1 // SPDX-License-Identifier: GPL-2.0
2 // TI LM3697 LED chip family driver
3 // Copyright (C) 2018 Texas Instruments Incorporated - https://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 int num_banks;
82
83 struct lm3697_led leds[];
84 };
85
86 static const struct reg_default lm3697_reg_defs[] = {
87 {LM3697_OUTPUT_CONFIG, 0x6},
88 {LM3697_CTRL_A_RAMP, 0x0},
89 {LM3697_CTRL_B_RAMP, 0x0},
90 {LM3697_CTRL_A_B_RT_RAMP, 0x0},
91 {LM3697_CTRL_A_B_RAMP_CFG, 0x0},
92 {LM3697_CTRL_A_B_BRT_CFG, 0x0},
93 {LM3697_CTRL_A_FS_CURR_CFG, 0x13},
94 {LM3697_CTRL_B_FS_CURR_CFG, 0x13},
95 {LM3697_PWM_CFG, 0xc},
96 {LM3697_CTRL_A_BRT_LSB, 0x0},
97 {LM3697_CTRL_A_BRT_MSB, 0x0},
98 {LM3697_CTRL_B_BRT_LSB, 0x0},
99 {LM3697_CTRL_B_BRT_MSB, 0x0},
100 {LM3697_CTRL_ENABLE, 0x0},
101 };
102
103 static const struct regmap_config lm3697_regmap_config = {
104 .reg_bits = 8,
105 .val_bits = 8,
106
107 .max_register = LM3697_CTRL_ENABLE,
108 .reg_defaults = lm3697_reg_defs,
109 .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),
110 .cache_type = REGCACHE_FLAT,
111 };
112
lm3697_brightness_set(struct led_classdev * led_cdev,enum led_brightness brt_val)113 static int lm3697_brightness_set(struct led_classdev *led_cdev,
114 enum led_brightness brt_val)
115 {
116 struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,
117 led_dev);
118 int ctrl_en_val = (1 << led->control_bank);
119 struct device *dev = led->priv->dev;
120 int ret;
121
122 mutex_lock(&led->priv->lock);
123
124 if (brt_val == LED_OFF) {
125 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,
126 ctrl_en_val, ~ctrl_en_val);
127 if (ret) {
128 dev_err(dev, "Cannot write ctrl register\n");
129 goto brightness_out;
130 }
131
132 led->enabled = LED_OFF;
133 } else {
134 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
135 if (ret) {
136 dev_err(dev, "Cannot write brightness\n");
137 goto brightness_out;
138 }
139
140 if (!led->enabled) {
141 ret = regmap_update_bits(led->priv->regmap,
142 LM3697_CTRL_ENABLE,
143 ctrl_en_val, ctrl_en_val);
144 if (ret) {
145 dev_err(dev, "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 device *dev = priv->dev;
161 struct lm3697_led *led;
162 int i, ret;
163
164 if (priv->enable_gpio) {
165 gpiod_direction_output(priv->enable_gpio, 1);
166 } else {
167 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);
168 if (ret) {
169 dev_err(dev, "Cannot reset the device\n");
170 goto out;
171 }
172 }
173
174 ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);
175 if (ret) {
176 dev_err(dev, "Cannot write ctrl enable\n");
177 goto out;
178 }
179
180 ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);
181 if (ret)
182 dev_err(dev, "Cannot write OUTPUT config\n");
183
184 for (i = 0; i < priv->num_banks; i++) {
185 led = &priv->leds[i];
186 ret = ti_lmu_common_set_ramp(&led->lmu_data);
187 if (ret)
188 dev_err(dev, "Setting the ramp rate failed\n");
189 }
190 out:
191 return ret;
192 }
193
lm3697_probe_dt(struct lm3697 * priv)194 static int lm3697_probe_dt(struct lm3697 *priv)
195 {
196 struct fwnode_handle *child = NULL;
197 struct device *dev = priv->dev;
198 struct lm3697_led *led;
199 int ret = -EINVAL;
200 int control_bank;
201 size_t i = 0;
202 int j;
203
204 priv->enable_gpio = devm_gpiod_get_optional(dev, "enable",
205 GPIOD_OUT_LOW);
206 if (IS_ERR(priv->enable_gpio)) {
207 ret = PTR_ERR(priv->enable_gpio);
208 dev_err(dev, "Failed to get enable gpio: %d\n", ret);
209 return ret;
210 }
211
212 priv->regulator = devm_regulator_get(dev, "vled");
213 if (IS_ERR(priv->regulator))
214 priv->regulator = NULL;
215
216 device_for_each_child_node(dev, child) {
217 struct led_init_data init_data = {};
218
219 ret = fwnode_property_read_u32(child, "reg", &control_bank);
220 if (ret) {
221 dev_err(dev, "reg property missing\n");
222 fwnode_handle_put(child);
223 goto child_out;
224 }
225
226 if (control_bank > LM3697_CONTROL_B) {
227 dev_err(dev, "reg property is invalid\n");
228 ret = -EINVAL;
229 fwnode_handle_put(child);
230 goto child_out;
231 }
232
233 led = &priv->leds[i];
234
235 ret = ti_lmu_common_get_brt_res(dev, child, &led->lmu_data);
236 if (ret)
