35fcb0ca909295e404caefdfdefcb8218a9d1d93
[sfrench/cifs-2.6.git] / drivers / leds / leds-aat1290.c
1 /*
2  *      LED Flash class driver for the AAT1290
3  *      1.5A Step-Up Current Regulator for Flash LEDs
4  *
5  *      Copyright (C) 2015, Samsung Electronics Co., Ltd.
6  *      Author: Jacek Anaszewski <j.anaszewski@samsung.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  */
12
13 #include <linux/delay.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/led-class-flash.h>
16 #include <linux/leds.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/of.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 #include <media/v4l2-flash-led-class.h>
24
25 #define AAT1290_MOVIE_MODE_CURRENT_ADDR 17
26 #define AAT1290_MAX_MM_CURR_PERCENT_0   16
27 #define AAT1290_MAX_MM_CURR_PERCENT_100 1
28
29 #define AAT1290_FLASH_SAFETY_TIMER_ADDR 18
30
31 #define AAT1290_MOVIE_MODE_CONFIG_ADDR  19
32 #define AAT1290_MOVIE_MODE_OFF          1
33 #define AAT1290_MOVIE_MODE_ON           3
34
35 #define AAT1290_MM_CURRENT_RATIO_ADDR   20
36 #define AAT1290_MM_TO_FL_1_92           1
37
38 #define AAT1290_MM_TO_FL_RATIO          1000 / 1920
39 #define AAT1290_MAX_MM_CURRENT(fl_max)  (fl_max * AAT1290_MM_TO_FL_RATIO)
40
41 #define AAT1290_LATCH_TIME_MIN_US       500
42 #define AAT1290_LATCH_TIME_MAX_US       1000
43 #define AAT1290_EN_SET_TICK_TIME_US     1
44 #define AAT1290_FLEN_OFF_DELAY_TIME_US  10
45 #define AAT1290_FLASH_TM_NUM_LEVELS     16
46 #define AAT1290_MM_CURRENT_SCALE_SIZE   15
47
48
49 struct aat1290_led_config_data {
50         /* maximum LED current in movie mode */
51         u32 max_mm_current;
52         /* maximum LED current in flash mode */
53         u32 max_flash_current;
54         /* maximum flash timeout */
55         u32 max_flash_tm;
56         /* external strobe capability */
57         bool has_external_strobe;
58         /* max LED brightness level */
59         enum led_brightness max_brightness;
60 };
61
62 struct aat1290_led {
63         /* platform device data */
64         struct platform_device *pdev;
65         /* secures access to the device */
66         struct mutex lock;
67
68         /* corresponding LED Flash class device */
69         struct led_classdev_flash fled_cdev;
70         /* V4L2 Flash device */
71         struct v4l2_flash *v4l2_flash;
72
73         /* FLEN pin */
74         struct gpio_desc *gpio_fl_en;
75         /* EN|SET pin  */
76         struct gpio_desc *gpio_en_set;
77         /* movie mode current scale */
78         int *mm_current_scale;
79         /* device mode */
80         bool movie_mode;
81
82         /* brightness cache */
83         unsigned int torch_brightness;
84 };
85
86 static struct aat1290_led *fled_cdev_to_led(
87                                 struct led_classdev_flash *fled_cdev)
88 {
89         return container_of(fled_cdev, struct aat1290_led, fled_cdev);
90 }
91
92 static struct led_classdev_flash *led_cdev_to_fled_cdev(
93                                 struct led_classdev *led_cdev)
94 {
95         return container_of(led_cdev, struct led_classdev_flash, led_cdev);
96 }
97
98 static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value)
99 {
100         int i;
101
102         gpiod_direction_output(led->gpio_fl_en, 0);
103         gpiod_direction_output(led->gpio_en_set, 0);
104
105         udelay(AAT1290_FLEN_OFF_DELAY_TIME_US);
106
107         /* write address */
108         for (i = 0; i < addr; ++i) {
109                 udelay(AAT1290_EN_SET_TICK_TIME_US);
110                 gpiod_direction_output(led->gpio_en_set, 0);
111                 udelay(AAT1290_EN_SET_TICK_TIME_US);
112                 gpiod_direction_output(led->gpio_en_set, 1);
113         }
114
115         usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
116
117         /* write data */
118         for (i = 0; i < value; ++i) {
