diff options
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/core.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index df6ce4a06cf..1445ea8f10a 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -21,6 +21,7 @@ #include <linux/leds.h> #include <linux/scatterlist.h> #include <linux/log2.h> +#include <linux/regulator/consumer.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -523,6 +524,105 @@ u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max) } EXPORT_SYMBOL(mmc_vddrange_to_ocrmask); +#ifdef CONFIG_REGULATOR + +/** + * mmc_regulator_get_ocrmask - return mask of supported voltages + * @supply: regulator to use + * + * This returns either a negative errno, or a mask of voltages that + * can be provided to MMC/SD/SDIO devices using the specified voltage + * regulator. This would normally be called before registering the + * MMC host adapter. + */ +int mmc_regulator_get_ocrmask(struct regulator *supply) +{ + int result = 0; + int count; + int i; + + count = regulator_count_voltages(supply); + if (count < 0) + return count; + + for (i = 0; i < count; i++) { + int vdd_uV; + int vdd_mV; + + vdd_uV = regulator_list_voltage(supply, i); + if (vdd_uV <= 0) + continue; + + vdd_mV = vdd_uV / 1000; + result |= mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV); + } + + return result; +} +EXPORT_SYMBOL(mmc_regulator_get_ocrmask); + +/** + * mmc_regulator_set_ocr - set regulator to match host->ios voltage + * @vdd_bit: zero for power off, else a bit number (host->ios.vdd) + * @supply: regulator to use + * + * Returns zero on success, else negative errno. + * + * MMC host drivers may use this to enable or disable a regulator using + * a particular supply voltage. This would normally be called from the + * set_ios() method. + */ +int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit) +{ + int result = 0; + int min_uV, max_uV; + int enabled; + + enabled = regulator_is_enabled(supply); + if (enabled < 0) + return enabled; + + if (vdd_bit) { + int tmp; + int voltage; + + /* REVISIT mmc_vddrange_to_ocrmask() may have set some + * bits this regulator doesn't quite support ... don't + * be too picky, most cards and regulators are OK with + * a 0.1V range goof (it's a small error percentage). + */ + tmp = vdd_bit - ilog2(MMC_VDD_165_195); + if (tmp == 0) { + min_uV = 1650 * 1000; + max_uV = 1950 * 1000; + } else { + min_uV = 1900 * 1000 + tmp * 100 * 1000; + max_uV = min_uV + 100 * 1000; + } + + /* avoid needless changes to this voltage; the regulator + * might not allow this operation + */ + voltage = regulator_get_voltage(supply); + if (voltage < 0) + result = voltage; + else if (voltage < min_uV || voltage > max_uV) + result = regulator_set_voltage(supply, min_uV, max_uV); + else + result = 0; + + if (result == 0 && !enabled) + result = regulator_enable(supply); + } else if (enabled) { + result = regulator_disable(supply); + } + + return result; +} +EXPORT_SYMBOL(mmc_regulator_set_ocr); + +#endif + /* * Mask off any voltages we don't support and select * the lowest voltage |