Skip to content

Commit

Permalink
Merge series "spi: stm32: various fixes & cleanup" from Alain Volmat …
Browse files Browse the repository at this point in the history 
…<alain.volmat@foss.st.com>:

This series contains fixes & cleanup mainly regarding fifo
and the way end of transfer triggered, when used with or
without DMA.
An additional patch cleans up the pm_runtime calls and another
one enables the autosuspend.

v2: - split pm_runtime fix patch into two
    - correct revert commit subject line

Alain Volmat (6):
  spi: stm32: fixes pm_runtime calls in probe/remove
  spi: stm32: enable pm_runtime autosuspend
  spi: stm32h7: fix full duplex irq handler handling
  spi: stm32: Revert "properly handle 0 byte transfer"
  spi: stm32h7: don't wait for EOT and flush fifo on disable
  spi: stm32: finalize message either on dma callback or EOT

Amelie Delaunay (1):
  spi: stm32h7: rework rx fifo read function

 drivers/spi/spi-stm32.c | 146 +++++++++++++++++-----------------------
 1 file changed, 61 insertions(+), 85 deletions(-)

--
2.25.1
  • Loading branch information
Mark Brown committed Jul 12, 2021
2 parents 162a31e + 7ceb0b8 commit 65ab894
Showing 1 changed file with 44 additions and 78 deletions.
122 changes: 44 additions & 78 deletions drivers/spi/spi-stm32.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down Expand Up @@ -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);
Expand All @@ -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);
}

/**
Expand Down Expand Up @@ -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");

Expand All @@ -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)
Expand Down Expand Up @@ -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
Expand All @@ -932,8 +910,11 @@ 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_usedma && (spi->cur_comm == SPI_SIMPLEX_TX ||
spi->cur_comm == SPI_3WIRE_TX)))
end = true;
}

if (sr & STM32H7_SPI_SR_TXP)
Expand All @@ -942,7 +923,7 @@ 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);

Expand Down Expand Up @@ -1041,42 +1022,17 @@ 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);
}

/**
Expand Down Expand Up @@ -1242,11 +1198,13 @@ 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);

Expand Down Expand Up @@ -1645,10 +1603,6 @@ 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;
Expand Down Expand Up @@ -1762,7 +1716,7 @@ 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,
Expand All @@ -1782,8 +1736,11 @@ 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,
Expand Down Expand Up @@ -1927,6 +1884,9 @@ 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);
Expand All @@ -1938,6 +1898,9 @@ 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;
Expand All @@ -1946,6 +1909,7 @@ static int stm32_spi_probe(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);
err_dma_release:
if (spi->dma_tx)
dma_release_channel(spi->dma_tx);
Expand All @@ -1970,6 +1934,8 @@ 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)
Expand Down

0 comments on commit 65ab894

Please sign in to comment.