Thanks for your patch Vijaya,
On 21/11/2022 14:19, Vijaya Krishna Nivarthi wrote:
SE DMA mode can be used for larger transfers and FIFO mode
for smaller transfers.
Over all the patch looks good, but with few minor nits around coding
conventions.
Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
---
drivers/spi/spi-geni-qcom.c | 211 ++++++++++++++++++++++++++++++++++----------
1 file changed, 165 insertions(+), 46 deletions(-)
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 4e83cc5..102529a 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -87,6 +87,8 @@ struct spi_geni_master {
struct completion cs_done;
struct completion cancel_done;
struct completion abort_done;
+ struct completion tx_reset_done;
+ struct completion rx_reset_done;
unsigned int oversampling;
spinlock_t lock;
int irq;
@@ -95,6 +97,7 @@ struct spi_geni_master {
struct dma_chan *tx;
struct dma_chan *rx;
int cur_xfer_mode;
+ u32 cur_m_cmd;
};
static int get_spi_clk_cfg(unsigned int speed_hz,
@@ -129,23 +132,26 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
return ret;
}
-static void handle_fifo_timeout(struct spi_master *spi,
+static void handle_se_timeout(struct spi_master *spi,
struct spi_message *msg)
indentation looks off.
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
unsigned long time_left;
struct geni_se *se = &mas->se;
+ const struct spi_transfer *xfer;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->cancel_done);
- writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ if (mas->cur_xfer_mode == GENI_SE_FIFO)
+ writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
empty line here would make the code more readable.
+ xfer = mas->cur_xfer;
mas->cur_xfer = NULL;
geni_se_cancel_m_cmd(se);
spin_unlock_irq(&mas->lock);
time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
if (time_left)
- return;
+ goto unmap_if_dma;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->abort_done);
@@ -162,6 +168,45 @@ static void handle_fifo_timeout(struct spi_master *spi,
*/
mas->abort_failed = true;
}
+
+unmap_if_dma:
+ if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ if (mas->cur_m_cmd & SPI_TX_ONLY) {
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->tx_reset_done);
+ writel(1, se->base + SE_DMA_TX_FSM_RST);
+ spin_unlock_irq(&mas->lock);
+ time_left = wait_for_completion_timeout(&mas->tx_reset_done, HZ);
+ if (!time_left)
+ dev_err(mas->dev, "DMA TX RESET failed\n");
+ }
+ if (mas->cur_m_cmd & SPI_RX_ONLY) {
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->rx_reset_done);
+ writel(1, se->base + SE_DMA_RX_FSM_RST);
+ spin_unlock_irq(&mas->lock);
+ time_left = wait_for_completion_timeout(&mas->rx_reset_done, HZ);
+ if (!time_left)
+ dev_err(mas->dev, "DMA RX RESET failed\n");
+ }
+
+ if (xfer) {
+ if (xfer->tx_buf && xfer->tx_dma)
+ geni_se_tx_dma_unprep(se, xfer->tx_dma, xfer->len);
+ if (xfer->rx_buf && xfer->rx_dma)
+ geni_se_rx_dma_unprep(se, xfer->rx_dma, xfer->len);
+ } else {
+ /*
+ * This can happen if a timeout happened and we had to wait
+ * for lock in this function because isr was holding the lock
+ * and handling transfer completion at that time.
+ * isr will set cur_xfer to NULL when done.
+ * Unnecessary error but cannot be helped.
+ * Only do reset, dma_unprep is already done by isr.
+ */
+ dev_err(mas->dev, "Cancel/Abort on completed SPI transfer\n");
+ }
+ }
}
static void handle_gpi_timeout(struct spi_master *spi, struct spi_message *msg)
@@ -178,7 +223,8 @@ static void spi_geni_handle_err(struct spi_master *spi, struct spi_message *msg)
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
- handle_fifo_timeout(spi, msg);
+ case GENI_SE_DMA:
+ handle_se_timeout(spi, msg);
break;
case GENI_GPI_DMA:
handle_gpi_timeout(spi, msg);
@@ -260,7 +306,7 @@ static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
if (!time_left) {
dev_warn(mas->dev, "Timeout setting chip select\n");
- handle_fifo_timeout(spi, NULL);
+ handle_se_timeout(spi, NULL);
}
exit:
@@ -482,8 +528,12 @@ static bool geni_can_dma(struct spi_controller *ctlr,
{
struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
- /* check if dma is supported */
- return mas->cur_xfer_mode != GENI_SE_FIFO;
+ /*
+ * Return true if transfer needs to be mapped prior to
+ * calling transfer_one which is the case only for GPI_DMA.
+ * For SE_DMA mode, map/unmap is done in geni_se_*x_dma_prep.
