1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2014 Belkin Inc.
4  * Copyright 2015 Andrew Lunn <andrew@lunn.ch>
5  */
6 
7 #include <linux/i2c.h>
8 #include <linux/leds.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/of_device.h>
12 #include <linux/regmap.h>
13 #include <linux/slab.h>
14 
15 #define TLC591XX_MAX_LEDS	16
16 #define TLC591XX_MAX_BRIGHTNESS	256
17 
18 #define TLC591XX_REG_MODE1	0x00
19 #define MODE1_RESPON_ADDR_MASK	0xF0
20 #define MODE1_NORMAL_MODE	(0 << 4)
21 #define MODE1_SPEED_MODE	(1 << 4)
22 
23 #define TLC591XX_REG_MODE2	0x01
24 #define MODE2_DIM		(0 << 5)
25 #define MODE2_BLINK		(1 << 5)
26 #define MODE2_OCH_STOP		(0 << 3)
27 #define MODE2_OCH_ACK		(1 << 3)
28 
29 #define TLC591XX_REG_PWM(x)	(0x02 + (x))
30 
31 #define TLC591XX_REG_GRPPWM	0x12
32 #define TLC591XX_REG_GRPFREQ	0x13
33 
34 /* LED Driver Output State, determine the source that drives LED outputs */
35 #define LEDOUT_OFF		0x0	/* Output LOW */
36 #define LEDOUT_ON		0x1	/* Output HI-Z */
37 #define LEDOUT_DIM		0x2	/* Dimming */
38 #define LEDOUT_BLINK		0x3	/* Blinking */
39 #define LEDOUT_MASK		0x3
40 
41 #define ldev_to_led(c)		container_of(c, struct tlc591xx_led, ldev)
42 
43 struct tlc591xx_led {
44 	bool active;
45 	unsigned int led_no;
46 	struct led_classdev ldev;
47 	struct tlc591xx_priv *priv;
48 };
49 
50 struct tlc591xx_priv {
51 	struct tlc591xx_led leds[TLC591XX_MAX_LEDS];
52 	struct regmap *regmap;
53 	unsigned int reg_ledout_offset;
54 };
55 
56 struct tlc591xx {
57 	unsigned int max_leds;
58 	unsigned int reg_ledout_offset;
59 };
60 
61 static const struct tlc591xx tlc59116 = {
62 	.max_leds = 16,
63 	.reg_ledout_offset = 0x14,
64 };
65 
66 static const struct tlc591xx tlc59108 = {
67 	.max_leds = 8,
68 	.reg_ledout_offset = 0x0c,
69 };
70 
71 static int
tlc591xx_set_mode(struct regmap * regmap,u8 mode)72 tlc591xx_set_mode(struct regmap *regmap, u8 mode)
73 {
74 	int err;
75 	u8 val;
76 
77 	err = regmap_write(regmap, TLC591XX_REG_MODE1, MODE1_NORMAL_MODE);
78 	if (err)
79 		return err;
80 
81 	val = MODE2_OCH_STOP | mode;
82 
83 	return regmap_write(regmap, TLC591XX_REG_MODE2, val);
84 }
85 
86 static int
tlc591xx_set_ledout(struct tlc591xx_priv * priv,struct tlc591xx_led * led,u8 val)87 tlc591xx_set_ledout(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
88 		    u8 val)
89 {
90 	unsigned int i = (led->led_no % 4) * 2;
91 	unsigned int mask = LEDOUT_MASK << i;
92 	unsigned int addr = priv->reg_ledout_offset + (led->led_no >> 2);
93 
94 	val = val << i;
95 
96 	return regmap_update_bits(priv->regmap, addr, mask, val);
97 }
98 
99 static int
tlc591xx_set_pwm(struct tlc591xx_priv * priv,struct tlc591xx_led * led,u8 brightness)100 tlc591xx_set_pwm(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
101 		 u8 brightness)
102 {
103 	u8 pwm = TLC591XX_REG_PWM(led->led_no);
104 
105 	return regmap_write(priv->regmap, pwm, brightness);
106 }
107 
108 static int
tlc591xx_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)109 tlc591xx_brightness_set(struct led_classdev *led_cdev,
110 			enum led_brightness brightness)
111 {
112 	struct tlc591xx_led *led = ldev_to_led(led_cdev);
113 	struct tlc591xx_priv *priv = led->priv;
114 	int err;
115 
116 	switch ((int)brightness) {
117 	case 0:
118 		err = tlc591xx_set_ledout(priv, led, LEDOUT_OFF);
119 		break;
120 	case TLC591XX_MAX_BRIGHTNESS:
