[U-Boot] [PATCH 10/22] mmc: refactor MMC startup to make it easier to support new modes
Jaehoon Chung
jh80.chung at samsung.com
Fri May 26 01:12:05 UTC 2017
On 05/25/2017 11:40 PM, Jean-Jacques Hiblot wrote:
> Hi,
>
>
> On 25/05/2017 14:25, Jaehoon Chung wrote:
>> On 05/13/2017 03:16 AM, Jean-Jacques Hiblot wrote:
>>> The MMC startup process currently handles 4 modes. To make it easier to
>>> add support for more modes, let's make the process more generic and use a
>>> list of the modes to try.
>>> The major functional change is that when a mode fails we try the next one.
>>> Not all modes are tried, only those supported by the card and the host.
>>>
>>> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
>>> ---
>>> drivers/mmc/mmc.c | 238 +++++++++++++++++++++++++++++++++---------------------
>>> include/mmc.h | 15 +++-
>>> 2 files changed, 157 insertions(+), 96 deletions(-)
>>>
>>> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
>>> index f42a0fe..2931871 100644
>>> --- a/drivers/mmc/mmc.c
>>> +++ b/drivers/mmc/mmc.c
>>> @@ -200,6 +200,7 @@ static int mmc_select_mode(struct mmc *mmc, enum bus_mode mode)
>>> {
>>> mmc->selected_mode = mode;
>>> mmc->tran_speed = mmc_mode2freq(mmc, mode);
>>> + mmc->ddr_mode = mmc_is_mode_ddr(mode);
>>> debug("selecting mode %s (freq : %d MHz)\n", mmc_mode_name(mode),
>>> mmc->tran_speed / 1000000);
>>> return 0;
>>> @@ -602,11 +603,46 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value)
>>> }
>>> -static int mmc_change_freq(struct mmc *mmc)
>>> +static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode)
>>> {
>>> - ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
>>> - char cardtype;
>>> int err;
>>> + int speed_bits;
>>> + ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
>>> +
>>> + switch (mode) {
>>> + case MMC_HS:
>>> + case MMC_HS_52:
>>> + case MMC_DDR_52:
>>> + speed_bits = EXT_CSD_TIMING_HS;
>>> + case MMC_LEGACY:
>>> + speed_bits = EXT_CSD_TIMING_LEGACY;
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> + err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
>>> + speed_bits);
>>> + if (err)
>>> + return err;
>>> +
>>> + if ((mode == MMC_HS) || (mode == MMC_HS_52)) {
>>> + /* Now check to see that it worked */
>>> + err = mmc_send_ext_csd(mmc, test_csd);
>>> + if (err)
>>> + return err;
>>> +
>>> + /* No high-speed support */
>>> + if (!test_csd[EXT_CSD_HS_TIMING])
>>> + return -ENOTSUPP;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mmc_get_capabilities(struct mmc *mmc)
>>> +{
>>> + u8 *ext_csd = mmc->ext_csd;
>>> + char cardtype;
>>> mmc->card_caps = MMC_MODE_1BIT;
>>> @@ -617,38 +653,23 @@ static int mmc_change_freq(struct mmc *mmc)
>>> if (mmc->version < MMC_VERSION_4)
>>> return 0;
>>> - mmc->card_caps |= MMC_MODE_4BIT | MMC_MODE_8BIT;
>>> -
>>> - err = mmc_send_ext_csd(mmc, ext_csd);
>>> + if (!ext_csd) {
>>> + error("No ext_csd found!\n"); /* this should enver happen */
