From: David Brownell <[email protected]> Add optional glue between MMC and regulator stacks, using a new regulator interface to learn what voltages are available.
This is intended to be selected and driven by MMC host adapters. It only handles reusable parts of the regulator-to-MMC glue; the adapter drivers will have access to details that affect how this is used. Examples include when to use multiple voltage rails or configure (internal or external) level shifters. Signed-off-by: David Brownell <[email protected]> --- Changes from previous version: adapter must select this, and callers now pass in the regulator. mmc_regulator_set_ocr() is still not tested, mmc_regulator_get_ocrmask() passed sanity testing. Pierre: Mark may have a need for this soonish. The omap_hsmmc code will want it at some point. drivers/mmc/core/Kconfig | 7 +++ drivers/mmc/core/core.c | 84 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/mmc/host.h | 5 ++ 3 files changed, 96 insertions(+) --- a/drivers/mmc/core/Kconfig +++ b/drivers/mmc/core/Kconfig @@ -14,3 +14,10 @@ config MMC_UNSAFE_RESUME This option is usually just for embedded systems which use a MMC/SD card for rootfs. Most people should say N here. +config MMC_REGULATOR + bool + depends on REGULATOR + help + Select this if your MMC host adapter driver wants helper + utilities for accessing power rails. + --- 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 +524,89 @@ u32 mmc_vddrange_to_ocrmask(int vdd_min, } EXPORT_SYMBOL(mmc_vddrange_to_ocrmask); +#ifdef CONFIG_MMC_REGULATOR + +/** + * mmc_regulator_get_ocrmask - return mask of supported voltages + * @host: mmc host whose supply will be consulted + * @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 mmc_host *host, 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 + * @host: mmc host whose supply voltage will be changed + * @supply: regulator to use + * + * 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 mmc_host *host, struct regulator *supply) +{ + int result = 0; + int min_mV, max_mV; + int enabled; + + enabled = regulator_is_enabled(supply); + if (enabled < 0) + return enabled; + + if (host->ios.vdd) { + int tmp; + + tmp = host->ios.vdd - ilog2(MMC_VDD_165_195); + if (tmp == 0) { + min_mV = 1650; + max_mV = 1950; + } else { + min_mV = 2000 + tmp * 100; + max_mV = min_mV + 100; + } + + result = regulator_set_voltage(supply, + min_mV * 1000, max_mV * 1000); + 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 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -192,5 +192,10 @@ static inline void mmc_signal_sdio_irq(s wake_up_process(host->sdio_irq_thread); } +struct regulator; + +int mmc_regulator_get_ocrmask(struct mmc_host *host, struct regulator *supply); +int mmc_regulator_set_ocr(struct mmc_host *host, struct regulator *supply); + #endif -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
