfer task. + * @cur_mode: Stores the active configuration of the controller. + * @cur_bpw: Stores the active bits per word settings. + * @cur_speed: Stores the active xfer clock speed. + */ +struct s3c64xx_spi_driver_data { + void __iomem *regs; + struct clk *clk; + struct clk *src_clk; + struct platform_device *pdev; + struct spi_master *master; + struct workqueue_struct *workqueue; + struct s3c64xx_spi_info *cntrlr_info; + struct spi_device *tgl_spi; + struct work_struct work; + struct list_head queue; + spinlock_t lock; + enum dma_ch rx_dmach; + enum dma_ch tx_dmach; + unsigned long sfr_start; + struct completion xfer_completion; + unsigned state; + unsigned cur_mode, cur_bpw; + unsigned cur_speed; +}; + +static struct s3c2410_dma_client s3c64xx_spi_dma_client = { + .name = "samsung-spi-dma", +}; + +static void flush_fifo(struct s3c64xx_spi_driver_data *sdd) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + void __iomem *regs = sdd->regs; + unsigned long loops; + u32 val; + + writel(0, regs + S3C64XX_SPI_PACKET_CNT); + + val = readl(regs + S3C64XX_SPI_CH_CFG); + val |= S3C64XX_SPI_CH_SW_RST; + val &= ~S3C64XX_SPI_CH_HS_EN; + writel(val, regs + S3C64XX_SPI_CH_CFG); + + /* Flush TxFIFO*/ + loops = msecs_to_loops(1); + do { + val = readl(regs + S3C64XX_SPI_STATUS); + } while (TX_FIFO_LVL(val, sci) && loops--); + + if (loops == 0) + dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n"); + + /* Flush RxFIFO*/ + loops = msecs_to_loops(1); + do { + val = readl(regs + S3C64XX_SPI_STATUS); + if (RX_FIFO_LVL(val, sci)) + readl(regs + S3C64XX_SPI_RX_DATA); + else + break; + } while (loops--); + + if (loops == 0) + dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n"); + + val = readl(regs + S3C64XX_SPI_CH_CFG); + val &= ~S3C64XX_SPI_CH_SW_RST; + writel(val, regs + S3C64XX_SPI_CH_CFG); + + val = readl(regs + S3C64XX_SPI_MODE_CFG); + val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON); + writel(val, regs + S3C64XX_SPI_MODE_CFG); + + val = readl(regs + S3C64XX_SPI_CH_CFG); + val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON); + writel(val, regs + S3C64XX_SPI_CH_CFG); +} + +static void enable_datapath(struct s3c64xx_spi_driver_data *sdd, + struct spi_device *spi, + struct spi_transfer *xfer, int dma_mode) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + void __iomem *regs = sdd->regs; + u32 modecfg, chcfg; + + modecfg = readl(regs + S3C64XX_SPI_MODE_CFG); + modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON); + + chcfg = readl(regs + S3C64XX_SPI_CH_CFG); + chcfg &= ~S3C64XX_SPI_CH_TXCH_ON; + + if (dma_mode) { + chcfg &= ~S3C64XX_SPI_CH_RXCH_ON; + } else { + /* Always shift in data in FIFO, even if xfer is Tx only, + * this helps setting PCKT_CNT value for generating clocks + * as exactly needed. + */ + chcfg |= S3C64XX_SPI_CH_RXCH_ON; + writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff) + | S3C64XX_SPI_PACKET_CNT_EN, + regs + S3C64XX_SPI_PACKET_CNT); + } + + if (xfer->tx_buf != NULL) { + sdd->state |= TXBUSY; + chcfg |= S3C64XX_SPI_CH_TXCH_ON; + if (dma_mode) { + modecfg |= S3C64XX_SPI_MODE_TXDMA_ON; + s3c2410_dma_config(sdd->tx_dmach, sdd->cur_bpw / 8); + s3c2410_dma_enqueue(sdd->tx_dmach, (void *)sdd, + xfer->tx_dma, xfer->len); + s3c2410_dma_ctrl(sdd->tx_dmach, S3C2410_DMAOP_START); + } else { + switch (sdd->cur_bpw) { + case 32: + iowrite32_rep(regs + S3C64XX_SPI_TX_DATA, + xfer->tx_buf, xfer->len / 4); + break; + case 16: + iowrite16_rep(regs + S3C64XX_SPI_TX_DATA, + xfer->tx_buf, xfer->len / 2); + break; + default: + iowrite8_rep(regs + S3C64XX_SPI_TX_DATA, + xfer->tx_buf, xfer->len); + break; + } + } + } + + if (xfer->rx_buf != NULL) { + sdd->state |= RXBUSY; + + if (sci->high_speed && sdd->cur_speed >= 30000000UL + && !