1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * LED driver for Mediatek MT6323 PMIC
4 *
5 * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
6 */
7 #include <linux/kernel.h>
8 #include <linux/leds.h>
9 #include <linux/mfd/mt6323/registers.h>
10 #include <linux/mfd/mt6397/core.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15
16 /*
17 * Register field for MT6323_TOP_CKPDN0 to enable
18 * 32K clock common for LED device.
19 */
20 #define MT6323_RG_DRV_32K_CK_PDN BIT(11)
21 #define MT6323_RG_DRV_32K_CK_PDN_MASK BIT(11)
22
23 /*
24 * Register field for MT6323_TOP_CKPDN2 to enable
25 * individual clock for LED device.
26 */
27 #define MT6323_RG_ISINK_CK_PDN(i) BIT(i)
28 #define MT6323_RG_ISINK_CK_PDN_MASK(i) BIT(i)
29
30 /*
31 * Register field for MT6323_TOP_CKCON1 to select
32 * clock source.
33 */
34 #define MT6323_RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))
35
36 /*
37 * Register for MT6323_ISINK_CON0 to setup the
38 * duty cycle of the blink.
39 */
40 #define MT6323_ISINK_CON0(i) (MT6323_ISINK0_CON0 + 0x8 * (i))
41 #define MT6323_ISINK_DIM_DUTY_MASK (0x1f << 8)
42 #define MT6323_ISINK_DIM_DUTY(i) (((i) << 8) & \
43 MT6323_ISINK_DIM_DUTY_MASK)
44
45 /* Register to setup the period of the blink. */
46 #define MT6323_ISINK_CON1(i) (MT6323_ISINK0_CON1 + 0x8 * (i))
47 #define MT6323_ISINK_DIM_FSEL_MASK (0xffff)
48 #define MT6323_ISINK_DIM_FSEL(i) ((i) & MT6323_ISINK_DIM_FSEL_MASK)
49
50 /* Register to control the brightness. */
51 #define MT6323_ISINK_CON2(i) (MT6323_ISINK0_CON2 + 0x8 * (i))
52 #define MT6323_ISINK_CH_STEP_SHIFT 12
53 #define MT6323_ISINK_CH_STEP_MASK (0x7 << 12)
54 #define MT6323_ISINK_CH_STEP(i) (((i) << 12) & \
55 MT6323_ISINK_CH_STEP_MASK)
56 #define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1)
57 #define MT6323_ISINK_SFSTR0_TC(i) (((i) << 1) & \
58 MT6323_ISINK_SFSTR0_TC_MASK)
59 #define MT6323_ISINK_SFSTR0_EN_MASK BIT(0)
60 #define MT6323_ISINK_SFSTR0_EN BIT(0)
61
62 /* Register to LED channel enablement. */
63 #define MT6323_ISINK_CH_EN_MASK(i) BIT(i)
64 #define MT6323_ISINK_CH_EN(i) BIT(i)
65
66 #define MT6323_MAX_PERIOD 10000
67 #define MT6323_MAX_LEDS 4
68 #define MT6323_MAX_BRIGHTNESS 6
69 #define MT6323_UNIT_DUTY 3125
70 #define MT6323_CAL_HW_DUTY(o, p) DIV_ROUND_CLOSEST((o) * 100000ul,\
71 (p) * MT6323_UNIT_DUTY)
72
73 struct mt6323_leds;
74
75 /**
76 * struct mt6323_led - state container for the LED device
77 * @id: the identifier in MT6323 LED device
78 * @parent: the pointer to MT6323 LED controller
79 * @cdev: LED class device for this LED device
80 * @current_brightness: current state of the LED device
81 */
82 struct mt6323_led {
83 int id;
84 struct mt6323_leds *parent;
85 struct led_classdev cdev;
86 enum led_brightness current_brightness;
87 };
88
89 /**
90 * struct mt6323_leds - state container for holding LED controller
91 * of the driver
92 * @dev: the device pointer
93 * @hw: the underlying hardware providing shared
94 * bus for the register operations
95 * @lock: the lock among process context
96 * @led: the array that contains the state of individual
97 * LED device
98 */
99 struct mt6323_leds {
100 struct device *dev;
101 struct mt6397_chip *hw;
102 /* protect among process context */
103 struct mutex lock;
104 struct mt6323_led *led[MT6323_MAX_LEDS];
105 };
106
mt6323_led_hw_brightness(struct led_classdev * cdev,enum led_brightness brightness)107 static int mt6323_led_hw_brightness(struct led_classdev *cdev,
108 enum led_brightness brightness)
109 {
110 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
111 struct mt6323_leds *leds = led->parent;
112 struct regmap *regmap = leds->hw->regmap;
113 u32 con2_mask = 0, con2_val = 0;
114 int ret;
115
116 /*
117 * Setup current output for the corresponding
118 * brightness level.