121 		err = tlc591xx_set_ledout(priv, led, LEDOUT_ON);
122 		break;
123 	default:
124 		err = tlc591xx_set_ledout(priv, led, LEDOUT_DIM);
125 		if (!err)
126 			err = tlc591xx_set_pwm(priv, led, brightness);
127 	}
128 
129 	return err;
130 }
131 
132 static const struct regmap_config tlc591xx_regmap = {
133 	.reg_bits = 8,
134 	.val_bits = 8,
135 	.max_register = 0x1e,
136 };
137 
138 static const struct of_device_id of_tlc591xx_leds_match[] = {
139 	{ .compatible = "ti,tlc59116",
140 	  .data = &tlc59116 },
141 	{ .compatible = "ti,tlc59108",
142 	  .data = &tlc59108 },
143 	{},
144 };
145 MODULE_DEVICE_TABLE(of, of_tlc591xx_leds_match);
146 
147 static int
tlc591xx_probe(struct i2c_client * client,const struct i2c_device_id * id)148 tlc591xx_probe(struct i2c_client *client,
149 	       const struct i2c_device_id *id)
150 {
151 	struct device_node *np, *child;
152 	struct device *dev = &client->dev;
153 	const struct tlc591xx *tlc591xx;
154 	struct tlc591xx_priv *priv;
155 	int err, count, reg;
156 
157 	np = dev_of_node(dev);
158 	if (!np)
159 		return -ENODEV;
160 
161 	tlc591xx = device_get_match_data(dev);
162 	if (!tlc591xx)
163 		return -ENODEV;
164 
165 	count = of_get_available_child_count(np);
166 	if (!count || count > tlc591xx->max_leds)
167 		return -EINVAL;
168 
169 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
170 	if (!priv)
171 		return -ENOMEM;
172 
173 	priv->regmap = devm_regmap_init_i2c(client, &tlc591xx_regmap);
174 	if (IS_ERR(priv->regmap)) {
175 		err = PTR_ERR(priv->regmap);
176 		dev_err(dev, "Failed to allocate register map: %d\n", err);
177 		return err;
178 	}
179 	priv->reg_ledout_offset = tlc591xx->reg_ledout_offset;
180 
181 	i2c_set_clientdata(client, priv);
182 
183 	err = tlc591xx_set_mode(priv->regmap, MODE2_DIM);
184 	if (err < 0)
185 		return err;
186 
187 	for_each_available_child_of_node(np, child) {
188 		struct tlc591xx_led *led;
189 		struct led_init_data init_data = {};
190 
191 		init_data.fwnode = of_fwnode_handle(child);
192 
193 		err = of_property_read_u32(child, "reg", &reg);
194 		if (err) {
195 			of_node_put(child);
196 			return err;
197 		}
198 		if (reg < 0 || reg >= tlc591xx->max_leds ||
199 		    priv->leds[reg].active) {
200 			of_node_put(child);
201 			return -EINVAL;
202 		}
203 		led = &priv->leds[reg];
204 
205 		led->active = true;
206 		led->priv = priv;
207 		led->led_no = reg;
208 		led->ldev.brightness_set_blocking = tlc591xx_brightness_set;
209 		led->ldev.max_brightness = TLC591XX_MAX_BRIGHTNESS;
210 		err = devm_led_classdev_register_ext(dev, &led->ldev,
211 						     &init_data);
212 		if (err < 0) {
213 			of_node_put(child);
214 			return dev_err_probe(dev, err,
215 					     "couldn't register LED %s\n",
216 					     led->ldev.name);
217 		}
218 	}
219 	return 0;
220 }
221 
222 static const struct i2c_device_id tlc591xx_id[] = {
223 	{ "tlc59116" },
224 	{ "tlc59108" },
225 	{},
226 };
227 MODULE_DEVICE_TABLE(i2c, tlc591xx_id);
228 
229 static struct i2c_driver tlc591xx_driver = {
230 	.driver = {
231 		.name = "tlc591xx",
232 		.of_match_table = of_match_ptr(of_tlc591xx_leds_match),
233 	},
234 	.probe = tlc591xx_probe,
235 	.id_table = tlc591xx_id,
236 };
237 
238 module_i2c_driver(tlc591xx_driver);
239 
240 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
241 MODULE_LICENSE("GPL");
242 MODULE_DESCRIPTION("TLC591XX LED driver");
243