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mmc: at91_mci: fix hanging and rework to match flowcharts
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Fixes hanging using multi block operations (seen during CMD25).
Follows closely the datasheet flowcharts.

This piece of code handles better big file writing. I had to take care
of the notbusy signal during write (at91_mci_handle_cmdrdy function) and
to rearrange the AT91_MCI_ENDRX and AT91_MCI_RXBUFF flag usage.

Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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Nicolas Ferre authored and Pierre Ossman committed Jul 9, 2007
1 parent e8d04d3 commit ed99c54
Showing 1 changed file with 108 additions and 91 deletions.
199 changes: 108 additions & 91 deletions drivers/mmc/host/at91_mci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -78,8 +78,6 @@

#define DRIVER_NAME "at91_mci"

#undef SUPPORT_4WIRE

#define FL_SENT_COMMAND (1 << 0)
#define FL_SENT_STOP (1 << 1)

Expand Down Expand Up @@ -268,8 +266,6 @@ static void at91_mci_post_dma_read(struct at91mci_host *host)
}

while (host->in_use_index < host->transfer_index) {
unsigned int *buffer;

struct scatterlist *sg;

pr_debug("finishing index %d\n", host->in_use_index);
Expand All @@ -280,29 +276,31 @@ static void at91_mci_post_dma_read(struct at91mci_host *host)

dma_unmap_page(NULL, sg->dma_address, sg->length, DMA_FROM_DEVICE);

/* Swap the contents of the buffer */
buffer = kmap_atomic(sg->page, KM_BIO_SRC_IRQ) + sg->offset;
pr_debug("buffer = %p, length = %d\n", buffer, sg->length);

data->bytes_xfered += sg->length;

if (cpu_is_at91rm9200()) { /* AT91RM9200 errata */
unsigned int *buffer;
int index;

/* Swap the contents of the buffer */
buffer = kmap_atomic(sg->page, KM_BIO_SRC_IRQ) + sg->offset;
pr_debug("buffer = %p, length = %d\n", buffer, sg->length);

for (index = 0; index < (sg->length / 4); index++)
buffer[index] = swab32(buffer[index]);

kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
}

kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
flush_dcache_page(sg->page);
}

/* Is there another transfer to trigger? */
if (host->transfer_index < data->sg_len)
at91_mci_pre_dma_read(host);
else {
at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_ENDRX);
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_RXBUFF);
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
}

pr_debug("post dma read done\n");
Expand All @@ -323,26 +321,60 @@ static void at91_mci_handle_transmitted(struct at91mci_host *host)

/* Now wait for cmd ready */
at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_TXBUFE);
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);

cmd = host->cmd;
if (!cmd) return;

data = cmd->data;
if (!data) return;

if (cmd->data->flags & MMC_DATA_MULTI) {
pr_debug("multiple write : wait for BLKE...\n");
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_BLKE);
} else
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);

data->bytes_xfered = host->total_length;
}

/*Handle after command sent ready*/
static int at91_mci_handle_cmdrdy(struct at91mci_host *host)
{
if (!host->cmd)
return 1;
else if (!host->cmd->data) {
if (host->flags & FL_SENT_STOP) {
/*After multi block write, we must wait for NOTBUSY*/
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
} else return 1;
} else if (host->cmd->data->flags & MMC_DATA_WRITE) {
/*After sendding multi-block-write command, start DMA transfer*/
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_TXBUFE);
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_BLKE);
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
}

/* command not completed, have to wait */
return 0;
}


/*
* Enable the controller
*/
static void at91_mci_enable(struct at91mci_host *host)
{
unsigned int mr;

at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
at91_mci_write(host, AT91_MCI_IDR, 0xffffffff);
at91_mci_write(host, AT91_MCI_DTOR, AT91_MCI_DTOMUL_1M | AT91_MCI_DTOCYC);
at91_mci_write(host, AT91_MCI_MR, AT91_MCI_PDCMODE | 0x34a);
mr = AT91_MCI_PDCMODE | 0x34a;

if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
mr |= AT91_MCI_RDPROOF | AT91_MCI_WRPROOF;

at91_mci_write(host, AT91_MCI_MR, mr);