119 */
120 con2_mask |= MT6323_ISINK_CH_STEP_MASK |
121 MT6323_ISINK_SFSTR0_TC_MASK |
122 MT6323_ISINK_SFSTR0_EN_MASK;
123 con2_val |= MT6323_ISINK_CH_STEP(brightness - 1) |
124 MT6323_ISINK_SFSTR0_TC(2) |
125 MT6323_ISINK_SFSTR0_EN;
126
127 ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
128 con2_mask, con2_val);
129 return ret;
130 }
131
mt6323_led_hw_off(struct led_classdev * cdev)132 static int mt6323_led_hw_off(struct led_classdev *cdev)
133 {
134 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
135 struct mt6323_leds *leds = led->parent;
136 struct regmap *regmap = leds->hw->regmap;
137 unsigned int status;
138 int ret;
139
140 status = MT6323_ISINK_CH_EN(led->id);
141 ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
142 MT6323_ISINK_CH_EN_MASK(led->id), ~status);
143 if (ret < 0)
144 return ret;
145
146 usleep_range(100, 300);
147 ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
148 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
149 MT6323_RG_ISINK_CK_PDN(led->id));
150 if (ret < 0)
151 return ret;
152
153 return 0;
154 }
155
156 static enum led_brightness
mt6323_get_led_hw_brightness(struct led_classdev * cdev)157 mt6323_get_led_hw_brightness(struct led_classdev *cdev)
158 {
159 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
160 struct mt6323_leds *leds = led->parent;
161 struct regmap *regmap = leds->hw->regmap;
162 unsigned int status;
163 int ret;
164
165 ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
166 if (ret < 0)
167 return ret;
168
169 if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
170 return 0;
171
172 ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
173 if (ret < 0)
174 return ret;
175
176 if (!(status & MT6323_ISINK_CH_EN(led->id)))
177 return 0;
178
179 ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
180 if (ret < 0)
181 return ret;
182
183 return ((status & MT6323_ISINK_CH_STEP_MASK)
184 >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
185 }
186
mt6323_led_hw_on(struct led_classdev * cdev,enum led_brightness brightness)187 static int mt6323_led_hw_on(struct led_classdev *cdev,
188 enum led_brightness brightness)
189 {
190 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
191 struct mt6323_leds *leds = led->parent;
192 struct regmap *regmap = leds->hw->regmap;
193 unsigned int status;
194 int ret;
195
196 /*
197 * Setup required clock source, enable the corresponding
198 * clock and channel and let work with continuous blink as
199 * the default.
