diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-of-esdhc.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-esdhc.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index e328252ebf2a..0b249970b119 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -199,6 +199,14 @@ static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host) static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) { + + int pre_div = 2; + int div = 1; + u32 temp; + + if (clock == 0) + goto out; + /* Workaround to reduce the clock frequency for p1010 esdhc */ if (of_find_compatible_node(NULL, NULL, "fsl,p1010-esdhc")) { if (clock > 20000000) @@ -207,8 +215,31 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) clock -= 5000000; } - /* Set the clock */ - esdhc_set_clock(host, clock, host->max_clk); + temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL); + temp &= ~(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN + | ESDHC_CLOCK_MASK); + sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL); + + while (host->max_clk / pre_div / 16 > clock && pre_div < 256) + pre_div *= 2; + + while (host->max_clk / pre_div / div > clock && div < 16) + div++; + + dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n", + clock, host->max_clk / pre_div / div); + + pre_div >>= 1; + div--; + + temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL); + temp |= (ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN + | (div << ESDHC_DIVIDER_SHIFT) + | (pre_div << ESDHC_PREDIV_SHIFT)); + sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL); + mdelay(1); +out: + host->clock = clock; } #ifdef CONFIG_PM |