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path: root/drivers/spi/spi-stm32.c
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Diffstat (limited to 'drivers/spi/spi-stm32.c')
-rw-r--r--drivers/spi/spi-stm32.c121
1 files changed, 43 insertions, 78 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 05618a618939..9bd3fd1652f7 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -162,6 +162,8 @@
#define SPI_3WIRE_TX 3
#define SPI_3WIRE_RX 4
+#define STM32_SPI_AUTOSUSPEND_DELAY 1 /* 1 ms */
+
/*
* use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
* without fifo buffers.
@@ -568,29 +570,30 @@ static void stm32f4_spi_read_rx(struct stm32_spi *spi)
/**
* stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register
* @spi: pointer to the spi controller data structure
- * @flush: boolean indicating that FIFO should be flushed
*
* Write in rx_buf depends on remaining bytes to avoid to write beyond
* rx_buf end.
*/
-static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush)
+static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi)
{
u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
while ((spi->rx_len > 0) &&
((sr & STM32H7_SPI_SR_RXP) ||
- (flush && ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
+ ((sr & STM32H7_SPI_SR_EOT) &&
+ ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
u32 offs = spi->cur_xferlen - spi->rx_len;
if ((spi->rx_len >= sizeof(u32)) ||
- (flush && (sr & STM32H7_SPI_SR_RXWNE))) {
+ (sr & STM32H7_SPI_SR_RXWNE)) {
u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs);
*rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR);
spi->rx_len -= sizeof(u32);
} else if ((spi->rx_len >= sizeof(u16)) ||
- (flush && (rxplvl >= 2 || spi->cur_bpw > 8))) {
+ (!(sr & STM32H7_SPI_SR_RXWNE) &&
+ (rxplvl >= 2 || spi->cur_bpw > 8))) {
u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
*rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR);
@@ -606,8 +609,8 @@ static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush)
rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
}
- dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__,
- flush ? "(flush)" : "", spi->rx_len);
+ dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
+ __func__, spi->rx_len, sr);
}
/**
@@ -674,18 +677,12 @@ static void stm32f4_spi_disable(struct stm32_spi *spi)
* stm32h7_spi_disable - Disable SPI controller
* @spi: pointer to the spi controller data structure
*
- * RX-Fifo is flushed when SPI controller is disabled. To prevent any data
- * loss, use stm32h7_spi_read_rxfifo(flush) to read the remaining bytes in
- * RX-Fifo.
- * Normally, if TSIZE has been configured, we should relax the hardware at the
- * reception of the EOT interrupt. But in case of error, EOT will not be
- * raised. So the subsystem unprepare_message call allows us to properly
- * complete the transfer from an hardware point of view.
+ * RX-Fifo is flushed when SPI controller is disabled.
*/
static void stm32h7_spi_disable(struct stm32_spi *spi)
{
unsigned long flags;
- u32 cr1, sr;
+ u32 cr1;
dev_dbg(spi->dev, "disable controller\n");
@@ -698,25 +695,6 @@ static void stm32h7_spi_disable(struct stm32_spi *spi)
return;
}
- /* Wait on EOT or suspend the flow */
- if (readl_relaxed_poll_timeout_atomic(spi->base + STM32H7_SPI_SR,
- sr, !(sr & STM32H7_SPI_SR_EOT),
- 10, 100000) < 0) {
- if (cr1 & STM32H7_SPI_CR1_CSTART) {
- writel_relaxed(cr1 | STM32H7_SPI_CR1_CSUSP,
- spi->base + STM32H7_SPI_CR1);
- if (readl_relaxed_poll_timeout_atomic(
- spi->base + STM32H7_SPI_SR,
- sr, !(sr & STM32H7_SPI_SR_SUSP),
- 10, 100000) < 0)
- dev_warn(spi->dev,
- "Suspend request timeout\n");
- }
- }
-
- if (!spi->cur_usedma && spi->rx_buf && (spi->rx_len > 0))
- stm32h7_spi_read_rxfifo(spi, true);
-
if (spi->cur_usedma && spi->dma_tx)
dmaengine_terminate_all(spi->dma_tx);
if (spi->cur_usedma && spi->dma_rx)
@@ -911,7 +889,7 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
if (__ratelimit(&rs))
dev_dbg_ratelimited(spi->dev, "Communication suspended\n");
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
- stm32h7_spi_read_rxfifo(spi, false);
+ stm32h7_spi_read_rxfifo(spi);
/*
* If communication is suspended while using DMA, it means
* that something went wrong, so stop the current transfer
@@ -932,8 +910,10 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
if (sr & STM32H7_SPI_SR_EOT) {
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
- stm32h7_spi_read_rxfifo(spi, true);
- end = true;
+ stm32h7_spi_read_rxfifo(spi);
+ if (!spi->cur_usedma ||
+ (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX))
+ end = true;
}
if (sr & STM32H7_SPI_SR_TXP)
@@ -942,7 +922,7 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
if (sr & STM32H7_SPI_SR_RXP)
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
- stm32h7_spi_read_rxfifo(spi, false);
+ stm32h7_spi_read_rxfifo(spi);
writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR);
@@ -1041,42 +1021,17 @@ static void stm32f4_spi_dma_tx_cb(void *data)
}
/**
- * stm32f4_spi_dma_rx_cb - dma callback
+ * stm32_spi_dma_rx_cb - dma callback
* @data: pointer to the spi controller data structure
*
* DMA callback is called when the transfer is complete for DMA RX channel.
