On 12/22/2011 08:37 PM, Kishore Kadiyala wrote:

On Wed, Dec 14, 2011 at 6:52 PM, Daniel Mack [off-list ref] wrote:

quoted

External circuitry like level shifters may limit the maximum operation
speed of the hsmmc controller. Add a field to struct omap2_hsmmc_info
so boards can adjust the setting on demand.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/hsmmc.c   |    1 +
 arch/arm/mach-omap2/hsmmc.h   |    2 ++
 drivers/mmc/host/omap_hsmmc.c |    8 ++++++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
index f4a1020..4c7bc36 100644
--- a/arch/arm/mach-omap2/hsmmc.c
+++ b/arch/arm/mach-omap2/hsmmc.c

@@ -298,6 +298,7 @@ static int __init omap_hsmmc_pdata_init(struct omap2_hsmmc_info *c,
       mmc->slots[0].caps = c->caps;
       mmc->slots[0].internal_clock = !c->ext_clock;
       mmc->dma_mask = 0xffffffff;
+       mmc->max_freq = c->max_freq;
       if (cpu_is_omap44xx())
               mmc->reg_offset = OMAP4_MMC_REG_OFFSET;
       else

diff --git a/arch/arm/mach-omap2/hsmmc.h b/arch/arm/mach-omap2/hsmmc.h
index f757e78..65a8c12 100644
--- a/arch/arm/mach-omap2/hsmmc.h
+++ b/arch/arm/mach-omap2/hsmmc.h

@@ -25,6 +25,8 @@ struct omap2_hsmmc_info {
       char    *name;          /* or NULL for default */
       struct device *dev;     /* returned: pointer to mmc adapter */
       int     ocr_mask;       /* temporary HACK */
+       int     max_freq;       /* maximum clock, if constrained by external
+                                * circuitry, or 0 for default */
       /* Remux (pad configuration) when powering on/off */
       void (*remux)(struct device *dev, int slot, int power_on);
       /* init some special card */

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 101cd31..8215ef9 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c

@@ -1927,8 +1927,12 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
       if (mmc_slot(host).vcc_aux_disable_is_sleep)
               mmc_slot(host).no_off = 1;

-       mmc->f_min      = OMAP_MMC_MIN_CLOCK;
-       mmc->f_max      = OMAP_MMC_MAX_CLOCK;
+       mmc->f_min = OMAP_MMC_MIN_CLOCK;
+
+       if (pdata->max_freq > 0)

What about having check as below:
if (pdata->max_freq > 0 && pdata->max_freq < OMAP_MMC_MAX_CLOCK)

I can quickly do that if Tony agrees on it. Any opinions?

Thanks,
Daniel