1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2023 Richtek Technology Corp.
4 *
5 * Authors:
6 * Alice Chen <alice_chen@richtek.com>
7 * ChiYuan Huang <cy_huang@richtek.com>
8 */
9
10 #include <linux/bitops.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/led-class-flash.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/platform_device.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21
22 #include <media/v4l2-flash-led-class.h>
23
24 enum {
25 MT6370_LED_FLASH1 = 0,
26 MT6370_LED_FLASH2,
27 MT6370_MAX_LEDS
28 };
29
30 /* Virtual definition for multicolor */
31
32 #define MT6370_REG_FLEDEN 0x17E
33 #define MT6370_REG_STRBTO 0x173
34 #define MT6370_REG_CHGSTAT2 0x1D1
35 #define MT6370_REG_FLEDSTAT1 0x1D9
36 #define MT6370_REG_FLEDISTRB(_id) (0x174 + 4 * (_id))
37 #define MT6370_REG_FLEDITOR(_id) (0x175 + 4 * (_id))
38 #define MT6370_ITORCH_MASK GENMASK(4, 0)
39 #define MT6370_ISTROBE_MASK GENMASK(6, 0)
40 #define MT6370_STRBTO_MASK GENMASK(6, 0)
41 #define MT6370_TORCHEN_MASK BIT(3)
42 #define MT6370_STROBEN_MASK BIT(2)
43 #define MT6370_FLCSEN_MASK(_id) BIT(MT6370_LED_FLASH2 - (_id))
44 #define MT6370_FLCSEN_MASK_ALL GENMASK(1, 0)
45 #define MT6370_FLEDCHGVINOVP_MASK BIT(3)
46 #define MT6370_FLED1STRBTO_MASK BIT(11)
47 #define MT6370_FLED2STRBTO_MASK BIT(10)
48 #define MT6370_FLED1STRB_MASK BIT(9)
49 #define MT6370_FLED2STRB_MASK BIT(8)
50 #define MT6370_FLED1SHORT_MASK BIT(7)
51 #define MT6370_FLED2SHORT_MASK BIT(6)
52 #define MT6370_FLEDLVF_MASK BIT(3)
53
54 #define MT6370_LED_JOINT 2
55 #define MT6370_RANGE_FLED_REG 4
56 #define MT6370_ITORCH_MIN_uA 25000
57 #define MT6370_ITORCH_STEP_uA 12500
58 #define MT6370_ITORCH_MAX_uA 400000
59 #define MT6370_ITORCH_DOUBLE_MAX_uA 800000
60 #define MT6370_ISTRB_MIN_uA 50000
61 #define MT6370_ISTRB_STEP_uA 12500
62 #define MT6370_ISTRB_MAX_uA 1500000
63 #define MT6370_ISTRB_DOUBLE_MAX_uA 3000000
64 #define MT6370_STRBTO_MIN_US 64000
65 #define MT6370_STRBTO_STEP_US 32000
66 #define MT6370_STRBTO_MAX_US 2432000
67
68 #define to_mt6370_led(ptr, member) container_of(ptr, struct mt6370_led, member)
69
70 struct mt6370_led {
71 struct led_classdev_flash flash;
72 struct v4l2_flash *v4l2_flash;
73 struct mt6370_priv *priv;
74 u8 led_no;
75 };
76
77 struct mt6370_priv {
78 struct regmap *regmap;
79 struct mutex lock;
80 unsigned int fled_strobe_used;
81 unsigned int fled_torch_used;
82 unsigned int leds_active;
83 unsigned int leds_count;
84 struct mt6370_led leds[] __counted_by(leds_count);
85 };
86
mt6370_torch_brightness_set(struct led_classdev * lcdev,enum led_brightness level)87 static int mt6370_torch_brightness_set(struct led_classdev *lcdev, enum led_brightness level)
88 {
89 struct mt6370_led *led = to_mt6370_led(lcdev, flash.led_cdev);
90 struct mt6370_priv *priv = led->priv;
91 u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
92 MT6370_FLCSEN_MASK(led->led_no);
93 u32 enable_mask = MT6370_TORCHEN_MASK | led_enable_mask;
94 u32 val = level ? led_enable_mask : 0;
95 u32 curr;
96 int ret, i;
97
98 mutex_lock(&priv->lock);
99
100 /*
101 * There is only one set of flash control logic, and this flag is used to check if 'strobe'
102 * is currently being used.
