| Message ID | 1433412938-1761-1-git-send-email-yi.y.sun@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 4 June 2015 at 12:15, Yi Sun <yi.y.sun@intel.com> wrote: > Enhance Strobe is defined in v5.1 eMMC spec. This commit > is to implement it. Please elaborate in the change log. I want to understand what this commit does, at least in a more detailed summary and without having to read the eMMC spec. You may also describe *why* we want this. I have browsed through the code and seems okay, but I will make a more detailed review once I get a better change log. Kind regards Uffe > > Signed-off-by: Yi Sun <yi.y.sun@intel.com> > --- > drivers/mmc/core/mmc.c | 61 ++++++++++++++++++++++++++++++++++++++++++---- > include/linux/mmc/card.h | 1 + > include/linux/mmc/mmc.h | 2 ++ > 3 files changed, 59 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index e519e31..c9ef2de 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -585,6 +585,12 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd) > card->ext_csd.ffu_capable = > (ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) && > !(ext_csd[EXT_CSD_FW_CONFIG] & 0x1); > + > + /* Enhance Strobe is supported since v5.1 which rev should be > + * 8 but some eMMC devices can support it with rev 7. So handle > + * Enhance Strobe here. > + */ > + card->ext_csd.strobe_support = ext_csd[EXT_CSD_STROBE_SUPPORT]; > } > out: > return err; > @@ -1049,9 +1055,28 @@ static int mmc_select_hs400(struct mmc_card *card) > /* > * HS400 mode requires 8-bit bus width > */ > - if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > - host->ios.bus_width == MMC_BUS_WIDTH_8)) > - return 0; > + if (card->ext_csd.strobe_support) { > + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + host->caps & MMC_CAP_8_BIT_DATA)) > + return 0; > + > + /* For Enhance Strobe flow. For non Enhance Strobe, signal > + * voltage will not be set. > + */ > + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) > + err = __mmc_set_signal_voltage(host, > + MMC_SIGNAL_VOLTAGE_120); > + > + if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V) > + err = __mmc_set_signal_voltage(host, > + MMC_SIGNAL_VOLTAGE_180); > + if (err) > + return err; > + } else { > + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + host->ios.bus_width == MMC_BUS_WIDTH_8)) > + return 0; > + } > > /* > * Before switching to dual data rate operation for HS400, > @@ -1072,15 +1097,36 @@ static int mmc_select_hs400(struct mmc_card *card) > return err; > } > > + val = EXT_CSD_DDR_BUS_WIDTH_8; > + if (card->ext_csd.strobe_support) > + val |= EXT_CSD_BUS_WIDTH_STROBE; > err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > EXT_CSD_BUS_WIDTH, > - EXT_CSD_DDR_BUS_WIDTH_8, > + val, > card->ext_csd.generic_cmd6_time); > if (err) { > pr_err("%s: switch to bus width for hs400 failed, err:%d\n", > mmc_hostname(host), err); > return err; > } > + if (card->ext_csd.strobe_support) { > + mmc_set_bus_width(host, MMC_BUS_WIDTH_8); > + /* > + * If controller can't handle bus width test, > + * compare ext_csd previously read in 1 bit mode > + * against ext_csd at new bus width > + */ > + if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) > + err = mmc_compare_ext_csds(card, MMC_BUS_WIDTH_8); > + else > + err = mmc_bus_test(card, MMC_BUS_WIDTH_8); > + > + if (err) { > + pr_warn("%s: switch to bus width %d failed\n", > + mmc_hostname(host), MMC_BUS_WIDTH_8); > + return err; > + } > + } > > val = EXT_CSD_TIMING_HS400 | > card->drive_strength << EXT_CSD_DRV_STR_SHIFT; > @@ -1263,7 +1309,12 @@ static int mmc_select_timing(struct mmc_card *card) > if (!mmc_can_ext_csd(card)) > goto bus_speed; > > - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) > + /* For Enhance Strobe HS400 flow */ > + if (card->ext_csd.strobe_support && > + card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + card->host->caps & MMC_CAP_8_BIT_DATA) > + err = mmc_select_hs400(card); > + else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) > err = mmc_select_hs200(card); > else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) > err = mmc_select_hs(card); > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 4d3776d..b793b61 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -95,6 +95,7 @@ struct mmc_ext_csd { > u8 raw_partition_support; /* 160 */ > u8 raw_rpmb_size_mult; /* 168 */ > u8 raw_erased_mem_count; /* 181 */ > + u8 strobe_support; /* 184 */ > u8 raw_ext_csd_structure; /* 194 */ > u8 raw_card_type; /* 196 */ > u8 raw_driver_strength; /* 197 */ > diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h > index 15f2c4a..a1bb32c 100644 > --- a/include/linux/mmc/mmc.h > +++ b/include/linux/mmc/mmc.h > @@ -297,6 +297,7 @@ struct _mmc_csd { > #define EXT_CSD_PART_CONFIG 179 /* R/W */ > #define EXT_CSD_ERASED_MEM_CONT 181 /* RO */ > #define EXT_CSD_BUS_WIDTH 183 /* R/W */ > +#define EXT_CSD_STROBE_SUPPORT 184 /* RO */ > #define EXT_CSD_HS_TIMING 185 /* R/W */ > #define EXT_CSD_POWER_CLASS 187 /* R/W */ > #define EXT_CSD_REV 192 /* RO */ > @@ -386,6 +387,7 @@ struct _mmc_csd { > #define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */ > #define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */ > #define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */ > +#define EXT_CSD_BUS_WIDTH_STROBE 0x80 /* Card is in 8 bit DDR mode */ > > #define EXT_CSD_TIMING_BC 0 /* Backwards compatility */ > #define EXT_CSD_TIMING_HS 1 /* High speed */ > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On 06/04/2015 07:15 PM, Yi Sun wrote: > Enhance Strobe is defined in v5.1 eMMC spec. This commit > is to implement it. I know what enhance strobe is. I think good that there is more information for enhance strobe into commit message. > > Signed-off-by: Yi Sun <yi.y.sun@intel.com> > --- > drivers/mmc/core/mmc.c | 61 ++++++++++++++++++++++++++++++++++++++++++---- > include/linux/mmc/card.h | 1 + > include/linux/mmc/mmc.h | 2 ++ > 3 files changed, 59 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index e519e31..c9ef2de 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -585,6 +585,12 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd) > card->ext_csd.ffu_capable = > (ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) && > !(ext_csd[EXT_CSD_FW_CONFIG] & 0x1); > + > + /* Enhance Strobe is supported since v5.1 which rev should be > + * 8 but some eMMC devices can support it with rev 7. So handle > + * Enhance Strobe here. > + */ Fix the comment style. > + card->ext_csd.strobe_support = ext_csd[EXT_CSD_STROBE_SUPPORT]; > } > out: > return err; > @@ -1049,9 +1055,28 @@ static int mmc_select_hs400(struct mmc_card *card) > /* > * HS400 mode requires 8-bit bus width > */ > - if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > - host->ios.bus_width == MMC_BUS_WIDTH_8)) > - return 0; Why do you remove these? Can be remained? > + if (card->ext_csd.strobe_support) { > + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + host->caps & MMC_CAP_8_BIT_DATA)) > + return 0; What's difference between (host->ios.bus_width == MMC_BUS_WIDTH_8) and (host->caps & MMC_CAP_8_BIT_DATA)? > + > + /* For Enhance Strobe flow. For non Enhance Strobe, signal > + * voltage will not be set. > + */ > + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) > + err = __mmc_set_signal_voltage(host, > + MMC_SIGNAL_VOLTAGE_120); > + > + if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V) > + err = __mmc_set_signal_voltage(host, > + MMC_SIGNAL_VOLTAGE_180); > + if (err) > + return err; Doesn't need to return here? > + } else { > + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + host->ios.bus_width == MMC_BUS_WIDTH_8)) > + return 0; > + } > > /* > * Before switching to dual data rate operation for HS400, > @@ -1072,15 +1097,36 @@ static int