1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LED driver : leds-ktd2692.c
4 *
5 * Copyright (C) 2015 Samsung Electronics
6 * Ingi Kim <ingi2.kim@samsung.com>
7 */
8
9 #include <linux/cleanup.h>
10 #include <linux/err.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/leds-expresswire.h>
13 #include <linux/led-class-flash.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/consumer.h>
19
20 /* Value related the movie mode */
21 #define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
22 #define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
23 #define KTD2692_MM_MIN_CURR_THRESHOLD_SCALE 8
24
25 /* Value related the flash mode */
26 #define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
27 #define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
28 #define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)
29
30 /* Macro for getting offset of flash timeout */
31 #define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))
32
33 /* Base register address */
34 #define KTD2692_REG_LVP_BASE 0x00
35 #define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
36 #define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
37 #define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
38 #define KTD2692_REG_FLASH_CURRENT_BASE 0x80
39 #define KTD2692_REG_MODE_BASE 0xA0
40
41 /* KTD2692 default length of name */
42 #define KTD2692_NAME_LENGTH 20
43
44 /* Movie / Flash Mode Control */
45 enum ktd2692_led_mode {
46 KTD2692_MODE_DISABLE = 0, /* default */
47 KTD2692_MODE_MOVIE,
48 KTD2692_MODE_FLASH,
49 };
50
51 struct ktd2692_led_config_data {
52 /* maximum LED current in movie mode */
53 u32 movie_max_microamp;
54 /* maximum LED current in flash mode */
55 u32 flash_max_microamp;
56 /* maximum flash timeout */
57 u32 flash_max_timeout;
58 /* max LED brightness level */
59 enum led_brightness max_brightness;
60 };
61
62 const struct expresswire_timing ktd2692_timing = {
63 .poweroff_us = 700,
64 .data_start_us = 10,
65 .end_of_data_low_us = 10,
66 .end_of_data_high_us = 350,
67 .short_bitset_us = 4,
68 .long_bitset_us = 12
69 };
70
71 struct ktd2692_context {
72 /* Common ExpressWire properties (ctrl GPIO and timing) */
73 struct expresswire_common_props props;
74
75 /* Related LED Flash class device */
76 struct led_classdev_flash fled_cdev;
77
78 /* secures access to the device */
79 struct mutex lock;
80 struct regulator *regulator;
81
82 struct gpio_desc *aux_gpio;
83
84 enum ktd2692_led_mode mode;
85 enum led_brightness torch_brightness;
86 };
87
fled_cdev_to_led(struct led_classdev_flash * fled_cdev)88 static struct ktd2692_context *fled_cdev_to_led(
89 struct led_classdev_flash *fled_cdev)
90 {
91 return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
92 }
93
ktd2692_led_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)94 static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
95 enum led_brightness brightness)
96 {
97 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
98 struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
99
100 mutex_lock(&led->lock);
101
102 if (brightness == LED_OFF) {
103 led->mode = KTD2692_MODE_DISABLE;
104 gpiod_direction_output(led->aux_gpio, 0);
105 } else {
106 expresswire_write_u8(&led->props, brightness |
107 KTD2692_REG_MOVIE_CURRENT_BASE);
108 led->mode = KTD2692_MODE_MOVIE;
109 }
110
111 expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
112 mutex_unlock(&led->lock);
113
114 return 0;
115 }
116
ktd2692_led_flash_strobe_set(struct led_classdev_flash * fled_cdev,bool state)117 static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
118 bool state)
119 {
120 struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
121 struct led_flash_setting *timeout = &fled_cdev->timeout;
122 u32 flash_tm_reg;
123
124 mutex_lock(&led->lock);
125
126 if (state) {
127 flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
128 expresswire_write_u8(&led->props, flash_tm_reg
129 | KTD2692_REG_FLASH_TIMEOUT_BASE);
130
131 led->mode = KTD2692_MODE_FLASH;
132 gpiod_direction_output(led->aux_gpio, 1);
133 } else {
134 led->mode = KTD2692_MODE_DISABLE;
135 gpiod_direction_output(led->aux_gpio, 0);
136 }
137
138 expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
139
140 fled_cdev->led_cdev.brightness = LED_OFF;
141 led->mode = KTD2692_MODE_DISABLE;
142
143 mutex_unlock(&led->lock);
144
145 return 0;
146 }
147
ktd2692_led_flash_timeout_set(struct led_classdev_flash * fled_cdev,u32 timeout)148 static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
149 u32 timeout)
150 {
151 return 0;
152 }
153
ktd2692_init_movie_current_max(struct ktd2692_led_config_data * cfg)154 static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
155 {
156 u32 offset, step;
157 u32 movie_current_microamp;
158
159 offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
160 step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
161 / KTD2692_MOVIE_MODE_CURRENT_LEVELS;
162
163 do {
164 movie_current_microamp = step * offset;
165 offset--;
166 } while ((movie_current_microamp > cfg->movie_max_microamp) &&
167 (offset > 0));
168
169 cfg->max_brightness = offset;
170 }
171
ktd2692_init_flash_timeout(struct led_classdev_flash * fled_cdev,struct ktd2692_led_config_data * cfg)172 static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
173 struct ktd2692_led_config_data *cfg)
174 {
175 struct led_flash_setting *setting;
176
177 setting = &fled_cdev->timeout;