103 */
104 if (priv->fled_strobe_used) {
105 dev_warn(lcdev->dev, "Please disable strobe first [%d]\n", priv->fled_strobe_used);
106 ret = -EBUSY;
107 goto unlock;
108 }
109
110 if (level)
111 curr = priv->fled_torch_used | BIT(led->led_no);
112 else
113 curr = priv->fled_torch_used & ~BIT(led->led_no);
114
115 if (curr)
116 val |= MT6370_TORCHEN_MASK;
117
118 if (level) {
119 level -= 1;
120 if (led->led_no == MT6370_LED_JOINT) {
121 u32 flevel[MT6370_MAX_LEDS];
122
123 /*
124 * There're two flash channels in MT6370. If joint flash output is used,
125 * torch current will be averaged output from both channels.
126 */
127 flevel[0] = level / 2;
128 flevel[1] = level - flevel[0];
129 for (i = 0; i < MT6370_MAX_LEDS; i++) {
130 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(i),
131 MT6370_ITORCH_MASK, flevel[i]);
132 if (ret)
133 goto unlock;
134 }
135 } else {
136 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(led->led_no),
137 MT6370_ITORCH_MASK, level);
138 if (ret)
139 goto unlock;
140 }
141 }
142
143 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
144 if (ret)
145 goto unlock;
146
147 priv->fled_torch_used = curr;
148
149 unlock:
150 mutex_unlock(&priv->lock);
151 return ret;
152 }
153
mt6370_flash_brightness_set(struct led_classdev_flash * fl_cdev,u32 brightness)154 static int mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
155 {
156 /*
157 * Because of the current spikes when turning on the flash, the brightness should be kept
158 * by the LED framework. This empty function is used to prevent checking failure when
159 * led_classdev_flash registers ops.
160 */
161 return 0;
162 }
163
_mt6370_flash_brightness_set(struct led_classdev_flash * fl_cdev,u32 brightness)164 static int _mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
165 {
166 struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
167 struct mt6370_priv *priv = led->priv;
168 struct led_flash_setting *setting = &fl_cdev->brightness;
169 u32 val = (brightness - setting->min) / setting->step;
170 int ret, i;
171
172 if (led->led_no == MT6370_LED_JOINT) {
173 u32 flevel[MT6370_MAX_LEDS];
174
175 /*
176 * There're two flash channels in MT6370. If joint flash output is used, storbe
177 * current will be averaged output from both channels.
178 */
179 flevel[0] = val / 2;
180 flevel[1] = val - flevel[0];
181 for (i = 0; i < MT6370_MAX_LEDS; i++) {
182 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(i),
183 MT6370_ISTROBE_MASK, flevel[i]);
184 if (ret)
185 break;
186 }
187 } else {
188 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(led->led_no),
189 MT6370_ISTROBE_MASK, val);
190 }
191
192 return ret;
193 }
194
mt6370_strobe_set(struct led_classdev_flash * fl_cdev,bool state)195 static int mt6370_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
196 {
197 struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
198 struct mt6370_priv *priv = led->priv;
199 struct led_classdev *lcdev = &fl_cdev->led_cdev;
200 struct led_flash_setting *s = &fl_cdev->brightness;
201 u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
202 MT6370_FLCSEN_MASK(led->led_no);
203 u32 enable_mask = MT6370_STROBEN_MASK | led_enable_mask;
204 u32 val = state ? led_enable_mask : 0;
205 u32 curr;
206 int ret;
207
208 mutex_lock(&priv->lock);
209
210 /*
211 * There is only one set of flash control logic, and this flag is used to check if 'torch'
212 * is currently being used.
213 */
214 if (priv->fled_torch_used) {
215 dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n", priv->fled_torch_used);
216 ret = -EBUSY;
217 goto unlock;
218 }
219
220 if (state)
221 curr = priv->fled_strobe_used | BIT(led->led_no);
222 else
223 curr = priv->fled_strobe_used & ~BIT(led->led_no);
224
225 if (curr)
226 val |= MT6370_STROBEN_MASK;
227
228 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
229 if (ret) {
230 dev_err(lcdev->dev, "[%d] control current source %d fail\n", led->led_no, state);
231 goto unlock;
232 }
233
234 /*
235 * If the flash needs to turn on, configure the flash current to ramp up to the setting
236 * value. Otherwise, always revert to the minimum one.
237 */
238 ret = _mt6370_flash_brightness_set(fl_cdev, state ? s->val : s->min);
239 if (ret) {
240 dev_err(lcdev->dev, "[%d] Failed to set brightness\n", led->led_no);
241 goto unlock;
242 }
243
244 /*
245 * For the flash to turn on/off, we must wait for HW ramping up/down time 5ms/500us to
246 * prevent the unexpected problem.
