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mmc: Test bus-width for old MMC devices

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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 <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Aries Lee
2010-12-15 08:14:24 +01:00
committed by Chris Ball
parent e6f29a8dc1
commit 22113efd00
7 changed files with 158 additions and 29 deletions
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74
drivers/mmc/core/mmc.c
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@@ -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;
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) {
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;
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);
}
}