diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/core/mmc.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 7adc30d..c2334d6 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -532,6 +532,86 @@ static struct device_type mmc_type = { }; /* + * Select the PowerClass for the current bus width + * If power class is defined for 4/8 bit bus in the + * extended CSD register, select it by executing the + * mmc_switch command. + */ +static int mmc_select_powerclass(struct mmc_card *card, + unsigned int bus_width, u8 *ext_csd) +{ + int err = 0; + unsigned int pwrclass_val; + unsigned int index = 0; + struct mmc_host *host; + + BUG_ON(!card); + + host = card->host; + BUG_ON(!host); + + if (ext_csd == NULL) + return 0; + + /* Power class selection is supported for versions >= 4.0 */ + if (card->csd.mmca_vsn < CSD_SPEC_VER_4) + return 0; + + /* Power class values are defined only for 4/8 bit bus */ + if (bus_width == EXT_CSD_BUS_WIDTH_1) + return 0; + + switch (1 << host->ios.vdd) { + case MMC_VDD_165_195: + if (host->ios.clock <= 26000000) + index = EXT_CSD_PWR_CL_26_195; + else if (host->ios.clock <= 52000000) + index = (bus_width <= EXT_CSD_BUS_WIDTH_8) ? + EXT_CSD_PWR_CL_52_195 : + EXT_CSD_PWR_CL_DDR_52_195; + else if (host->ios.clock <= 200000000) + index = EXT_CSD_PWR_CL_200_195; + break; + case MMC_VDD_32_33: + case MMC_VDD_33_34: + case MMC_VDD_34_35: + case MMC_VDD_35_36: + if (host->ios.clock <= 26000000) + index = EXT_CSD_PWR_CL_26_360; + else if (host->ios.clock <= 52000000) + index = (bus_width <= EXT_CSD_BUS_WIDTH_8) ? + EXT_CSD_PWR_CL_52_360 : + EXT_CSD_PWR_CL_DDR_52_360; + else if (host->ios.clock <= 200000000) + index = EXT_CSD_PWR_CL_200_360; + break; + default: + pr_warning("%s: Voltage range not supported " + "for power class.\n", mmc_hostname(host)); + return -EINVAL; + } + + pwrclass_val = ext_csd[index]; + + if (bus_width & (EXT_CSD_BUS_WIDTH_8 | EXT_CSD_DDR_BUS_WIDTH_8)) + pwrclass_val = (pwrclass_val & EXT_CSD_PWR_CL_8BIT_MASK) >> + EXT_CSD_PWR_CL_8BIT_SHIFT; + else + pwrclass_val = (pwrclass_val & EXT_CSD_PWR_CL_4BIT_MASK) >> + EXT_CSD_PWR_CL_4BIT_SHIFT; + + /* If the power class is different from the default value */ + if (pwrclass_val > 0) { + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_POWER_CLASS, + pwrclass_val, + 0); + } + + return err; +} + +/* * Handle the detection and initialisation of a card. * * In the case of a resume, "oldcard" will contain the card @@ -787,6 +867,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, bus_width = bus_widths[idx]; if (bus_width == MMC_BUS_WIDTH_1) ddr = 0; /* no DDR for 1-bit width */ + err = mmc_select_powerclass(card, ext_csd_bits[idx][0], + ext_csd); + if (err) + pr_err("%s: power class selection to " + "bus width %d failed\n", + mmc_hostname(card->host), + 1 << bus_width); + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, ext_csd_bits[idx][0], @@ -810,6 +898,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, } if (!err && ddr) { + err = mmc_select_powerclass(card, ext_csd_bits[idx][1], + ext_csd); + if (err) + pr_err("%s: power class selection to " + "bus width %d ddr %d failed\n", + mmc_hostname(card->host), + 1 << bus_width, ddr); + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, ext_csd_bits[idx][1], |