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mmc: mmci: add hardware busy timeout feature 

In the stm32_sdmmc variant, the datatimer is active not only during
data transfers with the DPSM, but also while waiting for the busyend
IRQs from commands having the MMC_RSP_BUSY flag set. This leads to an
incorrect IRQ being raised to signal MCI_DATATIMEOUT error, which
simply breaks the behaviour.

Address this by updating the datatimer value before sending a command
having the MMC_RSP_BUSY flag set. To inform the mmc core about the
maximum supported busy timeout, which also depends on the current
clock rate, set ->max_busy_timeout (in ms).

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Ludovic Barre 2019-10-08 11:56:02 +02:00 committed by Ulf Hansson
parent e2b98d83ff
commit 8266c585f4
2 changed files with 40 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/mmc/host/mmci.c
View File

@ -1075,6 +1075,7 @@ static void
mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
{
void __iomem *base = host->base;
unsigned long long clks;
dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
cmd->opcode, cmd->arg, cmd->flags);
@ -1097,6 +1098,16 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
else
c |= host->variant->cmdreg_srsp;
}
if (host->variant->busy_timeout && cmd->flags & MMC_RSP_BUSY) {
if (!cmd->busy_timeout)
cmd->busy_timeout = 10 * MSEC_PER_SEC;
clks = (unsigned long long)cmd->busy_timeout * host->cclk;
do_div(clks, MSEC_PER_SEC);
writel_relaxed(clks, host->base + MMCIDATATIMER);
}
if (/*interrupt*/0)
c |= MCI_CPSM_INTERRUPT;
@ -1201,6 +1212,7 @@ static void
mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
unsigned int status)
{
u32 err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT;
void __iomem *base = host->base;
bool sbc, busy_resp;
@ -1215,8 +1227,11 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
* handling. Note that we tag on any latent IRQs postponed
* due to waiting for busy status.
*/
if (!((status|host->busy_status) &
(MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND)))
if (host->variant->busy_timeout && busy_resp)
err_msk |= MCI_DATATIMEOUT;
if (!((status | host->busy_status) &
(err_msk | MCI_CMDSENT | MCI_CMDRESPEND)))
return;
/* Handle busy detection on DAT0 if the variant supports it. */
@ -1235,8 +1250,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
* while, to allow it to be set, but tests indicates that it
* isn't needed.
*/
if (!host->busy_status &&
!(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
if (!host->busy_status && !(status & err_msk) &&
(readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
writel(readl(base + MMCIMASK0) |
@ -1290,6 +1304,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
cmd->error = -ETIMEDOUT;
} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
cmd->error = -EILSEQ;
} else if (host->variant->busy_timeout && busy_resp &&
status & MCI_DATATIMEOUT) {
cmd->error = -ETIMEDOUT;
} else {
cmd->resp[0] = readl(base + MMCIRESPONSE0);
cmd->resp[1] = readl(base + MMCIRESPONSE1);
@ -1583,6 +1600,20 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
spin_unlock_irqrestore(&host->lock, flags);
}
static void mmci_set_max_busy_timeout(struct mmc_host *mmc)
{
struct mmci_host *host = mmc_priv(mmc);
u32 max_busy_timeout = 0;
if (!host->variant->busy_detect)
return;
if (host->variant->busy_timeout && mmc->actual_clock)
max_busy_timeout = ~0UL / (mmc->actual_clock / MSEC_PER_SEC);
mmc->max_busy_timeout = max_busy_timeout;
}
static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct mmci_host *host = mmc_priv(mmc);
@ -1687,6 +1718,8 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
else
mmci_set_clkreg(host, ios->clock);
mmci_set_max_busy_timeout(mmc);
if (host->ops && host->ops->set_pwrreg)
host->ops->set_pwrreg(host, pwr);
else
@ -1957,7 +1990,6 @@ static int mmci_probe(struct amba_device *dev,
mmci_write_datactrlreg(host,
host->variant->busy_dpsm_flag);
mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
mmc->max_busy_timeout = 0;
}
/* Prepare a CMD12 - needed to clear the DPSM on some variants. */

3
drivers/mmc/host/mmci.h
View File

@ -287,6 +287,8 @@ struct mmci_host;
* @signal_direction: input/out direction of bus signals can be indicated
* @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
* @busy_detect: true if the variant supports busy detection on DAT0.
* @busy_timeout: true if the variant starts data timer when the DPSM
* enter in Wait_R or Busy state.
* @busy_dpsm_flag: bitmask enabling busy detection in the DPSM
* @busy_detect_flag: bitmask identifying the bit in the MMCISTATUS register
* indicating that the card is busy
@ -333,6 +335,7 @@ struct variant_data {
u8 signal_direction:1;
u8 pwrreg_clkgate:1;
u8 busy_detect:1;
u8 busy_timeout:1;
u32 busy_dpsm_flag;
u32 busy_detect_flag;
u32 busy_detect_mask;