xref: /linux/drivers/video/backlight/aw99706.c (revision c31f4aa8fed048fa70e742c4bb49bb48dc489ab3) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * aw99706 - Backlight driver for the AWINIC AW99706
4  *
5  * Copyright (C) 2025 Junjie Cao <caojunjie650@gmail.com>
6  * Copyright (C) 2025 Pengyu Luo <mitltlatltl@gmail.com>
7  *
8  * Based on vendor driver:
9  * Copyright (c) 2023 AWINIC Technology CO., LTD
10  */
11 
12 #include <linux/backlight.h>
13 #include <linux/bitfield.h>
14 #include <linux/delay.h>
15 #include <linux/gpio.h>
16 #include <linux/i2c.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/regmap.h>
20 
21 #define AW99706_MAX_BRT_LVL		4095
22 #define AW99706_REG_MAX			0x1F
23 #define AW99706_ID			0x07
24 
25 /* registers list */
26 #define AW99706_CFG0_REG			0x00
27 #define AW99706_DIM_MODE_MASK			GENMASK(1, 0)
28 
29 #define AW99706_CFG1_REG			0x01
30 #define AW99706_SW_FREQ_MASK			GENMASK(3, 0)
31 #define AW99706_SW_ILMT_MASK			GENMASK(5, 4)
32 
33 #define AW99706_CFG2_REG			0x02
34 #define AW99706_ILED_MAX_MASK			GENMASK(6, 0)
35 #define AW99706_UVLOSEL_MASK			BIT(7)
36 
37 #define AW99706_CFG3_REG			0x03
38 #define AW99706_CFG4_REG			0x04
39 #define AW99706_BRT_MSB_MASK			GENMASK(3, 0)
40 
41 #define AW99706_CFG5_REG			0x05
42 #define AW99706_BRT_LSB_MASK			GENMASK(7, 0)
43 
44 #define AW99706_CFG6_REG			0x06
45 #define AW99706_RAMP_CTL_MASK			GENMASK(7, 6)
46 
47 #define AW99706_CFG7_REG			0x07
48 #define AW99706_CFG8_REG			0x08
49 #define AW99706_CFG9_REG			0x09
50 #define AW99706_CFGA_REG			0x0A
51 #define AW99706_CFGB_REG			0x0B
52 #define AW99706_CFGC_REG			0x0C
53 #define AW99706_CFGD_REG			0x0D
54 #define AW99706_FLAG_REG			0x10
55 #define AW99706_BACKLIGHT_EN_MASK		BIT(7)
56 
57 #define AW99706_CHIPID_REG			0x11
58 #define AW99706_LED_OPEN_FLAG_REG		0x12
59 #define AW99706_LED_SHORT_FLAG_REG		0x13
60 #define AW99706_MTPLDOSEL_REG			0x1E
61 #define AW99706_MTPRUN_REG			0x1F
62 
63 #define RESV	0
64 
65 /* Boost switching frequency table, in Hz */
66 static const u32 aw99706_sw_freq_tbl[] = {
67 	RESV, RESV, RESV, RESV, 300000, 400000, 500000, 600000,
68 	660000, 750000, 850000, 1000000, 1200000, 1330000, 1500000, 1700000
69 };
70 
71 /* Switching current limitation table, in uA */
72 static const u32 aw99706_sw_ilmt_tbl[] = {
73 	1500000, 2000000, 2500000, 3000000
74 };
75 
76 /* ULVO threshold table, in uV */
77 static const u32 aw99706_ulvo_thres_tbl[] = {
78 	2200000, 5000000
79 };
80 
81 struct aw99706_dt_prop {
82 	const char * const name;
83 	int (*lookup)(const struct aw99706_dt_prop *prop, u32 dt_val, u8 *val);
84 	const u32 * const lookup_tbl;
85 	u8 tbl_size;
86 	u8 reg;
87 	u8 mask;
88 	u32 def_val;
89 };
90 
91 static int aw99706_dt_property_lookup(const struct aw99706_dt_prop *prop,
92 				      u32 dt_val, u8 *val)
93 {
94 	int i;
95 
96 	if (!prop->lookup_tbl) {
97 		*val = dt_val;
98 		return 0;
99 	}
100 
101 	for (i = 0; i < prop->tbl_size; i++)
102 		if (prop->lookup_tbl[i] == dt_val)
103 			break;
104 
105 	*val = i;
106 
107 	return i == prop->tbl_size ? -1 : 0;
108 }
109 
110 #define MIN_ILED_MAX	5000
111 #define MAX_ILED_MAX	50000
112 #define STEP_ILED_MAX	500
113 
114 static int
