Re: [U-Boot] [PATCH 10/22] mmc: refactor MMC startup to make it easier to support new modes

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@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

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().