xref: /openbmc/linux/drivers/leds/leds-tlc591xx.c (revision 8730046c)
1 /*
2  * Copyright 2014 Belkin Inc.
3  * Copyright 2015 Andrew Lunn <andrew@lunn.ch>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; version 2 of the License.
8  */
9 
10 #include <linux/i2c.h>
11 #include <linux/leds.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/regmap.h>
16 #include <linux/slab.h>
17 
18 #define TLC591XX_MAX_LEDS	16
19 
20 #define TLC591XX_REG_MODE1	0x00
21 #define MODE1_RESPON_ADDR_MASK	0xF0
22 #define MODE1_NORMAL_MODE	(0 << 4)
23 #define MODE1_SPEED_MODE	(1 << 4)
24 
25 #define TLC591XX_REG_MODE2	0x01
26 #define MODE2_DIM		(0 << 5)
27 #define MODE2_BLINK		(1 << 5)
28 #define MODE2_OCH_STOP		(0 << 3)
29 #define MODE2_OCH_ACK		(1 << 3)
30 
31 #define TLC591XX_REG_PWM(x)	(0x02 + (x))
32 
33 #define TLC591XX_REG_GRPPWM	0x12
34 #define TLC591XX_REG_GRPFREQ	0x13
35 
36 /* LED Driver Output State, determine the source that drives LED outputs */
37 #define LEDOUT_OFF		0x0	/* Output LOW */
38 #define LEDOUT_ON		0x1	/* Output HI-Z */
39 #define LEDOUT_DIM		0x2	/* Dimming */
40 #define LEDOUT_BLINK		0x3	/* Blinking */
41 #define LEDOUT_MASK		0x3
42 
43 #define ldev_to_led(c)		container_of(c, struct tlc591xx_led, ldev)
44 
45 struct tlc591xx_led {
46 	bool active;
47 	unsigned int led_no;
48 	struct led_classdev ldev;
49 	struct tlc591xx_priv *priv;
50 };
51 
52 struct tlc591xx_priv {
53 	struct tlc591xx_led leds[TLC591XX_MAX_LEDS];
54 	struct regmap *regmap;
55 	unsigned int reg_ledout_offset;
56 };
57 
58 struct tlc591xx {
59 	unsigned int max_leds;
60 	unsigned int reg_ledout_offset;
61 };
62 
63 static const struct tlc591xx tlc59116 = {
64 	.max_leds = 16,
65 	.reg_ledout_offset = 0x14,
66 };
67 
68 static const struct tlc591xx tlc59108 = {
69 	.max_leds = 8,
70 	.reg_ledout_offset = 0x0c,
71 };
72 
73 static int
74 tlc591xx_set_mode(struct regmap *regmap, u8 mode)
75 {
76 	int err;
77 	u8 val;
78 
79 	err = regmap_write(regmap, TLC591XX_REG_MODE1, MODE1_NORMAL_MODE);
80 	if (err)
81 		return err;
82 
83 	val = MODE2_OCH_STOP | mode;
84 
85 	return regmap_write(regmap, TLC591XX_REG_MODE2, val);
86 }
87 
88 static int
89 tlc591xx_set_ledout(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
90 		    u8 val)
91 {
92 	unsigned int i = (led->led_no % 4) * 2;
93 	unsigned int mask = LEDOUT_MASK << i;
94 	unsigned int addr = priv->reg_ledout_offset + (led->led_no >> 2);
95 
96 	val = val << i;
97 
98 	return regmap_update_bits(priv->regmap, addr, mask, val);
99 }
100 
101 static int
102 tlc591xx_set_pwm(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
103 		 u8 brightness)
104 {
105 	u8 pwm = TLC591XX_REG_PWM(led->led_no);
106 
107 	return regmap_write(priv->regmap, pwm, brightness);
108 }
109 
110 static int
111 tlc591xx_brightness_set(struct led_classdev *led_cdev,
112 			enum led_brightness brightness)
113 {
114 	struct tlc591xx_led *led = ldev_to_led(led_cdev);
115 	struct tlc591xx_priv *priv = led->priv;
116 	int err;
117 
118 	switch (brightness) {
119 	case 0:
120 		err = tlc591xx_set_ledout(priv, led, LEDOUT_OFF);
121 		break;
122 	case LED_FULL:
123 		err = tlc591xx_set_ledout(priv, led, LEDOUT_ON);
124 		break;
125 	default:
126 		err = tlc591xx_set_ledout(priv, led, LEDOUT_DIM);
127 		if (!err)
128 			err = tlc591xx_set_pwm(priv, led, brightness);
129 	}
130 
131 	return err;
132 }
133 
134 static void
135 tlc591xx_destroy_devices(struct tlc591xx_priv *priv, unsigned int j)
136 {
137 	int i = j;
138 
139 	while (--i >= 0) {
140 		if (priv->leds[i].active)
141 			led_classdev_unregister(&priv->leds[i].ldev);
142 	}
143 }
144 
145 static int
146 tlc591xx_configure(struct device *dev,
