[PATCH] spi: atmel: Refactor spi-atmel to use SPI framework queue

From: Wenyou Yang
Date: Wed Jan 08 2014 - 00:56:59 EST

Replace the deprecated master->transfer with transfer_one_message()
and allow the SPI subsystem handle all the queuing of messages.

Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
---
Hi Mark,

The patch is based on for-next branch of
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git

It is tested on sama5d3xek and at91sam9m10g45ek board.

Best Regards,
Wenyou Yang

drivers/spi/spi-atmel.c | 681 +++++++++++++++--------------------------------
1 file changed, 220 insertions(+), 461 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 57fa738..2a8c1d0 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -189,6 +189,8 @@
*/
#define DMA_MIN_BYTES 16

+#define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
+
struct atmel_spi_dma {
struct dma_chan *chan_rx;
struct dma_chan *chan_tx;
@@ -220,17 +222,14 @@ struct atmel_spi {
int irq;
struct clk *clk;
struct platform_device *pdev;
- struct spi_device *stay;

u8 stopping;
- struct list_head queue;
- struct tasklet_struct tasklet;
struct spi_transfer *current_transfer;
unsigned long current_remaining_bytes;
- struct spi_transfer *next_transfer;
- unsigned long next_remaining_bytes;
int done_status;

+ struct completion xfer_completion;
+
/* scratch buffer */
void *buffer;
dma_addr_t buffer_dma;
@@ -376,17 +375,6 @@ static inline bool atmel_spi_use_dma(struct atmel_spi *as,
return as->use_dma && xfer->len >= DMA_MIN_BYTES;
}

-static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
- struct spi_transfer *xfer)
-{
- return msg->transfers.prev == &xfer->transfer_list;
-}
-
-static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer)
-{
- return xfer->delay_usecs == 0 && !xfer->cs_change;
-}
-
static int atmel_spi_dma_slave_config(struct atmel_spi *as,
struct dma_slave_config *slave_config,
u8 bits_per_word)
@@ -507,29 +495,28 @@ static void atmel_spi_release_dma(struct atmel_spi *as)
dma_release_channel(as->dma.chan_tx);
}

-/* This function is called by the DMA driver from tasklet context */
+/* This function is called by the DMA driver */
static void dma_callback(void *data)
{
struct spi_master *master = data;
struct atmel_spi *as = spi_master_get_devdata(master);

- /* trigger SPI tasklet */
- tasklet_schedule(&as->tasklet);
+ atmel_spi_lock(as);
+ complete(&as->xfer_completion);
+ atmel_spi_unlock(as);
}

/*
* Next transfer using PIO.
- * lock is held, spi tasklet is blocked
*/
static void atmel_spi_next_xfer_pio(struct spi_master *master,
struct spi_transfer *xfer)
{
struct atmel_spi *as = spi_master_get_devdata(master);
+ unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;

dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n");

- as->current_remaining_bytes = xfer->len;
-
/* Make sure data is not remaining in RDR */
spi_readl(as, RDR);
while (spi_readl(as, SR) & SPI_BIT(RDRF)) {
@@ -537,13 +524,14 @@ static void atmel_spi_next_xfer_pio(struct spi_master *master,
cpu_relax();
}

- if (xfer->tx_buf)
+ if (xfer->tx_buf) {
if (xfer->bits_per_word > 8)
- spi_writel(as, TDR, *(u16 *)(xfer->tx_buf));
+ spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
else
- spi_writel(as, TDR, *(u8 *)(xfer->tx_buf));
- else
+ spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
+ } else {
spi_writel(as, TDR, 0);
+ }

dev_dbg(master->dev.parent,
" start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
@@ -556,7 +544,6 @@ static void atmel_spi_next_xfer_pio(struct spi_master *master,

/*
* Submit next transfer for DMA.
- * lock is held, spi tasklet is blocked
*/
static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
struct spi_transfer *xfer,
@@ -696,72 +683,39 @@ static void atmel_spi_next_xfer_data(struct spi_master *master,

/*
* Submit next transfer for PDC.
- * lock is held, spi irq is blocked
*/
static void atmel_spi_pdc_next_xfer(struct spi_master *master,
- struct spi_message *msg)
+ struct spi_message *msg,
+ struct spi_transfer *xfer)
{
struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_transfer *xfer;
- u32 len, remaining;
- u32 ieval;
+ u32 len;
dma_addr_t tx_dma, rx_dma;