178 setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
179 setting->max = cfg->flash_max_timeout;
180 setting->step = cfg->flash_max_timeout
181 / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
182 setting->val = cfg->flash_max_timeout;
183 }
184
ktd2692_setup(struct ktd2692_context * led)185 static void ktd2692_setup(struct ktd2692_context *led)
186 {
187 led->mode = KTD2692_MODE_DISABLE;
188 expresswire_power_off(&led->props);
189 gpiod_direction_output(led->aux_gpio, 0);
190
191 expresswire_write_u8(&led->props, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
192 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
193 expresswire_write_u8(&led->props, KTD2692_FLASH_MODE_CURR_PERCENT(45)
194 | KTD2692_REG_FLASH_CURRENT_BASE);
195 }
196
regulator_disable_action(void * _data)197 static void regulator_disable_action(void *_data)
198 {
199 struct device *dev = _data;
200 struct ktd2692_context *led = dev_get_drvdata(dev);
201 int ret;
202
203 ret = regulator_disable(led->regulator);
204 if (ret)
205 dev_err(dev, "Failed to disable supply: %d\n", ret);
206 }
207
ktd2692_parse_dt(struct ktd2692_context * led,struct device * dev,struct ktd2692_led_config_data * cfg)208 static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
209 struct ktd2692_led_config_data *cfg)
210 {
211 struct device_node *np = dev_of_node(dev);
212 int ret;
213
214 if (!np)
215 return -ENXIO;
216
217 led->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
218 ret = PTR_ERR_OR_ZERO(led->props.ctrl_gpio);
219 if (ret)
220 return dev_err_probe(dev, ret, "cannot get ctrl-gpios\n");
221
222 led->aux_gpio = devm_gpiod_get_optional(dev, "aux", GPIOD_ASIS);
223 if (IS_ERR(led->aux_gpio))
224 return dev_err_probe(dev, PTR_ERR(led->aux_gpio), "cannot get aux-gpios\n");
225
226 led->regulator = devm_regulator_get(dev, "vin");
227 if (IS_ERR(led->regulator))
228 led->regulator = NULL;
229
230 if (led->regulator) {
231 ret = regulator_enable(led->regulator);
232 if (ret) {
233 dev_err(dev, "Failed to enable supply: %d\n", ret);
234 } else {
235 ret = devm_add_action_or_reset(dev,
236 regulator_disable_action, dev);
237 if (ret)
238 return ret;
239 }
240 }
241
242 struct device_node *child_node __free(device_node) =
243 of_get_next_available_child(np, NULL);
244 if (!child_node) {
245 dev_err(dev, "No DT child node found for connected LED.\n");
246 return -EINVAL;
247 }
248
249 led->fled_cdev.led_cdev.name =
250 of_get_property(child_node, "label", NULL) ? : child_node->name;
251
252 ret = of_property_read_u32(child_node, "led-max-microamp",
253 &cfg->movie_max_microamp);
254 if (ret) {
255 dev_err(dev, "failed to parse led-max-microamp\n");
256 return ret;
257 }
258
259 ret = of_property_read_u32(child_node, "flash-max-microamp",
260 &cfg->flash_max_microamp);
261 if (ret) {
262 dev_err(dev, "failed to parse flash-max-microamp\n");
263 return ret;
264 }
265
266 ret = of_property_read_u32(child_node, "flash-max-timeout-us",
267 &cfg->flash_max_timeout);
268 if (ret) {
269 dev_err(dev, "failed to parse flash-max-timeout-us\n");
270 return ret;
271 }
272
273 return 0;
274 }
275
276 static const struct led_flash_ops flash_ops = {
277 .strobe_set = ktd2692_led_flash_strobe_set,
278 .timeout_set = ktd2692_led_flash_timeout_set,
279 };
280
ktd2692_probe(struct platform_device * pdev)281 static int ktd2692_probe(struct platform_device *pdev)
282 {
283 struct ktd2692_context *led;
284 struct led_classdev *led_cdev;
285 struct led_classdev_flash *fled_cdev;
286 struct ktd2692_led_config_data led_cfg;
287 int ret;
288
289 led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
290 if (!led)
291 return -ENOMEM;
292
293 fled_cdev = &led->fled_cdev;
294 led_cdev = &fled_cdev->led_cdev;
295 led->props.timing = ktd2692_timing;
296
297 ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
298 if (ret)
299 return ret;
300
301 ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
302 ktd2692_init_movie_current_max(&led_cfg);
303
304 fled_cdev->ops = &flash_ops;
305
306 led_cdev->max_brightness = led_cfg.max_brightness;
307 led_cdev->brightness_set_blocking = ktd2692_led_brightness_set;
308 led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
309
310 mutex_init(&led->lock);
311
312 platform_set_drvdata(pdev, led);
313
314 ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
315 if (ret) {
316 dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
317 mutex_destroy(&led->lock);
318 return ret;
319 }
320
321 ktd2692_setup(led);
322
323 return 0;
324 }
325
ktd2692_remove(struct platform_device * pdev)326 static void ktd2692_remove(struct platform_device *pdev)
327 {
328 struct ktd2692_context *led = platform_get_drvdata(pdev);
329
330 led_classdev_flash_unregister(&led->fled_cdev);
331
332 mutex_destroy(&led->lock);
333 }
334
335 static const struct of_device_id ktd2692_match[] = {
336 { .compatible = "kinetic,ktd2692", },
337 { /* sentinel */ },
338 };
339 MODULE_DEVICE_TABLE(of, ktd2692_match);
340
341 static struct platform_driver ktd2692_driver = {
342 .driver = {
343 .name = "ktd2692",
344 .of_match_table = ktd2692_match,
345 },
346 .probe = ktd2692_probe,
347 .remove = ktd2692_remove,
348 };
349
350 module_platform_driver(ktd2692_driver);
351
352 MODULE_IMPORT_NS("EXPRESSWIRE");
353 MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
354 MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
355 MODULE_LICENSE("GPL v2");
356