1 /*
2 * LED driver for Mediatek MT6323 PMIC
3 *
4 * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of
9 * the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16 #include <linux/kernel.h>
17 #include <linux/leds.h>
18 #include <linux/mfd/mt6323/registers.h>
19 #include <linux/mfd/mt6397/core.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24
25 /*
26 * Register field for MT6323_TOP_CKPDN0 to enable
27 * 32K clock common for LED device.
28 */
29 #define MT6323_RG_DRV_32K_CK_PDN BIT(11)
30 #define MT6323_RG_DRV_32K_CK_PDN_MASK BIT(11)
31
32 /*
33 * Register field for MT6323_TOP_CKPDN2 to enable
34 * individual clock for LED device.
35 */
36 #define MT6323_RG_ISINK_CK_PDN(i) BIT(i)
37 #define MT6323_RG_ISINK_CK_PDN_MASK(i) BIT(i)
38
39 /*
40 * Register field for MT6323_TOP_CKCON1 to select
41 * clock source.
42 */
43 #define MT6323_RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))
44
45 /*
46 * Register for MT6323_ISINK_CON0 to setup the
47 * duty cycle of the blink.
48 */
49 #define MT6323_ISINK_CON0(i) (MT6323_ISINK0_CON0 + 0x8 * (i))
50 #define MT6323_ISINK_DIM_DUTY_MASK (0x1f << 8)
51 #define MT6323_ISINK_DIM_DUTY(i) (((i) << 8) & \
52 MT6323_ISINK_DIM_DUTY_MASK)
53
54 /* Register to setup the period of the blink. */
55 #define MT6323_ISINK_CON1(i) (MT6323_ISINK0_CON1 + 0x8 * (i))
56 #define MT6323_ISINK_DIM_FSEL_MASK (0xffff)
57 #define MT6323_ISINK_DIM_FSEL(i) ((i) & MT6323_ISINK_DIM_FSEL_MASK)
58
59 /* Register to control the brightness. */
60 #define MT6323_ISINK_CON2(i) (MT6323_ISINK0_CON2 + 0x8 * (i))
61 #define MT6323_ISINK_CH_STEP_SHIFT 12
62 #define MT6323_ISINK_CH_STEP_MASK (0x7 << 12)
63 #define MT6323_ISINK_CH_STEP(i) (((i) << 12) & \
64 MT6323_ISINK_CH_STEP_MASK)
65 #define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1)
66 #define MT6323_ISINK_SFSTR0_TC(i) (((i) << 1) & \
67 MT6323_ISINK_SFSTR0_TC_MASK)
68 #define MT6323_ISINK_SFSTR0_EN_MASK BIT(0)
69 #define MT6323_ISINK_SFSTR0_EN BIT(0)
70
71 /* Register to LED channel enablement. */
72 #define MT6323_ISINK_CH_EN_MASK(i) BIT(i)
73 #define MT6323_ISINK_CH_EN(i) BIT(i)
74
75 #define MT6323_MAX_PERIOD 10000
76 #define MT6323_MAX_LEDS 4
77 #define MT6323_MAX_BRIGHTNESS 6
78 #define MT6323_UNIT_DUTY 3125
79 #define MT6323_CAL_HW_DUTY(o, p) DIV_ROUND_CLOSEST((o) * 100000ul,\
80 (p) * MT6323_UNIT_DUTY)
81
82 struct mt6323_leds;
83
84 /**
85 * struct mt6323_led - state container for the LED device
86 * @id: the identifier in MT6323 LED device
87 * @parent: the pointer to MT6323 LED controller
88 * @cdev: LED class device for this LED device
89 * @current_brightness: current state of the LED device
90 */
91 struct mt6323_led {
92 int id;
93 struct mt6323_leds *parent;
94 struct led_classdev cdev;
95 enum led_brightness current_brightness;
96 };
97
98 /**
99 * struct mt6323_leds - state container for holding LED controller
100 * of the driver
101 * @dev: the device pointer
102 * @hw: the underlying hardware providing shared
103 * bus for the register operations
104 * @lock: the lock among process context
105 * @led: the array that contains the state of individual
106 * LED device
107 */
108 struct mt6323_leds {
109 struct device *dev;
110 struct mt6397_chip *hw;
111 /* protect among process context */
112 struct mutex lock;
113 struct mt6323_led *led[MT6323_MAX_LEDS];
114 };
115
mt6323_led_hw_brightness(struct led_classdev * cdev,enum led_brightness brightness)116 static int mt6323_led_hw_brightness(struct led_classdev *cdev,
117 enum led_brightness brightness)
118 {
119 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
120 struct mt6323_leds *leds = led->parent;
121 struct regmap *regmap = leds->hw->regmap;
122 u32 con2_mask = 0, con2_val = 0;
123 int ret;
124
125 /*
126 * Setup current output for the corresponding
127 * brightness level.