- if (!as->current_transfer)
- xfer = list_entry(msg->transfers.next,
- struct spi_transfer, transfer_list);
- else if (!as->next_transfer)
- xfer = list_entry(as->current_transfer->transfer_list.next,
- struct spi_transfer, transfer_list);
- else
- xfer = NULL;
+ spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));

- if (xfer) {
- spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+ len = as->current_remaining_bytes;
+ atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
+ as->current_remaining_bytes -= len;

- len = xfer->len;
- atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
- remaining = xfer->len - len;
+ spi_writel(as, RPR, rx_dma);
+ spi_writel(as, TPR, tx_dma);

- spi_writel(as, RPR, rx_dma);
- spi_writel(as, TPR, tx_dma);
+ if (msg->spi->bits_per_word > 8)
+ len >>= 1;
+ spi_writel(as, RCR, len);
+ spi_writel(as, TCR, len);

- if (msg->spi->bits_per_word > 8)
- len >>= 1;
- spi_writel(as, RCR, len);
- spi_writel(as, TCR, len);
-
- dev_dbg(&msg->spi->dev,
- " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
- xfer, xfer->len, xfer->tx_buf,
- (unsigned long long)xfer->tx_dma, xfer->rx_buf,
- (unsigned long long)xfer->rx_dma);
- } else {
- xfer = as->next_transfer;
- remaining = as->next_remaining_bytes;
- }
-
- as->current_transfer = xfer;
- as->current_remaining_bytes = remaining;
-
- if (remaining > 0)
- len = remaining;
- else if (!atmel_spi_xfer_is_last(msg, xfer)
- && atmel_spi_xfer_can_be_chained(xfer)) {
- xfer = list_entry(xfer->transfer_list.next,
- struct spi_transfer, transfer_list);
- len = xfer->len;
- } else
- xfer = NULL;
+ dev_dbg(&msg->spi->dev,
+ " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
+ xfer, xfer->len, xfer->tx_buf,
+ (unsigned long long)xfer->tx_dma, xfer->rx_buf,
+ (unsigned long long)xfer->rx_dma);

- as->next_transfer = xfer;
-
- if (xfer) {
- u32 total;
-
- total = len;
+ if (as->current_remaining_bytes) {
+ len = as->current_remaining_bytes;
atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
- as->next_remaining_bytes = total - len;
+ as->current_remaining_bytes -= len;

spi_writel(as, RNPR, rx_dma);
spi_writel(as, TNPR, tx_dma);
@@ -776,11 +730,6 @@ static void atmel_spi_pdc_next_xfer(struct spi_master *master,
xfer, xfer->len, xfer->tx_buf,
(unsigned long long)xfer->tx_dma, xfer->rx_buf,
(unsigned long long)xfer->rx_dma);
- ieval = SPI_BIT(ENDRX) | SPI_BIT(OVRES);
- } else {
- spi_writel(as, RNCR, 0);
- spi_writel(as, TNCR, 0);
- ieval = SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) | SPI_BIT(OVRES);
}

/* REVISIT: We're waiting for ENDRX before we start the next
@@ -793,83 +742,11 @@ static void atmel_spi_pdc_next_xfer(struct spi_master *master,
*
* It should be doable, though. Just not now...
*/
- spi_writel(as, IER, ieval);
+ spi_writel(as, IER, SPI_BIT(ENDRX) | SPI_BIT(OVRES));
spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
}

