1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // sy8106a-regulator.c - Regulator device driver for SY8106A 4 // 5 // Copyright (C) 2016 Ondřej Jirman <megous@megous.com> 6 // Copyright (c) 2017-2018 Icenowy Zheng <icenowy@aosc.io> 7 8 #include <linux/err.h> 9 #include <linux/i2c.h> 10 #include <linux/module.h> 11 #include <linux/regmap.h> 12 #include <linux/regulator/driver.h> 13 #include <linux/regulator/of_regulator.h> 14 15 #define SY8106A_REG_VOUT1_SEL 0x01 16 #define SY8106A_REG_VOUT_COM 0x02 17 #define SY8106A_REG_VOUT1_SEL_MASK 0x7f 18 #define SY8106A_DISABLE_REG BIT(0) 19 /* 20 * The I2C controlled voltage will only work when this bit is set; otherwise 21 * it will behave like a fixed regulator. 22 */ 23 #define SY8106A_GO_BIT BIT(7) 24 25 struct sy8106a { 26 struct regulator_dev *rdev; 27 struct regmap *regmap; 28 u32 fixed_voltage; 29 }; 30 31 static const struct regmap_config sy8106a_regmap_config = { 32 .reg_bits = 8, 33 .val_bits = 8, 34 }; 35 36 static const struct regulator_ops sy8106a_ops = { 37 .set_voltage_sel = regulator_set_voltage_sel_regmap, 38 .set_voltage_time_sel = regulator_set_voltage_time_sel, 39 .get_voltage_sel = regulator_get_voltage_sel_regmap, 40 .list_voltage = regulator_list_voltage_linear, 41 /* Enabling/disabling the regulator is not yet implemented */ 42 }; 43 44 /* Default limits measured in millivolts */ 45 #define SY8106A_MIN_MV 680 46 #define SY8106A_MAX_MV 1950 47 #define SY8106A_STEP_MV 10 48 49 static const struct regulator_desc sy8106a_reg = { 50 .name = "SY8106A", 51 .id = 0, 52 .ops = &sy8106a_ops, 53 .type = REGULATOR_VOLTAGE, 54 .n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / SY8106A_STEP_MV) + 1, 55 .min_uV = (SY8106A_MIN_MV * 1000), 56 .uV_step = (SY8106A_STEP_MV * 1000), 57 .vsel_reg = SY8106A_REG_VOUT1_SEL, 58 .vsel_mask = SY8106A_REG_VOUT1_SEL_MASK, 59 /* 60 * This ramp_delay is a conservative default value which works on 61 * H3/H5 boards VDD-CPUX situations. 62 */ 63 .ramp_delay = 200, 64 .owner = THIS_MODULE, 65 }; 66 67 /* 68 * I2C driver interface functions 69 */ 70 static int sy8106a_i2c_probe(struct i2c_client *i2c, 71 const struct i2c_device_id *id) 72 { 73 struct sy8106a *chip; 74 struct device *dev = &i2c->dev; 75 struct regulator_dev *rdev = NULL; 76 struct regulator_config config = { }; 77 unsigned int reg, vsel; 78 int error; 79 80 chip = devm_kzalloc(&i2c->dev, sizeof(struct sy8106a), GFP_KERNEL); 81 if (!chip) 82 return -ENOMEM; 83 84 error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt", 85 &chip->fixed_voltage); 86 if (error) 87 return error; 88 89 if (chip->fixed_voltage < SY8106A_MIN_MV * 1000 || 90 chip->fixed_voltage > SY8106A_MAX_MV * 1000) 91 return -EINVAL; 92 93 chip->regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config); 94 if (IS_ERR(chip->regmap)) { 95 error = PTR_ERR(chip->regmap); 96 dev_err(dev, "Failed to allocate register map: %d\n", error); 97 return error; 98 } 99 100 config.dev = &i2c->dev; 101 config.regmap = chip->regmap; 102 config.driver_data = chip; 103 104 config.of_node = dev->of_node; 105 config.init_data = of_get_regulator_init_data(dev, dev->of_node, 106 &sy8106a_reg); 107 108 if (!config.init_data) 109 return -ENOMEM; 110 111 /* Ensure GO_BIT is enabled when probing */ 112 error = regmap_read(chip->regmap, SY8106A_REG_VOUT1_SEL, ®); 113 if (error) 114 return error; 115 116 if (!(reg & SY8106A_GO_BIT)) { 117 vsel = (chip->fixed_voltage / 1000 - SY8106A_MIN_MV) / 118 SY8106A_STEP_MV; 119 120 error = regmap_write(chip->regmap, SY8106A_REG_VOUT1_SEL, 121 vsel | SY8106A_GO_BIT); 122 if (error) 123 return error; 124 } 125 126 /* Probe regulator */ 127 rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config); 128 if (IS_ERR(rdev)) { 129 error = PTR_ERR(rdev); 130 dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error); 131 return error; 132 } 133 134 chip->rdev = rdev; 135 136 i2c_set_clientdata(i2c, chip); 137 138 return 0; 139 } 140 141 static const struct of_device_id sy8106a_i2c_of_match[] = { 142 { .compatible = "silergy,sy8106a" }, 143 { }, 144 }; 145 MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match); 146 147 static const struct i2c_device_id sy8106a_i2c_id[] = { 148 { "sy8106a", 0 }, 149 { }, 150 }; 151 MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id); 152 153 static struct i2c_driver sy8106a_regulator_driver = { 154 .driver = { 155 .name = "sy8106a", 156 .of_match_table = of_match_ptr(sy8106a_i2c_of_match), 157 }, 158 .probe = sy8106a_i2c_probe, 159 .id_table = sy8106a_i2c_id, 160 }; 161 162 module_i2c_driver(sy8106a_regulator_driver); 163 164 MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>"); 165 MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>"); 166 MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A"); 167 MODULE_LICENSE("GPL"); 168