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 */
58struct 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 */
81struct 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
95static 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
112static 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
122static 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(map: led->priv->regmap, LM3697_CTRL_ENABLE,
135 mask: ctrl_en_val, 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(lmu_bank: &led->lmu_data, brightness: 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(map: led->priv->regmap,
151 LM3697_CTRL_ENABLE,
152 mask: ctrl_en_val, 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
162brightness_out:
163 mutex_unlock(lock: &led->priv->lock);
164 return ret;
165}
166
167static 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(desc: priv->enable_gpio, value: 1);
175 } else {
176 ret = regmap_write(map: 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(map: priv->regmap, LM3697_CTRL_ENABLE, val: 0x0);
184 if (ret) {
185 dev_err(dev, "Cannot write ctrl enable\n");
186 goto out;
187 }
188
189 ret = regmap_write(map: priv->regmap, LM3697_OUTPUT_CONFIG, val: 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(lmu_bank: &led->lmu_data);
196 if (ret)
197 dev_err(dev, "Setting the ramp rate failed\n");
198 }
199out:
200 return ret;
201}
202
203static int lm3697_probe_dt(struct lm3697 *priv)
204{
205 struct device *dev = priv->dev;
206 struct lm3697_led *led;
207 int ret = -EINVAL;
208 int control_bank;
209 size_t i = 0;
210 int j;
211
212 priv->enable_gpio = devm_gpiod_get_optional(dev, con_id: "enable",
213 flags: GPIOD_OUT_LOW);
214 if (IS_ERR(ptr: priv->enable_gpio))
215 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->enable_gpio),
216 fmt: "Failed to get enable GPIO\n");
217
218 priv->regulator = devm_regulator_get(dev, id: "vled");
219 if (IS_ERR(ptr: priv->regulator))
220 priv->regulator = NULL;
221
222 device_for_each_child_node_scoped(dev, child) {
223 struct led_init_data init_data = {};
224
225 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &control_bank);
226 if (ret) {
227 dev_err(dev, "reg property missing\n");
228 return ret;
229 }
230
231 if (control_bank > LM3697_CONTROL_B) {
232 dev_err(dev, "reg property is invalid\n");
233 return -EINVAL;
234 }
235
236 led = &priv->leds[i];
237
238 ret = ti_lmu_common_get_brt_res(dev, child, lmu_data: &led->lmu_data);
239 if (ret)
240 dev_warn(dev,
241 "brightness resolution property missing\n");
242
243 led->control_bank = control_bank;
244 led->lmu_data.regmap = priv->regmap;
245 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
246 control_bank;
247 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
248 led->control_bank * 2;
249 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
250 led->control_bank * 2;
251
252 led->num_leds = fwnode_property_count_u32(fwnode: child, propname: "led-sources");
253 if (led->num_leds > LM3697_MAX_LED_STRINGS) {
254 dev_err(dev, "Too many LED strings defined\n");
255 continue;
256 }
257
258 ret = fwnode_property_read_u32_array(fwnode: child, propname: "led-sources",
259 val: led->hvled_strings,
260 nval: led->num_leds);
261 if (ret) {
262 dev_err(dev, "led-sources property missing\n");
263 return ret;
264 }
265
266 for (j = 0; j < led->num_leds; j++)
267 priv->bank_cfg |=
268 (led->control_bank << led->hvled_strings[j]);
269
270 ret = ti_lmu_common_get_ramp_params(dev, child, lmu_data: &led->lmu_data);
271 if (ret)
272 dev_warn(dev, "runtime-ramp properties missing\n");
273
274 init_data.fwnode = child;
275 init_data.devicename = priv->client->name;
276 /* for backwards compatibility if `label` is not present */
277 init_data.default_label = ":";
278
279 led->priv = priv;
280 led->led_dev.max_brightness = led->lmu_data.max_brightness;
281 led->led_dev.brightness_set_blocking = lm3697_brightness_set;
282
283 ret = devm_led_classdev_register_ext(parent: dev, led_cdev: &led->led_dev,
284 init_data: &init_data);
285 if (ret) {
286 dev_err(dev, "led register err: %d\n", ret);
287 return ret;
288 }
289
290 i++;
291 }
292
293 return 0;
294}
295
296static int lm3697_probe(struct i2c_client *client)
297{
298 struct device *dev = &client->dev;
299 struct lm3697 *led;
300 int count;
301 int ret;
302
303 count = device_get_child_node_count(dev);
304 if (!count || count > LM3697_MAX_CONTROL_BANKS) {
305 dev_err(dev, "Strange device tree!");
306 return -ENODEV;
307 }
308
309 led = devm_kzalloc(dev, struct_size(led, leds, count), GFP_KERNEL);
310 if (!led)
311 return -ENOMEM;
312
313 mutex_init(&led->lock);
314 i2c_set_clientdata(client, data: led);
315
316 led->client = client;
317 led->dev = dev;
318 led->num_banks = count;
319 led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config);
320 if (IS_ERR(ptr: led->regmap)) {
321 ret = PTR_ERR(ptr: led->regmap);
322 dev_err(dev, "Failed to allocate register map: %d\n", ret);
323 return ret;
324 }
325
326 ret = lm3697_probe_dt(priv: led);
327 if (ret)
328 return ret;
329
330 return lm3697_init(priv: led);
331}
332
333static void lm3697_remove(struct i2c_client *client)
334{
335 struct lm3697 *led = i2c_get_clientdata(client);
336 struct device *dev = &led->client->dev;
337 int ret;
338
339 ret = regmap_update_bits(map: led->regmap, LM3697_CTRL_ENABLE,
340 LM3697_CTRL_A_B_EN, val: 0);
341 if (ret)
342 dev_err(dev, "Failed to disable the device\n");
343
344 if (led->enable_gpio)
345 gpiod_direction_output(desc: led->enable_gpio, value: 0);
346
347 if (led->regulator) {
348 ret = regulator_disable(regulator: led->regulator);
349 if (ret)
350 dev_err(dev, "Failed to disable regulator\n");
351 }
352
353 mutex_destroy(lock: &led->lock);
354}
355
356static const struct i2c_device_id lm3697_id[] = {
357 { "lm3697" },
358 { }
359};
360MODULE_DEVICE_TABLE(i2c, lm3697_id);
361
362static const struct of_device_id of_lm3697_leds_match[] = {
363 { .compatible = "ti,lm3697", },
364 {},
365};
366MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
367
368static struct i2c_driver lm3697_driver = {
369 .driver = {
370 .name = "lm3697",
371 .of_match_table = of_lm3697_leds_match,
372 },
373 .probe = lm3697_probe,
374 .remove = lm3697_remove,
375 .id_table = lm3697_id,
376};
377module_i2c_driver(lm3697_driver);
378
379MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
380MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
381MODULE_LICENSE("GPL v2");
382

Provided by KDAB

Privacy Policy
Improve your Profiling and Debugging skills
Find out more

source code of linux/drivers/leds/leds-lm3697.c