/*
- * Choose way to submit next transfer and start it.
- * lock is held, spi tasklet is blocked
- */
-static void atmel_spi_dma_next_xfer(struct spi_master *master,
- struct spi_message *msg)
-{
- struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_transfer *xfer;
- u32 remaining, len;
-
- remaining = as->current_remaining_bytes;
- if (remaining) {
- xfer = as->current_transfer;
- len = remaining;
- } else {
- if (!as->current_transfer)
- xfer = list_entry(msg->transfers.next,
- struct spi_transfer, transfer_list);
- else
- xfer = list_entry(
- as->current_transfer->transfer_list.next,
- struct spi_transfer, transfer_list);
-
- as->current_transfer = xfer;
- len = xfer->len;
- }
-
- if (atmel_spi_use_dma(as, xfer)) {
- u32 total = len;
- if (!atmel_spi_next_xfer_dma_submit(master, xfer, &len)) {
- as->current_remaining_bytes = total - len;
- return;
- } else {
- dev_err(&msg->spi->dev, "unable to use DMA, fallback to PIO\n");
- }
- }
-
- /* use PIO if error appened using DMA */
- atmel_spi_next_xfer_pio(master, xfer);
-}
-
-static void atmel_spi_next_message(struct spi_master *master)
-{
- struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_message *msg;
- struct spi_device *spi;
-
- BUG_ON(as->current_transfer);
-
- msg = list_entry(as->queue.next, struct spi_message, queue);
- spi = msg->spi;
-
- dev_dbg(master->dev.parent, "start message %p for %s\n",
- msg, dev_name(&spi->dev));
-
- /* select chip if it's not still active */
- if (as->stay) {
- if (as->stay != spi) {
- cs_deactivate(as, as->stay);
- cs_activate(as, spi);
- }
- as->stay = NULL;
- } else
- cs_activate(as, spi);
-
- if (as->use_pdc)
- atmel_spi_pdc_next_xfer(master, msg);
- else
- atmel_spi_dma_next_xfer(master, msg);
-}
-
-/*
* For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
* - The buffer is either valid for CPU access, else NULL
* - If the buffer is valid, so is its DMA address
@@ -924,41 +801,7 @@ static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
}

-static void
-atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
- struct spi_message *msg, int stay)
-{
- if (!stay || as->done_status < 0)
- cs_deactivate(as, msg->spi);
- else
- as->stay = msg->spi;
-
- list_del(&msg->queue);
- msg->status = as->done_status;
-
- dev_dbg(master->dev.parent,
- "xfer complete: %u bytes transferred\n",
- msg->actual_length);
-
- atmel_spi_unlock(as);
- msg->complete(msg->context);
- atmel_spi_lock(as);
-
- as->current_transfer = NULL;
- as->next_transfer = NULL;
- as->done_status = 0;
-
- /* continue if needed */
- if (list_empty(&as->queue) || as->stopping) {
- if (as->use_pdc)
- atmel_spi_disable_pdc_transfer(as);
- } else {
- atmel_spi_next_message(master);
- }
-}
-
/* Called from IRQ
- * lock is held
*
* Must update "current_remaining_bytes" to keep track of data
* to transfer.
@@ -966,9 +809,7 @@ atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
static void
atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
{
- u8 *txp;
u8 *rxp;
- u16 *txp16;
u16 *rxp16;
unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;

@@ -990,96 +831,12 @@ atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
} else {
as->current_remaining_bytes--;
}
-
- if (as->current_remaining_bytes) {
- if (xfer->tx_buf) {
- if (xfer->bits_per_word > 8) {
- txp16 = (u16 *)(((u8 *)xfer->tx_buf)
- + xfer_pos + 2);
- spi_writel(as, TDR, *txp16);
- } else {
- txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1;
- spi_writel(as, TDR, *txp);
- }
- } else {
- spi_writel(as, TDR, 0);
- }
- }
-}
-
-/* Tasklet
- * Called from DMA callback + pio transfer and overrun IRQ.
- */
-static void atmel_spi_tasklet_func(unsigned long data)
-{
- struct spi_master *master = (struct spi_master *)data;
- struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_message *msg;
- struct spi_transfer *xfer;
-
- dev_vdbg(master->dev.parent, "atmel_spi_tasklet_func\n");
-
- atmel_spi_lock(as);
-
- xfer = as->current_transfer;
-
- if (xfer == NULL)
- /* already been there */
- goto tasklet_out;
-
- msg = list_entry(as->queue.next, struct spi_message, queue);
-
- if (as->current_remaining_bytes == 0) {
- if (as->done_status < 0) {
- /* error happened (overrun) */
- if (atmel_spi_use_dma(as, xfer))
- atmel_spi_stop_dma(as);
- } else {
- /* only update length if no error */
- msg->actual_length += xfer->len;
- }
-
- if (atmel_spi_use_dma(as, xfer))
- if (!msg->is_dma_mapped)
- atmel_spi_dma_unmap_xfer(master, xfer);
-
- if (xfer->delay_usecs)
- udelay(xfer->delay_usecs);
-
- if (atmel_spi_xfer_is_last(msg, xfer) || as->done_status < 0) {
- /* report completed (or erroneous) message */
- atmel_spi_msg_done(master, as, msg, xfer->cs_change);
- } else {
- if (xfer->cs_change) {
- cs_deactivate(as, msg->spi);
- udelay(1);
- cs_activate(as, msg->spi);
- }
-
- /*
- * Not done yet. Submit the next transfer.
- *
- * FIXME handle protocol options for xfer
- */
- atmel_spi_dma_next_xfer(master, msg);
- }
- } else {
- /*
- * Keep going, we still have data to send in
- * the current transfer.
- */
- atmel_spi_dma_next_xfer(master, msg);
- }
-
-tasklet_out:
- atmel_spi_unlock(as);
}