247 */
248 if (!priv->fled_strobe_used && curr)
249 usleep_range(5000, 6000);
250 else if (priv->fled_strobe_used && !curr)
251 usleep_range(500, 600);
252
253 priv->fled_strobe_used = curr;
254
255 unlock:
256 mutex_unlock(&priv->lock);
257 return ret;
258 }
259
mt6370_strobe_get(struct led_classdev_flash * fl_cdev,bool * state)260 static int mt6370_strobe_get(struct led_classdev_flash *fl_cdev, bool *state)
261 {
262 struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
263 struct mt6370_priv *priv = led->priv;
264
265 mutex_lock(&priv->lock);
266 *state = !!(priv->fled_strobe_used & BIT(led->led_no));
267 mutex_unlock(&priv->lock);
268
269 return 0;
270 }
271
mt6370_timeout_set(struct led_classdev_flash * fl_cdev,u32 timeout)272 static int mt6370_timeout_set(struct led_classdev_flash *fl_cdev, u32 timeout)
273 {
274 struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
275 struct mt6370_priv *priv = led->priv;
276 struct led_flash_setting *s = &fl_cdev->timeout;
277 u32 val = (timeout - s->min) / s->step;
278
279 return regmap_update_bits(priv->regmap, MT6370_REG_STRBTO, MT6370_STRBTO_MASK, val);
280 }
281
mt6370_fault_get(struct led_classdev_flash * fl_cdev,u32 * fault)282 static int mt6370_fault_get(struct led_classdev_flash *fl_cdev, u32 *fault)
283 {
284 struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
285 struct mt6370_priv *priv = led->priv;
286 u16 fled_stat;
287 unsigned int chg_stat, strobe_timeout_mask, fled_short_mask;
288 u32 rfault = 0;
289 int ret;
290
291 ret = regmap_read(priv->regmap, MT6370_REG_CHGSTAT2, &chg_stat);
292 if (ret)
293 return ret;
294
295 ret = regmap_raw_read(priv->regmap, MT6370_REG_FLEDSTAT1, &fled_stat, sizeof(fled_stat));
296 if (ret)
297 return ret;
298
299 switch (led->led_no) {
300 case MT6370_LED_FLASH1:
301 strobe_timeout_mask = MT6370_FLED1STRBTO_MASK;
302 fled_short_mask = MT6370_FLED1SHORT_MASK;
303 break;
304
305 case MT6370_LED_FLASH2:
306 strobe_timeout_mask = MT6370_FLED2STRBTO_MASK;
307 fled_short_mask = MT6370_FLED2SHORT_MASK;
308 break;
309
310 case MT6370_LED_JOINT:
311 strobe_timeout_mask = MT6370_FLED1STRBTO_MASK | MT6370_FLED2STRBTO_MASK;
312 fled_short_mask = MT6370_FLED1SHORT_MASK | MT6370_FLED2SHORT_MASK;
313 break;
314 default:
315 return -EINVAL;
316 }
317
318 if (chg_stat & MT6370_FLEDCHGVINOVP_MASK)
319 rfault |= LED_FAULT_INPUT_VOLTAGE;
320
321 if (fled_stat & strobe_timeout_mask)
322 rfault |= LED_FAULT_TIMEOUT;
323
324 if (fled_stat & fled_short_mask)
325 rfault |= LED_FAULT_SHORT_CIRCUIT;
326
327 if (fled_stat & MT6370_FLEDLVF_MASK)
328 rfault |= LED_FAULT_UNDER_VOLTAGE;
329
330 *fault = rfault;
331 return ret;
332 }
333
334 static const struct led_flash_ops mt6370_flash_ops = {
335 .flash_brightness_set = mt6370_flash_brightness_set,
336 .strobe_set = mt6370_strobe_set,
337 .strobe_get = mt6370_strobe_get,
338 .timeout_set = mt6370_timeout_set,
339 .fault_get = mt6370_fault_get,
340 };
341
342 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
mt6370_flash_external_strobe_set(struct v4l2_flash * v4l2_flash,bool enable)343 static int mt6370_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
344 bool enable)
345 {
346 struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
347 struct mt6370_led *led = to_mt6370_led(flash, flash);
348 struct mt6370_priv *priv = led->priv;
349 u32 mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
350 MT6370_FLCSEN_MASK(led->led_no);
351 u32 val = enable ? mask : 0;
352 int ret;
353
354 mutex_lock(&priv->lock);