115 aw99706_dt_property_iled_max_convert(const struct aw99706_dt_prop *prop,
116 				     u32 dt_val, u8 *val)
117 {
118 	if (dt_val > MAX_ILED_MAX || dt_val < MIN_ILED_MAX)
119 		return -1;
120 
121 	*val = (dt_val - MIN_ILED_MAX) / STEP_ILED_MAX;
122 
123 	return (dt_val - MIN_ILED_MAX) % STEP_ILED_MAX;
124 }
125 
126 static const struct aw99706_dt_prop aw99706_dt_props[] = {
127 	{
128 		"awinic,dim-mode", aw99706_dt_property_lookup,
129 		NULL, 0,
130 		AW99706_CFG0_REG, AW99706_DIM_MODE_MASK, 1,
131 	},
132 	{
133 		"awinic,sw-freq", aw99706_dt_property_lookup,
134 		aw99706_sw_freq_tbl, ARRAY_SIZE(aw99706_sw_freq_tbl),
135 		AW99706_CFG1_REG, AW99706_SW_FREQ_MASK, 750000,
136 	},
137 	{
138 		"awinic,sw-ilmt", aw99706_dt_property_lookup,
139 		aw99706_sw_ilmt_tbl, ARRAY_SIZE(aw99706_sw_ilmt_tbl),
140 		AW99706_CFG1_REG, AW99706_SW_ILMT_MASK, 3000000,
141 	},
142 	{
143 		"awinic,iled-max", aw99706_dt_property_iled_max_convert,
144 		NULL, 0,
145 		AW99706_CFG2_REG, AW99706_ILED_MAX_MASK, 20000,
146 
147 	},
148 	{
149 		"awinic,uvlo-thres", aw99706_dt_property_lookup,
150 		aw99706_ulvo_thres_tbl, ARRAY_SIZE(aw99706_ulvo_thres_tbl),
151 		AW99706_CFG2_REG, AW99706_UVLOSEL_MASK, 2200000,
152 	},
153 	{
154 		"awinic,ramp-ctl", aw99706_dt_property_lookup,
155 		NULL, 0,
156 		AW99706_CFG6_REG, AW99706_RAMP_CTL_MASK, 2,
157 	}
158 };
159 
160 struct reg_init_data {
161 	u8 reg;
162 	u8 mask;
163 	u8 val;
164 };
165 
166 struct aw99706_device {
167 	struct i2c_client *client;
168 	struct device *dev;
169 	struct regmap *regmap;
170 	struct backlight_device *bl_dev;
171 	struct gpio_desc *hwen_gpio;
172 	struct reg_init_data init_tbl[ARRAY_SIZE(aw99706_dt_props)];
173 	bool bl_enable;
174 };
175 
176 enum reg_access {
177 	REG_NONE_ACCESS	= 0,
178 	REG_RD_ACCESS	= 1,
179 	REG_WR_ACCESS	= 2,
180 };
181 
182 static const u8 aw99706_regs[AW99706_REG_MAX + 1] = {
183 	[AW99706_CFG0_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
184 	[AW99706_CFG1_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
185 	[AW99706_CFG2_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
186 	[AW99706_CFG3_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
187 	[AW99706_CFG4_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
188 	[AW99706_CFG5_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
189 	[AW99706_CFG6_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
190 	[AW99706_CFG7_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
191 	[AW99706_CFG8_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
192 	[AW99706_CFG9_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
193 	[AW99706_CFGA_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
194 	[AW99706_CFGB_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
195 	[AW99706_CFGC_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
196 	[AW99706_CFGD_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
197 	[AW99706_FLAG_REG]		= REG_RD_ACCESS,
198 	[AW99706_CHIPID_REG]		= REG_RD_ACCESS,
199 	[AW99706_LED_OPEN_FLAG_REG]	= REG_RD_ACCESS,
200 	[AW99706_LED_SHORT_FLAG_REG]	= REG_RD_ACCESS,
201 
202 	/*
203 	 * Write bit is dropped here, writing BIT(0) to MTPLDOSEL will unlock
204 	 * Multi-time Programmable (MTP).