(sdd->cur_mode & SPI_CPHA)) + chcfg |= S3C64XX_SPI_CH_HS_EN; + + if (dma_mode) { + modecfg |= S3C64XX_SPI_MODE_RXDMA_ON; + chcfg |= S3C64XX_SPI_CH_RXCH_ON; + writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff) + | S3C64XX_SPI_PACKET_CNT_EN, + regs + S3C64XX_SPI_PACKET_CNT); + s3c2410_dma_config(sdd->rx_dmach, sdd->cur_bpw / 8); + s3c2410_dma_enqueue(sdd->rx_dmach, (void *)sdd, + xfer->rx_dma, xfer->len); + s3c2410_dma_ctrl(sdd->rx_dmach, S3C2410_DMAOP_START); + } + } + + writel(modecfg, regs + S3C64XX_SPI_MODE_CFG); + writel(chcfg, regs + S3C64XX_SPI_CH_CFG); +} + +static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, + struct spi_device *spi) +{ + struct s3c64xx_spi_csinfo *cs; + + if (sdd->tgl_spi != NULL) { /* If last device toggled after mssg */ + if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ + /* Deselect the last toggled device */ + cs = sdd->tgl_spi->controller_data; + cs->set_level(cs->line, + spi->mode & SPI_CS_HIGH ? 0 : 1); + } + sdd->tgl_spi = NULL; + } + + cs = spi->controller_data; + cs->set_level(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); +} + +static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, + struct spi_transfer *xfer, int dma_mode) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + void __iomem *regs = sdd->regs; + unsigned long val; + int ms; + + /* millisecs to xfer 'len' bytes @ 'cur_speed' */ + ms = xfer->len * 8 * 1000 / sdd->cur_speed; + ms += 10; /* some tolerance */ + + if (dma_mode) { + val = msecs_to_jiffies(ms) + 10; + val = wait_for_completion_timeout(&sdd->xfer_completion, val); + } else { + u32 status; + val = msecs_to_loops(ms); + do { + status = readl(regs + S3C64XX_SPI_STATUS); + } while (RX_FIFO_LVL(status, sci) < xfer->len && --val); + } + + if (!val) + return -EIO; + + if (dma_mode) { + u32 status; + + /* + * DmaTx returns after simply writing data in the FIFO, + * w/o waiting for real transmission on the bus to finish. + * DmaRx returns only after Dma read data from FIFO which + * needs bus transmission to finish, so we don't worry if + * Xfer involved Rx(with or without Tx). + */ + if (xfer->rx_buf == NULL) { + val = msecs_to_loops(10); + status = readl(regs + S3C64XX_SPI_STATUS); + while ((TX_FIFO_LVL(status, sci) + || !S3C64XX_SPI_ST_TX_DONE(status, sci)) + && --val) { + cpu_relax(); + status = readl(regs + S3C64XX_SPI_STATUS); + } + + if (!val) + return -EIO; + } + } else { + /* If it was only Tx */ + if (xfer->rx_buf == NULL) { + sdd->state &= ~TXBUSY; + return 0; + } + + switch (sdd->cur_bpw) { + case 32: + ioread32_rep(regs + S3C64XX_SPI_RX_DATA, + xfer->rx_buf, xfer->len / 4); + break; + case 16: + ioread16_rep(regs + S3C64XX_SPI_RX_DATA, + xfer->rx_buf, xfer->len / 2); + break; + default: + ioread8_rep(regs + S3C64XX_SPI_RX_DATA, + xfer->rx_buf, xfer->len); + break; + } + sdd->state &= ~RXBUSY; + } + + return 0; +} + +static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, + struct spi_device *spi) +{ + struct s3c64xx_spi_csinfo *cs = spi->controller_data; + + if (sdd->tgl_spi == spi) + sdd->tgl_spi = NULL; + + cs->set_level(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); +} + +static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + void __iomem *regs = sdd->regs; + u32 val; + + /* Disable Clock */ + if (sci->clk_from_cmu) { + clk_disable(sdd->src_clk); + } else { + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val &= ~S3C64XX_SPI_ENCLK_ENABLE; + writel(val, regs + S3C64XX_SPI_CLK_CFG); + } + + /* Set Polarity and Phase */ + val = readl(regs + S3C64XX_SPI_CH_CFG); + val &= ~(S3C64XX_SPI_CH_SLAVE | + S3C64XX_SPI_CPOL_L | + S3C64XX_SPI_CPHA_B); + + if (sdd->cur_mode & SPI_CPOL) + val |= S3C64XX_SPI_CPOL_L; + + if (sdd->cur_mode & SPI_CPHA) + val |= S3C64XX_SPI_CPHA_B; + + writel(val, regs + S3C64XX_SPI_CH_CFG); + + /* Set Channel & DMA Mode */ + val = readl(regs + S3C64XX_SPI_MODE_CFG); + val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK + | S3C64XX_SPI_MODE_CH_TSZ_MASK); + + switch (sdd->cur_bpw) { + case 32: + val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD; + val |= S3C64XX_SPI_MODE_CH_TSZ_WORD; + break; + case 16: + val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD; + val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD; + break; + default: + val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE; + val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE; + break; + } + + writel(val, regs + S3C64XX_SPI_MODE_CFG); + + if (sci->clk_from_cmu) { + /* Configure Clock */ + /* There is half-multiplier before the SPI */ + clk_set_rate(sdd->src_clk, sdd->cur_speed * 2); + /* Enable Clock */ + clk_enable(sdd->src_clk); + } else { + /* Configure Clock */ + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val &= ~S3C64XX_SPI_PSR_MASK; + val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1) + & S3C64XX_SPI_PSR_MASK); + writel(val, regs + S3C64XX_SPI_CLK_CFG); + + /* Enable Clock */ + val = readl(regs + S3C64XX_SPI_CLK_CFG); + val |= S3C64XX_SPI_ENCLK_ENABLE; + writel(val, regs + S3C64XX_SPI_CLK_CFG); + } +} + +static void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan, void *buf_id, + int size, enum s3c2410_dma_buffresult res) +{ + struct s3c64xx_spi_driver_data *sdd = buf_id; + unsigned long flags; + + spin_lock_irqsave(&sdd->lock, flags); + + if (res == S3C2410_RES_OK) + sdd->state &= ~RXBUSY; + else + dev_err(&sdd->pdev->dev, "DmaAbrtRx-%d\n", size); + + /* If the other done */ + if (!(sdd->state & TXBUSY)) + complete(&sdd->xfer_completion); + + spin_unlock_irqrestore(&sdd->lock, flags); +} + +static void s3c64xx_spi_dma_txcb(struct s3c2410_dma_chan *chan, void *buf_id, + int size, enum s3c2410_dma_buffresult res) +{ + struct s3c64xx_spi_driver_data *sdd = buf_id; + unsigned long flags; + + spin_lock_irqsave(&sdd->lock, flags); + + if (res == S3C2410_RES_OK) + sdd->state &= ~TXBUSY; + else + dev_err(&sdd->pdev->dev, "DmaAbrtTx-%d \n", size); + + /* If the other done */ + if (!