1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI/National Semiconductor LP3943 MFD Core Driver 4 * 5 * Copyright 2013 Texas Instruments 6 * 7 * Author: Milo Kim <milo.kim@ti.com> 8 * 9 * Driver structure: 10 * LP3943 is an integrated device capable of driving 16 output channels. 11 * It can be used for a GPIO expander and PWM generators. 12 * 13 * LED control General usage for a device 14 * ___________ ____________________________ 15 * 16 * LP3943 MFD ---- GPIO expander leds-gpio eg) HW enable pin 17 * | 18 * --- PWM generator leds-pwm eg) PWM input 19 * 20 * Internal two PWM channels are used for LED dimming effect. 21 * And each output pin can be used as a GPIO as well. 22 * The LED functionality can work with GPIOs or PWMs. 23 * LEDs can be controlled with legacy leds-gpio(static brightness) or 24 * leds-pwm drivers(dynamic brightness control). 25 * Alternatively, it can be used for generic GPIO and PWM controller. 26 * For example, a GPIO is HW enable pin of a device. 27 * A PWM is input pin of a backlight device. 28 */ 29 30 #include <linux/err.h> 31 #include <linux/gpio.h> 32 #include <linux/i2c.h> 33 #include <linux/mfd/core.h> 34 #include <linux/mfd/lp3943.h> 35 #include <linux/module.h> 36 #include <linux/of.h> 37 #include <linux/slab.h> 38 39 #define LP3943_MAX_REGISTERS 0x09 40 41 /* Register configuration for pin MUX */ 42 static const struct lp3943_reg_cfg lp3943_mux_cfg[] = { 43 /* address, mask, shift */ 44 { LP3943_REG_MUX0, 0x03, 0 }, 45 { LP3943_REG_MUX0, 0x0C, 2 }, 46 { LP3943_REG_MUX0, 0x30, 4 }, 47 { LP3943_REG_MUX0, 0xC0, 6 }, 48 { LP3943_REG_MUX1, 0x03, 0 }, 49 { LP3943_REG_MUX1, 0x0C, 2 }, 50 { LP3943_REG_MUX1, 0x30, 4 }, 51 { LP3943_REG_MUX1, 0xC0, 6 }, 52 { LP3943_REG_MUX2, 0x03, 0 }, 53 { LP3943_REG_MUX2, 0x0C, 2 }, 54 { LP3943_REG_MUX2, 0x30, 4 }, 55 { LP3943_REG_MUX2, 0xC0, 6 }, 56 { LP3943_REG_MUX3, 0x03, 0 }, 57 { LP3943_REG_MUX3, 0x0C, 2 }, 58 { LP3943_REG_MUX3, 0x30, 4 }, 59 { LP3943_REG_MUX3, 0xC0, 6 }, 60 }; 61 62 static const struct mfd_cell lp3943_devs[] = { 63 { 64 .name = "lp3943-pwm", 65 .of_compatible = "ti,lp3943-pwm", 66 }, 67 { 68 .name = "lp3943-gpio", 69 .of_compatible = "ti,lp3943-gpio", 70 }, 71 }; 72 73 int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read) 74 { 75 int ret; 76 unsigned int val; 77 78 ret = regmap_read(lp3943->regmap, reg, &val); 79 if (ret < 0) 80 return ret; 81 82 *read = (u8)val; 83 return 0; 84 } 85 EXPORT_SYMBOL_GPL(lp3943_read_byte); 86 87 int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data) 88 { 89 return regmap_write(lp3943->regmap, reg, data); 90 } 91 EXPORT_SYMBOL_GPL(lp3943_write_byte); 92 93 int lp3943_update_bits(struct lp3943 *lp3943, u8 reg, u8 mask, u8 data) 94 { 95 return regmap_update_bits(lp3943->regmap, reg, mask, data); 96 } 97 EXPORT_SYMBOL_GPL(lp3943_update_bits); 98 99 static const struct regmap_config lp3943_regmap_config = { 100 .reg_bits = 8, 101 .val_bits = 8, 102 .max_register = LP3943_MAX_REGISTERS, 103 }; 104 105 static int lp3943_probe(struct i2c_client *cl, const struct i2c_device_id *id) 106 { 107 struct lp3943 *lp3943; 108 struct device *dev = &cl->dev; 109 110 lp3943 = devm_kzalloc(dev, sizeof(*lp3943), GFP_KERNEL); 111 if (!lp3943) 112 return -ENOMEM; 113 114 lp3943->regmap = devm_regmap_init_i2c(cl, &lp3943_regmap_config); 115 if (IS_ERR(lp3943->regmap)) 116 return PTR_ERR(lp3943->regmap); 117 118 lp3943->pdata = dev_get_platdata(dev); 119 lp3943->dev = dev; 120 lp3943->mux_cfg = lp3943_mux_cfg; 121 i2c_set_clientdata(cl, lp3943); 122 123 return devm_mfd_add_devices(dev, -1, lp3943_devs, 124 ARRAY_SIZE(lp3943_devs), 125 NULL, 0, NULL); 126 } 127 128 static const struct i2c_device_id lp3943_ids[] = { 129 { "lp3943", 0 }, 130 { } 131 }; 132 MODULE_DEVICE_TABLE(i2c, lp3943_ids); 133 134 #ifdef CONFIG_OF 135 static const struct of_device_id lp3943_of_match[] = { 136 { .compatible = "ti,lp3943", }, 137 { } 138 }; 139 MODULE_DEVICE_TABLE(of, lp3943_of_match); 140 #endif 141 142 static struct i2c_driver lp3943_driver = { 143 .probe = lp3943_probe, 144 .driver = { 145 .name = "lp3943", 146 .of_match_table = of_match_ptr(lp3943_of_match), 147 }, 148 .id_table = lp3943_ids, 149 }; 150 151 module_i2c_driver(lp3943_driver); 152 153 MODULE_DESCRIPTION("LP3943 MFD Core Driver"); 154 MODULE_AUTHOR("Milo Kim"); 155 MODULE_LICENSE("GPL"); 156