+ */
+ return mas->cur_xfer_mode == GENI_GPI_DMA;
}
static int spi_geni_prepare_message(struct spi_master *spi,
@@ -494,6 +544,7 @@ static int spi_geni_prepare_message(struct spi_master *spi,
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
+ case GENI_SE_DMA:
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
ret = setup_fifo_params(spi_msg->spi, spi);
@@ -597,7 +648,7 @@ static int spi_geni_init(struct spi_geni_master *mas)
break;
}
/*
- * in case of failure to get dma channel, we can still do the
+ * in case of failure to get gpi dma channel, we can still do the
* FIFO mode, so fallthrough
*/
dev_warn(mas->dev, "FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode\n");
@@ -716,12 +767,12 @@ static void geni_spi_handle_rx(struct spi_geni_master *mas)
mas->rx_rem_bytes -= rx_bytes;
}
-static void setup_fifo_xfer(struct spi_transfer *xfer,
+static int setup_se_xfer(struct spi_transfer *xfer,
struct spi_geni_master *mas,
u16 mode, struct spi_master *spi)
consider adjusting the tabs once you change the function name.
{
u32 m_cmd = 0;
- u32 len;
+ u32 len, fifo_size;
struct geni_se *se = &mas->se;
int ret;
@@ -748,7 +799,7 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
/* Speed and bits per word can be overridden per transfer */
ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
if (ret)
- return;
+ return ret;
mas->tx_rem_bytes = 0;
mas->rx_rem_bytes = 0;xxxxxxx
@@ -771,6 +822,13 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
writel(len, se->base + SE_SPI_RX_TRANS_LEN);
mas->rx_rem_bytes = xfer->len;
}
+ mas->cur_m_cmd = m_cmd;
+
+ /* Select transfer mode based on transfer length */
+ fifo_size =
+ mas->tx_fifo_depth * mas->fifo_width_bits / mas->cur_bits_per_word;
line can go up to 100 chars
+ mas->cur_xfer_mode = (len <= fifo_size) ? GENI_SE_FIFO : GENI_SE_DMA;
I do not see any protection for cur_xfer_mode? Isn't it true that it
could be modified here while an interrupt handler is using this?
+ geni_se_select_mode(se, mas->cur_xfer_mode);
/*
* Lock around right before we start the transfer since our
@@ -778,11 +836,39 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
*/
spin_lock_irq(&mas->lock);
geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
- if (m_cmd & SPI_TX_ONLY) {
+
+ if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ if (m_cmd & SPI_RX_ONLY) {
+ ret = geni_se_rx_dma_prep(se, xfer->rx_buf,
+ xfer->len, &xfer->rx_dma);
+ if (ret) {
+ dev_err(mas->dev, "Failed to setup Rx dma %d\n", ret);
+ xfer->rx_dma = 0;
+ goto unlock_and_return;
+ }
+ }
+ if (m_cmd & SPI_TX_ONLY) {
+ ret = geni_se_tx_dma_prep(se, (void *)xfer->tx_buf,
+ xfer->len, &xfer->tx_dma);
+ if (ret) {
+ dev_err(mas->dev, "Failed to setup Tx dma %d\n", ret);
+ xfer->tx_dma = 0;
+ if (m_cmd & SPI_RX_ONLY && xfer->rx_dma) {
+ /* Unmap rx buffer if duplex transfer */
+ geni_se_rx_dma_unprep(se, xfer->rx_dma, xfer->len);
+ xfer->rx_dma = 0;
+ }
+ goto unlock_and_return;
+ }
+ }
+ } else if (m_cmd & SPI_TX_ONLY) {
if (geni_spi_handle_tx(mas))
writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
}
+
+unlock_and_return:
spin_unlock_irq(&mas->lock);
+ return ret;
}
static int spi_geni_transfer_one(struct spi_master *spi,
@@ -790,6 +876,7 @@ static int spi_geni_transfer_one(struct spi_master *spi,
struct spi_transfer *xfer)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ int ret;
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
@@ -798,9 +885,12 @@ static int spi_geni_transfer_one(struct spi_master *spi,
if (!xfer->len)
return 0;
- if (mas->cur_xfer_mode == GENI_SE_FIFO) {
- setup_fifo_xfer(xfer, mas, slv->mode, spi);
- return 1;
+ if (mas->cur_xfer_mode == GENI_SE_FIFO || mas->cur_xfer_mode == GENI_SE_DMA) {
+ ret = setup_se_xfer(xfer, mas, slv->mode, spi);
+ /* SPI framework expects +ve ret code to wait for transfer complete */
+ if (!ret)
+ ret = 1;
+ return ret;
}
return setup_gsi_xfer(xfer, mas, slv, spi);
}
@@ -823,39 +913,66 @@ static irqreturn_t geni_spi_isr(int irq, void *data)
spin_lock(&mas->lock);
- if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
- geni_spi_handle_rx(mas);
-
- if (m_irq & M_TX_FIFO_WATERMARK_EN)
- geni_spi_handle_tx(mas);
-
- if (m_irq & M_CMD_DONE_EN) {
- if (mas->cur_xfer) {
+ if (mas->cur_xfer_mode == GENI_SE_FIFO) {
Switch case?
...
+ }
+ } else if (mas->cur_xfer_mode == GENI_SE_DMA) {
+ const struct spi_transfer *xfer = mas->cur_xfer;
--srini
