From 22113efd00491310da802f3b1a9a66cfcf415fac Mon Sep 17 00:00:00 2001 From: Aries Lee Date: Wed, 15 Dec 2010 08:14:24 +0100 Subject: mmc: Test bus-width for old MMC devices Some old MMC devices fail with the 4/8 bits the driver tries to use exclusively. This patch adds a test for the given bus setup and falls back to the lower bit mode (until 1-bit mode) when the test fails. [Major rework and refactoring by tiwai] [Quirk addition and many fixes by prakity] Signed-off-by: Aries Lee Signed-off-by: Takashi Iwai Signed-off-by: Philip Rakity Tested-by: Philip Rakity Signed-off-by: Chris Ball --- drivers/mmc/core/mmc.c | 76 +++++++++++++++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 29 deletions(-) (limited to 'drivers/mmc/core/mmc.c') diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 76bb621..1d8409f 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -534,39 +534,57 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, */ if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) && (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) { - unsigned ext_csd_bit, bus_width; - - if (host->caps & MMC_CAP_8_BIT_DATA) { - if (ddr) - ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_8; - else - ext_csd_bit = EXT_CSD_BUS_WIDTH_8; - bus_width = MMC_BUS_WIDTH_8; - } else { - if (ddr) - ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_4; - else - ext_csd_bit = EXT_CSD_BUS_WIDTH_4; - bus_width = MMC_BUS_WIDTH_4; + static unsigned ext_csd_bits[][2] = { + { EXT_CSD_BUS_WIDTH_8, EXT_CSD_DDR_BUS_WIDTH_8 }, + { EXT_CSD_BUS_WIDTH_4, EXT_CSD_DDR_BUS_WIDTH_4 }, + { EXT_CSD_BUS_WIDTH_1, EXT_CSD_BUS_WIDTH_1 }, + }; + static unsigned bus_widths[] = { + MMC_BUS_WIDTH_8, + MMC_BUS_WIDTH_4, + MMC_BUS_WIDTH_1 + }; + unsigned idx, bus_width = 0; + + if (host->caps & MMC_CAP_8_BIT_DATA) + idx = 0; + else + idx = 1; + for (; idx < ARRAY_SIZE(bus_widths); idx++) { + bus_width = bus_widths[idx]; + if (bus_width == MMC_BUS_WIDTH_1) + ddr = 0; /* no DDR for 1-bit width */ + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_BUS_WIDTH, + ext_csd_bits[idx][0]); + if (!err) { + /* + * If controller can't handle bus width test, + * use the highest bus width to maintain + * compatibility with previous MMC behavior. + */ + if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) + break; + mmc_set_bus_width_ddr(card->host, + bus_width, MMC_SDR_MODE); + err = mmc_bus_test(card, bus_width); + if (!err) + break; + } } - err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_BUS_WIDTH, ext_csd_bit); - - if (err && err != -EBADMSG) - goto free_card; - + if (!err && ddr) { + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_BUS_WIDTH, + ext_csd_bits[idx][1]); + } if (err) { printk(KERN_WARNING "%s: switch to bus width %d ddr %d " - "failed\n", mmc_hostname(card->host), - 1 << bus_width, ddr); - err = 0; - } else { - if (ddr) - mmc_card_set_ddr_mode(card); - else - ddr = MMC_SDR_MODE; - + "failed\n", mmc_hostname(card->host), + 1 << bus_width, ddr); + goto free_card; + } else if (ddr) { + mmc_card_set_ddr_mode(card); mmc_set_bus_width_ddr(card->host, bus_width, ddr); } } -- cgit v1.1