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(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
162brightness_out:
163	mutex_unlock(&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(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	}
199out:
200	return ret;
201}
202
203static 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
297child_out:
298	fwnode_handle_put(child);
299	return ret;
300}
301
302static 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
339static 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
362static const struct i2c_device_id lm3697_id[] = {
363	{ "lm3697", 0 },
364	{ }
365};
366MODULE_DEVICE_TABLE(i2c, lm3697_id);
367
368static const struct of_device_id of_lm3697_leds_match[] = {
369	{ .compatible = "ti,lm3697", },
370	{},
371};
372MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
373
374static 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};
383module_i2c_driver(lm3697_driver);
384
385MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
386MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
387MODULE_LICENSE("GPL v2");
388