@@ -635,11 +635,14 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
{
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+ const void *tx_buf = NULL;
+ void *rx_buf = NULL;
+ int target_len = 0, origin_len = 0;
+ int use_dma = 0;
int status;
u32 speed;
u8 bpw;
unsigned long flags;
- int use_dma;
reinit_completion(&sdd->xfer_completion);
@@ -654,47 +657,77 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
s3c64xx_spi_config(sdd);
}
- /* Polling method for xfers not bigger than FIFO capacity */
- use_dma = 0;
if (!is_polling(sdd) && (xfer->len > fifo_len) &&
- sdd->rx_dma.ch && sdd->tx_dma.ch)
+ sdd->rx_dma.ch && sdd->tx_dma.ch) {
use_dma = 1;
- spin_lock_irqsave(&sdd->lock, flags);
+ } else if (is_polling(sdd) && xfer->len > fifo_len) {
+ tx_buf = xfer->tx_buf;
+ rx_buf = xfer->rx_buf;
+ origin_len = xfer->len;
- /* Pending only which is to be done */
- sdd->state &= ~RXBUSY;
- sdd->state &= ~TXBUSY;
+ target_len = xfer->len;
+ if (xfer->len > fifo_len)
+ xfer->len = fifo_len;
+ }
+
+ do {
+ spin_lock_irqsave(&sdd->lock, flags);
- s3c64xx_enable_datapath(sdd, xfer, use_dma);
+ /* Pending only which is to be done */
+ sdd->state &= ~RXBUSY;
+ sdd->state &= ~TXBUSY;
- /* Start the signals */
- s3c64xx_spi_set_cs(spi, true);
+ s3c64xx_enable_datapath(sdd, xfer, use_dma);
- spin_unlock_irqrestore(&sdd->lock, flags);
+ /* Start the signals */
+ s3c64xx_spi_set_cs(spi, true);
- if (use_dma)
- status = s3c64xx_wait_for_dma(sdd, xfer);
- else
- status = s3c64xx_wait_for_pio(sdd, xfer);
-
- 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))
- dmaengine_terminate_all(sdd->tx_dma.ch);
- if (xfer->rx_buf != NULL
- && (sdd->state & RXBUSY))
- dmaengine_terminate_all(sdd->rx_dma.ch);
+ spin_unlock_irqrestore(&sdd->lock, flags);
+
+ if (use_dma)
+ status = s3c64xx_wait_for_dma(sdd, xfer);
+ else
+ status = s3c64xx_wait_for_pio(sdd, xfer);
+
+ 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 && (sdd->state & TXBUSY))
+ dmaengine_terminate_all(sdd->tx_dma.ch);
+ if (xfer->rx_buf && (sdd->state & RXBUSY))
+ dmaengine_terminate_all(sdd->rx_dma.ch);
+ }
+ } else {
+ s3c64xx_flush_fifo(sdd);
}
- } else {
- s3c64xx_flush_fifo(sdd);
+ if (target_len > 0) {
+ target_len -= xfer->len;
+
+ if (xfer->tx_buf)
+ xfer->tx_buf += xfer->len;
+
+ if (xfer->rx_buf)
+ xfer->rx_buf += xfer->len;
+
+ if (target_len > fifo_len)
+ xfer->len = fifo_len;
+ else
+ xfer->len = target_len;
+ }
+ } while (target_len > 0);
+
+ if (origin_len) {
+ /* Restore original xfer buffers and length */
+ xfer->tx_buf = tx_buf;
+ xfer->rx_buf = rx_buf;
+ xfer->len = origin_len;
}
return status;
Some variants of the SPI controller have no DMA support, in such case SPI transfers longer than the FIFO length are not currently properly handled by the driver. Fix it by doing multiple transfers in the s3c64xx_spi_transfer_one() function if the SPI transfer length exceeds the FIFO size. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> --- drivers/spi/spi-s3c64xx.c | 99 +++++++++++++++++++++++++++++++---------------- 1 file changed, 66 insertions(+), 33 deletions(-)