[PATCH 2/4] mmc: atmel-mci: change the state machine
ludovic.desroches at atmel.com
ludovic.desroches at atmel.com
Wed May 16 09:25:59 EDT 2012
From: Ludovic Desroches <ludovic.desroches at atmel.com>
The state machine use in atmel-mci can't work with old IP versions (< 0x200).
This patch allows to have a common state machine for all versions in order to
remove at91-mci driver only used for old versions.
Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
---
drivers/mmc/host/atmel-mci.c | 278 ++++++++++++++++++++++++------------------
1 files changed, 162 insertions(+), 116 deletions(-)
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 308f8ae..cad830f 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -45,19 +45,19 @@
#define ATMCI_DMA_THRESHOLD 16
enum {
- EVENT_CMD_COMPLETE = 0,
+ EVENT_CMD_RDY = 0,
EVENT_XFER_COMPLETE,
- EVENT_DATA_COMPLETE,
+ EVENT_NOTBUSY,
EVENT_DATA_ERROR,
};
enum atmel_mci_state {
STATE_IDLE = 0,
STATE_SENDING_CMD,
- STATE_SENDING_DATA,
- STATE_DATA_BUSY,
+ STATE_DATA_XFER,
+ STATE_WAITING_NOTBUSY,
STATE_SENDING_STOP,
- STATE_DATA_ERROR,
+ STATE_END_REQUEST,
};
enum atmci_xfer_dir {
@@ -709,7 +709,6 @@ static void atmci_pdc_complete(struct atmel_mci *host)
if (host->data) {
atmci_set_pending(host, EVENT_XFER_COMPLETE);
tasklet_schedule(&host->tasklet);
- atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
}
}
@@ -834,7 +833,7 @@ atmci_prepare_data_pdc(struct atmel_mci *host, struct mmc_data *data)
iflags |= ATMCI_ENDRX | ATMCI_RXBUFF;
} else {
dir = DMA_TO_DEVICE;
- iflags |= ATMCI_ENDTX | ATMCI_TXBUFE;
+ iflags |= ATMCI_ENDTX | ATMCI_TXBUFE | ATMCI_BLKE;
}
/* Set BLKLEN */
@@ -976,8 +975,7 @@ static void atmci_stop_transfer(struct atmel_mci *host)
*/
static void atmci_stop_transfer_pdc(struct atmel_mci *host)
{
- atmci_set_pending(host, EVENT_XFER_COMPLETE);
- atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
+ atmci_writel(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
}
static void atmci_stop_transfer_dma(struct atmel_mci *host)
@@ -1013,6 +1011,7 @@ static void atmci_start_request(struct atmel_mci *host,
host->pending_events = 0;
host->completed_events = 0;
+ host->cmd_status = 0;
host->data_status = 0;
if (host->need_reset) {
@@ -1030,7 +1029,7 @@ static void atmci_start_request(struct atmel_mci *host,
iflags = atmci_readl(host, ATMCI_IMR);
if (iflags & ~(ATMCI_SDIOIRQA | ATMCI_SDIOIRQB))
- dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
+ dev_dbg(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
iflags);
if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
@@ -1368,19 +1367,6 @@ static void atmci_command_complete(struct atmel_mci *host,
cmd->error = -EIO;
else
cmd->error = 0;
-
- if (cmd->error) {
- dev_dbg(&host->pdev->dev,
- "command error: status=0x%08x\n", status);
-
- if (cmd->data) {
- host->stop_transfer(host);
- host->data = NULL;
- atmci_writel(host, ATMCI_IDR, ATMCI_NOTBUSY
- | ATMCI_TXRDY | ATMCI_RXRDY
- | ATMCI_DATA_ERROR_FLAGS);