>>> + return -ENOTSUPP;
>>> + }
>>> - if (err)
>>> - return err;
>>> + mmc->card_caps |= MMC_MODE_4BIT | MMC_MODE_8BIT;
>>> cardtype = ext_csd[EXT_CSD_CARD_TYPE] & 0xf;
>>> - err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, 1);
>>> -
>>> - if (err)
>>> - return err;
>>> -
>>> - /* Now check to see that it worked */
>>> - err = mmc_send_ext_csd(mmc, ext_csd);
>>> -
>>> - if (err)
>>> - return err;
>>> -
>>> - /* No high-speed support */
>>> - if (!ext_csd[EXT_CSD_HS_TIMING])
>>> - return 0;
>>> -
>>> /* High Speed is set, there are two types: 52MHz and 26MHz */
>>> if (cardtype & EXT_CSD_CARD_TYPE_52) {
>>> - if (cardtype & EXT_CSD_CARD_TYPE_DDR_1_8V)
>>> + if (cardtype & EXT_CSD_CARD_TYPE_DDR_52)
>>> mmc->card_caps |= MMC_MODE_DDR_52MHz;
>>> - mmc->card_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
>>> - } else {
>>> - mmc->card_caps |= MMC_MODE_HS;
>>> + mmc->card_caps |= MMC_MODE_HS_52MHz;
>>> }
>>> + if (cardtype & EXT_CSD_CARD_TYPE_26)
>>> + mmc->card_caps |= MMC_MODE_HS;
>>> return 0;
>>> }
>>> @@ -1320,33 +1341,58 @@ static int mmc_read_and_compare_ext_csd(struct mmc *mmc)
>>> }
>>> -static int mmc_select_bus_freq_width(struct mmc *mmc)
>>> +static const struct mode_width_tuning mmc_modes_by_pref[] = {
>>> + {
>>> + .mode = MMC_HS_200,
>>> + .widths = MMC_MODE_8BIT | MMC_MODE_4BIT,
>>> + },
>>> + {
>>> + .mode = MMC_DDR_52,
>>> + .widths = MMC_MODE_8BIT | MMC_MODE_4BIT,
>>> + },
>>> + {
>>> + .mode = MMC_HS_52,
>>> + .widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
>>> + },
>>> + {
>>> + .mode = MMC_HS,
>>> + .widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
>>> + },
>>> + {
>>> + .mode = MMC_LEGACY,
>>> + .widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
>>> + }
>>> +};
>>> +#define for_each_mmc_mode_by_pref(caps, mwt) \
>>> + for (mwt = mmc_modes_by_pref;\
>>> + mwt < mmc_modes_by_pref + ARRAY_SIZE(mmc_modes_by_pref);\
>>> + mwt++) \
>>> + if (caps & MMC_CAP(mwt->mode))
>>> +
>>> +static const struct ext_csd_bus_width {
>>> + uint cap;
>>> + bool is_ddr;
>>> + uint ext_csd_bits;
>>> +} ext_csd_bus_width[] = {
>>> + {MMC_MODE_8BIT, true, EXT_CSD_BUS_WIDTH_8 | EXT_CSD_DDR},
>>> + {MMC_MODE_4BIT, true, EXT_CSD_BUS_WIDTH_4 | EXT_CSD_DDR},
>>> + {MMC_MODE_8BIT, false, EXT_CSD_BUS_WIDTH_8},
>>> + {MMC_MODE_4BIT, false, EXT_CSD_BUS_WIDTH_4},
>>> + {MMC_MODE_1BIT, false, EXT_CSD_BUS_WIDTH_1},
>>> +};
>>> +#define for_each_supported_width(caps, ddr, ecbv) \
>>> + for (ecbv = ext_csd_bus_width;\
>>> + ecbv < ext_csd_bus_width + ARRAY_SIZE(ext_csd_bus_width);\
>>> + ecbv++) \
>>> + if ((ddr == ecbv->is_ddr) && (caps & ecbv->cap))
>>> +
>>> +static int mmc_select_mode_and_width(struct mmc *mmc)
>>> {
>>> - /* An array of possible bus widths in order of preference */
>>> - static const unsigned ext_csd_bits[] = {
>>> - EXT_CSD_DDR_BUS_WIDTH_8,
>>> - EXT_CSD_DDR_BUS_WIDTH_4,