355
356 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, mask, val);
357 if (ret)
358 goto unlock;
359
360 if (enable)
361 priv->fled_strobe_used |= BIT(led->led_no);
362 else
363 priv->fled_strobe_used &= ~BIT(led->led_no);
364
365 unlock:
366 mutex_unlock(&priv->lock);
367 return ret;
368 }
369
370 static const struct v4l2_flash_ops v4l2_flash_ops = {
371 .external_strobe_set = mt6370_flash_external_strobe_set,
372 };
373
mt6370_init_v4l2_flash_config(struct mt6370_led * led,struct v4l2_flash_config * cfg)374 static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
375 {
376 struct led_classdev *lcdev;
377 struct led_flash_setting *s = &cfg->intensity;
378
379 lcdev = &led->flash.led_cdev;
380
381 s->min = MT6370_ITORCH_MIN_uA;
382 s->step = MT6370_ITORCH_STEP_uA;
383 s->val = s->max = s->min + (lcdev->max_brightness - 1) * s->step;
384
385 cfg->has_external_strobe = 1;
386 strscpy(cfg->dev_name, dev_name(lcdev->dev), sizeof(cfg->dev_name));
387
388 cfg->flash_faults = LED_FAULT_SHORT_CIRCUIT | LED_FAULT_TIMEOUT |
389 LED_FAULT_INPUT_VOLTAGE | LED_FAULT_UNDER_VOLTAGE;
390 }
391 #else
392 static const struct v4l2_flash_ops v4l2_flash_ops;
mt6370_init_v4l2_flash_config(struct mt6370_led * led,struct v4l2_flash_config * cfg)393 static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
394 {
395 }
396 #endif
397
mt6370_v4l2_flash_release(void * v4l2_flash)398 static void mt6370_v4l2_flash_release(void *v4l2_flash)
399 {
400 v4l2_flash_release(v4l2_flash);
401 }
402
mt6370_led_register(struct device * parent,struct mt6370_led * led,struct fwnode_handle * fwnode)403 static int mt6370_led_register(struct device *parent, struct mt6370_led *led,
404 struct fwnode_handle *fwnode)
405 {
406 struct led_init_data init_data = { .fwnode = fwnode };
407 struct v4l2_flash_config v4l2_config = {};
408 int ret;
409
410 ret = devm_led_classdev_flash_register_ext(parent, &led->flash, &init_data);
411 if (ret)
412 return dev_err_probe(parent, ret, "Couldn't register flash %d\n", led->led_no);
413
414 mt6370_init_v4l2_flash_config(led, &v4l2_config);
415 led->v4l2_flash = v4l2_flash_init(parent, fwnode, &led->flash, &v4l2_flash_ops,
416 &v4l2_config);
417 if (IS_ERR(led->v4l2_flash))
418 return dev_err_probe(parent, PTR_ERR(led->v4l2_flash),
419 "Failed to register %d v4l2 sd\n", led->led_no);
420
421 return devm_add_action_or_reset(parent, mt6370_v4l2_flash_release, led->v4l2_flash);
422 }
423
mt6370_clamp(u32 val,u32 min,u32 max,u32 step)424 static u32 mt6370_clamp(u32 val, u32 min, u32 max, u32 step)
425 {
426 u32 retval;
427
428 retval = clamp_val(val, min, max);
429 if (step > 1)
430 retval = rounddown(retval - min, step) + min;
431
432 return retval;
433 }
434
mt6370_init_flash_properties(struct device * dev,struct mt6370_led * led,struct fwnode_handle * fwnode)435 static int mt6370_init_flash_properties(struct device *dev, struct mt6370_led *led,
436 struct fwnode_handle *fwnode)
437 {
438 struct led_classdev_flash *flash = &led->flash;
439 struct led_classdev *lcdev = &flash->led_cdev;
440 struct mt6370_priv *priv = led->priv;
441 struct led_flash_setting *s;
442 u32 sources[MT6370_MAX_LEDS];
443 u32 max_ua, val;
444 int i, ret, num;
445
446 num = fwnode_property_count_u32(fwnode, "led-sources");
447 if (num < 1)
448 return dev_err_probe(dev, -EINVAL,
449 "Not specified or wrong number of led-sources\n");
450
451 ret = fwnode_property_read_u32_array(fwnode, "led-sources", sources, num);
452 if (ret)
453 return ret;
454
455 for (i = 0; i < num; i++) {
