xref: /linux/drivers/leds/leds-lm3697.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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