237 dev_warn(dev,
238 "brightness resolution property missing\n");
239
240 led->control_bank = control_bank;
241 led->lmu_data.regmap = priv->regmap;
242 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
243 control_bank;
244 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
245 led->control_bank * 2;
246 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
247 led->control_bank * 2;
248
249 led->num_leds = fwnode_property_count_u32(child, "led-sources");
250 if (led->num_leds > LM3697_MAX_LED_STRINGS) {
251 dev_err(dev, "Too many LED strings defined\n");
252 continue;
253 }
254
255 ret = fwnode_property_read_u32_array(child, "led-sources",
256 led->hvled_strings,
257 led->num_leds);
258 if (ret) {
259 dev_err(dev, "led-sources property missing\n");
260 fwnode_handle_put(child);
261 goto child_out;
262 }
263
264 for (j = 0; j < led->num_leds; j++)
265 priv->bank_cfg |=
266 (led->control_bank << led->hvled_strings[j]);
267
268 ret = ti_lmu_common_get_ramp_params(dev, child, &led->lmu_data);
269 if (ret)
270 dev_warn(dev, "runtime-ramp properties missing\n");
271
272 init_data.fwnode = child;
273 init_data.devicename = priv->client->name;
274 /* for backwards compatibility if `label` is not present */
275 init_data.default_label = ":";
276
277 led->priv = priv;
278 led->led_dev.max_brightness = led->lmu_data.max_brightness;
279 led->led_dev.brightness_set_blocking = lm3697_brightness_set;
280
281 ret = devm_led_classdev_register_ext(dev, &led->led_dev,
282 &init_data);
283 if (ret) {
284 dev_err(dev, "led register err: %d\n", ret);
285 fwnode_handle_put(child);
286 goto child_out;
287 }
288
289 i++;
290 }
291
292 child_out:
293 return ret;
294 }
295
lm3697_probe(struct i2c_client * client,const struct i2c_device_id * id)296 static int lm3697_probe(struct i2c_client *client,
297 const struct i2c_device_id *id)
298 {
299 struct device *dev = &client->dev;
300 struct lm3697 *led;
301 int count;
302 int ret;
303
304 count = device_get_child_node_count(dev);
305 if (!count || count > LM3697_MAX_CONTROL_BANKS) {
306 dev_err(dev, "Strange device tree!");
307 return -ENODEV;
308 }
309
310 led = devm_kzalloc(dev, struct_size(led, leds, count), GFP_KERNEL);
311 if (!led)
312 return -ENOMEM;
313
314 mutex_init(&led->lock);
315 i2c_set_clientdata(client, led);
316
317 led->client = client;
318 led->dev = dev;
319 led->num_banks = count;
320 led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config);
321 if (IS_ERR(led->regmap)) {
322 ret = PTR_ERR(led->regmap);
323 dev_err(dev, "Failed to allocate register map: %d\n", ret);
324 return ret;
325 }
326
327 ret = lm3697_probe_dt(led);
328 if (ret)
329 return ret;
330
331 return lm3697_init(led);
332 }
333
lm3697_remove(struct i2c_client * client)334 static int lm3697_remove(struct i2c_client *client)
335 {
336 struct lm3697 *led = i2c_get_clientdata(client);
337 struct device *dev = &led->client->dev;
338 int ret;
339
340 ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,
341 LM3697_CTRL_A_B_EN, 0);
342 if (ret) {
343 dev_err(dev, "Failed to disable the device\n");
344 return ret;
345 }
346
347 if (led->enable_gpio)
348 gpiod_direction_output(led->enable_gpio, 0);
349
350 if (led->regulator) {
351 ret = regulator_disable(led->regulator);
352 if (ret)
353 dev_err(dev, "Failed to disable regulator\n");
354 }
355
356 mutex_destroy(&led->lock);
357
358 return 0;
359 }
360
361 static const struct i2c_device_id lm3697_id[] = {
362 { "lm3697", 0 },
363 { }
364 };
365 MODULE_DEVICE_TABLE(i2c, lm3697_id);
366
367 static const struct of_device_id of_lm3697_leds_match[] = {
368 { .compatible = "ti,lm3697", },
369 {},
370 };
371 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
372
373 static struct i2c_driver lm3697_driver = {
374 .driver = {
375 .name = "lm3697",
376 .of_match_table = of_lm3697_leds_match,
377 },
378 .probe = lm3697_probe,
379 .remove = lm3697_remove,
380 .id_table = lm3697_id,
381 };
382 module_i2c_driver(lm3697_driver);
383
384 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
385 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
386 MODULE_LICENSE("GPL v2");
387