On Mon, Aug 16, 2010 at 9:41 AM, zhangfei gao <[email protected]> wrote:
> From fd40adef6ce474d5323edcaa833f675b0eb649cb Mon Sep 17 00:00:00 2001
> From: Zhangfei Gao <[email protected]>
> Date: Fri, 6 Aug 2010 07:10:01 +0800
> Subject: [PATCH] sdhci: support 10-bit divided clock Mode
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> Cc: Matt Fleming <[email protected]>
> Cc: Michał Mirosław <[email protected]>
> Signed-off-by: Zhangfei Gao <[email protected]>
> ---
> drivers/mmc/host/sdhci.c | 22 ++++++++++++++++------
> drivers/mmc/host/sdhci.h | 5 +++++
> 2 files changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 913555e..32dcac9 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -983,7 +983,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
>
> static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> {
> - int div;
> + int div, max_div;
> u16 clk;
> unsigned long timeout;
>
> @@ -1001,13 +1001,23 @@ 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)
> + max_div = 2046;
> + else
> + max_div = 256;
> +
> + if(host->max_clk <= clock)
> + div = 1;
> + else {
> + for (div = 2; div < max_div; 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);
>
> @@ -1707,7 +1717,7 @@ 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 036cfae..50860dc 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;
>
> --
> 1.7.0.4
>
The v2 fix add else condition to v1
if(host->max_clk <= clock)
div = 1;
> + else {
--
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