- }
- }
}
static void atmci_detect_change(unsigned long data)
@@ -1443,23 +1429,21 @@ static void atmci_detect_change(unsigned long data)
break;
case STATE_SENDING_CMD:
mrq->cmd->error = -ENOMEDIUM;
- if (!mrq->data)
- break;
- /* fall through */
- case STATE_SENDING_DATA:
+ if (mrq->data)
+ host->stop_transfer(host);
+ break;
+ case STATE_DATA_XFER:
mrq->data->error = -ENOMEDIUM;
host->stop_transfer(host);
break;
- case STATE_DATA_BUSY:
- case STATE_DATA_ERROR:
- if (mrq->data->error == -EINPROGRESS)
- mrq->data->error = -ENOMEDIUM;
- if (!mrq->stop)
- break;
- /* fall through */
+ case STATE_WAITING_NOTBUSY:
+ mrq->data->error = -ENOMEDIUM;
+ break;
case STATE_SENDING_STOP:
mrq->stop->error = -ENOMEDIUM;
break;
+ case STATE_END_REQUEST:
+ break;
}
atmci_request_end(host, mrq);
@@ -1487,7 +1471,6 @@ static void atmci_tasklet_func(unsigned long priv)
struct atmel_mci *host = (struct atmel_mci *)priv;
struct mmc_request *mrq = host->mrq;
struct mmc_data *data = host->data;
- struct mmc_command *cmd = host->cmd;
enum atmel_mci_state state = host->state;
enum atmel_mci_state prev_state;
u32 status;
@@ -1509,101 +1492,164 @@ static void atmci_tasklet_func(unsigned long priv)
break;
case STATE_SENDING_CMD:
+ /*
+ * Command has been sent, we are waiting for command
+ * ready. Then we have three next states possible:
+ * END_REQUEST by default, WAITING_NOTBUSY if it's a
+ * command needing it or DATA_XFER if there is data.
+ */
if (!atmci_test_and_clear_pending(host,
- EVENT_CMD_COMPLETE))
+ EVENT_CMD_RDY))
break;
host->cmd = NULL;
- atmci_set_completed(host, EVENT_CMD_COMPLETE);
+ atmci_set_completed(host, EVENT_CMD_RDY);
atmci_command_complete(host, mrq->cmd);
- if (!mrq->data || cmd->error) {
- atmci_request_end(host, host->mrq);
- goto unlock;
- }
+ if (mrq->data) {
+ /*
+ * If there is a command error don't start
+ * data transfer.
+ */
+ if (mrq->cmd->error) {
+ host->stop_transfer(host);
+ host->data = NULL;
+ atmci_writel(host, ATMCI_IDR,
+ ATMCI_TXRDY | ATMCI_RXRDY
+ | ATMCI_DATA_ERROR_FLAGS);
+ state = STATE_END_REQUEST;
+ } else
+ state = STATE_DATA_XFER;
+ } else if ((!mrq->data) && (mrq->cmd->flags & MMC_RSP_BUSY)) {
+ atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
+ state = STATE_WAITING_NOTBUSY;
+ } else
+ state = STATE_END_REQUEST;
- prev_state = state = STATE_SENDING_DATA;
- /* fall through */
+ break;
- case STATE_SENDING_DATA:
+ case STATE_DATA_XFER:
if (atmci_test_and_clear_pending(host,
EVENT_DATA_ERROR)) {
- host->stop_transfer(host);
- if (data->stop)
- atmci_send_stop_cmd(host, data);
- state = STATE_DATA_ERROR;
+ atmci_set_completed(host, EVENT_DATA_ERROR);
+ state = STATE_END_REQUEST;
break;
}
+ /*
+ * A data transfer is in progress. The event expected
+ * to move to the next state depends of data transfer
+ * type (PDC or DMA). Once transfer done we can move
+ * to the next step which is WAITING_NOTBUSY in write
+ * case and directly SENDING_STOP in read case.
