1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Driver for Panasonic AN30259A 3-channel LED driver
4 //
5 // Copyright (c) 2018 Simon Shields <simon@lineageos.org>
6 //
7 // Datasheet:
8 // https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf
9
10 #include <linux/i2c.h>
11 #include <linux/leds.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/of.h>
15 #include <linux/regmap.h>
16
17 #define AN30259A_MAX_LEDS 3
18
19 #define AN30259A_REG_SRESET 0x00
20 #define AN30259A_LED_SRESET BIT(0)
21
22 /* LED power registers */
23 #define AN30259A_REG_LED_ON 0x01
24 #define AN30259A_LED_EN(x) BIT((x) - 1)
25 #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
26
27 #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
28
29 /* slope control registers */
30 #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
31 #define AN30259A_LED_SLOPETIME1(x) (x)
32 #define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
33
34 #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
35 #define AN30259A_LED_DUTYMAX(x) ((x) << 4)
36 #define AN30259A_LED_DUTYMID(x) (x)
37
38 #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
39 #define AN30259A_LED_DELAY(x) ((x) << 4)
40 #define AN30259A_LED_DUTYMIN(x) (x)
41
42 /* detention time control (length of each slope step) */
43 #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
44 #define AN30259A_LED_DT1(x) (x)
45 #define AN30259A_LED_DT2(x) ((x) << 4)
46
47 #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
48 #define AN30259A_LED_DT3(x) (x)
49 #define AN30259A_LED_DT4(x) ((x) << 4)
50
51 #define AN30259A_REG_MAX 0x14
52
53 #define AN30259A_BLINK_MAX_TIME 7500 /* ms */
54 #define AN30259A_SLOPE_RESOLUTION 500 /* ms */
55
56 #define AN30259A_NAME "an30259a"
57
58 struct an30259a;
59
60 struct an30259a_led {
61 struct an30259a *chip;
62 struct fwnode_handle *fwnode;
63 struct led_classdev cdev;
64 u32 num;
65 enum led_default_state default_state;
66 bool sloping;
67 };
68
69 struct an30259a {
70 struct mutex mutex; /* held when writing to registers */
71 struct i2c_client *client;
72 struct an30259a_led leds[AN30259A_MAX_LEDS];
73 struct regmap *regmap;
74 int num_leds;
75 };
76
an30259a_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)77 static int an30259a_brightness_set(struct led_classdev *cdev,
78 enum led_brightness brightness)
79 {
80 struct an30259a_led *led;
81 int ret;
82 unsigned int led_on;
83
84 led = container_of(cdev, struct an30259a_led, cdev);
85 mutex_lock(&led->chip->mutex);
86
87 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
88 if (ret)
89 goto error;
90
91 switch (brightness) {
92 case LED_OFF:
93 led_on &= ~AN30259A_LED_EN(led->num);
94 led_on &= ~AN30259A_LED_SLOPE(led->num);
95 led->sloping = false;
96 break;
97 default:
98 led_on |= AN30259A_LED_EN(led->num);
99 if (led->sloping)
100 led_on |= AN30259A_LED_SLOPE(led->num);
101 ret = regmap_write(led->chip->regmap,
102 AN30259A_REG_LEDCNT1(led->num),
103 AN30259A_LED_DUTYMAX(0xf) |
104 AN30259A_LED_DUTYMID(0xf));
105 if (ret)
106 goto error;
107 break;
108 }
109
110 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
111 if (ret)
112 goto error;
113
114 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num),
115 brightness);
116
117 error:
118 mutex_unlock(&led->chip->mutex);
119
120 return ret;
121 }
122
an30259a_blink_set(struct led_classdev * cdev,unsigned long * delay_off,unsigned long * delay_on)123 static int an30259a_blink_set(struct led_classdev *cdev,
124 unsigned long *delay_off, unsigned long *delay_on)
125 {
126 struct an30259a_led *led;
127 int ret, num;
128 unsigned int led_on;
129 unsigned long off = *delay_off, on = *delay_on;
130
131 led = container_of(cdev, struct an30259a_led, cdev);
132
133 mutex_lock(&led->chip->mutex);
134 num = led->num;
135
136 /* slope time can only be a multiple of 500ms. */
137 if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
138 ret = -EINVAL;
139 goto error;
140 }
141
142 /* up to a maximum of 7500ms. */
143 if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) {
144 ret = -EINVAL;
145 goto error;
146 }
147
148 /* if no blink specified, default to 1 Hz. */
149 if (!off && !on) {
150 *delay_off = off = 500;
151 *delay_on = on = 500;
152 }
153
154 /* convert into values the HW will understand. */
155 off /= AN30259A_SLOPE_RESOLUTION;
156 on /= AN30259A_SLOPE_RESOLUTION;
157
158 /* duty min should be zero (=off), delay should be zero. */
159 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
160 AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
161 if (ret)
162 goto error;
163
164 /* reset detention time (no "breathing" effect). */
165 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
166 AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