mmc_select_hs400(struct mmc_card *card) > return err; > } > > + val = EXT_CSD_DDR_BUS_WIDTH_8; > + if (card->ext_csd.strobe_support) > + val |= EXT_CSD_BUS_WIDTH_STROBE; > err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > EXT_CSD_BUS_WIDTH, > - EXT_CSD_DDR_BUS_WIDTH_8, > + val, > card->ext_csd.generic_cmd6_time); > if (err) { > pr_err("%s: switch to bus width for hs400 failed, err:%d\n", > mmc_hostname(host), err); > return err; > } > + if (card->ext_csd.strobe_support) { > + mmc_set_bus_width(host, MMC_BUS_WIDTH_8); > + /* > + * If controller can't handle bus width test, > + * compare ext_csd previously read in 1 bit mode > + * against ext_csd at new bus width > + */ > + if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) > + err = mmc_compare_ext_csds(card, MMC_BUS_WIDTH_8); > + else > + err = mmc_bus_test(card, MMC_BUS_WIDTH_8); > + > + if (err) { > + pr_warn("%s: switch to bus width %d failed\n", > + mmc_hostname(host), MMC_BUS_WIDTH_8); > + return err; > + } > + } > > val = EXT_CSD_TIMING_HS400 | > card->drive_strength << EXT_CSD_DRV_STR_SHIFT; > @@ -1263,7 +1309,12 @@ static int mmc_select_timing(struct mmc_card *card) > if (!mmc_can_ext_csd(card)) > goto bus_speed; > > - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) > + /* For Enhance Strobe HS400 flow */ > + if (card->ext_csd.strobe_support && > + card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && > + card->host->caps & MMC_CAP_8_BIT_DATA) Could you modify more readable? > + err = mmc_select_hs400(card); > + else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) > err = mmc_select_hs200(card); > else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) > err = mmc_select_hs(card); > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 4d3776d..b793b61 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -95,6 +95,7 @@ struct mmc_ext_csd { > u8 raw_partition_support; /* 160 */ > u8 raw_rpmb_size_mult; /* 168 */ > u8 raw_erased_mem_count; /* 181 */ > + u8 strobe_support; /* 184 */ > u8 raw_ext_csd_structure; /* 194 */ > u8 raw_card_type; /* 196 */ > u8 raw_driver_strength; /* 197 */ > diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h > index 15f2c4a..a1bb32c 100644 > --- a/include/linux/mmc/mmc.h > +++ b/include/linux/mmc/mmc.h > @@ -297,6 +297,7 @@ struct _mmc_csd { > #define EXT_CSD_PART_CONFIG 179 /* R/W */ > #define EXT_CSD_ERASED_MEM_CONT 181 /* RO */ > #define EXT_CSD_BUS_WIDTH 183 /* R/W */ > +#define EXT_CSD_STROBE_SUPPORT 184 /* RO */ > #define EXT_CSD_HS_TIMING 185 /* R/W */ > #define EXT_CSD_POWER_CLASS 187 /* R/W */ > #define EXT_CSD_REV 192 /* RO */ > @@ -386,6 +387,7 @@ struct _mmc_csd { > #define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */ > #define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */ > #define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */ > +#define EXT_CSD_BUS_WIDTH_STROBE 0x80 /* Card is in 8 bit DDR mode */ Is Comment right? it's enhanced strobe bit. Best Regards, Jaehoon Chung > > #define EXT_CSD_TIMING_BC 0 /* Backwards compatility */ > #define EXT_CSD_TIMING_HS 1 /* High speed */ > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index e519e31..c9ef2de 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -585,6 +585,12 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd) card->ext_csd.ffu_capable = (ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) && !