>>> - EXT_CSD_BUS_WIDTH_8,
>>> - EXT_CSD_BUS_WIDTH_4,
>>> - EXT_CSD_BUS_WIDTH_1,
>>> - };
>>> - /* An array to map CSD bus widths to host cap bits */
>>> - static const unsigned ext_to_hostcaps[] = {
>>> - [EXT_CSD_DDR_BUS_WIDTH_4] =
>>> - MMC_MODE_DDR_52MHz | MMC_MODE_4BIT,
>>> - [EXT_CSD_DDR_BUS_WIDTH_8] =
>>> - MMC_MODE_DDR_52MHz | MMC_MODE_8BIT,
>>> - [EXT_CSD_BUS_WIDTH_4] = MMC_MODE_4BIT,
>>> - [EXT_CSD_BUS_WIDTH_8] = MMC_MODE_8BIT,
>>> - };
>>> - /* An array to map chosen bus width to an integer */
>>> - static const unsigned widths[] = {
>>> - 8, 4, 8, 4, 1,
>>> - };
>>> int err;
>>> - int idx;
>>> + const struct mode_width_tuning *mwt;
>>> + const struct ext_csd_bus_width *ecbw;
>>> - err = mmc_change_freq(mmc);
>>> + err = mmc_get_capabilities(mmc);
>>> if (err)
>>> return err;
>>> @@ -1357,60 +1403,64 @@ static int mmc_select_bus_freq_width(struct mmc *mmc)
>>> if (mmc->version < MMC_VERSION_4)
>>> return 0;
>>> +
>>> if (!mmc->ext_csd) {
>>> error("No ext_csd found!\n"); /* this should enver happen */
>>> return -ENOTSUPP;
>>> }
>>> - for (idx = 0; idx < ARRAY_SIZE(ext_csd_bits); idx++) {
>>> - unsigned int extw = ext_csd_bits[idx];
>>> - unsigned int caps = ext_to_hostcaps[extw];
>>> + for_each_mmc_mode_by_pref(mmc->card_caps, mwt) {
>>> + for_each_supported_width(mmc->card_caps & mwt->widths,
>>> + mmc_is_mode_ddr(mwt->mode), ecbw) {
>>> + debug("trying mode %s width %d (at %d MHz)\n",
>>> + mmc_mode_name(mwt->mode),
>>> + bus_width(ecbw->cap),
>>> + mmc_mode2freq(mmc, mwt->mode) / 1000000);
>>> - /*
>>> - * If the bus width is still not changed,
>>> - * don't try to set the default again.
>>> - * Otherwise, recover from switch attempts
>>> - * by switching to 1-bit bus width.
>>> - */
>>> - if (extw == EXT_CSD_BUS_WIDTH_1 &&
>>> - mmc->bus_width == 1) {
>>> - err = 0;
>>> - break;
>>> - }
>>> -
>>> - /*
>>> - * Check to make sure the card and controller support
>>> - * these capabilities
>>> - */
>>> - if ((mmc->card_caps & caps) != caps)
>>> - continue;
>>> -
>>> - err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
>>> - EXT_CSD_BUS_WIDTH, extw);
>>> + /* configure the bus width (card + host) */
>>> + err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
>>> + EXT_CSD_BUS_WIDTH,
>>> + ecbw->ext_csd_bits & ~EXT_CSD_DDR);
>>> + if (err)
>>> + goto error;
>>> + mmc_set_bus_width(mmc, bus_width(ecbw->cap));
>>> - if (err)
>>> - continue;
>>> + /* configure the bus speed (card) */
>>> + err = mmc_set_card_speed(mmc, mwt->mode);
>>> + if (err)
>>> + goto error;
>>> +
>>> + /*
>>> + * configure the bus width AND the ddr mode (card)
>>> + * The host side will be taken care of in the next step
>>> + */
>>> + if (ecbw->ext_csd_bits & EXT_CSD_DDR) {
>>> + err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
>>> + EXT_CSD_BUS_WIDTH, ecbw->ext_csd_bits);
>>> + if (err)
>>> + goto error;
>>> + }
