On 20/10/11 09:31, Giuseppe CAVALLARO wrote: > Hello Adrian > > On 10/20/2011 8:22 AM, Adrian Hunter wrote: >> On 19/10/11 16:45, Giuseppe CAVALLARO wrote: >>> This patch is to expose the SDCLK frequency in the ios /sys entry. >>> >>> For example, if the max clk for a normal speed card is 20MHz >>> this will be reported in /sys/kernel/debug/mmc0/ios instead of >>> the real SDCLK frequency (calculated as Baseclock / divisor; >>> divisor used for programming the Clock Control Register). >>> >>> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx> >>> --- >>> drivers/mmc/host/sdhci.c | 9 ++++++++- >>> 1 files changed, 8 insertions(+), 1 deletions(-) >>> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >>> index 0e02cc1..6bdf64f 100644 >>> --- a/drivers/mmc/host/sdhci.c >>> +++ b/drivers/mmc/host/sdhci.c >>> @@ -1045,6 +1045,7 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) >>> int div = 0; /* Initialized for compiler warning */ >>> u16 clk = 0; >>> unsigned long timeout; >>> + unsigned int new_hc_clock = host->max_clk; >>> >>> if (clock == host->clock) >>> return; >>> @@ -1134,7 +1135,10 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) >>> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); >>> >>> out: >>> - host->clock = clock; >>> + if (div) >>> + new_hc_clock = host->max_clk / div; >> >> At this point div is the value written to the register not the >> divisor > > Hmm, you are right. I'll fix it. > >>> + >>> + host->clock = new_hc_clock; >>> } >>> >>> static void sdhci_set_power(struct sdhci_host *host, unsigned short power) >>> @@ -1293,6 +1297,9 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) >>> >>> sdhci_set_clock(host, ios->clock); >>> >>> + /* Clock provided to the HC */ >>> + ios->clock = host->clock; >> >> It would be nicer to keep ios->clock as the target >> frequency and add a new member to struct mmc_host for >> the actual frequency. > > Why not! I like it. I'll rework the patch and send it again. > Just a question: do I have to dump both in /sys/.../ios? > If yes, maybe it's worth using: card_clock and hc_clock as names. > What do you think? For me hc_clock is confusing. Potentially the host controller has lots of clocks e.g. interface clock, functional clock, debounce clock Also, I would not rename anything. You could add /sys/kernel/debug/mmcx/actual_clock or amend /sys/kernel/debug/mmcx/ios e.g. clock: 26000000 Hz (actual 25000000 Hz) vdd: 17 (2.9 ~ 3.0 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 0 (legacy) > > Regards > Peppe > >> >>> + >>> if (ios->power_mode == MMC_POWER_OFF) >>> sdhci_set_power(host, -1); >>> else >> >> > > -- 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