(sdd->state & RXBUSY)) + complete(&sdd->xfer_completion); + + spin_unlock_irqrestore(&sdd->lock, flags); +} + +#define XFER_DMAADDR_INVALID DMA_BIT_MASK(32) + +static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd, + struct spi_message *msg) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + struct device *dev = &sdd->pdev->dev; + struct spi_transfer *xfer; + + if (msg->is_dma_mapped) + return 0; + + /* First mark all xfer unmapped */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + xfer->rx_dma = XFER_DMAADDR_INVALID; + xfer->tx_dma = XFER_DMAADDR_INVALID; + } + + /* Map until end or first fail */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + + if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1)) + continue; + + if (xfer->tx_buf != NULL) { + xfer->tx_dma = dma_map_single(dev, + (void *)xfer->tx_buf, xfer->len, + DMA_TO_DEVICE); + if (dma_mapping_error(dev, xfer->tx_dma)) { + dev_err(dev, "dma_map_single Tx failed\n"); + xfer->tx_dma = XFER_DMAADDR_INVALID; + return -ENOMEM; + } + } + + if (xfer->rx_buf != NULL) { + xfer->rx_dma = dma_map_single(dev, xfer->rx_buf, + xfer->len, DMA_FROM_DEVICE); + if (dma_mapping_error(dev, xfer->rx_dma)) { + dev_err(dev, "dma_map_single Rx failed\n"); + dma_unmap_single(dev, xfer->tx_dma, + xfer->len, DMA_TO_DEVICE); + xfer->tx_dma = XFER_DMAADDR_INVALID; + xfer->rx_dma = XFER_DMAADDR_INVALID; + return -ENOMEM; + } + } + } + + return 0; +} + +static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd, + struct spi_message *msg) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + struct device *dev = &sdd->pdev->dev; + struct spi_transfer *xfer; + + if (msg->is_dma_mapped) + return; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + + if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1)) + continue; + + if (xfer->rx_buf != NULL + && xfer->rx_dma != XFER_DMAADDR_INVALID) + dma_unmap_single(dev, xfer->rx_dma, + xfer->len, DMA_FROM_DEVICE); + + if (xfer->tx_buf != NULL + && xfer->tx_dma != XFER_DMAADDR_INVALID) + dma_unmap_single(dev, xfer->tx_dma, + xfer->len, DMA_TO_DEVICE); + } +} + +static void handle_msg(struct s3c64xx_spi_driver_data *sdd, + struct spi_message *msg) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + struct spi_device *spi = msg->spi; + struct s3c64xx_spi_csinfo *cs = spi->controller_data; + struct spi_transfer *xfer; + int status = 0, cs_toggle = 0; + u32 speed; + u8 bpw; + + /* If Master's(controller) state differs from that needed by Slave */ + if (sdd->cur_speed != spi->max_speed_hz + || sdd->cur_mode != spi->mode + || sdd->cur_bpw != spi->bits_per_word) { + sdd->cur_bpw = spi->bits_per_word; + sdd->cur_speed = spi->max_speed_hz; + sdd->cur_mode = spi->mode; + s3c64xx_spi_config(sdd); + } + + /* Map all the transfers if needed */ + if (s3c64xx_spi_map_mssg(sdd, msg)) { + dev_err(&spi->dev, + "Xfer: Unable to map message buffers!\n"); + status = -ENOMEM; + goto out; + } + + /* Configure feedback delay */ + writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK); + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + + unsigned long flags; + int use_dma; + + INIT_COMPLETION(sdd->xfer_completion); + + /* Only BPW and Speed may change across transfers */ + bpw = xfer->bits_per_word ? : spi->bits_per_word; + speed = xfer->speed_hz ? : spi->max_speed_hz; + + if (xfer->len % (bpw / 8)) { + dev_err(&spi->dev, + "Xfer length(%u) not a multiple of word size(%u)\n", + xfer->len, bpw / 8); + status = -EIO; + goto out; + } + + if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) { + sdd->cur_bpw = bpw; + sdd->cur_speed = speed; + s3c64xx_spi_config(sdd); + } + + /* Polling method for xfers not bigger than FIFO capacity */ + if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1)) + use_dma = 0; + else + use_dma = 1; + + spin_lock_irqsave(&sdd->lock, flags); + + /* Pending only which is to be done */ + sdd->state &= ~RXBUSY; + sdd->state &= ~TXBUSY; + + enable_datapath(sdd, spi, xfer, use_dma); + + /* Slave Select */ + enable_cs(sdd, spi); + + /* Start the signals */ + S3C64XX_SPI_ACT(sdd); + + spin_unlock_irqrestore(&sdd->lock, flags); + + status = wait_for_xfer(sdd, xfer, use_dma); + + /* Quiese the signals */ + S3C64XX_SPI_DEACT(sdd); + + if (status) { + dev_err(&spi->dev, "I/O Error: " + "rx-%d tx-%d res:rx-%c tx-%c len-%d\n", + xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0, + (sdd->state & RXBUSY) ? 