mmc: refactor MMC startup to make it easier to support new modes
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> Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Jean-Jacques Hiblot
Jaehoon Chung
parent
d0c221fe73
commit
3862b85474
@ -202,6 +202,7 @@ static int mmc_select_mode(struct mmc *mmc, enum bus_mode mode)
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{
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mmc->selected_mode = mode;
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mmc->tran_speed = mmc_mode2freq(mmc, mode);
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mmc->ddr_mode = mmc_is_mode_ddr(mode);
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debug("selecting mode %s (freq : %d MHz)\n", mmc_mode_name(mode),
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mmc->tran_speed / 1000000);
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return 0;
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@ -605,11 +606,47 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value)
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}
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static int mmc_change_freq(struct mmc *mmc)
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static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode)
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{
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ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
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char cardtype;
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int err;
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int speed_bits;
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ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
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switch (mode) {
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case MMC_HS:
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case MMC_HS_52:
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case MMC_DDR_52:
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speed_bits = EXT_CSD_TIMING_HS;
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case MMC_LEGACY:
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speed_bits = EXT_CSD_TIMING_LEGACY;
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break;
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default:
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return -EINVAL;
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}
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err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
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speed_bits);
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if (err)
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return err;
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if ((mode == MMC_HS) || (mode == MMC_HS_52)) {
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/* Now check to see that it worked */
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err = mmc_send_ext_csd(mmc, test_csd);
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if (err)
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return err;
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/* No high-speed support */
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if (!test_csd[EXT_CSD_HS_TIMING])
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return -ENOTSUPP;
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}
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return 0;
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}
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static int mmc_get_capabilities(struct mmc *mmc)
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{
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u8 *ext_csd = mmc->ext_csd;
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char cardtype;
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mmc->card_caps = MMC_MODE_1BIT;
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@ -620,38 +657,23 @@ static int mmc_change_freq(struct mmc *mmc)
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if (mmc->version < MMC_VERSION_4)
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return 0;
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if (!ext_csd) {
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printf("No ext_csd found!\n"); /* this should enver happen */
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return -ENOTSUPP;
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}
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mmc->card_caps |= MMC_MODE_4BIT | MMC_MODE_8BIT;
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err = mmc_send_ext_csd(mmc, ext_csd);
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if (err)
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return err;
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cardtype = ext_csd[EXT_CSD_CARD_TYPE] & 0xf;
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err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, 1);
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if (err)
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return err;
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/* Now check to see that it worked */
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err = mmc_send_ext_csd(mmc, ext_csd);
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if (err)
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return err;
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/* No high-speed support */
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if (!ext_csd[EXT_CSD_HS_TIMING])
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return 0;
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/* High Speed is set, there are two types: 52MHz and 26MHz */
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if (cardtype & EXT_CSD_CARD_TYPE_52) {
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if (cardtype & EXT_CSD_CARD_TYPE_DDR_1_8V)
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if (cardtype & EXT_CSD_CARD_TYPE_DDR_52)
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mmc->card_caps |= MMC_MODE_DDR_52MHz;
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mmc->card_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
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} else {
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mmc->card_caps |= MMC_MODE_HS;
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mmc->card_caps |= MMC_MODE_HS_52MHz;
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}
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if (cardtype & EXT_CSD_CARD_TYPE_26)
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mmc->card_caps |= MMC_MODE_HS;
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return 0;
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}
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@ -1334,33 +1356,60 @@ static int mmc_read_and_compare_ext_csd(struct mmc *mmc)
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return -EBADMSG;