/* use Slot A or B (only one at same time) */
at91_mci_write(host, AT91_MCI_SDCR, host->board->slot_b);
Expand All @@ -358,9 +390,8 @@ static void at91_mci_disable(struct at91mci_host *host)

/*
* Send a command
* return the interrupts to enable
*/
static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_command *cmd)
static void at91_mci_send_command(struct at91mci_host *host, struct mmc_command *cmd)
{
unsigned int cmdr, mr;
unsigned int block_length;
Expand All @@ -371,8 +402,7 @@ static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_

host->cmd = cmd;

/* Not sure if this is needed */
#if 0
/* Needed for leaving busy state before CMD1 */
if ((at91_mci_read(host, AT91_MCI_SR) & AT91_MCI_RTOE) && (cmd->opcode == 1)) {
pr_debug("Clearing timeout\n");
at91_mci_write(host, AT91_MCI_ARGR, 0);
Expand All @@ -382,7 +412,7 @@ static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_
pr_debug("Clearing: SR = %08X\n", at91_mci_read(host, AT91_MCI_SR));
}
}
#endif

cmdr = cmd->opcode;

if (mmc_resp_type(cmd) == MMC_RSP_NONE)
Expand Down Expand Up @@ -439,50 +469,48 @@ static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_
at91_mci_write(host, ATMEL_PDC_TCR, 0);
at91_mci_write(host, ATMEL_PDC_TNPR, 0);
at91_mci_write(host, ATMEL_PDC_TNCR, 0);
ier = AT91_MCI_CMDRDY;
} else {
/* zero block length and PDC mode */
mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff;
at91_mci_write(host, AT91_MCI_MR, mr | (block_length << 16) | AT91_MCI_PDCMODE);

at91_mci_write(host, AT91_MCI_ARGR, cmd->arg);
at91_mci_write(host, AT91_MCI_CMDR, cmdr);
return AT91_MCI_CMDRDY;
}

mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff; /* zero block length and PDC mode */
at91_mci_write(host, AT91_MCI_MR, mr | (block_length << 16) | AT91_MCI_PDCMODE);

/*
* Disable the PDC controller
*/
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);

if (cmdr & AT91_MCI_TRCMD_START) {
data->bytes_xfered = 0;
host->transfer_index = 0;
host->in_use_index = 0;
if (cmdr & AT91_MCI_TRDIR) {
/*
* Handle a read
*/
host->buffer = NULL;
host->total_length = 0;

at91_mci_pre_dma_read(host);
ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
}
else {
/*
* Handle a write
*/
host->total_length = block_length * blocks;
host->buffer = dma_alloc_coherent(NULL,
host->total_length,
&host->physical_address, GFP_KERNEL);

at91_mci_sg_to_dma(host, data);

pr_debug("Transmitting %d bytes\n", host->total_length);
/*
* Disable the PDC controller
*/
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);

at91_mci_write(host, ATMEL_PDC_TPR, host->physical_address);
at91_mci_write(host, ATMEL_PDC_TCR, host->total_length / 4);
ier = AT91_MCI_TXBUFE;
if (cmdr & AT91_MCI_TRCMD_START) {
data->bytes_xfered = 0;
host->transfer_index = 0;
host->in_use_index = 0;
if (cmdr & AT91_MCI_TRDIR) {
/*
* Handle a read
*/
host->buffer = NULL;
host->total_length = 0;

at91_mci_pre_dma_read(host);
ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
}
else {
/*
* Handle a write
*/
host->total_length = block_length * blocks;
host->buffer = dma_alloc_coherent(NULL,
host->total_length,
&host->physical_address, GFP_KERNEL);

at91_mci_sg_to_dma(host, data);

pr_debug("Transmitting %d bytes\n", host->total_length);

at91_mci_write(host, ATMEL_PDC_TPR, host->physical_address);
at91_mci_write(host, ATMEL_PDC_TCR, host->total_length / 4);
ier = AT91_MCI_CMDRDY;
}
}
}

