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path: root/drivers/mmc/host/sdhci.c
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Diffstat (limited to 'drivers/mmc/host/sdhci.c')
-rw-r--r--drivers/mmc/host/sdhci.c81
1 files changed, 66 insertions, 15 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a1ab2241588..07cca557c4b 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1013,8 +1013,8 @@ static void sdhci_finish_command(struct sdhci_host *host)
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
- int div;
- u16 clk;
+ int div = 0; /* Initialized for compiler warning */
+ u16 clk = 0;
unsigned long timeout;
if (clock == host->clock)
@@ -1032,14 +1032,45 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
goto out;
if (host->version >= SDHCI_SPEC_300) {
- /* Version 3.00 divisors must be a multiple of 2. */
- if (host->max_clk <= clock)
- div = 1;
- else {
- for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) {
- if ((host->max_clk / div) <= clock)
- break;
+ /*
+ * Check if the Host Controller supports Programmable Clock
+ * Mode.
+ */
+ if (host->clk_mul) {
+ u16 ctrl;
+
+ /*
+ * We need to figure out whether the Host Driver needs
+ * to select Programmable Clock Mode, or the value can
+ * be set automatically by the Host Controller based on
+ * the Preset Value registers.
+ */
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ if (!(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
+ for (div = 1; div <= 1024; div++) {
+ if (((host->max_clk * host->clk_mul) /
+ div) <= clock)
+ break;
+ }
+ /*
+ * Set Programmable Clock Mode in the Clock
+ * Control register.
+ */
+ clk = SDHCI_PROG_CLOCK_MODE;
+ div--;
+ }
+ } else {
+ /* Version 3.00 divisors must be a multiple of 2. */
+ if (host->max_clk <= clock)
+ div = 1;
+ else {
+ for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
+ div += 2) {
+ if ((host->max_clk / div) <= clock)
+ break;
+ }
}
+ div >>= 1;
}
} else {
/* Version 2.00 divisors must be a power of 2. */
@@ -1047,10 +1078,10 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
if ((host->max_clk / div) <= clock)
break;
}
+ div >>= 1;
}
- div >>= 1;
- clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+ clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
<< SDHCI_DIVIDER_HI_SHIFT;
clk |= SDHCI_CLOCK_INT_EN;
@@ -2308,17 +2339,37 @@ int sdhci_add_host(struct sdhci_host *host)
host->timeout_clk *= 1000;
/*
+ * In case of Host Controller v3.00, find out whether clock
+ * multiplier is supported.
+ */
+ host->clk_mul = (caps[1] & SDHCI_CLOCK_MUL_MASK) >>
+ SDHCI_CLOCK_MUL_SHIFT;
+
+ /*
+ * In case the value in Clock Multiplier is 0, then programmable
+ * clock mode is not supported, otherwise the actual clock
+ * multiplier is one more than the value of Clock Multiplier
+ * in the Capabilities Register.
+ */
+ if (host->clk_mul)
+ host->clk_mul += 1;
+
+ /*
* Set host parameters.
*/
mmc->ops = &sdhci_ops;
+ mmc->f_max = host->max_clk;
if (host->ops->get_min_clock)
mmc->f_min = host->ops->get_min_clock(host);
- else if (host->version >= SDHCI_SPEC_300)
- mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
- else
+ else if (host->version >= SDHCI_SPEC_300) {
+ if (host->clk_mul) {
+ mmc->f_min = (host->max_clk * host->clk_mul) / 1024;
+ mmc->f_max = host->max_clk * host->clk_mul;
+ } else
+ mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
+ } else
mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
- mmc->f_max = host->max_clk;
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE;
/*