On 10/20/2011 9:38 AM, Adrian Hunter wrote: > 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 Indeed, it 's better to not rename clock field for compatibility. ;-) > /sys/kernel/debug/mmcx/actual_clock > > or amend /sys/kernel/debug/mmcx/ios e.g. > > clock: 26000000 Hz (actual 25000000 Hz) ok I prefer the latter. Thanks Peppe > 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