/* Interrupt
*
* No need for locking in this Interrupt handler: done_status is the
- * only information modified. What we need is the update of this field
- * before tasklet runs. This is ensured by using barrier.
+ * only information modified.
*/
static irqreturn_t
atmel_spi_pio_interrupt(int irq, void *dev_id)
@@ -1107,8 +864,6 @@ atmel_spi_pio_interrupt(int irq, void *dev_id)
*
* We will also not process any remaning transfers in
* the message.
- *
- * All actions are done in tasklet with done_status indication
*/
as->done_status = -EIO;
smp_wmb();
@@ -1116,7 +871,9 @@ atmel_spi_pio_interrupt(int irq, void *dev_id)
/* Clear any overrun happening while cleaning up */
spi_readl(as, SR);

- tasklet_schedule(&as->tasklet);
+ atmel_spi_lock(as);
+ complete(&as->xfer_completion);
+ atmel_spi_unlock(as);

} else if (pending & SPI_BIT(RDRF)) {
atmel_spi_lock(as);
@@ -1125,11 +882,10 @@ atmel_spi_pio_interrupt(int irq, void *dev_id)
ret = IRQ_HANDLED;
xfer = as->current_transfer;
atmel_spi_pump_pio_data(as, xfer);
- if (!as->current_remaining_bytes) {
- /* no more data to xfer, kick tasklet */
+ if (!as->current_remaining_bytes)
spi_writel(as, IDR, pending);
- tasklet_schedule(&as->tasklet);
- }
+
+ complete(&as->xfer_completion);
}

atmel_spi_unlock(as);
@@ -1147,116 +903,37 @@ atmel_spi_pdc_interrupt(int irq, void *dev_id)
{
struct spi_master *master = dev_id;
struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_message *msg;
- struct spi_transfer *xfer;
u32 status, pending, imr;
int ret = IRQ_NONE;

- atmel_spi_lock(as);
-
- xfer = as->current_transfer;
- msg = list_entry(as->queue.next, struct spi_message, queue);
-
imr = spi_readl(as, IMR);
status = spi_readl(as, SR);
pending = status & imr;

if (pending & SPI_BIT(OVRES)) {
- int timeout;
-
ret = IRQ_HANDLED;

spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
| SPI_BIT(OVRES)));

- /*
- * When we get an overrun, we disregard the current
- * transfer. Data will not be copied back from any
- * bounce buffer and msg->actual_len will not be
- * updated with the last xfer.
- *
- * We will also not process any remaning transfers in
- * the message.
- *
- * First, stop the transfer and unmap the DMA buffers.
- */
- spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
- if (!msg->is_dma_mapped)
- atmel_spi_dma_unmap_xfer(master, xfer);
-
- /* REVISIT: udelay in irq is unfriendly */
- if (xfer->delay_usecs)
- udelay(xfer->delay_usecs);
-
- dev_warn(master->dev.parent, "overrun (%u/%u remaining)\n",
- spi_readl(as, TCR), spi_readl(as, RCR));
-
- /*
- * Clean up DMA registers and make sure the data
- * registers are empty.
- */
- spi_writel(as, RNCR, 0);
- spi_writel(as, TNCR, 0);
- spi_writel(as, RCR, 0);
- spi_writel(as, TCR, 0);
- for (timeout = 1000; timeout; timeout--)
- if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
- break;
- if (!timeout)
- dev_warn(master->dev.parent,
- "timeout waiting for TXEMPTY");
- while (spi_readl(as, SR) & SPI_BIT(RDRF))
- spi_readl(as, RDR);
-
/* Clear any overrun happening while cleaning up */
spi_readl(as, SR);