119                 udelay(AAT1290_EN_SET_TICK_TIME_US);
120                 gpiod_direction_output(led->gpio_en_set, 0);
121                 udelay(AAT1290_EN_SET_TICK_TIME_US);
122                 gpiod_direction_output(led->gpio_en_set, 1);
123         }
124
125         usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
126 }
127
128 static void aat1290_set_flash_safety_timer(struct aat1290_led *led,
129                                         unsigned int micro_sec)
130 {
131         struct led_classdev_flash *fled_cdev = &led->fled_cdev;
132         struct led_flash_setting *flash_tm = &fled_cdev->timeout;
133         int flash_tm_reg = AAT1290_FLASH_TM_NUM_LEVELS -
134                                 (micro_sec / flash_tm->step) + 1;
135
136         aat1290_as2cwire_write(led, AAT1290_FLASH_SAFETY_TIMER_ADDR,
137                                                         flash_tm_reg);
138 }
139
140 /* LED subsystem callbacks */
141
142 static int aat1290_led_brightness_set(struct led_classdev *led_cdev,
143                                         enum led_brightness brightness)
144 {
145         struct led_classdev_flash *fled_cdev = led_cdev_to_fled_cdev(led_cdev);
146         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
147
148         mutex_lock(&led->lock);
149
150         if (brightness == 0) {
151                 gpiod_direction_output(led->gpio_fl_en, 0);
152                 gpiod_direction_output(led->gpio_en_set, 0);
153                 led->movie_mode = false;
154         } else {
155                 if (!led->movie_mode) {
156                         aat1290_as2cwire_write(led,
157                                 AAT1290_MM_CURRENT_RATIO_ADDR,
158                                 AAT1290_MM_TO_FL_1_92);
159                         led->movie_mode = true;
160                 }
161
162                 aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CURRENT_ADDR,
163                                 AAT1290_MAX_MM_CURR_PERCENT_0 - brightness);
164                 aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR,
165                                 AAT1290_MOVIE_MODE_ON);
166         }
167
168         mutex_unlock(&led->lock);
169
170         return 0;
171 }
172
173 static int aat1290_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
174                                          bool state)
175
176 {
177         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
178         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
179         struct led_flash_setting *timeout = &fled_cdev->timeout;
180
181         mutex_lock(&led->lock);
182
183         if (state) {
184                 aat1290_set_flash_safety_timer(led, timeout->val);
185                 gpiod_direction_output(led->gpio_fl_en, 1);
186         } else {
187                 gpiod_direction_output(led->gpio_fl_en, 0);
188                 gpiod_direction_output(led->gpio_en_set, 0);
189         }
190
191         /*
192          * To reenter movie mode after a flash event the part must be cycled
193          * off and back on to reset the movie mode and reprogrammed via the
194          * AS2Cwire. Therefore the brightness and movie_mode properties needs
195          * to be updated here to reflect the actual state.
196          */
197         led_cdev->brightness = 0;
198         led->movie_mode = false;
199
200         mutex_unlock(&led->lock);
201
202         return 0;
203 }
204
205 static int aat1290_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
206                                                 u32 timeout)
207 {
208         /*
209          * Don't do anything - flash timeout is cached in the led-class-flash
210          * core and will be applied in the strobe_set op, as writing the
211          * safety timer register spuriously turns the torch mode on.
