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