+ atmel_spi_lock(as);
as->done_status = -EIO;
- atmel_spi_msg_done(master, as, msg, 0);
+ complete(&as->xfer_completion);
+ atmel_spi_unlock(as);
+
} else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
ret = IRQ_HANDLED;

spi_writel(as, IDR, pending);

- if (as->current_remaining_bytes == 0) {
- msg->actual_length += xfer->len;
-
- if (!msg->is_dma_mapped)
- atmel_spi_dma_unmap_xfer(master, xfer);
-
- /* REVISIT: udelay in irq is unfriendly */
- if (xfer->delay_usecs)
- udelay(xfer->delay_usecs);
-
- if (atmel_spi_xfer_is_last(msg, xfer)) {
- /* report completed message */
- atmel_spi_msg_done(master, as, msg,
- xfer->cs_change);
- } else {
- if (xfer->cs_change) {
- cs_deactivate(as, msg->spi);
- udelay(1);
- cs_activate(as, msg->spi);
- }
-
- /*
- * Not done yet. Submit the next transfer.
- *
- * FIXME handle protocol options for xfer
- */
- atmel_spi_pdc_next_xfer(master, msg);
- }
- } else {
- /*
- * Keep going, we still have data to send in
- * the current transfer.
- */
- atmel_spi_pdc_next_xfer(master, msg);
- }
+ atmel_spi_lock(as);
+ complete(&as->xfer_completion);
+ atmel_spi_unlock(as);
}

- atmel_spi_unlock(as);
-
return ret;
}

@@ -1352,12 +1029,6 @@ static int atmel_spi_setup(struct spi_device *spi)
asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
- } else {
- atmel_spi_lock(as);
- if (as->stay == spi)
- as->stay = NULL;
- cs_deactivate(as, spi);
- atmel_spi_unlock(as);
}

asd->csr = csr;
@@ -1372,103 +1043,211 @@ static int atmel_spi_setup(struct spi_device *spi)
return 0;
}

-static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+static int atmel_spi_one_transfer(struct spi_master *master,
+ struct spi_message *msg,
+ struct spi_transfer *xfer)
{
- struct atmel_spi *as;
- struct spi_transfer *xfer;
- struct device *controller = spi->master->dev.parent;
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct spi_device *spi = msg->spi;
u8 bits;
+ u32 len;
struct atmel_spi_device *asd;
+ int timeout;
+ int ret;

- as = spi_master_get_devdata(spi->master);
-
- dev_dbg(controller, "new message %p submitted for %s\n",
- msg, dev_name(&spi->dev));
-
- if (unlikely(list_empty(&msg->transfers)))
+ if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
+ dev_dbg(&spi->dev, "missing rx or tx buf\n");
return -EINVAL;
+ }

- if (as->stopping)
- return -ESHUTDOWN;
+ if (xfer->bits_per_word) {
+ asd = spi->controller_state;
+ bits = (asd->csr >> 4) & 0xf;
+ if (bits != xfer->bits_per_word - 8) {
+ dev_dbg(&spi->dev,
+ "you can't yet change bits_per_word in transfers\n");
+ return -ENOPROTOOPT;
+ }
+ }

- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
- dev_dbg(&spi->dev, "missing rx or tx buf\n");
+ if (xfer->bits_per_word > 8) {
+ if (xfer->len % 2) {
+ dev_dbg(&spi->dev,
+ "buffer len should be 16 bits aligned\n");
return -EINVAL;
}
+ }

- if (xfer->bits_per_word) {
- asd = spi->controller_state;
- bits = (asd->csr >> 4) & 0xf;
- if (bits != xfer->bits_per_word - 8) {
- dev_dbg(&spi->dev,
- "you can't yet change bits_per_word in transfers\n");
- return -ENOPROTOOPT;
- }
- }
+ /* FIXME implement these protocol options!! */
+ if (xfer->speed_hz < spi->max_speed_hz) {
+ dev_dbg(&spi->dev, "can't change speed in transfer\n");
+ return -ENOPROTOOPT;
+ }

