The spi-s3c64xx currently doesn't support transfers from non-contiguous
client buffers.
This patch adds two coherent buffers which allow transfers from
non-contiguous client buffers without extra coherent memory allocation
in the client driver.
Buffer size is hardcoded to 16kB for Tx/Rx. Client drivers shouldn't
exceed that value.
Signed-off-by: Lukasz Czerwinski <l.czerwinski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/spi/spi-s3c64xx.c | 107 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 90 insertions(+), 17 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 28e8c71..1ec1244 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -113,6 +113,7 @@
#define S3C64XX_SPI_SWAP_TX_EN (1<<0)
#define S3C64XX_SPI_FBCLK_MSK (3<<0)
+#define S3C64XX_SPI_DMA_BUF_SIZE (16 * SZ_1K)
#define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
#define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
@@ -133,6 +134,8 @@
#define TXBUSY (1<<3)
struct s3c64xx_spi_dma_data {
+ u32 *vbuf;
+ dma_addr_t dma_phys;
struct dma_chan *ch;
enum dma_transfer_direction direction;
unsigned int dmach;
@@ -178,6 +181,7 @@ struct s3c64xx_spi_port_config {
* @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.
+ * @dma_buf_size: Stores buffer size for Rx/Tx.
* @cur_speed: Stores the active xfer clock speed.
*/
struct s3c64xx_spi_driver_data {
@@ -194,6 +198,7 @@ struct s3c64xx_spi_driver_data {
unsigned state;
unsigned cur_mode, cur_bpw;
unsigned cur_speed;
+ unsigned dma_buf_size;
struct s3c64xx_spi_dma_data rx_dma;
struct s3c64xx_spi_dma_data tx_dma;
@@ -279,8 +284,7 @@ static void s3c64xx_spi_dmacb(void *data)
spin_unlock_irqrestore(&sdd->lock, flags);
}
-static void s3c64xx_prepare_dma(struct s3c64xx_spi_dma_data *dma,
- unsigned len, dma_addr_t buf)
+static void s3c64xx_prepare_dma(struct s3c64xx_spi_dma_data *dma, unsigned len)
{
struct s3c64xx_spi_driver_data *sdd;
struct dma_slave_config config;
@@ -306,7 +310,7 @@ static void s3c64xx_prepare_dma(struct s3c64xx_spi_dma_data *dma,
dmaengine_slave_config(dma->ch, &config);
}
- desc = dmaengine_prep_slave_single(dma->ch, buf, len,
+ desc = dmaengine_prep_slave_single(dma->ch, dma->dma_phys, len,
dma->direction, DMA_PREP_INTERRUPT);
desc->callback = s3c64xx_spi_dmacb;
@@ -382,6 +386,34 @@ static void s3c64xx_spi_dma_stop(struct s3c64xx_spi_driver_data *sdd,
dmaengine_terminate_all(dma->ch);
}
+static void s3c64xx_copy_txbuf_to_spi(struct s3c64xx_spi_driver_data *sdd,
+ struct spi_transfer *xfer)
+{
+ struct device *dev = &sdd->pdev->dev;
+
+ dma_sync_single_for_cpu(dev, sdd->tx_dma.dma_phys,
+ sdd->dma_buf_size, DMA_TO_DEVICE);
+
+ memcpy(sdd->tx_dma.vbuf, xfer->tx_buf, xfer->len);
+
+ dma_sync_single_for_device(dev, sdd->tx_dma.dma_phys,
+ sdd->dma_buf_size, DMA_TO_DEVICE);
+}
+
+static void s3c64xx_copy_spi_to_rxbuf(struct s3c64xx_spi_driver_data *sdd,
+ struct spi_transfer *xfer)
+{
+ struct device *dev = &sdd->pdev->dev;
+
+ dma_sync_single_for_cpu(dev, sdd->rx_dma.dma_phys,
+ sdd->dma_buf_size, DMA_FROM_DEVICE);
+
+ memcpy(xfer->rx_buf, sdd->rx_dma.vbuf, xfer->len);
+
+ dma_sync_single_for_device(dev, sdd->rx_dma.dma_phys,
+ sdd->dma_buf_size, DMA_FROM_DEVICE);
+}
+
static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi,
