Commit df16219f authored by Giuseppe CAVALLARO's avatar Giuseppe CAVALLARO Committed by Chris Ball
Browse files

mmc: debugfs: expose the SDCLK frq in sys ios 



This patch is to expose the actual SDCLK frequency in
/sys/kernel/debug/mmcX/ios entry.

For example, if the max clk for a normal speed card is 20MHz this
is reported in /sys/kernel/debug/mmcX/ios.  Unfortunately the actual
SDCLK frequency (i.e. Baseclock / divisor) is not reported at all:
for example, in that case, on Arasan HC, it should be 48/4=12 (MHz).

Signed-off-by: default avatarGiuseppe Cavallaro <peppe.cavallaro@st.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 052d81da

drivers/mmc/core/debugfs.c

+2 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ static int mmc_ios_show(struct seq_file *s, void *data) 
	const char *str;



	seq_printf(s, "clock:\t\t%u Hz\n", ios->clock);

	if (host->actual_clock)

		seq_printf(s, "actual clock:\t%u Hz\n", host->actual_clock);

	seq_printf(s, "vdd:\t\t%u ", ios->vdd);

	if ((1 << ios->vdd) & MMC_VDD_165_195)

		seq_printf(s, "(1.65 - 1.95 V)\n");

drivers/mmc/host/sdhci.c

+10 −0
Original line number Diff line number Diff line
@@ -1066,12 +1066,15 @@ static void sdhci_finish_command(struct sdhci_host *host) 
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)

{

	int div = 0; /* Initialized for compiler warning */

	int real_div = div, clk_mul = 1;

	u16 clk = 0;

	unsigned long timeout;



	if (clock == host->clock)

		return;



	host->mmc->actual_clock = 0;



	if (host->ops->set_clock) {

		host->ops->set_clock(host, clock);

		if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
@@ -1109,6 +1112,8 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) 
				 * Control register.

				 */

				clk = SDHCI_PROG_CLOCK_MODE;

				real_div = div;

				clk_mul = host->clk_mul;

				div--;

			}

		} else {
@@ -1122,6 +1127,7 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) 
						break;

				}

			}

			real_div = div;

			div >>= 1;

		}

	} else {
@@ -1130,9 +1136,13 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) 
			if ((host->max_clk / div) <= clock)

				break;

		}

		real_div = div;

		div >>= 1;

	}



	if (real_div)

		host->mmc->actual_clock = (host->max_clk * clk_mul) / real_div;



	clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;

	clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)

		<< SDHCI_DIVIDER_HI_SHIFT;

include/linux/mmc/host.h

+2 −0
Original line number Diff line number Diff line
@@ -323,6 +323,8 @@ struct mmc_host { 
	struct fault_attr	fail_mmc_request;

#endif



	unsigned int		actual_clock;	/* Actual HC clock rate */



	unsigned long		private[0] ____cacheline_aligned;

};

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