205 	 */
206 	[AW99706_MTPLDOSEL_REG]		= REG_RD_ACCESS,
207 	[AW99706_MTPRUN_REG]		= REG_NONE_ACCESS,
208 };
209 
210 static bool aw99706_readable_reg(struct device *dev, unsigned int reg)
211 {
212 	return aw99706_regs[reg] & REG_RD_ACCESS;
213 }
214 
215 static bool aw99706_writeable_reg(struct device *dev, unsigned int reg)
216 {
217 	return aw99706_regs[reg] & REG_WR_ACCESS;
218 }
219 
220 static inline int aw99706_i2c_read(struct aw99706_device *aw, u8 reg,
221 				   unsigned int *val)
222 {
223 	return regmap_read(aw->regmap, reg, val);
224 }
225 
226 static inline int aw99706_i2c_write(struct aw99706_device *aw, u8 reg, u8 val)
227 {
228 	return regmap_write(aw->regmap, reg, val);
229 }
230 
231 static inline int aw99706_i2c_update_bits(struct aw99706_device *aw, u8 reg,
232 					  u8 mask, u8 val)
233 {
234 	return regmap_update_bits(aw->regmap, reg, mask, val);
235 }
236 
237 static void aw99706_dt_parse(struct aw99706_device *aw,
238 			     struct backlight_properties *bl_props)
239 {
240 	const struct aw99706_dt_prop *prop;
241 	u32 dt_val;
242 	int ret, i;
243 	u8 val;
244 
245 	for (i = 0; i < ARRAY_SIZE(aw99706_dt_props); i++) {
246 		prop = &aw99706_dt_props[i];
247 		ret = device_property_read_u32(aw->dev, prop->name, &dt_val);
248 		if (ret < 0)
249 			dt_val = prop->def_val;
250 
251 		if (prop->lookup(prop, dt_val, &val)) {
252 			dev_warn(aw->dev, "invalid value %d for property %s, using default value %d\n",
253 				 dt_val, prop->name, prop->def_val);
254 
255 			prop->lookup(prop, prop->def_val, &val);
256 		}
257 
258 		aw->init_tbl[i].reg = prop->reg;
259 		aw->init_tbl[i].mask = prop->mask;
260 		aw->init_tbl[i].val = val << __ffs(prop->mask);
261 	}
262 
263 	bl_props->brightness = AW99706_MAX_BRT_LVL >> 1;
264 	bl_props->max_brightness = AW99706_MAX_BRT_LVL;
265 	device_property_read_u32(aw->dev, "default-brightness",
266 				 &bl_props->brightness);
267 	device_property_read_u32(aw->dev, "max-brightness",
268 				 &bl_props->max_brightness);
269 
270 	if (bl_props->max_brightness > AW99706_MAX_BRT_LVL)
271 		bl_props->max_brightness = AW99706_MAX_BRT_LVL;
272 
273 	if (bl_props->brightness > bl_props->max_brightness)
274 		bl_props->brightness = bl_props->max_brightness;
275 }
276 
277 static int aw99706_hw_init(struct aw99706_device *aw)
278 {
279 	int ret, i;
280 
281 	gpiod_set_value_cansleep(aw->hwen_gpio, 1);
282 
283 	for (i = 0; i < ARRAY_SIZE(aw->init_tbl); i++) {
284 		ret = aw99706_i2c_update_bits(aw, aw->init_tbl[i].reg,
285 					      aw->init_tbl[i].mask,
286 					      aw->init_tbl[i].val);
287 		if (ret < 0) {
288 			dev_err(aw->dev, "Failed to write init data %d\n", ret);
289 			return ret;
290 		}
291 	}
292 
293 	return 0;
294 }
295 
296 static int aw99706_bl_enable(struct aw99706_device *aw, bool en)
297 {
298 	int ret;
299 	u8 val;
300 
301 	val = FIELD_PREP(AW99706_BACKLIGHT_EN_MASK, en);
302 	ret = aw99706_i2c_update_bits(aw, AW99706_CFGD_REG,
303 				      AW99706_BACKLIGHT_EN_MASK, val);
304 	if (ret)
305 		dev_err(aw->dev, "Failed to enable backlight!\n");
306 
307 	return ret;
308 }
309 
310 static int aw99706_update_brightness(struct aw99706_device *aw, u32 brt_lvl)
311 {
312 	bool bl_enable_now = !!brt_lvl;
313 	int ret;
314 
315 	ret = aw99706_i2c_write(aw, AW99706_CFG4_REG,
316 				(brt_lvl >> 8) & AW99706_BRT_MSB_MASK);
317 	if (ret < 0)
318 		return ret;
319 
320 	ret = aw99706_i2c_write(aw, AW99706_CFG5_REG,
321 				brt_lvl & AW99706_BRT_LSB_MASK);
322 	if (ret < 0)
323 		return ret;
324 
325 	if (aw->bl_enable != bl_enable_now) {
326 		ret = aw99706_bl_enable(aw, bl_enable_now);
327 		if (!ret)
328 			aw->bl_enable = bl_enable_now;
329 	}
330 
331 	return ret;
332 }
333 
334 static int aw99706_bl_update_status(struct backlight_device *bl)