struct spi_transfer *xfer, int dma_mode)
@@ -413,8 +445,8 @@ static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
chcfg |= S3C64XX_SPI_CH_TXCH_ON;
if (dma_mode) {
modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
- s3c64xx_prepare_dma(&sdd->tx_dma,
- xfer->len, xfer->tx_dma);
+ s3c64xx_copy_txbuf_to_spi(sdd, xfer);
+ s3c64xx_prepare_dma(&sdd->tx_dma, xfer->len);
} else {
switch (sdd->cur_bpw) {
case 32:
@@ -446,8 +478,8 @@ static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
| S3C64XX_SPI_PACKET_CNT_EN,
regs + S3C64XX_SPI_PACKET_CNT);
- s3c64xx_prepare_dma(&sdd->rx_dma,
- xfer->len, xfer->rx_dma);
+ s3c64xx_copy_spi_to_rxbuf(sdd, xfer);
+ s3c64xx_prepare_dma(&sdd->rx_dma, xfer->len);
}
}
@@ -782,14 +814,6 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
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);
@@ -804,6 +828,14 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
bpw = xfer->bits_per_word;
speed = xfer->speed_hz ? : spi->max_speed_hz;
+ if (xfer->len > sdd->dma_buf_size) {
+ dev_err(&spi->dev,
+ "Message length exceeds dma buffer size %d>%d\n",
+ xfer->len, sdd->dma_buf_size);
+ status = -EIO;
+ goto out;
+ }
+
if (xfer->len % (bpw / 8)) {
dev_err(&spi->dev,
"Xfer length(%u) not a multiple of word size(%u)\n",
@@ -881,8 +913,6 @@ out:
else
sdd->tgl_spi = spi;
- s3c64xx_spi_unmap_mssg(sdd, msg);
-
msg->status = status;
spi_finalize_current_message(master);
@@ -1168,6 +1198,28 @@ static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
platform_get_device_id(pdev)->driver_data;
}
+static int s3c64xx_init_buffer(struct s3c64xx_spi_driver_data *sdd,
+ struct s3c64xx_spi_dma_data *dma)
+{
+ struct device *dev = &sdd->pdev->dev;
+
+ dma->vbuf = dma_alloc_coherent(dev, S3C64XX_SPI_DMA_BUF_SIZE,
+ &dma->dma_phys, GFP_KERNEL);
+
+ if (!dma->vbuf)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void s3c64xx_deinit_buffer(struct s3c64xx_spi_driver_data *sdd,
+ struct s3c64xx_spi_dma_data *dma)
+{
+ struct device *dev = &sdd->pdev->dev;
+
+ dma_free_coherent(dev, sdd->dma_buf_size, dma->vbuf, dma->dma_phys);
+}
+
static int s3c64xx_spi_probe(struct platform_device *pdev)
{
struct resource *mem_res;
@@ -1250,6 +1302,16 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->rx_dma.dmach = res->start;
}
+ sdd->dma_buf_size = S3C64XX_SPI_DMA_BUF_SIZE;
+ if (s3c64xx_init_buffer(sdd, &sdd->rx_dma) < 0) {
+ ret = -ENOMEM;
+ goto err0;
+ }
+ if (s3c64xx_init_buffer(sdd, &sdd->tx_dma) < 0) {
+ ret = -ENOMEM;
+ goto err0;
+ }
+
sdd->tx_dma.direction = DMA_MEM_TO_DEV;
sdd->rx_dma.direction = DMA_DEV_TO_MEM;
@@ -1348,6 +1410,11 @@ err3:
err2:
clk_disable_unprepare(sdd->clk);
err0:
+ if (sdd->rx_dma.vbuf)
+ s3c64xx_deinit_buffer(sdd, &sdd->rx_dma);
+ if (sdd->tx_dma.vbuf)
+ s3c64xx_deinit_buffer(sdd, &sdd->tx_dma);
+
spi_master_put(master);
return ret;
@@ -1364,6 +1431,12 @@ static int s3c64xx_spi_remove(struct platform_device *pdev)
writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
+ if (sdd->rx_dma.vbuf)
+ s3c64xx_deinit_buffer(sdd, &sdd->rx_dma);
+
+ if (sdd->tx_dma.vbuf)
+ s3c64xx_deinit_buffer(sdd, &sdd->tx_dma);
+
clk_disable_unprepare(sdd->src_clk);
clk_disable_unprepare(sdd->clk);
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
