1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LED driver for PCA995x I2C LED drivers 4 * 5 * Copyright 2011 bct electronic GmbH 6 * Copyright 2013 Qtechnology/AS 7 * Copyright 2022 NXP 8 * Copyright 2023 Marek Vasut 9 */ 10 11 #include <linux/i2c.h> 12 #include <linux/leds.h> 13 #include <linux/module.h> 14 #include <linux/mod_devicetable.h> 15 #include <linux/property.h> 16 #include <linux/regmap.h> 17 18 /* Register definition */ 19 #define PCA995X_MODE1 0x00 20 #define PCA995X_MODE2 0x01 21 #define PCA995X_LEDOUT0 0x02 22 #define PCA9955B_PWM0 0x08 23 #define PCA9952_PWM0 0x0A 24 #define PCA9952_IREFALL 0x43 25 #define PCA9955B_IREFALL 0x45 26 27 /* Auto-increment disabled. Normal mode */ 28 #define PCA995X_MODE1_CFG 0x00 29 30 /* LED select registers determine the source that drives LED outputs */ 31 #define PCA995X_LED_OFF 0x0 32 #define PCA995X_LED_ON 0x1 33 #define PCA995X_LED_PWM_MODE 0x2 34 #define PCA995X_LDRX_MASK 0x3 35 #define PCA995X_LDRX_BITS 2 36 37 #define PCA995X_MAX_OUTPUTS 16 38 #define PCA995X_OUTPUTS_PER_REG 4 39 40 #define PCA995X_IREFALL_FULL_CFG 0xFF 41 #define PCA995X_IREFALL_HALF_CFG (PCA995X_IREFALL_FULL_CFG / 2) 42 43 #define PCA995X_TYPE_NON_B 0 44 #define PCA995X_TYPE_B 1 45 46 #define ldev_to_led(c) container_of(c, struct pca995x_led, ldev) 47 48 struct pca995x_led { 49 unsigned int led_no; 50 struct led_classdev ldev; 51 struct pca995x_chip *chip; 52 }; 53 54 struct pca995x_chip { 55 struct regmap *regmap; 56 struct pca995x_led leds[PCA995X_MAX_OUTPUTS]; 57 int btype; 58 }; 59 60 static int pca995x_brightness_set(struct led_classdev *led_cdev, 61 enum led_brightness brightness) 62 { 63 struct pca995x_led *led = ldev_to_led(led_cdev); 64 struct pca995x_chip *chip = led->chip; 65 u8 ledout_addr, pwmout_addr; 66 int shift, ret; 67 68 pwmout_addr = (chip->btype ? PCA9955B_PWM0 : PCA9952_PWM0) + led->led_no; 69 ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG); 70 shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG); 71 72 switch (brightness) { 73 case LED_FULL: 74 return regmap_update_bits(chip->regmap, ledout_addr, 75 PCA995X_LDRX_MASK << shift, 76 PCA995X_LED_ON << shift); 77 case LED_OFF: 78 return regmap_update_bits(chip->regmap, ledout_addr, 79 PCA995X_LDRX_MASK << shift, 0); 80 default: 81 /* Adjust brightness as per user input by changing individual PWM */ 82 ret = regmap_write(chip->regmap, pwmout_addr, brightness); 83 if (ret) 84 return ret; 85 86 /* 87 * Change LDRx configuration to individual brightness via PWM. 88 * LED will stop blinking if it's doing so. 89 */ 90 return regmap_update_bits(chip->regmap, ledout_addr, 91 PCA995X_LDRX_MASK << shift, 92 PCA995X_LED_PWM_MODE << shift); 93 } 94 } 95 96 static const struct regmap_config pca995x_regmap = { 97 .reg_bits = 8, 98 .val_bits = 8, 99 .max_register = 0x49, 100 }; 101 102 static int pca995x_probe(struct i2c_client *client) 103 { 104 struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 }; 105 struct fwnode_handle *np, *child; 106 struct device *dev = &client->dev; 107 struct pca995x_chip *chip; 108 struct pca995x_led *led; 109 int i, btype, reg, ret; 110 111 btype = (unsigned long)device_get_match_data(&client->dev); 112 113 np = dev_fwnode(dev); 114 if (!np) 115 return -ENODEV; 116 117 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 118 if (!chip) 119 return -ENOMEM; 120 121 chip->btype = btype; 122 chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap); 123 if (IS_ERR(chip->regmap)) 124 return PTR_ERR(chip->regmap); 125 126 i2c_set_clientdata(client, chip); 127 128 fwnode_for_each_available_child_node(np, child) { 129 ret = fwnode_property_read_u32(child, "reg", ®); 130 if (ret) { 131 fwnode_handle_put(child); 132 return ret; 133 } 134 135 if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg]) { 136 fwnode_handle_put(child); 137 return -EINVAL; 138 } 139 140 led = &chip->leds[reg]; 141 led_fwnodes[reg] = child; 142 led->chip = chip; 143 led->led_no = reg; 144 led->ldev.brightness_set_blocking = pca995x_brightness_set; 145 led->ldev.max_brightness = 255; 146 } 147 148 for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) { 149 struct led_init_data init_data = {}; 150 151 if (!led_fwnodes[i]) 152 continue; 153 154 init_data.fwnode = led_fwnodes[i]; 155 156 ret = devm_led_classdev_register_ext(dev, 157 &chip->leds[i].ldev, 158 &init_data); 159 if (ret < 0) { 160 fwnode_handle_put(child); 161 return dev_err_probe(dev, ret, 162 "Could not register LED %s\n", 163 chip->leds[i].ldev.name); 164 } 165 } 166 167 /* Disable LED all-call address and set normal mode */ 168 ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG); 169 if (ret) 170 return ret; 171 172 /* IREF Output current value for all LEDn outputs */ 173 return regmap_write(chip->regmap, 174 btype ? PCA9955B_IREFALL : PCA9952_IREFALL, 175 PCA995X_IREFALL_HALF_CFG); 176 } 177 178 static const struct i2c_device_id pca995x_id[] = { 179 { "pca9952", .driver_data = (kernel_ulong_t)PCA995X_TYPE_NON_B }, 180 { "pca9955b", .driver_data = (kernel_ulong_t)PCA995X_TYPE_B }, 181 {} 182 }; 183 MODULE_DEVICE_TABLE(i2c, pca995x_id); 184 185 static const struct of_device_id pca995x_of_match[] = { 186 { .compatible = "nxp,pca9952", .data = (void *)PCA995X_TYPE_NON_B }, 187 { .compatible = "nxp,pca9955b", .data = (void *)PCA995X_TYPE_B }, 188 {}, 189 }; 190 MODULE_DEVICE_TABLE(of, pca995x_of_match); 191 192 static struct i2c_driver pca995x_driver = { 193 .driver = { 194 .name = "leds-pca995x", 195 .of_match_table = pca995x_of_match, 196 }, 197 .probe = pca995x_probe, 198 .id_table = pca995x_id, 199 }; 200 module_i2c_driver(pca995x_driver); 201 202 MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>"); 203 MODULE_DESCRIPTION("PCA995x LED driver"); 204 MODULE_LICENSE("GPL"); 205