'f' : 'p', + (sdd->state & TXBUSY) ? 'f' : 'p', + xfer->len); + + if (use_dma) { + if (xfer->tx_buf != NULL + && (sdd->state & TXBUSY)) + s3c2410_dma_ctrl(sdd->tx_dmach, + S3C2410_DMAOP_FLUSH); + if (xfer->rx_buf != NULL + && (sdd->state & RXBUSY)) + s3c2410_dma_ctrl(sdd->rx_dmach, + S3C2410_DMAOP_FLUSH); + } + + goto out; + } + + if (xfer->delay_usecs) + udelay(xfer->delay_usecs); + + if (xfer->cs_change) { + /* Hint that the next mssg is gonna be + for the same device */ + if (list_is_last(&xfer->transfer_list, + &msg->transfers)) + cs_toggle = 1; + else + disable_cs(sdd, spi); + } + + msg->actual_length += xfer->len; + + flush_fifo(sdd); + } + +out: + if (!cs_toggle || status) + disable_cs(sdd, spi); + else + sdd->tgl_spi = spi; + + s3c64xx_spi_unmap_mssg(sdd, msg); + + msg->status = status; + + if (msg->complete) + msg->complete(msg->context); +} + +static int acquire_dma(struct s3c64xx_spi_driver_data *sdd) +{ + if (s3c2410_dma_request(sdd->rx_dmach, + &s3c64xx_spi_dma_client, NULL) < 0) { + dev_err(&sdd->pdev->dev, "cannot get RxDMA\n"); + return 0; + } + s3c2410_dma_set_buffdone_fn(sdd->rx_dmach, s3c64xx_spi_dma_rxcb); + s3c2410_dma_devconfig(sdd->rx_dmach, S3C2410_DMASRC_HW, + sdd->sfr_start + S3C64XX_SPI_RX_DATA); + + if (s3c2410_dma_request(sdd->tx_dmach, + &s3c64xx_spi_dma_client, NULL) < 0) { + dev_err(&sdd->pdev->dev, "cannot get TxDMA\n"); + s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client); + return 0; + } + s3c2410_dma_set_buffdone_fn(sdd->tx_dmach, s3c64xx_spi_dma_txcb); + s3c2410_dma_devconfig(sdd->tx_dmach, S3C2410_DMASRC_MEM, + sdd->sfr_start + S3C64XX_SPI_TX_DATA); + + return 1; +} + +static void s3c64xx_spi_work(struct work_struct *work) +{ + struct s3c64xx_spi_driver_data *sdd = container_of(work, + struct s3c64xx_spi_driver_data, work); + unsigned long flags; + + /* Acquire DMA channels */ + while (!acquire_dma(sdd)) + msleep(10); + + spin_lock_irqsave(&sdd->lock, flags); + + while (!list_empty(&sdd->queue) + && !(sdd->state & SUSPND)) { + + struct spi_message *msg; + + msg = container_of(sdd->queue.next, struct spi_message, queue); + + list_del_init(&msg->queue); + + /* Set Xfer busy flag */ + sdd->state |= SPIBUSY; + + spin_unlock_irqrestore(&sdd->lock, flags); + + handle_msg(sdd, msg); + + spin_lock_irqsave(&sdd->lock, flags); + + sdd->state &= ~SPIBUSY; + } + + spin_unlock_irqrestore(&sdd->lock, flags); + + /* Free DMA channels */ + s3c2410_dma_free(sdd->tx_dmach, &s3c64xx_spi_dma_client); + s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client); +} + +static int s3c64xx_spi_transfer(struct spi_device *spi, + struct spi_message *msg) +{ + struct s3c64xx_spi_driver_data *sdd; + unsigned long flags; + + sdd = spi_master_get_devdata(spi->master); + + spin_lock_irqsave(&sdd->lock, flags); + + if (sdd->state & SUSPND) { + spin_unlock_irqrestore(&sdd->lock, flags); + return -ESHUTDOWN; + } + + msg->status = -EINPROGRESS; + msg->actual_length = 0; + + list_add_tail(&msg->queue, &sdd->queue); + + queue_work(sdd->workqueue, &sdd->work); + + spin_unlock_irqrestore(&sdd->lock, flags); + + return 0; +} + +/* + * Here we only check the validity of requested configuration + * and save the configuration in a local data-structure. + * The controller is actually configured only just before we + * get a message to transfer. + */ +static int s3c64xx_spi_setup(struct spi_device *spi) +{ + struct s3c64xx_spi_csinfo *cs = spi->controller_data; + struct s3c64xx_spi_driver_data *sdd; + struct s3c64xx_spi_info *sci; + struct spi_message *msg; + unsigned long flags; + int err = 0; + + if (cs == NULL || cs->set_level == NULL) { + dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select); + return -ENODEV; + } + + sdd = spi_master_get_devdata(spi->master); + sci = sdd->cntrlr_info; + + spin_lock_irqsave(&sdd->lock, flags); + + list_for_each_entry(msg, &sdd->queue, queue) { + /* Is some mssg is already queued for this device */ + if (msg->spi == spi) { + dev_err(&spi->dev, + "setup: attempt while mssg in queue!\n"); + spin_unlock_irqrestore(&sdd->lock, flags); + return -EBUSY; + } + } + + if (sdd->state & SUSPND) { + spin_unlock_irqrestore(&sdd->lock, flags); + dev_err(&spi->dev, + "setup: SPI-%d not active!\n", spi->master->bus_num); + return -ESHUTDOWN; + } + + spin_unlock_irqrestore(&sdd->lock, flags); + + if (spi->bits_per_word != 8 + && spi->bits_per_word != 16 + && spi->bits_per_word != 32) { + dev_err(&spi->dev, "setup: %dbits/wrd not supported!\n", + spi->bits_per_word); + err = -EINVAL; + goto setup_exit; + } + + /* Check if we can provide the requested rate */ + if (!sci->clk_from_cmu) { + u32 psr, speed; + + /* Max possible */ + speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1); + + if (spi->max_speed_hz > speed) + spi->max_speed_hz = speed; + + psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1; + psr &= S3C64XX_SPI_PSR_MASK; + if (psr == S3C64XX_SPI_PSR_MASK) + psr--; + + speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); + if (spi->max_speed_hz < speed) { + if (psr+1 < S3C64XX_SPI_PSR_MASK) { + psr++; + } else { + err = -EINVAL; + goto setup_exit; + } + } + + speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1); + if (spi->max_speed_hz >= speed) + spi->max_speed_hz = speed; + else + err = -EINVAL; + } + +setup_exit: + + /* setup() returns with device de-selected */ + disable_cs(sdd, spi); + + return err; +} + +static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel) +{ + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + void __iomem *regs = sdd->regs; + unsigned int val; + + sdd->cur_speed = 0; + + S3C64XX_SPI_DEACT(sdd); + + /* Disable Interrupts - we use Polling if not DMA mode */ + writel(0, regs + S3C64XX_SPI_INT_EN); + + if (!sci->clk_from_cmu) + writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT, + regs + S3C64XX_SPI_CLK_CFG); + writel(0, regs + S3C64XX_SPI_MODE_CFG); + writel(0, regs + S3C64XX_SPI_PACKET_CNT); + + /* Clear any irq pending bits */ + writel(readl(regs + S3C64XX_SPI_PENDING_CLR), + regs + S3C64XX_SPI_PENDING_CLR); + + writel(0, regs + S3C64XX_SPI_SWAP_CFG); + + val = readl(regs + S3C64XX_SPI_MODE_CFG); + val &= ~S3C64XX_SPI_MODE_4BURST; + val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF); + val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF); + writel(val, regs + S3C64XX_SPI_MODE_CFG); + + flush_fifo(sdd); +} + +static int __init s3c64xx_spi_probe(struct platform_device *pdev) +{ + struct resource *mem_res, *dmatx_res, *dmarx_res; + struct s3c64xx_spi_driver_data *sdd; + struct s3c64xx_spi_info *sci; + struct spi_master *master; + int ret; + + if (pdev->id < 0) { + dev_err(&pdev->dev, + "Invalid platform device id-%d\n", pdev->id); + return -ENODEV; + } + + if (pdev->dev.platform_data == NULL) { + dev_err(&pdev->dev, "platform_data missing!