212          */
213
214         return 0;
215 }
216
217 static int aat1290_led_parse_dt(struct aat1290_led *led,
218                         struct aat1290_led_config_data *cfg,
219                         struct device_node **sub_node)
220 {
221         struct led_classdev *led_cdev = &led->fled_cdev.led_cdev;
222         struct device *dev = &led->pdev->dev;
223         struct device_node *child_node;
224 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
225         struct pinctrl *pinctrl;
226 #endif
227         int ret = 0;
228
229         led->gpio_fl_en = devm_gpiod_get(dev, "flen", GPIOD_ASIS);
230         if (IS_ERR(led->gpio_fl_en)) {
231                 ret = PTR_ERR(led->gpio_fl_en);
232                 dev_err(dev, "Unable to claim gpio \"flen\".\n");
233                 return ret;
234         }
235
236         led->gpio_en_set = devm_gpiod_get(dev, "enset", GPIOD_ASIS);
237         if (IS_ERR(led->gpio_en_set)) {
238                 ret = PTR_ERR(led->gpio_en_set);
239                 dev_err(dev, "Unable to claim gpio \"enset\".\n");
240                 return ret;
241         }
242
243 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
244         pinctrl = devm_pinctrl_get_select_default(&led->pdev->dev);
245         if (IS_ERR(pinctrl)) {
246                 cfg->has_external_strobe = false;
247                 dev_info(dev,
248                          "No support for external strobe detected.\n");
249         } else {
250                 cfg->has_external_strobe = true;
251         }
252 #endif
253
254         child_node = of_get_next_available_child(dev->of_node, NULL);
255         if (!child_node) {
256                 dev_err(dev, "No DT child node found for connected LED.\n");
257                 return -EINVAL;
258         }
259
260         led_cdev->name = of_get_property(child_node, "label", NULL) ? :
261                                                 child_node->name;
262
263         ret = of_property_read_u32(child_node, "led-max-microamp",
264                                 &cfg->max_mm_current);
265         /*
266          * led-max-microamp will default to 1/20 of flash-max-microamp
267          * in case it is missing.
268          */
269         if (ret < 0)
270                 dev_warn(dev,
271                         "led-max-microamp DT property missing\n");
272
273         ret = of_property_read_u32(child_node, "flash-max-microamp",
274                                 &cfg->max_flash_current);
275         if (ret < 0) {
276                 dev_err(dev,
277                         "flash-max-microamp DT property missing\n");
278                 goto err_parse_dt;
279         }
280
281         ret = of_property_read_u32(child_node, "flash-max-timeout-us",
282                                 &cfg->max_flash_tm);
283         if (ret < 0) {
284                 dev_err(dev,
285                         "flash-max-timeout-us DT property missing\n");
286                 goto err_parse_dt;
287         }
288
289         *sub_node = child_node;
290
291 err_parse_dt:
292         of_node_put(child_node);
293
294         return ret;
295 }
296
297 static void aat1290_led_validate_mm_current(struct aat1290_led *led,
298                                         struct aat1290_led_config_data *cfg)
299 {
300         int i, b = 0, e = AAT1290_MM_CURRENT_SCALE_SIZE;
301
302         while (e - b > 1) {
303                 i = b + (e - b) / 2;
304                 if (cfg->max_mm_current < led->mm_current_scale[i])
305                         e = i;
306                 else
307                         b = i;
308         }
309
310         cfg->max_mm_current = led->mm_current_scale[b];
311         cfg->max_brightness = b + 1;
312 }
313
314 static int init_mm_current_scale(struct aat1290_led *led,
315                         struct aat1290_led_config_data *cfg)
316 {
317         static const int max_mm_current_percent[] = {
318                 20, 22, 25, 28, 32, 36, 40, 45, 50, 56,
319                 63, 71, 79, 89, 100
320         };
321         int i, max_mm_current =
322                         AAT1290_MAX_MM_CURRENT(cfg->max_flash_current);
323
324         led->mm_current_scale = devm_kzalloc(&led->pdev->dev,
325                                         sizeof(max_mm_current_percent),
326                                         GFP_KERNEL);
327         if (!led->mm_current_scale)
328                 return -ENOMEM;
329
330         for (i = 0; i < AAT1290_MM_CURRENT_SCALE_SIZE; ++i)
331                 led->mm_current_scale[i] = max_mm_current *
332                                           max_mm_current_percent[i] / 100;
333
334         return 0;
335 }
336
337 static int aat1290_led_get_configuration(struct aat1290_led *led,
338                                         struct aat1290_led_config_data *cfg,
339                                         struct device_node **sub_node)
340 {
341         int ret;
342
343         ret = aat1290_led_parse_dt(led, cfg, sub_node);
344         if (ret < 0)
345                 return ret;
346         /*
347          * Init non-linear movie mode current scale basing
348          * on the max flash current from led configuration.