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}
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static int mmc_select_bus_freq_width(struct mmc *mmc)
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{
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/* An array of possible bus widths in order of preference */
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static const unsigned int ext_csd_bits[] = {
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EXT_CSD_DDR_BUS_WIDTH_8,
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EXT_CSD_DDR_BUS_WIDTH_4,
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EXT_CSD_BUS_WIDTH_8,
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EXT_CSD_BUS_WIDTH_4,
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EXT_CSD_BUS_WIDTH_1,
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};
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/* An array to map CSD bus widths to host cap bits */
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static const unsigned int ext_to_hostcaps[] = {
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[EXT_CSD_DDR_BUS_WIDTH_4] =
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MMC_MODE_DDR_52MHz | MMC_MODE_4BIT,
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[EXT_CSD_DDR_BUS_WIDTH_8] =
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MMC_MODE_DDR_52MHz | MMC_MODE_8BIT,
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[EXT_CSD_BUS_WIDTH_4] = MMC_MODE_4BIT,
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[EXT_CSD_BUS_WIDTH_8] = MMC_MODE_8BIT,
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};
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/* An array to map chosen bus width to an integer */
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static const unsigned int widths[] = {
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8, 4, 8, 4, 1,
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};
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int err;
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int idx;
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static const struct mode_width_tuning mmc_modes_by_pref[] = {
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{
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.mode = MMC_HS_200,
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.widths = MMC_MODE_8BIT | MMC_MODE_4BIT,
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},
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{
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.mode = MMC_DDR_52,
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.widths = MMC_MODE_8BIT | MMC_MODE_4BIT,
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},
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{
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.mode = MMC_HS_52,
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.widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
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},
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{
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.mode = MMC_HS,
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.widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
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},
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{
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.mode = MMC_LEGACY,
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.widths = MMC_MODE_8BIT | MMC_MODE_4BIT | MMC_MODE_1BIT,
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}
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};
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err = mmc_change_freq(mmc);
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#define for_each_mmc_mode_by_pref(caps, mwt) \
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for (mwt = mmc_modes_by_pref;\
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mwt < mmc_modes_by_pref + ARRAY_SIZE(mmc_modes_by_pref);\
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mwt++) \
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if (caps & MMC_CAP(mwt->mode))
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static const struct ext_csd_bus_width {
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uint cap;
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bool is_ddr;
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uint ext_csd_bits;
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} ext_csd_bus_width[] = {
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{MMC_MODE_8BIT, true, EXT_CSD_DDR_BUS_WIDTH_8},
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{MMC_MODE_4BIT, true, EXT_CSD_DDR_BUS_WIDTH_4},
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{MMC_MODE_8BIT, false, EXT_CSD_BUS_WIDTH_8},
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{MMC_MODE_4BIT, false, EXT_CSD_BUS_WIDTH_4},
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{MMC_MODE_1BIT, false, EXT_CSD_BUS_WIDTH_1},
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};
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#define for_each_supported_width(caps, ddr, ecbv) \
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for (ecbv = ext_csd_bus_width;\
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ecbv < ext_csd_bus_width + ARRAY_SIZE(ext_csd_bus_width);\
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ecbv++) \
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if ((ddr == ecbv->is_ddr) && (caps & ecbv->cap))
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static int mmc_select_mode_and_width(struct mmc *mmc)
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{
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int err;
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const struct mode_width_tuning *mwt;
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const struct ext_csd_bus_width *ecbw;
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err = mmc_get_capabilities(mmc);
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if (err)
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return err;
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@ -1376,54 +1425,58 @@ static int mmc_select_bus_freq_width(struct mmc *mmc)
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return -ENOTSUPP;
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}
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for (idx = 0; idx < ARRAY_SIZE(ext_csd_bits); idx++) {
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unsigned int extw = ext_csd_bits[idx];
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unsigned int caps = ext_to_hostcaps[extw];
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/*
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* If the bus width is still not changed,
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* don't try to set the default again.
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* Otherwise, recover from switch attempts
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* by switching to 1-bit bus width.