- if (xfer->bits_per_word > 8) {
- if (xfer->len % 2) {
- dev_dbg(&spi->dev, "buffer len should be 16 bits aligned\n");
- return -EINVAL;
+ /*
+ * DMA map early, for performance (empties dcache ASAP) and
+ * better fault reporting.
+ */
+ if ((!msg->is_dma_mapped)
+ && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) {
+ if (atmel_spi_dma_map_xfer(as, xfer) < 0)
+ return -ENOMEM;
+ }
+
+ as->done_status = 0;
+ as->current_transfer = xfer;
+ as->current_remaining_bytes = xfer->len;
+ while (as->current_remaining_bytes) {
+ reinit_completion(&as->xfer_completion);
+
+ if (as->use_pdc) {
+ atmel_spi_pdc_next_xfer(master, msg, xfer);
+ } else if (atmel_spi_use_dma(as, xfer)) {
+ len = as->current_remaining_bytes;
+ ret = atmel_spi_next_xfer_dma_submit(master,
+ xfer, &len);
+ if (ret) {
+ dev_err(&spi->dev,
+ "unable to use DMA, fallback to PIO\n");
+ atmel_spi_next_xfer_pio(master, xfer);
+ } else {
+ as->current_remaining_bytes -= len;
}
+ } else {
+ atmel_spi_next_xfer_pio(master, xfer);
}

- /* FIXME implement these protocol options!! */
- if (xfer->speed_hz < spi->max_speed_hz) {
- dev_dbg(&spi->dev, "can't change speed in transfer\n");
- return -ENOPROTOOPT;
+ ret = wait_for_completion_timeout(&as->xfer_completion,
+ SPI_DMA_TIMEOUT);
+ if (WARN_ON(ret == 0)) {
+ dev_err(&spi->dev,
+ "spi trasfer timeout, err %d\n", ret);
+ as->done_status = -EIO;
+ } else {
+ ret = 0;
}

- /*
- * DMA map early, for performance (empties dcache ASAP) and
- * better fault reporting.
- */
- if ((!msg->is_dma_mapped) && (atmel_spi_use_dma(as, xfer)
- || as->use_pdc)) {
- if (atmel_spi_dma_map_xfer(as, xfer) < 0)
- return -ENOMEM;
+ if (as->done_status)
+ break;
+ }
+
+ if (as->done_status) {
+ if (as->use_pdc) {
+ dev_warn(master->dev.parent,
+ "overrun (%u/%u remaining)\n",
+ spi_readl(as, TCR), spi_readl(as, RCR));
+
+ /*
+ * Clean up DMA registers and make sure the data
+ * registers are empty.
+ */
+ spi_writel(as, RNCR, 0);
+ spi_writel(as, TNCR, 0);
+ spi_writel(as, RCR, 0);
+ spi_writel(as, TCR, 0);
+ for (timeout = 1000; timeout; timeout--)
+ if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
+ break;
+ if (!timeout)
+ dev_warn(master->dev.parent,
+ "timeout waiting for TXEMPTY");
+ while (spi_readl(as, SR) & SPI_BIT(RDRF))
+ spi_readl(as, RDR);
+
+ /* Clear any overrun happening while cleaning up */
+ spi_readl(as, SR);
+
+ } else if (atmel_spi_use_dma(as, xfer)) {
+ atmel_spi_stop_dma(as);
}
+
+ if (!msg->is_dma_mapped
+ && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
+ atmel_spi_dma_unmap_xfer(master, xfer);
+
+ return 0;
+
+ } else {
+ /* only update length if no error */
+ msg->actual_length += xfer->len;
+ }
+
+ if (!msg->is_dma_mapped
+ && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
+ atmel_spi_dma_unmap_xfer(master, xfer);
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ if (xfer->cs_change) {
+ cs_deactivate(as, msg->spi);
+ udelay(1);
+ cs_activate(as, msg->spi);
+ }
+
+ return 0;
+}
+
+static int atmel_spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct atmel_spi *as;
+ struct spi_transfer *xfer;
+ struct spi_device *spi = msg->spi;
+ int ret = 0;
+
+ as = spi_master_get_devdata(master);
+
+ dev_dbg(&spi->dev, "new message %p submitted for %s\n",
+ msg, dev_name(&spi->dev));
+
+ if (unlikely(list_empty(&msg->transfers)))
+ return -EINVAL;
+
+ if (as->stopping)
+ return -ESHUTDOWN;
+
+ atmel_spi_lock(as);
+ cs_activate(as, spi);
+
+ msg->status = 0;
+ msg->actual_length = 0;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ ret = atmel_spi_one_transfer(master, msg, xfer);
+ if (ret)
+ goto msg_done;
}