147 		   struct tlc591xx_priv *priv,
148 		   const struct tlc591xx *tlc591xx)
149 {
150 	unsigned int i;
151 	int err = 0;
152 
153 	tlc591xx_set_mode(priv->regmap, MODE2_DIM);
154 	for (i = 0; i < TLC591XX_MAX_LEDS; i++) {
155 		struct tlc591xx_led *led = &priv->leds[i];
156 
157 		if (!led->active)
158 			continue;
159 
160 		led->priv = priv;
161 		led->led_no = i;
162 		led->ldev.brightness_set_blocking = tlc591xx_brightness_set;
163 		led->ldev.max_brightness = LED_FULL;
164 		err = led_classdev_register(dev, &led->ldev);
165 		if (err < 0) {
166 			dev_err(dev, "couldn't register LED %s\n",
167 				led->ldev.name);
168 			goto exit;
169 		}
170 	}
171 
172 	return 0;
173 
174 exit:
175 	tlc591xx_destroy_devices(priv, i);
176 	return err;
177 }
178 
179 static const struct regmap_config tlc591xx_regmap = {
180 	.reg_bits = 8,
181 	.val_bits = 8,
182 	.max_register = 0x1e,
183 };
184 
185 static const struct of_device_id of_tlc591xx_leds_match[] = {
186 	{ .compatible = "ti,tlc59116",
187 	  .data = &tlc59116 },
188 	{ .compatible = "ti,tlc59108",
189 	  .data = &tlc59108 },
190 	{},
191 };
192 MODULE_DEVICE_TABLE(of, of_tlc591xx_leds_match);
193 
194 static int
195 tlc591xx_probe(struct i2c_client *client,
196 	       const struct i2c_device_id *id)
197 {
198 	struct device_node *np = client->dev.of_node, *child;
199 	struct device *dev = &client->dev;
200 	const struct of_device_id *match;
201 	const struct tlc591xx *tlc591xx;
202 	struct tlc591xx_priv *priv;
203 	int err, count, reg;
204 
205 	match = of_match_device(of_tlc591xx_leds_match, dev);
206 	if (!match)
207 		return -ENODEV;
208 
209 	tlc591xx = match->data;
210 	if (!np)
211 		return -ENODEV;
212 
213 	count = of_get_child_count(np);
214 	if (!count || count > tlc591xx->max_leds)
215 		return -EINVAL;
216 
217 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
218 	if (!priv)
219 		return -ENOMEM;
220 
221 	priv->regmap = devm_regmap_init_i2c(client, &tlc591xx_regmap);
222 	if (IS_ERR(priv->regmap)) {
223 		err = PTR_ERR(priv->regmap);
224 		dev_err(dev, "Failed to allocate register map: %d\n", err);
225 		return err;
226 	}
227 	priv->reg_ledout_offset = tlc591xx->reg_ledout_offset;
228 
229 	i2c_set_clientdata(client, priv);
230 
231 	for_each_child_of_node(np, child) {
232 		err = of_property_read_u32(child, "reg", &reg);
233 		if (err)
234 			return err;
235 		if (reg < 0 || reg >= tlc591xx->max_leds)
236 			return -EINVAL;
237 		if (priv->leds[reg].active)
238 			return -EINVAL;
239 		priv->leds[reg].active = true;
240 		priv->leds[reg].ldev.name =
241 			of_get_property(child, "label", NULL) ? : child->name;
242 		priv->leds[reg].ldev.default_trigger =
243 			of_get_property(child, "linux,default-trigger", NULL);
244 	}
245 	return tlc591xx_configure(dev, priv, tlc591xx);
246 }
247 
248 static int
249 tlc591xx_remove(struct i2c_client *client)
250 {
251 	struct tlc591xx_priv *priv = i2c_get_clientdata(client);
252 
253 	tlc591xx_destroy_devices(priv, TLC591XX_MAX_LEDS);
254 
255 	return 0;
256 }
257 
258 static const struct i2c_device_id tlc591xx_id[] = {
259 	{ "tlc59116" },
260 	{ "tlc59108" },
261 	{},
262 };
263 MODULE_DEVICE_TABLE(i2c, tlc591xx_id);
264 
265 static struct i2c_driver tlc591xx_driver = {
266 	.driver = {
267 		.name = "tlc591xx",
268 		.of_match_table = of_match_ptr(of_tlc591xx_leds_match),
269 	},
270 	.probe = tlc591xx_probe,
271 	.remove = tlc591xx_remove,
272 	.id_table = tlc591xx_id,
273 };
274 
275 module_i2c_driver(tlc591xx_driver);
276 
277 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
278 MODULE_LICENSE("GPL");
279 MODULE_DESCRIPTION("TLC591XX LED driver");
280