\n"); + return -ENODEV; + } + + sci = pdev->dev.platform_data; + if (!sci->src_clk_name) { + dev_err(&pdev->dev, + "Board init must call s3c64xx_spi_set_info()\n"); + return -EINVAL; + } + + /* Check for availability of necessary resource */ + + dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0); + if (dmatx_res == NULL) { + dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n"); + return -ENXIO; + } + + dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1); + if (dmarx_res == NULL) { + dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n"); + return -ENXIO; + } + + mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (mem_res == NULL) { + dev_err(&pdev->dev, "Unable to get SPI MEM resource\n"); + return -ENXIO; + } + + master = spi_alloc_master(&pdev->dev, + sizeof(struct s3c64xx_spi_driver_data)); + if (master == NULL) { + dev_err(&pdev->dev, "Unable to allocate SPI Master\n"); + return -ENOMEM; + } + + platform_set_drvdata(pdev, master); + + sdd = spi_master_get_devdata(master); + sdd->master = master; + sdd->cntrlr_info = sci; + sdd->pdev = pdev; + sdd->sfr_start = mem_res->start; + sdd->tx_dmach = dmatx_res->start; + sdd->rx_dmach = dmarx_res->start; + + sdd->cur_bpw = 8; + + master->bus_num = pdev->id; + master->setup = s3c64xx_spi_setup; + master->transfer = s3c64xx_spi_transfer; + master->num_chipselect = sci->num_cs; + master->dma_alignment = 8; + /* the spi->mode bits understood by this driver: */ + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + + if (request_mem_region(mem_res->start, + resource_size(mem_res), pdev->name) == NULL) { + dev_err(&pdev->dev, "Req mem region failed\n"); + ret = -ENXIO; + goto err0; + } + + sdd->regs = ioremap(mem_res->start, resource_size(mem_res)); + if (sdd->regs == NULL) { + dev_err(&pdev->dev, "Unable to remap IO\n"); + ret = -ENXIO; + goto err1; + } + + if (sci->cfg_gpio == NULL || sci->cfg_gpio(pdev)) { + dev_err(&pdev->dev, "Unable to config gpio\n"); + ret = -EBUSY; + goto err2; + } + + /* Setup clocks */ + sdd->clk = clk_get(&pdev->dev, "spi"); + if (IS_ERR(sdd->clk)) { + dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n"); + ret = PTR_ERR(sdd->clk); + goto err3; + } + + if (clk_enable(sdd->clk)) { + dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n"); + ret = -EBUSY; + goto err4; + } + + sdd->src_clk = clk_get(&pdev->dev, sci->src_clk_name); + if (IS_ERR(sdd->src_clk)) { + dev_err(&pdev->dev, + "Unable to acquire clock '%s'\n", sci->src_clk_name); + ret = PTR_ERR(sdd->src_clk); + goto err5; + } + + if (clk_enable(sdd->src_clk)) { + dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", + sci->src_clk_name); + ret = -EBUSY; + goto err6; + } + + sdd->workqueue = create_singlethread_workqueue( + dev_name(master->dev.parent)); + if (sdd->workqueue == NULL) { + dev_err(&pdev->dev, "Unable to create workqueue\n"); + ret = -ENOMEM; + goto err7; + } + + /* Setup Deufult Mode */ + s3c64xx_spi_hwinit(sdd, pdev->id); + + spin_lock_init(&sdd->lock); + init_completion(&sdd->xfer_completion); + INIT_WORK(&sdd->work, s3c64xx_spi_work); + INIT_LIST_HEAD(&sdd->queue); + + if (spi_register_master(master)) { + dev_err(&pdev->dev, "cannot register SPI master\n"); + ret = -EBUSY; + goto err8; + } + + dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d " + "with %d Slaves attached\n", + pdev->id, master->num_chipselect); + dev_dbg(&pdev->dev, "\tIOmem=[0x%x-0x%x]\tDMA=[Rx-%d, Tx-%d]\n", + mem_res->end, mem_res->start, + sdd->rx_dmach, sdd->tx_dmach); + + return 0; + +err8: + destroy_workqueue(sdd->workqueue); +err7: + clk_disable(sdd->src_clk); +err6: + clk_put(sdd->src_clk); +err5: + clk_disable(sdd->clk); +err4: + clk_put(sdd->clk); +err3: +err2: + iounmap((void *) sdd->regs); +err1: + release_mem_region(mem_res->start, resource_size(mem_res)); +err0: + platform_set_drvdata(pdev, NULL); + spi_master_put(master); + + return ret; +} + +static int s3c64xx_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master); + struct resource *mem_res; + unsigned long flags; + + spin_lock_irqsave(&sdd->lock, flags); + sdd->state |= SUSPND; + spin_unlock_irqrestore(&sdd->lock, flags); + + while (sdd->state & SPIBUSY) + msleep(10); + + spi_unregister_master(master); + + destroy_workqueue(sdd->workqueue); + + clk_disable(sdd->src_clk); + clk_put(sdd->src_clk); + + clk_disable(sdd->clk); + clk_put(sdd->clk); + + iounmap((void *) sdd->regs); + + mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (mem_res != NULL) + release_mem_region(mem_res->start, resource_size(mem_res)); + + platform_set_drvdata(pdev, NULL); + spi_master_put(master); + + return 0; +} + +#ifdef CONFIG_PM +static int s3c64xx_spi_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master); + unsigned long flags; + + spin_lock_irqsave(&sdd->lock, flags); + sdd->state |= SUSPND; + spin_unlock_irqrestore(&sdd->lock, flags); + + while (sdd->state & SPIBUSY) + msleep(10); + + /* Disable the clock */ + clk_disable(sdd->src_clk); + clk_disable(sdd->clk); + + sdd->cur_speed = 0; /* Output Clock is stopped */ + + return 0; +} + +static int s3c64xx_spi_resume(struct platform_device *pdev) +{ + struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master); + struct s3c64xx_spi_info *sci = sdd->cntrlr_info; + unsigned long flags; + + sci->cfg_gpio(pdev); + + /* Enable the clock */ + clk_enable(sdd->src_clk); + clk_enable(sdd->clk); + + s3c64xx_spi_hwinit(sdd, pdev->id); + + spin_lock_irqsave(&sdd->lock, flags); + sdd->state &= ~SUSPND; + spin_unlock_irqrestore(&sdd->lock, flags); + + return 0; +} +#else +#define s3c64xx_spi_suspend NULL +#define s3c64xx_spi_resume NULL +#endif /* CONFIG_PM */ + +static struct platform_driver s3c64xx_spi_driver = { + .driver = { + .name = "s3c64xx-spi", + .owner = THIS_MODULE, + }, + .remove = s3c64xx_spi_remove, + .suspend = s3c64xx_spi_suspend, + .resume = s3c64xx_spi_resume, +}; +MODULE_ALIAS("platform:s3c64xx-spi"); + +static int __init s3c64xx_spi_init(void) +{ + return platform_driver_probe(&s3c64xx_spi_driver, s3c64xx_spi_probe); +} +subsys_initcall(s3c64xx_spi_init); + +static void __exit s3c64xx_spi_exit(void) +{ + platform_driver_unregister(&s3c64xx_spi_driver); +} +module_exit(s3c64xx_spi_exit); + +MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>"); +MODULE_DESCRIPTION("S3C64XX SPI Controller Driver"); +MODULE_LICENSE("GPL"); |