200 */
201 ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
202 MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
203 if (ret < 0)
204 return ret;
205
206 status = MT6323_RG_ISINK_CK_PDN(led->id);
207 ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
208 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
209 ~status);
210 if (ret < 0)
211 return ret;
212
213 usleep_range(100, 300);
214
215 ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
216 MT6323_ISINK_CH_EN_MASK(led->id),
217 MT6323_ISINK_CH_EN(led->id));
218 if (ret < 0)
219 return ret;
220
221 ret = mt6323_led_hw_brightness(cdev, brightness);
222 if (ret < 0)
223 return ret;
224
225 ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
226 MT6323_ISINK_DIM_DUTY_MASK,
227 MT6323_ISINK_DIM_DUTY(31));
228 if (ret < 0)
229 return ret;
230
231 ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
232 MT6323_ISINK_DIM_FSEL_MASK,
233 MT6323_ISINK_DIM_FSEL(1000));
234 if (ret < 0)
235 return ret;
236
237 return 0;
238 }
239
mt6323_led_set_blink(struct led_classdev * cdev,unsigned long * delay_on,unsigned long * delay_off)240 static int mt6323_led_set_blink(struct led_classdev *cdev,
241 unsigned long *delay_on,
242 unsigned long *delay_off)
243 {
244 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
245 struct mt6323_leds *leds = led->parent;
246 struct regmap *regmap = leds->hw->regmap;
247 unsigned long period;
248 u8 duty_hw;
249 int ret;
250
251 /*
252 * LED subsystem requires a default user
253 * friendly blink pattern for the LED so using
254 * 1Hz duty cycle 50% here if without specific
255 * value delay_on and delay off being assigned.
256 */
257 if (!*delay_on && !*delay_off) {
258 *delay_on = 500;
259 *delay_off = 500;
260 }
261
262 /*
263 * Units are in ms, if over the hardware able
264 * to support, fallback into software blink
265 */
266 period = *delay_on + *delay_off;
267
268 if (period > MT6323_MAX_PERIOD)
269 return -EINVAL;
270
271 /*
272 * Calculate duty_hw based on the percentage of period during
273 * which the led is ON.
274 */
275 duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);
276
277 /* hardware doesn't support zero duty cycle. */
278 if (!duty_hw)
279 return -EINVAL;
280
281 mutex_lock(&leds->lock);
282 /*
283 * Set max_brightness as the software blink behavior
284 * when no blink brightness.
285 */
286 if (!led->current_brightness) {
287 ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
288 if (ret < 0)
289 goto out;
290 led->current_brightness = cdev->max_brightness;
291 }
292
293 ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
294 MT6323_ISINK_DIM_DUTY_MASK,
295 MT6323_ISINK_DIM_DUTY(duty_hw - 1));
296 if (ret < 0)
297 goto out;
298
299 ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
300 MT6323_ISINK_DIM_FSEL_MASK,
301 MT6323_ISINK_DIM_FSEL(period - 1));
302 out:
303 mutex_unlock(&leds->lock);
304
305 return ret;
306 }
307
mt6323_led_set_brightness(struct led_classdev * cdev,enum led_brightness brightness)308 static int mt6323_led_set_brightness(struct led_classdev *cdev,
309 enum led_brightness brightness)
310 {
311 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
312 struct mt6323_leds *leds = led->parent;
313 int ret;
314
315 mutex_lock(&leds->lock);
316
317 if (!led->current_brightness && brightness) {
318 ret = mt6323_led_hw_on(cdev, brightness);
319 if (ret < 0)
320 goto out;
321 } else if (brightness) {
322 ret = mt6323_led_hw_brightness(cdev, brightness);
323 if (ret < 0)
324 goto out;
325 } else {
326 ret = mt6323_led_hw_off(cdev);
327 if (ret < 0)
328 goto out;
329 }
330
331 led->current_brightness = brightness;
332 out:
333 mutex_unlock(&leds->lock);
334
335 return ret;
336 }
337
mt6323_led_set_dt_default(struct led_classdev * cdev,struct device_node * np)338 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
339 struct device_node *np)
340 {
341 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
342 const char *state;
343 int ret = 0;
344
345 state = of_get_property(np, "default-state", NULL);
346 if (state) {
347 if (!strcmp(state, "keep")) {
348 ret = mt6323_get_led_hw_brightness(cdev);
349 if (ret < 0)
350 return ret;
351 led->current_brightness = ret;
352 ret = 0;
353 } else if (!strcmp(state, "on")) {
354 ret =
355 mt6323_led_set_brightness(cdev, cdev->max_brightness);
356 } else {
357 ret = mt6323_led_set_brightness(cdev, LED_OFF);
358 }
359 }
360
361 return ret;
362 }
363
mt6323_led_probe(struct platform_device * pdev)364 static int mt6323_led_probe(struct platform_device *pdev)
365 {
366 struct device *dev = &pdev->dev;
367 struct device_node *np = dev_of_node(dev);
368 struct device_node *child;
369 struct mt6397_chip *hw = dev_get_drvdata(dev->parent);
370 struct mt6323_leds *leds;
371 struct mt6323_led *led;
372 int ret;
373 unsigned int status;
374 u32 reg;
375
376 leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
377 if (!leds)
378 return -ENOMEM;
379
380 platform_set_drvdata(pdev, leds);
381 leds->dev = dev;
382
383 /*
384 * leds->hw points to the underlying bus for the register
385 * controlled.
