1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Silergy SY7758 6-channel High Efficiency LED Driver 4 * 5 * Copyright (C) 2025 Kancy Joe <kancy2333@outlook.com> 6 * Copyright (C) 2026 Linaro Limited 7 * Author: Neil Armstrong <neil.armstrong@linaro.org> 8 */ 9 #include <linux/backlight.h> 10 #include <linux/module.h> 11 #include <linux/i2c.h> 12 #include <linux/of.h> 13 #include <linux/err.h> 14 #include <linux/bits.h> 15 #include <linux/delay.h> 16 #include <linux/regmap.h> 17 #include <linux/bitfield.h> 18 #include <linux/gpio/consumer.h> 19 #include <linux/regulator/consumer.h> 20 21 #define DEFAULT_BRIGHTNESS 1024 22 #define MAX_BRIGHTNESS 4080 23 #define REG_MAX 0xAE 24 25 /* Registers */ 26 #define REG_DEV_CTL 0x01 27 #define REG_DEV_ID 0x03 28 #define REG_BRT_12BIT_L 0x10 29 #define REG_BRT_12BIT_H 0x11 30 31 /* OTP memory */ 32 #define REG_OTP_CFG0 0xA0 33 #define REG_OTP_CFG1 0xA1 34 #define REG_OTP_CFG2 0xA2 35 #define REG_OTP_CFG5 0xA5 36 #define REG_OTP_CFG9 0xA9 37 38 /* Fields */ 39 #define BIT_DEV_CTL_FAST BIT(7) 40 #define MSK_DEV_CTL_BRT_MODE GENMASK(2, 1) 41 #define BIT_DEV_CTL_BL_CTLB BIT(0) 42 43 #define MSK_BRT_12BIT_L GENMASK(7, 0) 44 #define MSK_BRT_12BIT_H GENMASK(3, 0) 45 46 #define MSK_CFG0_CURRENT_LOW GENMASK(7, 0) 47 48 #define BIT_CFG1_PDET_STDBY BIT(7) 49 #define MSK_CFG1_CURRENT_MAX GENMASK(6, 4) 50 #define MSK_CFG1_CURRENT_HIGH GENMASK(3, 0) 51 52 #define BIT_CFG2_UVLO_EN BIT(5) 53 #define BIT_CFG2_UVLO_TH BIT(4) 54 #define BIT_CFG2_BL_ON BIT(3) 55 #define BIT_CFG2_ISET_EN BIT(2) 56 #define BIT_CFG2_BST_ESET_EN BIT(1) 57 58 #define BIT_CFG5_PWM_DIRECT BIT(7) 59 #define MSK_CFG5_PS_MODE GENMASK(6, 4) 60 #define MSK_CFG5_PWM_FREQ GENMASK(3, 0) 61 62 #define MSK_CFG9_VBST_MAX GENMASK(7, 5) 63 #define BIT_CFG9_JUMP_EN BIT(4) 64 #define MSK_CFG9_JUMP_TH GENMASK(3, 2) 65 #define MSK_CFG9_JUMP_VOLTAGE GENMASK(1, 0) 66 67 struct sy7758 { 68 struct i2c_client *client; 69 struct regmap *regmap; 70 struct gpio_desc *gpio; 71 struct backlight_device *bl; 72 }; 73 74 static const struct regmap_config sy7758_regmap_config = { 75 .reg_bits = 8, 76 .val_bits = 8, 77 .max_register = REG_MAX, 78 }; 79 80 static int sy7758_backlight_update_status(struct backlight_device *backlight_dev) 81 { 82 struct sy7758 *sydev = bl_get_data(backlight_dev); 83 unsigned int brightness = backlight_get_brightness(backlight_dev); 84 int ret; 85 86 ret = regmap_write(sydev->regmap, REG_BRT_12BIT_L, 87 FIELD_PREP(MSK_BRT_12BIT_L, 88 brightness & 0xff)); 89 if (ret) 90 return ret; 91 92 ret = regmap_write(sydev->regmap, REG_BRT_12BIT_H, 93 FIELD_PREP(MSK_BRT_12BIT_H, 94 (brightness >> 8) & 0xf)); 95 if (ret) 96 return ret; 97 98 return 0; 99 } 100 101 static const struct backlight_ops sy7758_backlight_ops = { 102 .options = BL_CORE_SUSPENDRESUME, 103 .update_status = sy7758_backlight_update_status, 104 }; 105 106 static int sy7758_init(struct sy7758 *sydev) 107 { 108 int ret = 0; 109 110 ret = regmap_write(sydev->regmap, REG_DEV_CTL, 111 BIT_DEV_CTL_FAST | BIT_DEV_CTL_BL_CTLB | 112 FIELD_PREP(MSK_DEV_CTL_BRT_MODE, 2)); 113 if (ret) 114 return ret; 115 116 ret = regmap_write(sydev->regmap, REG_BRT_12BIT_L, 117 FIELD_PREP(MSK_BRT_12BIT_L, 118 DEFAULT_BRIGHTNESS & 0xff)); 119 if (ret) 120 return ret; 121 122 ret = regmap_write(sydev->regmap, REG_BRT_12BIT_H, 123 FIELD_PREP(MSK_BRT_12BIT_H, 124 (DEFAULT_BRIGHTNESS >> 8))); 125 if (ret) 126 return ret; 127 128 ret = regmap_write(sydev->regmap, REG_OTP_CFG5, 129 FIELD_PREP(MSK_CFG5_PS_MODE, 6) | 130 FIELD_PREP(MSK_CFG5_PWM_FREQ, 4)); 131 