1 // SPDX-License-Identifier: GPL-2.0
2 // TI LM3697 LED chip family driver
3 // Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
4
5 #include <linux/gpio/consumer.h>
6 #include <linux/i2c.h>
7 #include <linux/of.h>
8 #include <linux/of_gpio.h>
9 #include <linux/regulator/consumer.h>
10 #include <linux/leds-ti-lmu-common.h>
11
12 #define LM3697_REV 0x0
13 #define LM3697_RESET 0x1
14 #define LM3697_OUTPUT_CONFIG 0x10
15 #define LM3697_CTRL_A_RAMP 0x11
16 #define LM3697_CTRL_B_RAMP 0x12
17 #define LM3697_CTRL_A_B_RT_RAMP 0x13
18 #define LM3697_CTRL_A_B_RAMP_CFG 0x14
19 #define LM3697_CTRL_A_B_BRT_CFG 0x16
20 #define LM3697_CTRL_A_FS_CURR_CFG 0x17
21 #define LM3697_CTRL_B_FS_CURR_CFG 0x18
22 #define LM3697_PWM_CFG 0x1c
23 #define LM3697_CTRL_A_BRT_LSB 0x20
24 #define LM3697_CTRL_A_BRT_MSB 0x21
25 #define LM3697_CTRL_B_BRT_LSB 0x22
26 #define LM3697_CTRL_B_BRT_MSB 0x23
27 #define LM3697_CTRL_ENABLE 0x24
28
29 #define LM3697_SW_RESET BIT(0)
30
31 #define LM3697_CTRL_A_EN BIT(0)
32 #define LM3697_CTRL_B_EN BIT(1)
33 #define LM3697_CTRL_A_B_EN (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN)
34
35 #define LM3697_MAX_LED_STRINGS 3
36
37 #define LM3697_CONTROL_A 0
38 #define LM3697_CONTROL_B 1
39 #define LM3697_MAX_CONTROL_BANKS 2
40
41 /**
42 * struct lm3697_led -
43 * @hvled_strings: Array of LED strings associated with a control bank
44 * @label: LED label
45 * @led_dev: LED class device
46 * @priv: Pointer to the device struct
47 * @lmu_data: Register and setting values for common code
48 * @control_bank: Control bank the LED is associated to. 0 is control bank A
49 * 1 is control bank B
50 */
51 struct lm3697_led {
52 u32 hvled_strings[LM3697_MAX_LED_STRINGS];
53 char label[LED_MAX_NAME_SIZE];
54 struct led_classdev led_dev;
55 struct lm3697 *priv;
56 struct ti_lmu_bank lmu_data;
57 int control_bank;
58 int enabled;
59 int num_leds;
60 };
61
62 /**
63 * struct lm3697 -
64 * @enable_gpio: Hardware enable gpio
65 * @regulator: LED supply regulator pointer
66 * @client: Pointer to the I2C client
67 * @regmap: Devices register map
68 * @dev: Pointer to the devices device struct
69 * @lock: Lock for reading/writing the device
70 * @leds: Array of LED strings
71 */
72 struct lm3697 {
73 struct gpio_desc *enable_gpio;
74 struct regulator *regulator;
75 struct i2c_client *client;
76 struct regmap *regmap;
77 struct device *dev;
78 struct mutex lock;
79
80 int bank_cfg;
81
82 struct lm3697_led leds[];
83 };
84
85 static const struct reg_default lm3697_reg_defs[] = {
86 {LM3697_OUTPUT_CONFIG, 0x6},
87 {LM3697_CTRL_A_RAMP, 0x0},
88 {LM3697_CTRL_B_RAMP, 0x0},
89 {LM3697_CTRL_A_B_RT_RAMP, 0x0},
90 {LM3697_CTRL_A_B_RAMP_CFG, 0x0},
91 {LM3697_CTRL_A_B_BRT_CFG, 0x0},
92 {LM3697_CTRL_A_FS_CURR_CFG, 0x13},
93 {LM3697_CTRL_B_FS_CURR_CFG, 0x13},
94 {LM3697_PWM_CFG, 0xc},
95 {LM3697_CTRL_A_BRT_LSB, 0x0},
96 {LM3697_CTRL_A_BRT_MSB, 0x0},
97 {LM3697_CTRL_B_BRT_LSB, 0x0},
98 {LM3697_CTRL_B_BRT_MSB, 0x0},
99 {LM3697_CTRL_ENABLE, 0x0},
100 };
101
102 static const struct regmap_config lm3697_regmap_config = {
103 .reg_bits = 8,
104 .val_bits = 8,
105
106 .max_register = LM3697_CTRL_ENABLE,
107 .reg_defaults = lm3697_reg_defs,
108 .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),
109 .cache_type = REGCACHE_FLAT,
110 };
111
lm3697_brightness_set(struct led_classdev * led_cdev,enum led_brightness brt_val)112 static int lm3697_brightness_set(struct led_classdev *led_cdev,
113 enum led_brightness brt_val)
114 {
115 struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,
116 led_dev);
117 int ctrl_en_val = (1 << led->control_bank);
118 int ret;
119
120 mutex_lock(&led->priv->lock);
121
122 if (brt_val == LED_OFF) {