Expand All @@ -497,24 +525,9 @@ static unsigned int at91_mci_send_command(struct at91mci_host *host, struct mmc_
if (cmdr & AT91_MCI_TRCMD_START) {
if (cmdr & AT91_MCI_TRDIR)
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
else
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
}
return ier;
}

/*
* Wait for a command to complete
*/
static void at91_mci_process_command(struct at91mci_host *host, struct mmc_command *cmd)
{
unsigned int ier;

ier = at91_mci_send_command(host, cmd);

pr_debug("setting ier to %08X\n", ier);

/* Stop on errors or the required value */
/* Enable selected interrupts */
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_ERRORS | ier);
}

Expand All @@ -525,11 +538,11 @@ static void at91_mci_process_next(struct at91mci_host *host)
{
if (!(host->flags & FL_SENT_COMMAND)) {
host->flags |= FL_SENT_COMMAND;
at91_mci_process_command(host, host->request->cmd);
at91_mci_send_command(host, host->request->cmd);
}
else if ((!(host->flags & FL_SENT_STOP)) && host->request->stop) {
host->flags |= FL_SENT_STOP;
at91_mci_process_command(host, host->request->stop);
at91_mci_send_command(host, host->request->stop);
}
else
mmc_request_done(host->mmc, host->request);
Expand Down Expand Up @@ -698,29 +711,33 @@ static irqreturn_t at91_mci_irq(int irq, void *devid)
at91_mci_handle_transmitted(host);
}

if (int_status & AT91_MCI_ENDRX) {
pr_debug("ENDRX\n");
at91_mci_post_dma_read(host);
}

if (int_status & AT91_MCI_RXBUFF) {
pr_debug("RX buffer full\n");
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_CMDRDY);
at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_RXBUFF | AT91_MCI_ENDRX);
completed = 1;
}

if (int_status & AT91_MCI_ENDTX)
pr_debug("Transmit has ended\n");

if (int_status & AT91_MCI_ENDRX) {
pr_debug("Receive has ended\n");
at91_mci_post_dma_read(host);
}

if (int_status & AT91_MCI_NOTBUSY) {
pr_debug("Card is ready\n");
at91_mci_write(host, AT91_MCI_IER, AT91_MCI_CMDRDY);
completed = 1;
}

if (int_status & AT91_MCI_DTIP)
pr_debug("Data transfer in progress\n");

if (int_status & AT91_MCI_BLKE)
if (int_status & AT91_MCI_BLKE) {
pr_debug("Block transfer has ended\n");
completed = 1;
}

if (int_status & AT91_MCI_TXRDY)
pr_debug("Ready to transmit\n");
Expand All @@ -730,7 +747,7 @@ static irqreturn_t at91_mci_irq(int irq, void *devid)

if (int_status & AT91_MCI_CMDRDY) {
pr_debug("Command ready\n");
completed = 1;
completed = at91_mci_handle_cmdrdy(host);
}
}

Expand Down Expand Up @@ -830,11 +847,11 @@ static int __init at91_mci_probe(struct platform_device *pdev)
host->bus_mode = 0;
host->board = pdev->dev.platform_data;
if (host->board->wire4) {
#ifdef SUPPORT_4WIRE
mmc->caps |= MMC_CAP_4_BIT_DATA;
#else
printk("AT91 MMC: 4 wire bus mode not supported by this driver - using 1 wire\n");
#endif
if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
mmc->caps |= MMC_CAP_4_BIT_DATA;
else
printk("AT91 MMC: 4 wire bus mode not supported"
" - using 1 wire\n");
}

/*
Expand Down

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