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*/
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if (extw == EXT_CSD_BUS_WIDTH_1 &&
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mmc->bus_width == 1) {
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err = 0;
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break;
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for_each_mmc_mode_by_pref(mmc->card_caps, mwt) {
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for_each_supported_width(mmc->card_caps & mwt->widths,
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mmc_is_mode_ddr(mwt->mode), ecbw) {
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debug("trying mode %s width %d (at %d MHz)\n",
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mmc_mode_name(mwt->mode),
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bus_width(ecbw->cap),
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mmc_mode2freq(mmc, mwt->mode) / 1000000);
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/* configure the bus width (card + host) */
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err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
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EXT_CSD_BUS_WIDTH,
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ecbw->ext_csd_bits & ~EXT_CSD_DDR_FLAG);
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if (err)
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goto error;
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mmc_set_bus_width(mmc, bus_width(ecbw->cap));
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/* configure the bus speed (card) */
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err = mmc_set_card_speed(mmc, mwt->mode);
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if (err)
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goto error;
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/*
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* configure the bus width AND the ddr mode (card)
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* The host side will be taken care of in the next step
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*/
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if (ecbw->ext_csd_bits & EXT_CSD_DDR_FLAG) {
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err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
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EXT_CSD_BUS_WIDTH,
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ecbw->ext_csd_bits);
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if (err)
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goto error;
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}
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/* configure the bus mode (host) */
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mmc_select_mode(mmc, mwt->mode);
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mmc_set_clock(mmc, mmc->tran_speed);
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/* do a transfer to check the configuration */
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err = mmc_read_and_compare_ext_csd(mmc);
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if (!err)
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return 0;
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error:
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/* if an error occured, revert to a safer bus mode */
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mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
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EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_1);
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mmc_select_mode(mmc, MMC_LEGACY);
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mmc_set_bus_width(mmc, 1);
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}
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/*
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* Check to make sure the card and controller support
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* these capabilities
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*/
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if ((mmc->card_caps & caps) != caps)
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continue;
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err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
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EXT_CSD_BUS_WIDTH, extw);
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if (err)
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continue;
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mmc->ddr_mode = (caps & MMC_MODE_DDR_52MHz) ? 1 : 0;
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mmc_set_bus_width(mmc, widths[idx]);
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err = mmc_read_and_compare_ext_csd(mmc);
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if (!err)
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break;
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}
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if (err)
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return err;
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printf("unable to select a mode\n");
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if (mmc->card_caps & MMC_MODE_HS_52MHz) {
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if (mmc->ddr_mode)
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mmc_select_mode(mmc, MMC_DDR_52);
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else
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mmc_select_mode(mmc, MMC_HS_52);
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} else if (mmc->card_caps & MMC_MODE_HS)
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mmc_select_mode(mmc, MMC_HS);
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return err;
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return -ENOTSUPP;
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}
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static int mmc_startup_v4(struct mmc *mmc)
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@ -1762,7 +1815,7 @@ static int mmc_startup(struct mmc *mmc)
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if (IS_SD(mmc))
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err = sd_select_mode_and_width(mmc);
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else
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err = mmc_select_bus_freq_width(mmc);
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err = mmc_select_mode_and_width(mmc);
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if (err)
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return err;
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@ -215,7 +215,10 @@
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#define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */
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#define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */
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#define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */
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#define EXT_CSD_DDR_FLAG BIT(2) /* Flag for DDR mode */
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#define EXT_CSD_TIMING_LEGACY 0 /* no high speed */
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#define EXT_CSD_TIMING_HS 1 /* HS */
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#define EXT_CSD_BOOT_ACK_ENABLE (1 << 6)
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#define EXT_CSD_BOOT_PARTITION_ENABLE (1 << 3)
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#define EXT_CSD_PARTITION_ACCESS_ENABLE (1 << 0)
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@ -429,6 +432,14 @@ enum bus_mode {
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const char *mmc_mode_name(enum bus_mode mode);
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void mmc_dump_capabilities(const char *text, uint caps);
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static inline bool mmc_is_mode_ddr(enum bus_mode mode)
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{
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if ((mode == MMC_DDR_52) || (mode == UHS_DDR50))
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return true;
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else
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return false;
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}
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/*
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* With CONFIG_DM_MMC enabled, struct mmc can be accessed from the MMC device
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* with mmc_get_mmc_dev().
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