456 if (sources[i] >= MT6370_MAX_LEDS)
457 return -EINVAL;
458 if (priv->leds_active & BIT(sources[i]))
459 return -EINVAL;
460 priv->leds_active |= BIT(sources[i]);
461 }
462
463 /* If both channels are specified in 'led-sources', joint flash output mode is used */
464 led->led_no = num == 2 ? MT6370_LED_JOINT : sources[0];
465
466 max_ua = num == 2 ? MT6370_ITORCH_DOUBLE_MAX_uA : MT6370_ITORCH_MAX_uA;
467 val = MT6370_ITORCH_MIN_uA;
468 ret = fwnode_property_read_u32(fwnode, "led-max-microamp", &val);
469 if (!ret)
470 val = mt6370_clamp(val, MT6370_ITORCH_MIN_uA, max_ua, MT6370_ITORCH_STEP_uA);
471
472 lcdev->max_brightness = (val - MT6370_ITORCH_MIN_uA) / MT6370_ITORCH_STEP_uA + 1;
473 lcdev->brightness_set_blocking = mt6370_torch_brightness_set;
474 lcdev->flags |= LED_DEV_CAP_FLASH;
475
476 max_ua = num == 2 ? MT6370_ISTRB_DOUBLE_MAX_uA : MT6370_ISTRB_MAX_uA;
477 val = MT6370_ISTRB_MIN_uA;
478 ret = fwnode_property_read_u32(fwnode, "flash-max-microamp", &val);
479 if (!ret)
480 val = mt6370_clamp(val, MT6370_ISTRB_MIN_uA, max_ua, MT6370_ISTRB_STEP_uA);
481
482 s = &flash->brightness;
483 s->min = MT6370_ISTRB_MIN_uA;
484 s->step = MT6370_ISTRB_STEP_uA;
485 s->val = s->max = val;
486
487 /* Always configure to the minimum level when off to prevent flash current spikes. */
488 ret = _mt6370_flash_brightness_set(flash, s->min);
489 if (ret)
490 return ret;
491
492 val = MT6370_STRBTO_MIN_US;
493 ret = fwnode_property_read_u32(fwnode, "flash-max-timeout-us", &val);
494 if (!ret)
495 val = mt6370_clamp(val, MT6370_STRBTO_MIN_US, MT6370_STRBTO_MAX_US,
496 MT6370_STRBTO_STEP_US);
497
498 s = &flash->timeout;
499 s->min = MT6370_STRBTO_MIN_US;
500 s->step = MT6370_STRBTO_STEP_US;
501 s->val = s->max = val;
502
503 flash->ops = &mt6370_flash_ops;
504
505 return 0;
506 }
507
mt6370_led_probe(struct platform_device * pdev)508 static int mt6370_led_probe(struct platform_device *pdev)
509 {
510 struct device *dev = &pdev->dev;
511 struct mt6370_priv *priv;
512 size_t count;
513 int i = 0, ret;
514
515 count = device_get_child_node_count(dev);
516 if (!count || count > MT6370_MAX_LEDS)
517 return dev_err_probe(dev, -EINVAL,
518 "No child node or node count over max led number %zu\n", count);
519
520 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
521 if (!priv)
522 return -ENOMEM;
523
524 priv->leds_count = count;
525 mutex_init(&priv->lock);
526
527 priv->regmap = dev_get_regmap(dev->parent, NULL);
528 if (!priv->regmap)
529 return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
530
531 device_for_each_child_node_scoped(dev, child) {
532 struct mt6370_led *led = priv->leds + i;
533
534 led->priv = priv;
535
536 ret = mt6370_init_flash_properties(dev, led, child);
537 if (ret)
538 return ret;
539
540 ret = mt6370_led_register(dev, led, child);
541 if (ret)
542 return ret;
543
544 i++;
545 }
546
547 return 0;
548 }
549
550 static const struct of_device_id mt6370_led_of_id[] = {
551 { .compatible = "mediatek,mt6370-flashlight" },
552 {}
553 };
554 MODULE_DEVICE_TABLE(of, mt6370_led_of_id);
555
556 static struct platform_driver mt6370_led_driver = {
557 .driver = {
558 .name = "mt6370-flashlight",
559 .of_match_table = mt6370_led_of_id,
560 },
561 .probe = mt6370_led_probe,
562 };
563 module_platform_driver(mt6370_led_driver);
564
565 MODULE_AUTHOR("Alice Chen <alice_chen@richtek.com>");
566 MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
567 MODULE_DESCRIPTION("MT6370 FLASH LED Driver");
568 MODULE_LICENSE("GPL");
569