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 static const struct regmap_config sy8106a_regmap_config = { 26 .reg_bits = 8, 27 .val_bits = 8, 28 }; 29 30 static const struct regulator_ops sy8106a_ops = { 31 .set_voltage_sel = regulator_set_voltage_sel_regmap, 32 .set_voltage_time_sel = regulator_set_voltage_time_sel, 33 .get_voltage_sel = regulator_get_voltage_sel_regmap, 34 .list_voltage = regulator_list_voltage_linear, 35 /* Enabling/disabling the regulator is not yet implemented */ 36 }; 37 38 /* Default limits measured in millivolts */ 39 #define SY8106A_MIN_MV 680 40 #define SY8106A_MAX_MV 1950 41 #define SY8106A_STEP_MV 10 42 43 static const struct regulator_desc sy8106a_reg = { 44 .name = "SY8106A", 45 .id = 0, 46 .ops = &sy8106a_ops, 47 .type = REGULATOR_VOLTAGE, 48 .n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / SY8106A_STEP_MV) + 1, 49 .min_uV = (SY8106A_MIN_MV * 1000), 50 .uV_step = (SY8106A_STEP_MV * 1000), 51 .vsel_reg = SY8106A_REG_VOUT1_SEL, 52 .vsel_mask = SY8106A_REG_VOUT1_SEL_MASK, 53 /* 54 * This ramp_delay is a conservative default value which works on 55 * H3/H5 boards VDD-CPUX situations. 56 */ 57 .ramp_delay = 200, 58 .owner = THIS_MODULE, 59 }; 60 61 /* 62 * I2C driver interface functions 63 */ 64 static int sy8106a_i2c_probe(struct i2c_client *i2c) 65 { 66 struct device *dev = &i2c->dev; 67 struct regulator_dev *rdev; 68 struct regulator_config config = { }; 69 struct regmap *regmap; 70 unsigned int reg, vsel; 71 u32 fixed_voltage; 72 int error; 73 74 error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt", 75 &fixed_voltage); 76 if (error) 77 return error; 78 79 if (fixed_voltage < SY8106A_MIN_MV * 1000 || 80 fixed_voltage > SY8106A_MAX_MV * 1000) 81 return -EINVAL; 82 83 regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config); 84 if (IS_ERR(regmap)) { 85 error = PTR_ERR(regmap); 86 dev_err(dev, "Failed to allocate register map: %d\n", error); 87 return error; 88 } 89 90 config.dev = &i2c->dev; 91 config.regmap = regmap; 92 93 config.of_node = dev->of_node; 94 config.init_data = of_get_regulator_init_data(dev, dev->of_node, 95 &sy8106a_reg); 96 97 if (!config.init_data) 98 return -ENOMEM; 99 100 /* Ensure GO_BIT is enabled when probing */ 101 error = regmap_read(regmap, SY8106A_REG_VOUT1_SEL, ®); 102 if (error) 103 return error; 104 105 if (!(reg & SY8106A_GO_BIT)) { 106 vsel = (fixed_voltage / 1000 - SY8106A_MIN_MV) / 107 SY8106A_STEP_MV; 108 109 error = regmap_write(regmap, SY8106A_REG_VOUT1_SEL, 110 vsel | SY8106A_GO_BIT); 111 if (error) 112 return error; 113 } 114 115 /* Probe regulator */ 116 rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config); 117 if (IS_ERR(rdev)) { 118 error = PTR_ERR(rdev); 119 dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error); 120 return error; 121 } 122 123 return 0; 124 } 125 126 static const struct of_device_id sy8106a_i2c_of_match[] = { 127 { .compatible = "silergy,sy8106a" }, 128 { }, 129 }; 130 MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match); 131 132 static const struct i2c_device_id sy8106a_i2c_id[] = { 133 { "sy8106a" }, 134 { } 135 }; 136 MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id); 137 138 static struct i2c_driver sy8106a_regulator_driver = { 139 .driver = { 140 .name = "sy8106a", 141 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 142 .of_match_table = sy8106a_i2c_of_match, 143 }, 144 .probe = sy8106a_i2c_probe, 145 .id_table = sy8106a_i2c_id, 146 }; 147 148 module_i2c_driver(sy8106a_regulator_driver); 149 150 MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>"); 151 MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>"); 152 MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A"); 153 MODULE_LICENSE("GPL"); 154