*/
-static void stm32f4_spi_dma_rx_cb(void *data)
+static void stm32_spi_dma_rx_cb(void *data)
{
struct stm32_spi *spi = data;
spi_finalize_current_transfer(spi->master);
- stm32f4_spi_disable(spi);
-}
-
-/**
- * stm32h7_spi_dma_cb - dma callback
- * @data: pointer to the spi controller data structure
- *
- * DMA callback is called when the transfer is complete or when an error
- * occurs. If the transfer is complete, EOT flag is raised.
- */
-static void stm32h7_spi_dma_cb(void *data)
-{
- struct stm32_spi *spi = data;
- unsigned long flags;
- u32 sr;
-
- spin_lock_irqsave(&spi->lock, flags);
-
- sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
-
- spin_unlock_irqrestore(&spi->lock, flags);
-
- if (!(sr & STM32H7_SPI_SR_EOT))
- dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr);
-
- /* Now wait for EOT, or SUSP or OVR in case of error */
+ spi->cfg->disable(spi);
}
/**
@@ -1242,11 +1197,13 @@ static void stm32f4_spi_transfer_one_dma_start(struct stm32_spi *spi)
*/
static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
{
- /* Enable the interrupts relative to the end of transfer */
- stm32_spi_set_bits(spi, STM32H7_SPI_IER, STM32H7_SPI_IER_EOTIE |
- STM32H7_SPI_IER_TXTFIE |
- STM32H7_SPI_IER_OVRIE |
- STM32H7_SPI_IER_MODFIE);
+ uint32_t ier = STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
+
+ /* Enable the interrupts */
+ if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)
+ ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE;
+
+ stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
stm32_spi_enable(spi);
@@ -1645,10 +1602,6 @@ static int stm32_spi_transfer_one(struct spi_master *master,
struct stm32_spi *spi = spi_master_get_devdata(master);
int ret;
- /* Don't do anything on 0 bytes transfers */
- if (transfer->len == 0)
- return 0;
-
spi->tx_buf = transfer->tx_buf;
spi->rx_buf = transfer->rx_buf;
spi->tx_len = spi->tx_buf ? transfer->len : 0;
@@ -1762,7 +1715,7 @@ static const struct stm32_spi_cfg stm32f4_spi_cfg = {
.set_mode = stm32f4_spi_set_mode,
.transfer_one_dma_start = stm32f4_spi_transfer_one_dma_start,
.dma_tx_cb = stm32f4_spi_dma_tx_cb,
- .dma_rx_cb = stm32f4_spi_dma_rx_cb,
+ .dma_rx_cb = stm32_spi_dma_rx_cb,
.transfer_one_irq = stm32f4_spi_transfer_one_irq,
.irq_handler_event = stm32f4_spi_irq_event,
.irq_handler_thread = stm32f4_spi_irq_thread,
@@ -1782,8 +1735,11 @@ static const struct stm32_spi_cfg stm32h7_spi_cfg = {
.set_data_idleness = stm32h7_spi_data_idleness,
.set_number_of_data = stm32h7_spi_number_of_data,
.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
- .dma_rx_cb = stm32h7_spi_dma_cb,
- .dma_tx_cb = stm32h7_spi_dma_cb,
+ .dma_rx_cb = stm32_spi_dma_rx_cb,
+ /*
+ * dma_tx_cb is not necessary since in case of TX, dma is followed by
+ * SPI access hence handling is performed within the SPI interrupt
+ */
.transfer_one_irq = stm32h7_spi_transfer_one_irq,
.irq_handler_thread = stm32h7_spi_irq_thread,
.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
@@ -1927,6 +1883,9 @@ static int stm32_spi_probe(struct platform_device *pdev)
if (spi->dma_tx || spi->dma_rx)
master->can_dma = stm32_spi_can_dma;
+ pm_runtime_set_autosuspend_delay(&pdev->dev,
+ STM32_SPI_AUTOSUSPEND_DELAY);
+ pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_enable(&pdev->dev);
@@ -1938,6 +1897,9 @@ static int stm32_spi_probe(struct platform_device *pdev)
goto err_pm_disable;
}
+ pm_runtime_mark_last_busy(&pdev->dev);
+ pm_runtime_put_autosuspend(&pdev->dev);
+
dev_info(&pdev->dev, "driver initialized\n");
return 0;
@@ -1946,6 +1908,7 @@ err_pm_disable:
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
err_dma_release:
if (spi->dma_tx)
dma_release_channel(spi->dma_tx);
@@ -1970,6 +1933,8 @@ static int stm32_spi_remove(struct platform_device *pdev)
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+
if (master->dma_tx)
dma_release_channel(master->dma_tx);
if (master->dma_rx)