349          */
350         ret = init_mm_current_scale(led, cfg);
351         if (ret < 0)
352                 return ret;
353
354         aat1290_led_validate_mm_current(led, cfg);
355
356 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
357 #else
358         devm_kfree(&led->pdev->dev, led->mm_current_scale);
359 #endif
360
361         return 0;
362 }
363
364 static void aat1290_init_flash_timeout(struct aat1290_led *led,
365                                 struct aat1290_led_config_data *cfg)
366 {
367         struct led_classdev_flash *fled_cdev = &led->fled_cdev;
368         struct led_flash_setting *setting;
369
370         /* Init flash timeout setting */
371         setting = &fled_cdev->timeout;
372         setting->min = cfg->max_flash_tm / AAT1290_FLASH_TM_NUM_LEVELS;
373         setting->max = cfg->max_flash_tm;
374         setting->step = setting->min;
375         setting->val = setting->max;
376 }
377
378 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
379 static enum led_brightness aat1290_intensity_to_brightness(
380                                         struct v4l2_flash *v4l2_flash,
381                                         s32 intensity)
382 {
383         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
384         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
385         int i;
386
387         for (i = AAT1290_MM_CURRENT_SCALE_SIZE - 1; i >= 0; --i)
388                 if (intensity >= led->mm_current_scale[i])
389                         return i + 1;
390
391         return 1;
392 }
393
394 static s32 aat1290_brightness_to_intensity(struct v4l2_flash *v4l2_flash,
395                                         enum led_brightness brightness)
396 {
397         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
398         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
399
400         return led->mm_current_scale[brightness - 1];
401 }
402
403 static int aat1290_led_external_strobe_set(struct v4l2_flash *v4l2_flash,
404                                                 bool enable)
405 {
406         struct aat1290_led *led = fled_cdev_to_led(v4l2_flash->fled_cdev);
407         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
408         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
409         struct pinctrl *pinctrl;
410
411         gpiod_direction_output(led->gpio_fl_en, 0);
412         gpiod_direction_output(led->gpio_en_set, 0);
413
414         led->movie_mode = false;
415         led_cdev->brightness = 0;
416
417         pinctrl = devm_pinctrl_get_select(&led->pdev->dev,
418                                                 enable ? "isp" : "host");
419         if (IS_ERR(pinctrl)) {
420                 dev_warn(&led->pdev->dev, "Unable to switch strobe source.\n");
421                 return PTR_ERR(pinctrl);
422         }
423
424         return 0;
425 }
426
427 static void aat1290_init_v4l2_flash_config(struct aat1290_led *led,
428                                         struct aat1290_led_config_data *led_cfg,
429                                         struct v4l2_flash_config *v4l2_sd_cfg)
430 {
431         struct led_classdev *led_cdev = &led->fled_cdev.led_cdev;
432         struct led_flash_setting *s;
433
434         strlcpy(v4l2_sd_cfg->dev_name, led_cdev->name,
435                 sizeof(v4l2_sd_cfg->dev_name));
436
437         s = &v4l2_sd_cfg->torch_intensity;
438         s->min = led->mm_current_scale[0];
439         s->max = led_cfg->max_mm_current;
440         s->step = 1;
441         s->val = s->max;
442
443         v4l2_sd_cfg->has_external_strobe = led_cfg->has_external_strobe;
444 }
445
446 static const struct v4l2_flash_ops v4l2_flash_ops = {
447         .external_strobe_set = aat1290_led_external_strobe_set,
448         .intensity_to_led_brightness = aat1290_intensity_to_brightness,
