From 85105c53b0ce70a277160379f9d89309cefc0bfd Mon Sep 17 00:00:00 2001 From: Zhangfei Gao Date: Fri, 6 Aug 2010 07:10:01 +0800 Subject: [PATCH] mmc: SDHC 3.0: support 10-bit divided clock mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Zhangfei Gao Cc: Michał Mirosław Cc: David Vrabel Reviewed-by: Matt Fleming Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci.c | 25 ++++++++++++++++++++----- drivers/mmc/host/sdhci.h | 5 +++++ 2 files changed, 25 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index e0536175185a..4432fec7467a 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1001,13 +1001,28 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) if (clock == 0) goto out; - for (div = 1;div < 256;div *= 2) { - if ((host->max_clk / div) <= clock) - break; + 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 < 2046; div += 2) { + if ((host->max_clk / div) <= clock) + break; + } + } + } else { + /* Version 2.00 divisors must be a power of 2. */ + for (div = 1; div < 256; div *= 2) { + if ((host->max_clk / div) <= clock) + break; + } } div >>= 1; - clk = div << 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; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); @@ -1708,7 +1723,7 @@ int sdhci_add_host(struct sdhci_host *host) host->version = sdhci_readw(host, SDHCI_HOST_VERSION); host->version = (host->version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT; - if (host->version > SDHCI_SPEC_200) { + if (host->version > SDHCI_SPEC_300) { printk(KERN_ERR "%s: Unknown controller version (%d). " "You may experience problems.\n", mmc_hostname(mmc), host->version); diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index d316bc79b636..950d4fd90072 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -86,6 +86,10 @@ #define SDHCI_CLOCK_CONTROL 0x2C #define SDHCI_DIVIDER_SHIFT 8 +#define SDHCI_DIVIDER_HI_SHIFT 6 +#define SDHCI_DIV_MASK 0xFF +#define SDHCI_DIV_MASK_LEN 8 +#define SDHCI_DIV_HI_MASK 0x300 #define SDHCI_CLOCK_CARD_EN 0x0004 #define SDHCI_CLOCK_INT_STABLE 0x0002 #define SDHCI_CLOCK_INT_EN 0x0001 @@ -178,6 +182,7 @@ #define SDHCI_SPEC_VER_SHIFT 0 #define SDHCI_SPEC_100 0 #define SDHCI_SPEC_200 1 +#define SDHCI_SPEC_300 2 struct sdhci_ops;