386 */
387 leds->hw = hw;
388 mutex_init(&leds->lock);
389
390 status = MT6323_RG_DRV_32K_CK_PDN;
391 ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
392 MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
393 if (ret < 0) {
394 dev_err(leds->dev,
395 "Failed to update MT6323_TOP_CKPDN0 Register\n");
396 return ret;
397 }
398
399 for_each_available_child_of_node(np, child) {
400 struct led_init_data init_data = {};
401
402 ret = of_property_read_u32(child, "reg", ®);
403 if (ret) {
404 dev_err(dev, "Failed to read led 'reg' property\n");
405 goto put_child_node;
406 }
407
408 if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
409 dev_err(dev, "Invalid led reg %u\n", reg);
410 ret = -EINVAL;
411 goto put_child_node;
412 }
413
414 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
415 if (!led) {
416 ret = -ENOMEM;
417 goto put_child_node;
418 }
419
420 leds->led[reg] = led;
421 leds->led[reg]->id = reg;
422 leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
423 leds->led[reg]->cdev.brightness_set_blocking =
424 mt6323_led_set_brightness;
425 leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
426 leds->led[reg]->cdev.brightness_get =
427 mt6323_get_led_hw_brightness;
428 leds->led[reg]->parent = leds;
429
430 ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
431 if (ret < 0) {
432 dev_err(leds->dev,
433 "Failed to LED set default from devicetree\n");
434 goto put_child_node;
435 }
436
437 init_data.fwnode = of_fwnode_handle(child);
438
439 ret = devm_led_classdev_register_ext(dev, &leds->led[reg]->cdev,
440 &init_data);
441 if (ret) {
442 dev_err(dev, "Failed to register LED: %d\n", ret);
443 goto put_child_node;
444 }
445 }
446
447 return 0;
448
449 put_child_node:
450 of_node_put(child);
451 return ret;
452 }
453
mt6323_led_remove(struct platform_device * pdev)454 static int mt6323_led_remove(struct platform_device *pdev)
455 {
456 struct mt6323_leds *leds = platform_get_drvdata(pdev);
457 int i;
458
459 /* Turn the LEDs off on driver removal. */
460 for (i = 0 ; leds->led[i] ; i++)
461 mt6323_led_hw_off(&leds->led[i]->cdev);
462
463 regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
464 MT6323_RG_DRV_32K_CK_PDN_MASK,
465 MT6323_RG_DRV_32K_CK_PDN);
466
467 mutex_destroy(&leds->lock);
468
469 return 0;
470 }
471
472 static const struct of_device_id mt6323_led_dt_match[] = {
473 { .compatible = "mediatek,mt6323-led" },
474 {},
475 };
476 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
477
478 static struct platform_driver mt6323_led_driver = {
479 .probe = mt6323_led_probe,
480 .remove = mt6323_led_remove,
481 .driver = {
482 .name = "mt6323-led",
483 .of_match_table = mt6323_led_dt_match,
484 },
485 };
486
487 module_platform_driver(mt6323_led_driver);
488
489 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
490 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
491 MODULE_LICENSE("GPL");
492