(ext_csd[EXT_CSD_FW_CONFIG] & 0x1); + + /* Enhance Strobe is supported since v5.1 which rev should be + * 8 but some eMMC devices can support it with rev 7. So handle + * Enhance Strobe here. + */ + card->ext_csd.strobe_support = ext_csd[EXT_CSD_STROBE_SUPPORT]; } out: return err; @@ -1049,9 +1055,28 @@ static int mmc_select_hs400(struct mmc_card *card) /* * HS400 mode requires 8-bit bus width */ - if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && - host->ios.bus_width == MMC_BUS_WIDTH_8)) - return 0; + if (card->ext_csd.strobe_support) { + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && + host->caps & MMC_CAP_8_BIT_DATA)) + return 0; + + /* For Enhance Strobe flow. For non Enhance Strobe, signal + * voltage will not be set. + */ + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) + err = __mmc_set_signal_voltage(host, + MMC_SIGNAL_VOLTAGE_120); + + if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V) + err = __mmc_set_signal_voltage(host, + MMC_SIGNAL_VOLTAGE_180); + if (err) + return err; + } else { + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && + host->ios.bus_width == MMC_BUS_WIDTH_8)) + return 0; + } /* * Before switching to dual data rate operation for HS400, @@ -1072,15 +1097,36 @@ static int mmc_select_hs400(struct mmc_card *card) return err; } + val = EXT_CSD_DDR_BUS_WIDTH_8; + if (card->ext_csd.strobe_support) + val |= EXT_CSD_BUS_WIDTH_STROBE; err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, - EXT_CSD_DDR_BUS_WIDTH_8, + val, card->ext_csd.generic_cmd6_time); if (err) { pr_err("%s: switch to bus width for hs400 failed, err:%d\n", mmc_hostname(host), err); return err; } + if (card->ext_csd.strobe_support) { + mmc_set_bus_width(host, MMC_BUS_WIDTH_8); + /* + * If controller can't handle bus width test, + * compare ext_csd previously read in 1 bit mode + * against ext_csd at new bus width + */ + if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) + err = mmc_compare_ext_csds(card, MMC_BUS_WIDTH_8); + else + err = mmc_bus_test(card, MMC_BUS_WIDTH_8); + + if (err) { + pr_warn("%s: switch to bus width %d failed\n", + mmc_hostname(host), MMC_BUS_WIDTH_8); + return err; + } + } val = EXT_CSD_TIMING_HS400 | card->drive_strength << EXT_CSD_DRV_STR_SHIFT; @@ -1263,7 +1309,12 @@ static int mmc_select_timing(struct mmc_card *card) if (!mmc_can_ext_csd(card)) goto bus_speed; - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) + /* For Enhance Strobe HS400 flow */ + if (card->ext_csd.strobe_support && + card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 && + card->host->caps & MMC_CAP_8_BIT_DATA) + err = mmc_select_hs400(card); + else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) err = mmc_select_hs200(card); else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) err = mmc_select_hs(card); diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 4d3776d..b793b61 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -95,6 +95,7 @@ struct mmc_ext_csd { u8 raw_partition_support; /* 160 */ u8 raw_rpmb_size_mult; /* 168 */ u8 raw_erased_mem_count; /* 181 */ + u8 strobe_support; /* 184 */ u8 raw_ext_csd_structure; /* 194 */ u8 raw_card_type; /* 196 */ u8 raw_driver_strength; /* 197 */ diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index 15f2c4a..a1bb32c 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -297,6 +297,7 @@ struct _mmc_csd { #define EXT_CSD_PART_CONFIG 179 /* R/W */ #define EXT_CSD_ERASED_MEM_CONT 181 /* RO */ #define EXT_CSD_BUS_WIDTH 183 /* R/W */ +#define EXT_CSD_STROBE_SUPPORT 184 /* RO */ #define EXT_CSD_HS_TIMING 185 /* R/W */ #define EXT_CSD_POWER_CLASS 187 /* R/W */ #define EXT_CSD_REV 192 /* RO */ @@ -386,6 +387,7 @@ struct _mmc_csd { #define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */ #define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */ #define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */ +#define EXT_CSD_BUS_WIDTH_STROBE 0x80 /* Card is in 8 bit DDR mode */ #define EXT_CSD_TIMING_BC 0 /* Backwards compatility */ #define EXT_CSD_TIMING_HS 1 /* High speed */
Enhance Strobe is defined in v5.1 eMMC spec. This commit is to implement it. Signed-off-by: Yi Sun <yi.y.sun@intel.com> --- drivers/mmc/core/mmc.c | 61 ++++++++++++++++++++++++++++++++++++++++++---- include/linux/mmc/card.h | 1 + include/linux/mmc/mmc.h | 2 ++ 3 files changed, 59 insertions(+), 5 deletions(-)