123 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,
124 ctrl_en_val, ~ctrl_en_val);
125 if (ret) {
126 dev_err(&led->priv->client->dev, "Cannot write ctrl register\n");
127 goto brightness_out;
128 }
129
130 led->enabled = LED_OFF;
131 } else {
132 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
133 if (ret) {
134 dev_err(&led->priv->client->dev,
135 "Cannot write brightness\n");
136 goto brightness_out;
137 }
138
139 if (!led->enabled) {
140 ret = regmap_update_bits(led->priv->regmap,
141 LM3697_CTRL_ENABLE,
142 ctrl_en_val, ctrl_en_val);
143 if (ret) {
144 dev_err(&led->priv->client->dev,
145 "Cannot enable the device\n");
146 goto brightness_out;
147 }
148
149 led->enabled = brt_val;
150 }
151 }
152
153 brightness_out:
154 mutex_unlock(&led->priv->lock);
155 return ret;
156 }
157
lm3697_init(struct lm3697 * priv)158 static int lm3697_init(struct lm3697 *priv)
159 {
160 struct lm3697_led *led;
161 int i, ret;
162
163 if (priv->enable_gpio) {
164 gpiod_direction_output(priv->enable_gpio, 1);
165 } else {
166 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);
167 if (ret) {
168 dev_err(&priv->client->dev, "Cannot reset the device\n");
169 goto out;
170 }
171 }
172
173 ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);
174 if (ret) {
175 dev_err(&priv->client->dev, "Cannot write ctrl enable\n");
176 goto out;
177 }
178
179 ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);
180 if (ret)
181 dev_err(&priv->client->dev, "Cannot write OUTPUT config\n");
182
183 for (i = 0; i < LM3697_MAX_CONTROL_BANKS; i++) {
184 led = &priv->leds[i];
185 ret = ti_lmu_common_set_ramp(&led->lmu_data);
186 if (ret)
187 dev_err(&priv->client->dev, "Setting the ramp rate failed\n");
188 }
189 out:
190 return ret;
191 }
192
lm3697_probe_dt(struct lm3697 * priv)193 static int lm3697_probe_dt(struct lm3697 *priv)
194 {
195 struct fwnode_handle *child = NULL;
196 struct lm3697_led *led;
197 const char *name;
198 int control_bank;
199 size_t i = 0;
200 int ret = -EINVAL;
201 int j;
202
203 priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev,
204 "enable", GPIOD_OUT_LOW);
205 if (IS_ERR(priv->enable_gpio)) {
206 ret = PTR_ERR(priv->enable_gpio);
207 dev_err(&priv->client->dev, "Failed to get enable gpio: %d\n",
208 ret);
209 return ret;
210 }
211
212 priv->regulator = devm_regulator_get(&priv->client->dev, "vled");
213 if (IS_ERR(priv->regulator))
214 priv->regulator = NULL;
215
216 device_for_each_child_node(priv->dev, child) {
217 ret = fwnode_property_read_u32(child, "reg", &control_bank);
218 if (ret) {
219 dev_err(&priv->client->dev, "reg property missing\n");
220 fwnode_handle_put(child);
221 goto child_out;
222 }
223
224 if (control_bank > LM3697_CONTROL_B) {
225 dev_err(&priv->client->dev, "reg property is invalid\n");
226 ret = -EINVAL;
227 fwnode_handle_put(child);
228 goto child_out;
229 }
230
231 led = &priv->leds[i];
232
233 ret = ti_lmu_common_get_brt_res(&priv->client->dev,
234 child, &led->lmu_data);
235 if (ret)
236 dev_warn(&priv->client->dev, "brightness resolution property missing\n");
237
238 led->control_bank = control_bank;
239 led->lmu_data.regmap = priv->regmap;
240 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
241 control_bank;
242 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
243 led->control_bank * 2;
244 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
245 led->control_bank * 2;
246
247 led->num_leds = fwnode_property_count_u32(child, "led-sources");
248 if (led->num_leds > LM3697_MAX_LED_STRINGS) {
249 dev_err(&priv->client->dev, "To many LED strings defined\n");
250 continue;
251 }
252
253 ret = fwnode_property_read_u32_array(child, "led-sources",