-#ifdef VERBOSE
+ if (as->use_pdc)
+ atmel_spi_disable_pdc_transfer(as);
+
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- dev_dbg(controller,
+ dev_dbg(&spi->dev,
" xfer %p: len %u tx %p/%08x rx %p/%08x\n",
xfer, xfer->len,
xfer->tx_buf, xfer->tx_dma,
xfer->rx_buf, xfer->rx_dma);
}
-#endif

- msg->status = -EINPROGRESS;
- msg->actual_length = 0;
-
- atmel_spi_lock(as);
- list_add_tail(&msg->queue, &as->queue);
- if (!as->current_transfer)
- atmel_spi_next_message(spi->master);
+msg_done:
+ cs_deactivate(as, msg->spi);
atmel_spi_unlock(as);

- return 0;
+ msg->status = as->done_status;
+ spi_finalize_current_message(spi->master);
+
+ return ret;
}

static void atmel_spi_cleanup(struct spi_device *spi)
{
- struct atmel_spi *as = spi_master_get_devdata(spi->master);
struct atmel_spi_device *asd = spi->controller_state;
unsigned gpio = (unsigned) spi->controller_data;

if (!asd)
return;

- atmel_spi_lock(as);
- if (as->stay == spi) {
- as->stay = NULL;
- cs_deactivate(as, spi);
- }
- atmel_spi_unlock(as);
-
spi->controller_state = NULL;
gpio_free(gpio);
kfree(asd);
@@ -1527,7 +1306,7 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->bus_num = pdev->id;
master->num_chipselect = master->dev.of_node ? 0 : 4;
master->setup = atmel_spi_setup;
- master->transfer = atmel_spi_transfer;
+ master->transfer_one_message = atmel_spi_transfer_one_message;
master->cleanup = atmel_spi_cleanup;
platform_set_drvdata(pdev, master);

@@ -1543,7 +1322,6 @@ static int atmel_spi_probe(struct platform_device *pdev)
goto out_free;

spin_lock_init(&as->lock);
- INIT_LIST_HEAD(&as->queue);

as->pdev = pdev;
as->regs = devm_ioremap_resource(&pdev->dev, regs);
@@ -1555,6 +1333,8 @@ static int atmel_spi_probe(struct platform_device *pdev)
as->irq = irq;
as->clk = clk;

+ init_completion(&as->xfer_completion);
+
atmel_get_caps(as);

as->use_dma = false;
@@ -1573,9 +1353,6 @@ static int atmel_spi_probe(struct platform_device *pdev)
ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt,
0, dev_name(&pdev->dev), master);
} else {
- tasklet_init(&as->tasklet, atmel_spi_tasklet_func,
- (unsigned long)master);
-
ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt,
0, dev_name(&pdev->dev), master);
}
@@ -1619,8 +1396,6 @@ out_free_dma:
out_free_irq:
out_unmap_regs:
out_free_buffer:
- if (!as->use_pdc)
- tasklet_kill(&as->tasklet);
dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
as->buffer_dma);
out_free:
@@ -1632,8 +1407,6 @@ static int atmel_spi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct atmel_spi *as = spi_master_get_devdata(master);
- struct spi_message *msg;
- struct spi_transfer *xfer;

/* reset the hardware and block queue progress */
spin_lock_irq(&as->lock);
@@ -1648,20 +1421,6 @@ static int atmel_spi_remove(struct platform_device *pdev)
spi_readl(as, SR);
spin_unlock_irq(&as->lock);

- /* Terminate remaining queued transfers */
- list_for_each_entry(msg, &as->queue, queue) {
- list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!msg->is_dma_mapped
- && (atmel_spi_use_dma(as, xfer)
- || as->use_pdc))
- atmel_spi_dma_unmap_xfer(master, xfer);
- }
- msg->status = -ESHUTDOWN;
- msg->complete(msg->context);
- }
-
- if (!as->use_pdc)
- tasklet_kill(&as->tasklet);
dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
as->buffer_dma);

--
1.7.9.5

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