2010/8/12 zhangfei gao <zhangfei.gao@xxxxxxxxx>:
[...]
> updated patch:
> From b17eb3ca9dd23af63ada240e8f77bdd873e853a7 Mon Sep 17 00:00:00 2001
> From: Zhangfei Gao <zgao6@xxxxxxxxxxx>
> Date: Fri, 6 Aug 2010 07:10:01 +0800
> Subject: [PATCH] sdhc: support 10-bit divided clock Mode
>
> Signed-off-by: Zhangfei Gao <zgao6@xxxxxxxxxxx>
> Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 16 ++++++++++++----
> drivers/mmc/host/sdhci.h | 4 ++++
> 2 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 7855121..ccfbc40 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 +1001,21 @@ 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->version >= SDHCI_SPEC_300)
> + max_div = 2046;
> + else
> + max_div = 256;
> +
> + if(host->max_clk <= clock)
> + div = 1;
> + 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_DIVIDER_SHIFT) << SDHCI_DIVIDER_SHIFT_HI;
I think the right shift is using wrong #define, SDHCI_DIVIDER_SHIFT
(position of the bitfield in the register). It has a correct value of
8, though. This could be something like the following to reduce
confusion.
clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN) <<
SDHCI_DIVIDER_SHIFT_HI;
...
#define SDHCI_DIV_MASK 0xFF
#define SDHCI_DIV_MASK_LEN 8
#define SDHCI_DIV_HI_MASK 0x300
or maybe:
clk |= ((div >> SDHCI_DIV_MASK_LEN) & SDHCI_DIV_HI_MASK) <<
SDHCI_DIVIDER_SHIFT_HI;
...
#define SDHCI_DIV_MASK 0xFF
#define SDHCI_DIV_MASK_LEN 8
#define SDHCI_DIV_HI_MASK 0x03
> clk |= SDHCI_CLOCK_INT_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>
[...]
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -86,6 +86,9 @@
>
> #define SDHCI_CLOCK_CONTROL 0x2C
> #define SDHCI_DIVIDER_SHIFT 8
> +#define SDHCI_DIVIDER_SHIFT_HI 6
> +#define SDHCI_DIV_MASK 0xFF
> +#define SDHCI_DIV_HI_MASK 0x300
> #define SDHCI_CLOCK_CARD_EN 0x0004
> #define SDHCI_CLOCK_INT_STABLE 0x0002
> #define SDHCI_CLOCK_INT_EN 0x0001
[...]
SDHCI_DIVIDER_SHIFT_HI -> SDHCI_DIVIDER_HI_SHIFT
Best Regards,
Michał Mirosław
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