167 if (ret)
168 goto error;
169 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
170 AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
171 if (ret)
172 goto error;
173
174 /* slope time controls on/off cycle length. */
175 ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
176 AN30259A_LED_SLOPETIME1(off) |
177 AN30259A_LED_SLOPETIME2(on));
178 if (ret)
179 goto error;
180
181 /* Finally, enable slope mode. */
182 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
183 if (ret)
184 goto error;
185
186 led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
187
188 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
189
190 if (!ret)
191 led->sloping = true;
192 error:
193 mutex_unlock(&led->chip->mutex);
194
195 return ret;
196 }
197
an30259a_dt_init(struct i2c_client * client,struct an30259a * chip)198 static int an30259a_dt_init(struct i2c_client *client,
199 struct an30259a *chip)
200 {
201 struct device_node *np = dev_of_node(&client->dev), *child;
202 int count, ret;
203 int i = 0;
204 struct an30259a_led *led;
205
206 count = of_get_available_child_count(np);
207 if (!count || count > AN30259A_MAX_LEDS)
208 return -EINVAL;
209
210 for_each_available_child_of_node(np, child) {
211 u32 source;
212
213 ret = of_property_read_u32(child, "reg", &source);
214 if (ret != 0 || !source || source > AN30259A_MAX_LEDS) {
215 dev_err(&client->dev, "Couldn't read LED address: %d\n",
216 ret);
217 count--;
218 continue;
219 }
220
221 led = &chip->leds[i];
222
223 led->num = source;
224 led->chip = chip;
225 led->fwnode = of_fwnode_handle(child);
226 led->default_state = led_init_default_state_get(led->fwnode);
227
228 i++;
229 }
230
231 if (!count)
232 return -EINVAL;
233
234 chip->num_leds = i;
235
236 return 0;
237 }
238
239 static const struct regmap_config an30259a_regmap_config = {
240 .reg_bits = 8,
241 .val_bits = 8,
242 .max_register = AN30259A_REG_MAX,
243 };
244
an30259a_init_default_state(struct an30259a_led * led)245 static void an30259a_init_default_state(struct an30259a_led *led)
246 {
247 struct an30259a *chip = led->chip;
248 int led_on, err;
249
250 switch (led->default_state) {
251 case LEDS_DEFSTATE_ON:
252 led->cdev.brightness = LED_FULL;
253 break;
254 case LEDS_DEFSTATE_KEEP:
255 err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on);
256 if (err)
257 break;
258
259 if (!(led_on & AN30259A_LED_EN(led->num))) {
260 led->cdev.brightness = LED_OFF;
261 break;
262 }
263 regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num),
264 &led->cdev.brightness);
265 break;
266 default:
267 led->cdev.brightness = LED_OFF;
268 }
269
270 an30259a_brightness_set(&led->cdev, led->cdev.brightness);
271 }
272
an30259a_probe(struct i2c_client * client)273 static int an30259a_probe(struct i2c_client *client)
274 {
275 struct an30259a *chip;
276 int i, err;
277
278 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
279 if (!chip)
280 return -ENOMEM;
281
282 err = an30259a_dt_init(client, chip);
283 if (err < 0)
284 return err;
285
286 err = devm_mutex_init(&client->dev, &chip->mutex);
287 if (err)
288 return err;
289
290 chip->client = client;
291 i2c_set_clientdata(client, chip);
292
293 chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config);
294
295 if (IS_ERR(chip->regmap)) {
296 err = PTR_ERR(chip->regmap);
297 dev_err(&client->dev, "Failed to allocate register map: %d\n",
298 err);
299 goto exit;
300 }
301
302 for (i = 0; i < chip->num_leds; i++) {
303 struct led_init_data init_data = {};
304
305 an30259a_init_default_state(&chip->leds[i]);
306 chip->leds[i].cdev.brightness_set_blocking =
307 an30259a_brightness_set;
308 chip->leds[i].cdev.blink_set = an30259a_blink_set;
309
310 init_data.fwnode = chip->leds[i].fwnode;
311 init_data.devicename = AN30259A_NAME;
312 init_data.default_label = ":";
313
314 err = devm_led_classdev_register_ext(&client->dev,
315 &chip->leds[i].cdev,
316 &init_data);
317 if (err < 0)
318 goto exit;
319 }
320 return 0;
321
322 exit:
323 return err;
324 }
325
326 static const struct of_device_id an30259a_match_table[] = {
327 { .compatible = "panasonic,an30259a", },
328 { /* sentinel */ },
329 };
330
331 MODULE_DEVICE_TABLE(of, an30259a_match_table);
332
333 static const struct i2c_device_id an30259a_id[] = {
334 { "an30259a" },
335 { /* sentinel */ }
336 };
337 MODULE_DEVICE_TABLE(i2c, an30259a_id);
338
339 static struct i2c_driver an30259a_driver = {
340 .driver = {
341 .name = "leds-an30259a",
342 .of_match_table = an30259a_match_table,
343 },
344 .probe = an30259a_probe,
345 .id_table = an30259a_id,
346 };
347
348 module_i2c_driver(an30259a_driver);
349
350 MODULE_AUTHOR("Simon Shields <simon@lineageos.org>");
351 MODULE_DESCRIPTION("AN30259A LED driver");
352 MODULE_LICENSE("GPL v2");
353