>>> - mmc->ddr_mode = (caps & MMC_MODE_DDR_52MHz) ? 1 : 0;
>>> - mmc_set_bus_width(mmc, widths[idx]);
>>> + /* configure the bus mode (host) */
>>> + mmc_select_mode(mmc, mwt->mode);
>>> + mmc_set_clock(mmc, mmc->tran_speed);
>>> - err = mmc_read_and_compare_ext_csd(mmc);
>>> - if (!err)
>>> - break;
>>> + /* do a transfer to check the configuration */
>>> + err = mmc_read_and_compare_ext_csd(mmc);
>>> + if (!err)
>>> + return 0;
>>> +error:
>>> + /* if an error occured, revert to a safer bus mode */
>>> + mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
>>> + EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_1);
>>> + mmc_select_mode(mmc, MMC_LEGACY);
>>> + mmc_set_bus_width(mmc, 1);
>>> + }
>>> }
>>> - if (err)
>>> - return err;
>>> -
>>> - if (mmc->card_caps & MMC_MODE_HS_52MHz) {
>>> - if (mmc->ddr_mode)
>>> - mmc_select_mode(mmc, MMC_DDR_52);
>>> - else
>>> - mmc_select_mode(mmc, MMC_HS_52);
>>> - } else if (mmc->card_caps & MMC_MODE_HS)
>>> - mmc_select_mode(mmc, MMC_HS);
>>> + error("unable to select a mode\n");
>>> - return err;
>>> + return -ENOTSUPP;
>>> }
>>> static int mmc_startup_v4(struct mmc *mmc)
>>> @@ -1747,7 +1797,7 @@ static int mmc_startup(struct mmc *mmc)
>>> if (IS_SD(mmc))
>>> err = sd_select_mode_and_width(mmc);
>>> else
>>> - err = mmc_select_bus_freq_width(mmc);
>>> + err = mmc_select_mode_and_width(mmc);
>>> if (err)
>>> return err;
>>> diff --git a/include/mmc.h b/include/mmc.h
>>> index 1ffa7ec..3c6971d 100644
>>> --- a/include/mmc.h
>>> +++ b/include/mmc.h
>>> @@ -213,9 +213,10 @@
>>> #define EXT_CSD_BUS_WIDTH_1 0 /* Card is in 1 bit mode */
>>> #define EXT_CSD_BUS_WIDTH_4 1 /* Card is in 4 bit mode */
>>> #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_DDR 4 /* Card is in DDR mode */
>> Why do you change to 4 as DDR mode?
> It's a flag to add to EXT_CSD_BUS_WIDTH_x. for example EXT_CSD_BUS_WIDTH_4 | EXT_CSD_DDR = 1 | 4 = 5
I want to maintain the original flag values..because it's specified value at spec.
Someone can confuse about value 4 when just see this define.
(According to spec, value 4 is reserved.)
Best Regards,
Jaehoon Chung
>
> JJ
>>
>>> +#define EXT_CSD_TIMING_LEGACY 0 /* no high speed */
>>> +#define EXT_CSD_TIMING_HS 1 /* HS */
>>> #define EXT_CSD_BOOT_ACK_ENABLE (1 << 6)
>>> #define EXT_CSD_BOOT_PARTITION_ENABLE (1 << 3)
>>> #define EXT_CSD_PARTITION_ACCESS_ENABLE (1 << 0)
>>> @@ -424,6 +425,16 @@ enum bus_mode {
>>> const char *mmc_mode_name(enum bus_mode mode);
>>> void mmc_dump_capabilities(const char *text, uint caps);
>>> +
>>> +static inline bool mmc_is_mode_ddr(enum bus_mode mode)
>>> +{
>>> + if ((mode == MMC_DDR_52) || (mode == UHS_DDR50))
>>> + return true;
>>> + else
>>> + return false;
>>> +}
>>> +
>>> +
>>> /*
>>> * With CONFIG_DM_MMC enabled, struct mmc can be accessed from the MMC device
>>> * with mmc_get_mmc_dev().
>>>
>>
>
>
>
>
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