@@ -39,6 +39,7 @@
#endif
#define MAX_SPI_PORTS 3
+#define S3C64XX_SPI_QUIRK_POLL (1 << 0)
/* Registers and bit-fields */
@@ -130,6 +131,7 @@
#define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
+#define is_polling(x) (x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
#define RXBUSY (1<<2)
#define TXBUSY (1<<3)
@@ -158,6 +160,7 @@ struct s3c64xx_spi_port_config {
int fifo_lvl_mask[MAX_SPI_PORTS];
int rx_lvl_offset;
int tx_st_done;
+ int quirks;
bool high_speed;
bool clk_from_cmu;
};
@@ -344,8 +347,12 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
{
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
- /* Acquire DMA channels */
- while (!acquire_dma(sdd))
+ /*
+ * If DMA resource was not available during
+ * probe, no need to continue with dma requests
+ * else Acquire DMA channels
+ */
+ while (!is_polling(sdd) && !acquire_dma(sdd))
usleep_range(10000, 11000);
pm_runtime_get_sync(&sdd->pdev->dev);
@@ -358,9 +365,12 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
/* Free DMA channels */
- sdd->ops->release((enum dma_ch)sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
- sdd->ops->release((enum dma_ch)sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
-
+ if (!is_polling(sdd)) {
+ sdd->ops->release((enum dma_ch)sdd->rx_dma.ch,
+ &s3c64xx_spi_dma_client);
+ sdd->ops->release((enum dma_ch)sdd->tx_dma.ch,
+ &s3c64xx_spi_dma_client);
+ }
pm_runtime_put(&sdd->pdev->dev);
return 0;
@@ -464,8 +474,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
/* Free DMA channels */
- dma_release_channel(sdd->rx_dma.ch);
- dma_release_channel(sdd->tx_dma.ch);
+ if (!is_polling(sdd)) {
+ dma_release_channel(sdd->rx_dma.ch);
+ dma_release_channel(sdd->tx_dma.ch);
+ }
pm_runtime_put(&sdd->pdev->dev);
return 0;
@@ -566,6 +578,27 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
cs = spi->controller_data;
gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
+
+ /* Start the signals */
+ writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+}
+
+static u32 wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
+ int timeout_ms)
+{
+ void __iomem *regs = sdd->regs;
+ unsigned long val;
+ u32 status;
+ /* max fifo depth available */
+ u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+
+ val = msecs_to_loops(timeout_ms);
+ do {
+ status = readl(regs + S3C64XX_SPI_STATUS);
+ } while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
+
+ /* return the actual received data length */
+ return RX_FIFO_LVL(status, sdd);
}
static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
@@ -590,20 +623,19 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
}
- if (!val)
- return -EIO;
-
if (dma_mode) {
u32 status;
/*
+ * If the previous xfer was completed within timeout, then
+ * proceed further else return -EIO.
* 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) {
+ if (val && !xfer->rx_buf) {
val = msecs_to_loops(10);
status = readl(regs + S3C64XX_SPI_STATUS);
while ((TX_FIFO_LVL(status, sdd)
@@ -613,30 +645,53 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
status = readl(regs + S3C64XX_SPI_STATUS);
}
- if (!val)
- return -EIO;
}
+
+ /* If timed out while checking rx/tx status return error */
+ if (!val)
+ return -EIO;
} else {
+ int loops;
+ u32 cpy_len;
+ u8 *buf;
+
/* If it was only Tx */
- if (xfer->rx_buf == NULL) {
+ if (!xfer->rx_buf) {
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;
- }
+ /*
+ * If the receive length is bigger than the controller fifo
+ * size, calculate the loops and read the fifo as many times.
+ * loops = length / max fifo size (calculated by using the
+ * fifo mask).
+ * For any size less than the fifo size the below code is
+ * executed atleast once.
+ */
+ loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
+ buf = xfer->rx_buf;
+ do {
+ /* wait for data to be received in the fifo */
+ cpy_len = wait_for_timeout(sdd, ms);
+
+ switch (sdd->cur_bpw) {
+ case 32:
+ ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len / 4);
+ break;
+ case 16:
+ ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len / 2);
+ break;
+ default:
+ ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
+ buf, cpy_len);
+ break;
+ }
+
+ buf = buf + cpy_len;
+ } while (loops--);
sdd->state &= ~RXBUSY;
}
@@ -652,6 +707,9 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
sdd->tgl_spi = NULL;
gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
+ /* Quiese the signals */
+ writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
}
static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
@@ -733,7 +791,7 @@ static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
- if (msg->is_dma_mapped)
+ if (is_polling(sdd) || msg->is_dma_mapped)
return 0;
/* First mark all xfer unmapped */
@@ -782,7 +840,7 @@ static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
- if (msg->is_dma_mapped)
+ if (is_polling(sdd) || msg->is_dma_mapped)
return;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
@@ -861,8 +919,9 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
/* Polling method for xfers not bigger than FIFO capacity */
use_dma = 0;
- if (sdd->rx_dma.ch && sdd->tx_dma.ch &&
- (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1)))
+ if (!is_polling(sdd) &&
+ (sdd->rx_dma.ch && sdd->tx_dma.ch &&
+ (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
use_dma = 1;
spin_lock_irqsave(&sdd->lock, flags);
@@ -876,17 +935,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
/* Slave Select */
enable_cs(sdd, spi);
- /* Start the signals */
- writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
spin_unlock_irqrestore(&sdd->lock, flags);
status = wait_for_xfer(sdd, xfer, use_dma);
- /* Quiese the signals */
- writel(S3C64XX_SPI_SLAVE_SIG_INACT,
- sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
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,
@@ -1287,19 +1339,19 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
if (!sdd->pdev->dev.of_node) {
res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (!res) {
- dev_err(&pdev->dev, "Unable to get SPI tx dma "
- "resource\n");
- return -ENXIO;
- }
- sdd->tx_dma.dmach = res->start;
+ dev_warn(&pdev->dev, "Unable to get SPI tx dma "
+ "resource. Switching to poll mode\n");
+ sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+ } else
+ sdd->tx_dma.dmach = res->start;
res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
if (!res) {
- dev_err(&pdev->dev, "Unable to get SPI rx dma "
- "resource\n");
- return -ENXIO;
- }
- sdd->rx_dma.dmach = res->start;
+ dev_warn(&pdev->dev, "Unable to get SPI rx dma "
+ "resource. Switching to poll mode\n");
+ sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+ } else
+ sdd->rx_dma.dmach = res->start;
}
sdd->tx_dma.direction = DMA_MEM_TO_DEV;