449         .led_brightness_to_intensity = aat1290_brightness_to_intensity,
450 };
451 #else
452 static inline void aat1290_init_v4l2_flash_config(struct aat1290_led *led,
453                                 struct aat1290_led_config_data *led_cfg,
454                                 struct v4l2_flash_config *v4l2_sd_cfg)
455 {
456 }
457 static const struct v4l2_flash_ops v4l2_flash_ops;
458 #endif
459
460 static const struct led_flash_ops flash_ops = {
461         .strobe_set = aat1290_led_flash_strobe_set,
462         .timeout_set = aat1290_led_flash_timeout_set,
463 };
464
465 static int aat1290_led_probe(struct platform_device *pdev)
466 {
467         struct device *dev = &pdev->dev;
468         struct device_node *sub_node = NULL;
469         struct aat1290_led *led;
470         struct led_classdev *led_cdev;
471         struct led_classdev_flash *fled_cdev;
472         struct aat1290_led_config_data led_cfg = {};
473         struct v4l2_flash_config v4l2_sd_cfg = {};
474         int ret;
475
476         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
477         if (!led)
478                 return -ENOMEM;
479
480         led->pdev = pdev;
481         platform_set_drvdata(pdev, led);
482
483         fled_cdev = &led->fled_cdev;
484         fled_cdev->ops = &flash_ops;
485         led_cdev = &fled_cdev->led_cdev;
486
487         ret = aat1290_led_get_configuration(led, &led_cfg, &sub_node);
488         if (ret < 0)
489                 return ret;
490
491         mutex_init(&led->lock);
492
493         /* Initialize LED Flash class device */
494         led_cdev->brightness_set_blocking = aat1290_led_brightness_set;
495         led_cdev->max_brightness = led_cfg.max_brightness;
496         led_cdev->flags |= LED_DEV_CAP_FLASH;
497
498         aat1290_init_flash_timeout(led, &led_cfg);
499
500         /* Register LED Flash class device */
501         ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
502         if (ret < 0)
503                 goto err_flash_register;
504
505         aat1290_init_v4l2_flash_config(led, &led_cfg, &v4l2_sd_cfg);
506
507         /* Create V4L2 Flash subdev. */
508         led->v4l2_flash = v4l2_flash_init(dev, of_fwnode_handle(sub_node),
509                                           fled_cdev, NULL, &v4l2_flash_ops,
510                                           &v4l2_sd_cfg);
511         if (IS_ERR(led->v4l2_flash)) {
512                 ret = PTR_ERR(led->v4l2_flash);
513                 goto error_v4l2_flash_init;
514         }
515
516         return 0;
517
518 error_v4l2_flash_init:
519         led_classdev_flash_unregister(fled_cdev);
520 err_flash_register:
521         mutex_destroy(&led->lock);
522
523         return ret;
524 }
525
526 static int aat1290_led_remove(struct platform_device *pdev)
527 {
528         struct aat1290_led *led = platform_get_drvdata(pdev);
529
530         v4l2_flash_release(led->v4l2_flash);
531         led_classdev_flash_unregister(&led->fled_cdev);
532
533         mutex_destroy(&led->lock);
534
535         return 0;
536 }
537
538 static const struct of_device_id aat1290_led_dt_match[] = {
539         { .compatible = "skyworks,aat1290" },
540         {},
541 };
542 MODULE_DEVICE_TABLE(of, aat1290_led_dt_match);
543
544 static struct platform_driver aat1290_led_driver = {
545         .probe          = aat1290_led_probe,
546         .remove         = aat1290_led_remove,
547         .driver         = {
548                 .name   = "aat1290",
549                 .of_match_table = aat1290_led_dt_match,
550         },
551 };
552
553 module_platform_driver(aat1290_led_driver);
554
555 MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
556 MODULE_DESCRIPTION("Skyworks Current Regulator for Flash LEDs");
557 MODULE_LICENSE("GPL v2");