335 {
336 	struct aw99706_device *aw = bl_get_data(bl);
337 
338 	return aw99706_update_brightness(aw, bl->props.brightness);
339 }
340 
341 static const struct backlight_ops aw99706_bl_ops = {
342 	.options = BL_CORE_SUSPENDRESUME,
343 	.update_status = aw99706_bl_update_status,
344 };
345 
346 static const struct regmap_config aw99706_regmap_config = {
347 	.reg_bits = 8,
348 	.val_bits = 8,
349 	.max_register = AW99706_REG_MAX,
350 	.writeable_reg = aw99706_writeable_reg,
351 	.readable_reg = aw99706_readable_reg,
352 };
353 
354 static int aw99706_chip_id_read(struct aw99706_device *aw)
355 {
356 	int ret;
357 	unsigned int val;
358 
359 	ret = aw99706_i2c_read(aw, AW99706_CHIPID_REG, &val);
360 	if (ret < 0)
361 		return ret;
362 
363 	return val;
364 }
365 
366 static int aw99706_probe(struct i2c_client *client)
367 {
368 	struct device *dev = &client->dev;
369 	struct aw99706_device *aw;
370 	struct backlight_device *bl_dev;
371 	struct backlight_properties props = {};
372 	int ret = 0;
373 
374 	aw = devm_kzalloc(dev, sizeof(*aw), GFP_KERNEL);
375 	if (!aw)
376 		return -ENOMEM;
377 
378 	aw->client = client;
379 	aw->dev = dev;
380 	i2c_set_clientdata(client, aw);
381 
382 	aw->regmap = devm_regmap_init_i2c(client, &aw99706_regmap_config);
383 	if (IS_ERR(aw->regmap))
384 		return dev_err_probe(dev, PTR_ERR(aw->regmap),
385 				     "Failed to init regmap\n");
386 
387 	ret = aw99706_chip_id_read(aw);
388 	if (ret != AW99706_ID)
389 		return dev_err_probe(dev, -ENODEV,
390 				     "Unknown chip id 0x%02x\n", ret);
391 
392 	aw99706_dt_parse(aw, &props);
393 
394 	aw->hwen_gpio = devm_gpiod_get(aw->dev, "enable", GPIOD_OUT_LOW);
395 	if (IS_ERR(aw->hwen_gpio))
396 		return dev_err_probe(dev, PTR_ERR(aw->hwen_gpio),
397 				     "Failed to get enable gpio\n");
398 
399 	ret = aw99706_hw_init(aw);
400 	if (ret < 0)
401 		return dev_err_probe(dev, ret,
402 				     "Failed to initialize the chip\n");
403 
404 	props.type = BACKLIGHT_RAW;
405 	props.scale = BACKLIGHT_SCALE_LINEAR;
406 
407 	bl_dev = devm_backlight_device_register(dev, "aw99706-backlight", dev,
408 						aw, &aw99706_bl_ops, &props);
409 	if (IS_ERR(bl_dev))
410 		return dev_err_probe(dev, PTR_ERR(bl_dev),
411 				     "Failed to register backlight!\n");
412 
413 	aw->bl_dev = bl_dev;
414 
415 	return 0;
416 }
417 
418 static void aw99706_remove(struct i2c_client *client)
419 {
420 	struct aw99706_device *aw = i2c_get_clientdata(client);
421 
422 	aw99706_update_brightness(aw, 0);
423 
424 	msleep(50);
425 
426 	gpiod_set_value_cansleep(aw->hwen_gpio, 0);
427 }
428 
429 static int aw99706_suspend(struct device *dev)
430 {
431 	struct aw99706_device *aw = dev_get_drvdata(dev);
432 
433 	return aw99706_update_brightness(aw, 0);
434 }
435 
436 static int aw99706_resume(struct device *dev)
437 {
438 	struct aw99706_device *aw = dev_get_drvdata(dev);
439 
440 	return aw99706_hw_init(aw);
441 }
442 
443 static DEFINE_SIMPLE_DEV_PM_OPS(aw99706_pm_ops, aw99706_suspend, aw99706_resume);
444 
445 static const struct i2c_device_id aw99706_ids[] = {
446 	{ "aw99706" },
447 	{ }
448 };
449 MODULE_DEVICE_TABLE(i2c, aw99706_ids);
450 
451 static const struct of_device_id aw99706_match_table[] = {
452 	{ .compatible = "awinic,aw99706", },
453 	{ }
454 };
455 MODULE_DEVICE_TABLE(of, aw99706_match_table);
456 
457 static struct i2c_driver aw99706_i2c_driver = {
458 	.probe = aw99706_probe,
459 	.remove = aw99706_remove,
460 	.id_table = aw99706_ids,
461 	.driver = {
462 		.name = "aw99706",
463 		.of_match_table = aw99706_match_table,
464 		.pm = pm_ptr(&aw99706_pm_ops),
465 	},
466 };
467 
468 module_i2c_driver(aw99706_i2c_driver);
469 
470 MODULE_LICENSE("GPL v2");
471 MODULE_DESCRIPTION("BackLight driver for aw99706");
472