if (ret) 132 return ret; 133 134 ret = regmap_write(sydev->regmap, REG_OTP_CFG0, 135 FIELD_PREP(MSK_CFG0_CURRENT_LOW, 85)); 136 if (ret) 137 return ret; 138 139 ret = regmap_write(sydev->regmap, REG_OTP_CFG1, 140 BIT_CFG1_PDET_STDBY | 141 FIELD_PREP(MSK_CFG1_CURRENT_MAX, 1) | 142 FIELD_PREP(MSK_CFG1_CURRENT_HIGH, 10)); 143 if (ret) 144 return ret; 145 146 ret = regmap_write(sydev->regmap, REG_OTP_CFG9, 147 FIELD_PREP(MSK_CFG9_VBST_MAX, 4)); 148 if (ret) 149 return ret; 150 151 ret = regmap_write(sydev->regmap, REG_OTP_CFG2, 152 BIT_CFG2_BL_ON | BIT_CFG2_UVLO_EN); 153 if (ret) 154 return ret; 155 156 return 0; 157 } 158 159 static int sy7758_probe(struct i2c_client *client) 160 { 161 struct backlight_properties props = { }; 162 struct device *dev = &client->dev; 163 struct sy7758 *sydev; 164 unsigned int dev_id; 165 int ret; 166 167 sydev = devm_kzalloc(dev, sizeof(*sydev), GFP_KERNEL); 168 if (!sydev) 169 return -ENOMEM; 170 171 i2c_set_clientdata(client, sydev); 172 173 /* Initialize regmap */ 174 sydev->client = client; 175 sydev->regmap = devm_regmap_init_i2c(client, &sy7758_regmap_config); 176 if (IS_ERR(sydev->regmap)) 177 return dev_err_probe(dev, PTR_ERR(sydev->regmap), 178 "failed to init regmap\n"); 179 180 /* Get and enable regulator */ 181 ret = devm_regulator_get_enable(dev, "vdd"); 182 if (ret) 183 return dev_err_probe(dev, ret, "failed to get regulator\n"); 184 185 fsleep(100); 186 187 /* Get enable GPIO and set to high */ 188 sydev->gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH); 189 if (IS_ERR(sydev->gpio)) 190 return dev_err_probe(dev, PTR_ERR(sydev->gpio), 191 "failed to get enable GPIO\n"); 192 193 /* Let some time for HW to settle */ 194 fsleep(10000); 195 196 /* try read and check device id */ 197 ret = regmap_read(sydev->regmap, REG_DEV_ID, &dev_id); 198 if (ret < 0) 199 return dev_err_probe(dev, ret, "failed to read device id\n"); 200 if (dev_id != 0x63) { 201 dev_err(dev, "unexpected device id: 0x%02x\n", dev_id); 202 return -ENODEV; 203 } 204 205 /* Initialize and set default brightness */ 206 ret = sy7758_init(sydev); 207 if (ret) 208 return ret; 209 210 props.type = BACKLIGHT_RAW; 211 props.max_brightness = MAX_BRIGHTNESS; 212 props.brightness = DEFAULT_BRIGHTNESS; 213 props.scale = BACKLIGHT_SCALE_LINEAR; 214 215 sydev->bl = devm_backlight_device_register(dev, "sy7758-backlight", 216 dev, sydev, &sy7758_backlight_ops, 217 &props); 218 if (IS_ERR(sydev->bl)) 219 return dev_err_probe(dev, PTR_ERR(sydev->bl), 220 "failed to register backlight device\n"); 221 222 return backlight_update_status(sydev->bl); 223 } 224 225 static void sy7758_remove(struct i2c_client *client) 226 { 227 struct sy7758 *sydev = i2c_get_clientdata(client); 228 229 backlight_disable(sydev->bl); 230 } 231 232 static const struct i2c_device_id sy7758_ids[] = { 233 { "sy7758" }, 234 { } 235 }; 236 MODULE_DEVICE_TABLE(i2c, sy7758_ids); 237 238 static const struct of_device_id sy7758_match_table[] = { 239 { .compatible = "silergy,sy7758", }, 240 { }, 241 }; 242 MODULE_DEVICE_TABLE(of, sy7758_match_table); 243 244 static struct i2c_driver sy7758_driver = { 245 .driver = { 246 .name = "sy7758", 247 .of_match_table = sy7758_match_table, 248 }, 249 .probe = sy7758_probe, 250 .remove = sy7758_remove, 251 .id_table = sy7758_ids, 252 }; 253 254 module_i2c_driver(sy7758_driver); 255 256 MODULE_DESCRIPTION("Silergy SY7758 Backlight Driver"); 257 MODULE_AUTHOR("Kancy Joe <kancy2333@outlook.com>"); 258 MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>"); 259 MODULE_LICENSE("GPL"); 260