On Mon, Aug 9, 2010 at 6:10 PM, Matt Fleming <matt@xxxxxxxxxxxxxxxxx> wrote: > On Thu, Aug 05, 2010 at 03:09:14PM +0800, zhangfei gao wrote: >> >> >> >> 1. support 8 bit data transfer width >> > 8 bit buswidth patch is already merged to mm tree. >> > >> > http://marc.info/?l=linux-mmc&m=127783663526810&w=3 >> > >> > Thank you, >> > Kyungmin Park >> > >> >> Thanks Kyungmin, updated without 8 bit support. >> >> From 2b717444443acdac90c5f31522a1515a2000749a 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> >> --- >> drivers/mmc/host/sdhci.c | 5 +++-- >> drivers/mmc/host/sdhci.h | 4 ++++ >> 2 files changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index c6d1bd8..212dc9e 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -1002,7 +1002,8 @@ static void sdhci_set_clock(struct sdhci_host >> *host, unsigned int clock) >> } >> 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; >> clk |= SDHCI_CLOCK_INT_EN; >> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); >> > > This patch is missing a change to the way we calculate 'div'. While your > patch is correct, I think it would be better to fit some more things > into it. > > This is the current code for calculating the clock divider, > > > for (div = 1;div < 256;div *= 2) { > if ((host->max_clk / div) <= clock) > break; > } > div >>= 1; > > clk = div << SDHCI_DIVIDER_SHIFT; > > > even with your patch applied 'div' will never be greater 256 and we > won't be executing your changes. So I think this patch also needs to > bump the upper limit of 'div' to 2046. > > We should probably introduce some safety at this point and check that > the divider value is legal for the version of the host controller, to > stop people shooting themselves in the foot if they mess up their clock > settings. I was thinking of something like, > > if (host->version >= SDHCI_SPEC_300) > max_div = 2046; > else > max_div = 256; > > for (div = 1;div < max_div;div *= 2) { > if ((host->max_clk / div) <= clock) > break; > } > > What do you think? > Thanks for your careful review, in our platform, we use max/min for the max_div, so miss this modification :( Update the patch, help review again. >From 4b0a4d60fb39437a7fde7e52fb769fa0110c052f 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 | 14 ++++++++++---- drivers/mmc/host/sdhci.h | 4 ++++ 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index c6d1bd8..c4b3d6f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -978,7 +978,7 @@ 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; @@ -996,13 +996,19 @@ 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; + + for (div = 1;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; clk |= SDHCI_CLOCK_INT_EN; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); @@ -1681,7 +1687,7 @@ 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 c846813..7c09b4f 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -85,6 +85,9 @@ #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 @@ -177,6 +180,7 @@ #define SDHCI_SPEC_VER_SHIFT 0 #define SDHCI_SPEC_100 0 #define SDHCI_SPEC_200 1 +#define SDHCI_SPEC_300 2 struct sdhci_ops; -- 1.6.0.4
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0001-sdhc-support-10-bit-divided-clock-Mode.patch
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