254 led->hvled_strings,
255 led->num_leds);
256 if (ret) {
257 dev_err(&priv->client->dev, "led-sources property missing\n");
258 fwnode_handle_put(child);
259 goto child_out;
260 }
261
262 for (j = 0; j < led->num_leds; j++)
263 priv->bank_cfg |=
264 (led->control_bank << led->hvled_strings[j]);
265
266 ret = ti_lmu_common_get_ramp_params(&priv->client->dev,
267 child, &led->lmu_data);
268 if (ret)
269 dev_warn(&priv->client->dev, "runtime-ramp properties missing\n");
270
271 fwnode_property_read_string(child, "linux,default-trigger",
272 &led->led_dev.default_trigger);
273
274 ret = fwnode_property_read_string(child, "label", &name);
275 if (ret)
276 snprintf(led->label, sizeof(led->label),
277 "%s::", priv->client->name);
278 else
279 snprintf(led->label, sizeof(led->label),
280 "%s:%s", priv->client->name, name);
281
282 led->priv = priv;
283 led->led_dev.name = led->label;
284 led->led_dev.max_brightness = led->lmu_data.max_brightness;
285 led->led_dev.brightness_set_blocking = lm3697_brightness_set;
286
287 ret = devm_led_classdev_register(priv->dev, &led->led_dev);
288 if (ret) {
289 dev_err(&priv->client->dev, "led register err: %d\n",
290 ret);
291 fwnode_handle_put(child);
292 goto child_out;
293 }
294
295 i++;
296 }
297
298 child_out:
299 return ret;
300 }
301
lm3697_probe(struct i2c_client * client,const struct i2c_device_id * id)302 static int lm3697_probe(struct i2c_client *client,
303 const struct i2c_device_id *id)
304 {
305 struct lm3697 *led;
306 int count;
307 int ret;
308
309 count = device_get_child_node_count(&client->dev);
310 if (!count) {
311 dev_err(&client->dev, "LEDs are not defined in device tree!");
312 return -ENODEV;
313 }
314
315 led = devm_kzalloc(&client->dev, struct_size(led, leds, count),
316 GFP_KERNEL);
317 if (!led)
318 return -ENOMEM;
319
320 mutex_init(&led->lock);
321 i2c_set_clientdata(client, led);
322
323 led->client = client;
324 led->dev = &client->dev;
325 led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config);
326 if (IS_ERR(led->regmap)) {
327 ret = PTR_ERR(led->regmap);
328 dev_err(&client->dev, "Failed to allocate register map: %d\n",
329 ret);
330 return ret;
331 }
332
333 ret = lm3697_probe_dt(led);
334 if (ret)
335 return ret;
336
337 return lm3697_init(led);
338 }
339
lm3697_remove(struct i2c_client * client)340 static int lm3697_remove(struct i2c_client *client)
341 {
342 struct lm3697 *led = i2c_get_clientdata(client);
343 int ret;
344
345 ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,
346 LM3697_CTRL_A_B_EN, 0);
347 if (ret) {
348 dev_err(&led->client->dev, "Failed to disable the device\n");
349 return ret;
350 }
351
352 if (led->enable_gpio)
353 gpiod_direction_output(led->enable_gpio, 0);
354
355 if (led->regulator) {
356 ret = regulator_disable(led->regulator);
357 if (ret)
358 dev_err(&led->client->dev,
359 "Failed to disable regulator\n");
360 }
361
362 mutex_destroy(&led->lock);
363
364 return 0;
365 }
366
367 static const struct i2c_device_id lm3697_id[] = {
368 { "lm3697", 0 },
369 { }
370 };
371 MODULE_DEVICE_TABLE(i2c, lm3697_id);
372
373 static const struct of_device_id of_lm3697_leds_match[] = {
374 { .compatible = "ti,lm3697", },
375 {},
376 };
377 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
378
379 static struct i2c_driver lm3697_driver = {
380 .driver = {
381 .name = "lm3697",
382 .of_match_table = of_lm3697_leds_match,
383 },
384 .probe = lm3697_probe,
385 .remove = lm3697_remove,
386 .id_table = lm3697_id,
387 };
388 module_i2c_driver(lm3697_driver);
389
390 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
391 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
392 MODULE_LICENSE("GPL v2");
393