+ */
if (!atmci_test_and_clear_pending(host,
EVENT_XFER_COMPLETE))
break;
atmci_set_completed(host, EVENT_XFER_COMPLETE);
- prev_state = state = STATE_DATA_BUSY;
- /* fall through */
- case STATE_DATA_BUSY:
- if (!atmci_test_and_clear_pending(host,
- EVENT_DATA_COMPLETE))
- break;
-
- host->data = NULL;
- atmci_set_completed(host, EVENT_DATA_COMPLETE);
- status = host->data_status;
- if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
- if (status & ATMCI_DTOE) {
- dev_dbg(&host->pdev->dev,
- "data timeout error\n");
- data->error = -ETIMEDOUT;
- } else if (status & ATMCI_DCRCE) {
- dev_dbg(&host->pdev->dev,
- "data CRC error\n");
- data->error = -EILSEQ;
- } else {
- dev_dbg(&host->pdev->dev,
- "data FIFO error (status=%08x)\n",
- status);
- data->error = -EIO;
- }
+ if (host->data->flags & MMC_DATA_WRITE) {
+ atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
+ state = STATE_WAITING_NOTBUSY;
+ } else if (host->mrq->stop) {
+ atmci_writel(host, ATMCI_IER, ATMCI_CMDRDY);
+ atmci_send_stop_cmd(host, data);
+ state = STATE_SENDING_STOP;
} else {
+ host->data = NULL;
data->bytes_xfered = data->blocks * data->blksz;
data->error = 0;
- atmci_writel(host, ATMCI_IDR, ATMCI_DATA_ERROR_FLAGS);
+ state = STATE_END_REQUEST;
}
+ break;
- if (!data->stop) {
- atmci_request_end(host, host->mrq);
- goto unlock;
- }
+ case STATE_WAITING_NOTBUSY:
+ /*
+ * We can be in the state for two reasons: a command
+ * requiring waiting not busy signal (stop command
+ * included) or a write operation. In the latest case,
+ * we need to send a stop command.
+ */
+ if (!atmci_test_and_clear_pending(host,
+ EVENT_NOTBUSY))
+ break;
- prev_state = state = STATE_SENDING_STOP;
- if (!data->error)
- atmci_send_stop_cmd(host, data);
- /* fall through */
+ atmci_set_completed(host, EVENT_NOTBUSY);
+
+ if (host->data) {
+ /*
+ * For some commands such as CMD53, even if
+ * there is data transfer, there is no stop
+ * command to send.
+ */
+ if (host->mrq->stop) {
+ atmci_writel(host, ATMCI_IER,
+ ATMCI_CMDRDY);
+ atmci_send_stop_cmd(host, data);
+ state = STATE_SENDING_STOP;
+ } else {
+ host->data = NULL;
+ data->bytes_xfered = data->blocks
+ * data->blksz;
+ data->error = 0;
+ state = STATE_END_REQUEST;
+ }
+ } else
+ state = STATE_END_REQUEST;
+ break;
case STATE_SENDING_STOP:
+ /*
+ * In this state, it is important to set host->data to
+ * NULL (which is tested in the waiting notbusy state)
+ * in order to go to the end request state instead of
+ * sending stop again.
+ */
if (!atmci_test_and_clear_pending(host,
- EVENT_CMD_COMPLETE))
+ EVENT_CMD_RDY))
break;
host->cmd = NULL;
+ host->data = NULL;
+ data->bytes_xfered = data->blocks * data->blksz;
+ data->error = 0;
atmci_command_complete(host, mrq->stop);
- atmci_request_end(host, host->mrq);
- goto unlock;
+ if (mrq->stop->error) {
+ host->stop_transfer(host);
+ atmci_writel(host, ATMCI_IDR,
+ ATMCI_TXRDY | ATMCI_RXRDY
+ | ATMCI_DATA_ERROR_FLAGS);
+ state = STATE_END_REQUEST;
+ } else {
+ atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY);
+ state = STATE_WAITING_NOTBUSY;
+ }
+ break;
- case STATE_DATA_ERROR:
- if (!atmci_test_and_clear_pending(host,
- EVENT_XFER_COMPLETE))
- break;
+ case STATE_END_REQUEST:
+ atmci_writel(host, ATMCI_IDR, ATMCI_TXRDY | ATMCI_RXRDY
