On Thu, May 5, 2011 at 2:48 AM, Arindam Nath <arindam.n...@amd.com> wrote: > SD cards which conform to Physical Layer Spec v3.01 can support > additional Bus Speed Modes, Driver Strength, and Current Limit > other than the default values. We use CMD6 mode 0 to read these > additional card functions. The values read here will be used > during UHS-I initialization steps. > > Signed-off-by: Arindam Nath <arindam.n...@amd.com> > Reviewed-by: Philip Rakity <prak...@marvell.com> > Tested-by: Philip Rakity <prak...@marvell.com>
Acked-by: Zhangfei Gao<zhangfei....@marvell.com> Verified with Toshiba uhs card and general hs card, on mmp2 in SDMA mode. > --- > drivers/mmc/core/sd.c | 69 ++++++++++++++++++++++++++++++++++++++++----- > include/linux/mmc/card.h | 4 ++ > 2 files changed, 65 insertions(+), 8 deletions(-) > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > index b0cd285..d4410c9 100644 > --- a/drivers/mmc/core/sd.c > +++ b/drivers/mmc/core/sd.c > @@ -189,6 +189,9 @@ static int mmc_decode_scr(struct mmc_card *card) > > scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4); > scr->bus_widths = UNSTUFF_BITS(resp, 48, 4); > + if (scr->sda_vsn == SCR_SPEC_VER_2) > + /* Check if Physical Layer Spec v3.0 is supported*/ > + scr->sda_spec3 = UNSTUFF_BITS(resp, 47, 1); > > if (UNSTUFF_BITS(resp, 55, 1)) > card->erased_byte = 0xFF; > @@ -278,25 +281,75 @@ static int mmc_read_switch(struct mmc_card *card) > return -ENOMEM; > } > > + /* Find out the supported Bus Speed Modes. */ > err = mmc_sd_switch(card, 0, 0, 1, status); > if (err) { > - /* If the host or the card can't do the switch, > - * fail more gracefully. */ > + /* > + * If the host or the card can't do the switch, > + * fail more gracefully. > + */ > if ((err != -EINVAL) > - && (err != -ENOSYS) > - && (err != -EFAULT)) > + && (err != -ENOSYS) > + && (err != -EFAULT)) > goto out; > > - printk(KERN_WARNING "%s: problem reading switch " > - "capabilities, performance might suffer.\n", > + printk(KERN_WARNING "%s: problem reading Bus Speed modes.\n", > mmc_hostname(card->host)); > err = 0; > > goto out; > } > > - if (status[13] & 0x02) > - card->sw_caps.hs_max_dtr = 50000000; > + if (card->scr.sda_spec3) { > + card->sw_caps.sd3_bus_mode = status[13]; > + > + /* Find out Driver Strengths supported by the card */ > + err = mmc_sd_switch(card, 0, 2, 1, status); > + if (err) { > + /* > + * If the host or the card can't do the switch, > + * fail more gracefully. > + */ > + if ((err != -EINVAL) > + && (err != -ENOSYS) > + && (err != -EFAULT)) > + goto out; > + > + printk(KERN_WARNING "%s: problem reading " > + "Driver Strength.\n", > + mmc_hostname(card->host)); > + err = 0; > + > + goto out; > + } > + > + card->sw_caps.sd3_drv_type = status[9]; > + > + /* Find out Current Limits supported by the card */ > + err = mmc_sd_switch(card, 0, 3, 1, status); > + if (err) { > + /* > + * If the host or the card can't do the switch, > + * fail more gracefully. > + */ > + if ((err != -EINVAL) > + && (err != -ENOSYS) > + && (err != -EFAULT)) > + goto out; > + > + printk(KERN_WARNING "%s: problem reading " > + "Current Limit.\n", > + mmc_hostname(card->host)); > + err = 0; > + > + goto out; > + } > + > + card->sw_caps.sd3_curr_limit = status[7]; > + } else { > + if (status[13] & 0x02) > + card->sw_caps.hs_max_dtr = 50000000; > + } > > out: > kfree(status); > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 72a9868..56f4d92 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -67,6 +67,7 @@ struct mmc_ext_csd { > > struct sd_scr { > unsigned char sda_vsn; > + unsigned char sda_spec3; > unsigned char bus_widths; > #define SD_SCR_BUS_WIDTH_1 (1<<0) > #define SD_SCR_BUS_WIDTH_4 (1<<2) > @@ -80,6 +81,9 @@ struct sd_ssr { > > struct sd_switch_caps { > unsigned int hs_max_dtr; > + unsigned int sd3_bus_mode; > + unsigned int sd3_drv_type; > + unsigned int sd3_curr_limit; > }; > > struct sdio_cccr { > -- > 1.7.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html