// SPDX-License-Identifier: GPL-2.0-or-later /* * Monolithic Power Systems MPQ4210 buck-boost regulator * * Copyright (c) 2026 Vaisala Oyj */ #include #include #include #include #include #include #include #include #include #include #define MPQ4210_REF_LSB 0x00 #define MPQ4210_REF_LSB_MASK GENMASK(2, 0) #define MPQ4210_REF_LSB_BITS 3 #define MPQ4210_REF_MSB 0x01 #define MPQ4210_CONTROL1 0x02 #define MPQ4210_CONTROL1_SR GENMASK(7, 6) #define MPQ4210_CONTROL1_RESERVED BIT(2) #define MPQ4210_CONTROL1_GO BIT(1) #define MPQ4210_CONTROL1_ENPWR BIT(0) #define MPQ4210_INT_MASK 0x06 /* * The feedback reference is an 11 bit value with a 1mV step. The datasheet * specifies no reference below 0.3V, so those selectors are not offered. */ #define MPQ4210_REF_MIN 0x12c #define MPQ4210_REF_MAX 0x7ff #define MPQ4210_REF_STEP_UV 1000 #define MPQ4210_ENPWR_DELAY_MS 200 /* Feedback reference slew rate per MPQ4210_CONTROL1_SR value, in uV/us. */ static const unsigned int mpq4210_ref_slew_rate[] = { 38, 50, 75, 150 }; static const struct regmap_config mpq4210_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = MPQ4210_INT_MASK, }; /* Scale a feedback reference value by the output voltage divider ratio. */ static unsigned int mpq4210_scale(unsigned int val, u32 r1, u32 r2) { u64 tmp = (u64)val * (r1 + r2); do_div(tmp, r2); return tmp; } static int mpq4210_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel) { int ret; ret = regmap_write(rdev->regmap, MPQ4210_REF_LSB, sel & MPQ4210_REF_LSB_MASK); if (ret) return ret; ret = regmap_write(rdev->regmap, MPQ4210_REF_MSB, sel >> MPQ4210_REF_LSB_BITS); if (ret) return ret; return regmap_set_bits(rdev->regmap, MPQ4210_CONTROL1, MPQ4210_CONTROL1_GO); } static int mpq4210_get_voltage_sel(struct regulator_dev *rdev) { unsigned int lsb, msb; int ret; ret = regmap_read(rdev->regmap, MPQ4210_REF_MSB, &msb); if (ret) return ret; ret = regmap_read(rdev->regmap, MPQ4210_REF_LSB, &lsb); if (ret) return ret; return (msb << MPQ4210_REF_LSB_BITS) | (lsb & MPQ4210_REF_LSB_MASK); } static int mpq4210_enable(struct regulator_dev *rdev) { int ret; ret = regmap_set_bits(rdev->regmap, MPQ4210_CONTROL1, MPQ4210_CONTROL1_GO); if (ret) return ret; /* The reference has to settle before power switching may start. */ msleep(MPQ4210_ENPWR_DELAY_MS); return regmap_set_bits(rdev->regmap, MPQ4210_CONTROL1, MPQ4210_CONTROL1_ENPWR); } static const struct regulator_ops mpq4210_regulator_ops = { .set_voltage_sel = mpq4210_set_voltage_sel, .get_voltage_sel = mpq4210_get_voltage_sel, .list_voltage = regulator_list_voltage_linear, .set_ramp_delay = regulator_set_ramp_delay_regmap, .enable = mpq4210_enable, .disable = regulator_disable_regmap, .is_enabled = regulator_is_enabled_regmap, }; static const struct regulator_desc mpq4210_regulator = { .name = "mpq4210", .type = REGULATOR_VOLTAGE, .owner = THIS_MODULE, .ops = &mpq4210_regulator_ops, .n_voltages = MPQ4210_REF_MAX + 1, .linear_min_sel = MPQ4210_REF_MIN, .enable_reg = MPQ4210_CONTROL1, .enable_mask = MPQ4210_CONTROL1_ENPWR, .ramp_reg = MPQ4210_CONTROL1, .ramp_mask = MPQ4210_CONTROL1_SR, .n_ramp_values = ARRAY_SIZE(mpq4210_ref_slew_rate), }; static int mpq4210_i2c_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct regulator_config config = { }; struct regulator_desc *desc; struct regulator_dev *rdev; struct gpio_desc *enable; struct regmap *regmap; unsigned int *slew; unsigned int i, val; u32 r[2]; int ret; ret = of_property_read_u32_array(dev->of_node, "mps,fb-voltage-divider-ohms", r, ARRAY_SIZE(r)); if (ret) return dev_err_probe(dev, ret, "failed to read mps,fb-voltage-divider-ohms\n"); if (!r[1]) return dev_err_probe(dev, -EINVAL, "feedback divider R2 must not be zero\n"); /* The controller does not answer on the bus while EN is deasserted. */ enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH); if (IS_ERR(enable)) return dev_err_probe(dev, PTR_ERR(enable), "failed to get enable GPIO\n"); regmap = devm_regmap_init_i2c(client, &mpq4210_regmap_config); if (IS_ERR(regmap)) return dev_err_probe(dev, PTR_ERR(regmap), "failed to init regmap\n"); desc = devm_kmemdup(dev, &mpq4210_regulator, sizeof(*desc), GFP_KERNEL); if (!desc) return -ENOMEM; desc->min_uV = mpq4210_scale(MPQ4210_REF_MIN * MPQ4210_REF_STEP_UV, r[0], r[1]); desc->uV_step = mpq4210_scale(MPQ4210_REF_STEP_UV, r[0], r[1]); slew = devm_kcalloc(dev, ARRAY_SIZE(mpq4210_ref_slew_rate), sizeof(*slew), GFP_KERNEL); if (!slew) return -ENOMEM; for (i = 0; i < ARRAY_SIZE(mpq4210_ref_slew_rate); i++) slew[i] = mpq4210_scale(mpq4210_ref_slew_rate[i], r[0], r[1]); desc->ramp_delay_table = slew; ret = regmap_read(regmap, MPQ4210_CONTROL1, &val); if (ret) return dev_err_probe(dev, ret, "failed to read control 1\n"); /* The core overrides this if the board sets regulator-ramp-delay. */ desc->ramp_delay = slew[FIELD_GET(MPQ4210_CONTROL1_SR, val)]; /* * Documented as reserved, but the datasheet requires it to be set * before the controller starts up. */ ret = regmap_set_bits(regmap, MPQ4210_CONTROL1, MPQ4210_CONTROL1_RESERVED); if (ret) return dev_err_probe(dev, ret, "failed to write control 1\n"); config.dev = dev; config.regmap = regmap; config.of_node = dev->of_node; config.init_data = of_get_regulator_init_data(dev, dev->of_node, desc); if (!config.init_data) return -ENOMEM; rdev = devm_regulator_register(dev, desc, &config); if (IS_ERR(rdev)) return dev_err_probe(dev, PTR_ERR(rdev), "failed to register regulator\n"); return 0; } static const struct of_device_id mpq4210_of_match[] = { { .compatible = "mps,mpq4210" }, { } }; MODULE_DEVICE_TABLE(of, mpq4210_of_match); static const struct i2c_device_id mpq4210_i2c_id[] = { { .name = "mpq4210" }, { } }; MODULE_DEVICE_TABLE(i2c, mpq4210_i2c_id); static struct i2c_driver mpq4210_regulator_driver = { .driver = { .name = "mpq4210", .probe_type = PROBE_PREFER_ASYNCHRONOUS, .of_match_table = mpq4210_of_match, }, .probe = mpq4210_i2c_probe, .id_table = mpq4210_i2c_id, }; module_i2c_driver(mpq4210_regulator_driver); MODULE_DESCRIPTION("Monolithic Power Systems MPQ4210 voltage regulator driver"); MODULE_AUTHOR("Tapio Reijonen "); MODULE_LICENSE("GPL");