+ | ATMCI_DATA_ERROR_FLAGS);
+ status = host->data_status;
+ if (unlikely(status)) {
+ host->stop_transfer(host);
+ host->data = NULL;
+ if (status & ATMCI_DTOE) {
+ data->error = -ETIMEDOUT;
+ } else if (status & ATMCI_DCRCE) {
+ data->error = -EILSEQ;
+ } else {
+ data->error = -EIO;
+ }
+ }
- state = STATE_DATA_BUSY;
+ atmci_request_end(host, host->mrq);
+ state = STATE_IDLE;
break;
}
} while (state != prev_state);
host->state = state;
-unlock:
spin_unlock(&host->lock);
}
@@ -1656,9 +1702,6 @@ static void atmci_read_data_pio(struct atmel_mci *host)
| ATMCI_DATA_ERROR_FLAGS));
host->data_status = status;
data->bytes_xfered += nbytes;
- smp_wmb();
- atmci_set_pending(host, EVENT_DATA_ERROR);
- tasklet_schedule(&host->tasklet);
return;
}
} while (status & ATMCI_RXRDY);
@@ -1727,9 +1770,6 @@ static void atmci_write_data_pio(struct atmel_mci *host)
| ATMCI_DATA_ERROR_FLAGS));
host->data_status = status;
data->bytes_xfered += nbytes;
- smp_wmb();
- atmci_set_pending(host, EVENT_DATA_ERROR);
- tasklet_schedule(&host->tasklet);
return;
}
} while (status & ATMCI_TXRDY);
@@ -1747,16 +1787,6 @@ done:
atmci_set_pending(host, EVENT_XFER_COMPLETE);
}
-static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
-{
- atmci_writel(host, ATMCI_IDR, ATMCI_CMDRDY);
-
- host->cmd_status = status;
- smp_wmb();
- atmci_set_pending(host, EVENT_CMD_COMPLETE);
- tasklet_schedule(&host->tasklet);
-}
-
static void atmci_sdio_interrupt(struct atmel_mci *host, u32 status)
{
int i;
@@ -1785,8 +1815,9 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id)
if (pending & ATMCI_DATA_ERROR_FLAGS) {
atmci_writel(host, ATMCI_IDR, ATMCI_DATA_ERROR_FLAGS
- | ATMCI_RXRDY | ATMCI_TXRDY);
- pending &= atmci_readl(host, ATMCI_IMR);
+ | ATMCI_RXRDY | ATMCI_TXRDY
+ | ATMCI_ENDRX | ATMCI_ENDTX
+ | ATMCI_RXBUFF | ATMCI_TXBUFE);
host->data_status = status;
smp_wmb();
@@ -1844,23 +1875,38 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id)
}
}
+ /*
+ * First mci IPs, so mainly the ones having pdc, have some
+ * issues with the notbusy signal. You can't get it after
+ * data transmission if you have not sent a stop command.
+ * The appropriate workaround is to use the BLKE signal.
+ */
+ if (pending & ATMCI_BLKE) {
+ atmci_writel(host, ATMCI_IDR, ATMCI_BLKE);
+ smp_wmb();
+ atmci_set_pending(host, EVENT_NOTBUSY);
+ tasklet_schedule(&host->tasklet);
+ }
if (pending & ATMCI_NOTBUSY) {
- atmci_writel(host, ATMCI_IDR,
- ATMCI_DATA_ERROR_FLAGS | ATMCI_NOTBUSY);
- if (!host->data_status)
- host->data_status = status;
+ atmci_writel(host, ATMCI_IDR, ATMCI_NOTBUSY);
smp_wmb();
- atmci_set_pending(host, EVENT_DATA_COMPLETE);
+ atmci_set_pending(host, EVENT_NOTBUSY);
tasklet_schedule(&host->tasklet);
}
+
if (pending & ATMCI_RXRDY)
atmci_read_data_pio(host);
if (pending & ATMCI_TXRDY)
atmci_write_data_pio(host);
- if (pending & ATMCI_CMDRDY)
- atmci_cmd_interrupt(host, status);
+ if (pending & ATMCI_CMDRDY) {
+ atmci_writel(host, ATMCI_IDR, ATMCI_CMDRDY);
+ host->cmd_status = status;
+ smp_wmb();
+ atmci_set_pending(host, EVENT_CMD_RDY);
+ tasklet_schedule(&host->tasklet);
+ }
if (pending & (ATMCI_SDIOIRQA | ATMCI_SDIOIRQB))
atmci_sdio_interrupt(host, status);
--
1.7.5.4
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