// SPDX-License-Identifier: GPL-2.0 /* * Helper functions for MMC regulators. */ #include #include #include #include #include #include "core.h" #include "host.h" #ifdef CONFIG_REGULATOR /** * mmc_ocrbitnum_to_vdd - Convert a OCR bit number to its voltage * @vdd_bit: OCR bit number * @min_uV: minimum voltage value (mV) * @max_uV: maximum voltage value (mV) * * This function returns the voltage range according to the provided OCR * bit number. If conversion is not possible a negative errno value returned. */ static int mmc_ocrbitnum_to_vdd(int vdd_bit, int *min_uV, int *max_uV) { int tmp; if (!vdd_bit) return -EINVAL; /* * 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; } return 0; } /** * 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. */ static int mmc_regulator_get_ocrmask(struct regulator *supply) { int result = 0; int count; int i; int vdd_uV; int vdd_mV; count = regulator_count_voltages(supply); if (count < 0) return count; for (i = 0; i < count; i++) { 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); } if (!result) { vdd_uV = regulator_get_voltage(supply); if (vdd_uV <= 0) return vdd_uV; vdd_mV = vdd_uV / 1000; result = mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV); } return result; } /** * mmc_regulator_set_ocr - set regulator to match host->ios voltage * @mmc: the host to regulate * @supply: regulator to use * @vdd_bit: zero for power off, else a bit number (host->ios.vdd) * * 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 mmc_host *mmc, struct regulator *supply, unsigned short vdd_bit) { int result = 0; int min_uV, max_uV; if (IS_ERR(supply)) return 0; if (vdd_bit) { mmc_ocrbitnum_to_vdd(vdd_bit, &min_uV, &max_uV); result = regulator_set_voltage(supply, min_uV, max_uV); if (result == 0 && !mmc->regulator_enabled) { result = regulator_enable(supply); if (!result) mmc->regulator_enabled = true; } } else if (mmc->regulator_enabled) { result = regulator_disable(supply); if (result == 0) mmc->regulator_enabled = false; } if (result) dev_err(mmc_dev(mmc), "could not set regulator OCR (%d)\n", result); return result; } EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr); static int mmc_regulator_set_voltage_if_supported(struct regulator *regulator, int min_uV, int target_uV, int max_uV) { int current_uV; /* * Check if supported first to avoid errors since we may try several * signal levels during power up and don't want to show errors. */ if (!regulator_is_supported_voltage(regulator, min_uV, max_uV)) return -EINVAL; /* * The voltage is already set, no need to switch. * Return 1 to indicate that no switch happened. */ current_uV = regulator_get_voltage(regulator); if (current_uV == target_uV) return 1; return regulator_set_voltage_triplet(regulator, min_uV, target_uV, max_uV); } /** * mmc_regulator_set_vqmmc - Set VQMMC as per the ios * @mmc: the host to regulate * @ios: io bus settings * * For 3.3V signaling, we try to match VQMMC to VMMC as closely as possible. * That will match the behavior of old boards where VQMMC and VMMC were supplied * by the same supply. The Bus Operating conditions for 3.3V signaling in the * SD card spec also define VQMMC in terms of VMMC. * If this is not possible we'll try the full 2.7-3.6V of the spec. * * For 1.2V and 1.8V signaling we'll try to get as close as possible to the * requested voltage. This is definitely a good idea for UHS where there's a * separate regulator on the card that's trying to make 1.8V and it's best if * we match. * * This function is expected to be used by a controller's * start_signal_voltage_switch() function. */ int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios) { struct device *dev = mmc_dev(mmc); int ret, volt, min_uV, max_uV; /* If no vqmmc supply then we can't change the voltage */ if (IS_ERR(mmc->supply.vqmmc)) return -EINVAL; switch (ios->signal_voltage) { case MMC_SIGNAL_VOLTAGE_120: return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, 1100000, 1200000, 1300000); case MMC_SIGNAL_VOLTAGE_180: return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, 1700000, 1800000, 1950000); case MMC_SIGNAL_VOLTAGE_330: ret = mmc_ocrbitnum_to_vdd(mmc->ios.vdd, &volt, &max_uV); if (ret < 0) return ret; dev_dbg(dev, "%s: found vmmc voltage range of %d-%duV\n", __func__, volt, max_uV); min_uV = max(volt - 300000, 2700000); max_uV = min(max_uV + 200000, 3600000); /* * Due to a limitation in the current implementation of * regulator_set_voltage_triplet() which is taking the lowest * voltage possible if below the target, search for a suitable * voltage in two steps and try to stay close to vmmc * with a 0.3V tolerance at first. */ ret = mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, min_uV, volt, max_uV); if (ret >= 0) return ret; return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, 2700000, volt, 3600000); default: return -EINVAL; } } EXPORT_SYMBOL_GPL(mmc_regulator_set_vqmmc); #else static inline int mmc_regulator_get_ocrmask(struct regulator *supply) { return 0; } #endif /* CONFIG_REGULATOR */ /** * mmc_regulator_get_supply - try to get VMMC and VQMMC regulators for a host * @mmc: the host to regulate * * Returns 0 or errno. errno should be handled, it is either a critical error * or -EPROBE_DEFER. 0 means no critical error but it does not mean all * regulators have been found because they all are optional. If you require * certain regulators, you need to check separately in your driver if they got * populated after calling this function. */ int mmc_regulator_get_supply(struct mmc_host *mmc) { struct device *dev = mmc_dev(mmc); int ret; mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc"); mmc->supply.vqmmc = devm_regulator_get_optional(dev, "vqmmc"); if (IS_ERR(mmc->supply.vmmc)) { if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_dbg(dev, "No vmmc regulator found\n"); } else { ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc); if (ret > 0) mmc->ocr_avail = ret; else dev_warn(dev, "Failed getting OCR mask: %d\n", ret); } if (IS_ERR(mmc->supply.vqmmc)) { if (PTR_ERR(mmc->supply.vqmmc) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_dbg(dev, "No vqmmc regulator found\n"); } return 0; } EXPORT_SYMBOL_GPL(mmc_regulator_get_supply); /** * mmc_regulator_enable_vqmmc - enable VQMMC regulator for a host * @mmc: the host to regulate * * Returns 0 or errno. Enables the regulator for vqmmc. * Keeps track of the enable status for ensuring that calls to * regulator_enable/disable are balanced. */ int mmc_regulator_enable_vqmmc(struct mmc_host *mmc) { int ret = 0; if (!IS_ERR(mmc->supply.vqmmc) && !mmc->vqmmc_enabled) { ret = regulator_enable(mmc->supply.vqmmc); if (ret < 0) dev_err(mmc_dev(mmc), "enabling vqmmc regulator failed\n"); else mmc->vqmmc_enabled = true; } return ret; } EXPORT_SYMBOL_GPL(mmc_regulator_enable_vqmmc); /** * mmc_regulator_disable_vqmmc - disable VQMMC regulator for a host * @mmc: the host to regulate * * Returns 0 or errno. Disables the regulator for vqmmc. * Keeps track of the enable status for ensuring that calls to * regulator_enable/disable are balanced. */ void mmc_regulator_disable_vqmmc(struct mmc_host *mmc) { if (!IS_ERR(mmc->supply.vqmmc) && mmc->vqmmc_enabled) { regulator_disable(mmc->supply.vqmmc); mmc->vqmmc_enabled = false; } } EXPORT_SYMBOL_GPL(mmc_regulator_disable_vqmmc);