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(map: lp3943->regmap, reg, val: &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(map: lp3943->regmap, reg, val: 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(map: lp3943->regmap, reg, mask, val: 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) |
106 | { |
107 | struct lp3943 *lp3943; |
108 | struct device *dev = &cl->dev; |
109 | |
110 | lp3943 = devm_kzalloc(dev, size: 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(ptr: lp3943->regmap)) |
116 | return PTR_ERR(ptr: 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(client: cl, data: lp3943); |
122 | |
123 | return devm_mfd_add_devices(dev, id: -1, cells: lp3943_devs, |
124 | ARRAY_SIZE(lp3943_devs), |
125 | NULL, irq_base: 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 | |