128 */
129 con2_mask |= MT6323_ISINK_CH_STEP_MASK |
130 MT6323_ISINK_SFSTR0_TC_MASK |
131 MT6323_ISINK_SFSTR0_EN_MASK;
132 con2_val |= MT6323_ISINK_CH_STEP(brightness - 1) |
133 MT6323_ISINK_SFSTR0_TC(2) |
134 MT6323_ISINK_SFSTR0_EN;
135
136 ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
137 con2_mask, con2_val);
138 return ret;
139 }
140
mt6323_led_hw_off(struct led_classdev * cdev)141 static int mt6323_led_hw_off(struct led_classdev *cdev)
142 {
143 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
144 struct mt6323_leds *leds = led->parent;
145 struct regmap *regmap = leds->hw->regmap;
146 unsigned int status;
147 int ret;
148
149 status = MT6323_ISINK_CH_EN(led->id);
150 ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
151 MT6323_ISINK_CH_EN_MASK(led->id), ~status);
152 if (ret < 0)
153 return ret;
154
155 usleep_range(100, 300);
156 ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
157 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
158 MT6323_RG_ISINK_CK_PDN(led->id));
159 if (ret < 0)
160 return ret;
161
162 return 0;
163 }
164
165 static enum led_brightness
mt6323_get_led_hw_brightness(struct led_classdev * cdev)166 mt6323_get_led_hw_brightness(struct led_classdev *cdev)
167 {
168 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
169 struct mt6323_leds *leds = led->parent;
170 struct regmap *regmap = leds->hw->regmap;
171 unsigned int status;
172 int ret;
173
174 ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
175 if (ret < 0)
176 return ret;
177
178 if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
179 return 0;
180
181 ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
182 if (ret < 0)
183 return ret;
184
185 if (!(status & MT6323_ISINK_CH_EN(led->id)))
186 return 0;
187
188 ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
189 if (ret < 0)
190 return ret;
191
192 return ((status & MT6323_ISINK_CH_STEP_MASK)
193 >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
194 }
195
mt6323_led_hw_on(struct led_classdev * cdev,enum led_brightness brightness)196 static int mt6323_led_hw_on(struct led_classdev *cdev,
197 enum led_brightness brightness)
198 {
199 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
200 struct mt6323_leds *leds = led->parent;
201 struct regmap *regmap = leds->hw->regmap;
202 unsigned int status;
203 int ret;
204
205 /*
206 * Setup required clock source, enable the corresponding
207 * clock and channel and let work with continuous blink as
208 * the default.
209 */
210 ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
211 MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
212 if (ret < 0)
213 return ret;
214
215 status = MT6323_RG_ISINK_CK_PDN(led->id);
216 ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
217 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
218 ~status);
219 if (ret < 0)
220 return ret;
221
222 usleep_range(100, 300);
223
224 ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
225 MT6323_ISINK_CH_EN_MASK(led->id),
226 MT6323_ISINK_CH_EN(led->id));
227 if (ret < 0)
228 return ret;
229
230 ret = mt6323_led_hw_brightness(cdev, brightness);
231 if (ret < 0)
232 return ret;
233
234 ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
235 MT6323_ISINK_DIM_DUTY_MASK,
236 MT6323_ISINK_DIM_DUTY(31));
237 if (ret < 0)
238 return ret;
239
240 ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
241 MT6323_ISINK_DIM_FSEL_MASK,
242 MT6323_ISINK_DIM_FSEL(1000));
243 if (ret < 0)
244 return ret;
245
246 return 0;
247 }
248
mt6323_led_set_blink(struct led_classdev * cdev,unsigned long * delay_on,unsigned long * delay_off)249 static int mt6323_led_set_blink(struct led_classdev *cdev,
250 unsigned long *delay_on,
251 unsigned long *delay_off)
252 {
253 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
254 struct mt6323_leds *leds = led->parent;
255 struct regmap *regmap = leds->hw->regmap;
256 unsigned long period;
257 u8 duty_hw;
258 int ret;
259
260 /*
261 * Units are in ms, if over the hardware able
262 * to support, fallback into software blink
263 */
264 period = *delay_on + *delay_off;
265
266 if (period > MT6323_MAX_PERIOD)
267 return -EINVAL;
268
269 /*
270 * LED subsystem requires a default user
271 * friendly blink pattern for the LED so using
272 * 1Hz duty cycle 50% here if without specific
273 * value delay_on and delay off being assigned.
274 */
275 if (!*delay_on && !*delay_off) {
276 *delay_on = 500;
277 *delay_off = 500;
278 }
279
280 /*
281 * Calculate duty_hw based on the percentage of period during
282 * which the led is ON.
283 */
284 duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);
285
286 /* hardware doesn't support zero duty cycle. */
287 if (!duty_hw)
288 return -EINVAL;
289
290 mutex_lock(&leds->lock);
291 /*
292 * Set max_brightness as the software blink behavior
293 * when no blink brightness.
294 */
295 if (!led->current_brightness) {
296 ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
297 if (ret < 0)
298 goto out;
299 led->current_brightness = cdev->max_brightness;
300 }
301
302 ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
303 MT6323_ISINK_DIM_DUTY_MASK,
304 MT6323_ISINK_DIM_DUTY(duty_hw - 1));
305 if (ret < 0)
306 goto out;
307
308 ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
309 MT6323_ISINK_DIM_FSEL_MASK,
310 MT6323_ISINK_DIM_FSEL(period - 1));
311 out:
312 mutex_unlock(&leds->lock);
313
314 return ret;
315 }
316
mt6323_led_set_brightness(struct led_classdev * cdev,enum led_brightness brightness)317 static int mt6323_led_set_brightness(struct led_classdev *cdev,
318 enum led_brightness brightness)
319 {
320 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
321 struct mt6323_leds *leds = led->parent;
322 int ret;
323
324 mutex_lock(&leds->lock);
325
326 if (!led->current_brightness && brightness) {
327 ret = mt6323_led_hw_on(cdev, brightness);
328 if (ret < 0)
329 goto out;
330 } else if (brightness) {
331 ret = mt6323_led_hw_brightness(cdev, brightness);
332 if (ret < 0)
333 goto out;
334 } else {
335 ret = mt6323_led_hw_off(cdev);
336 if (ret < 0)
337 goto out;
338 }
339
340 led->current_brightness = brightness;
341 out:
342 mutex_unlock(&leds->lock);
343
344 return ret;
345 }
346
mt6323_led_set_dt_default(struct led_classdev * cdev,struct device_node * np)347 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
348 struct device_node *np)
349 {
350 struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
351 const char *state;
352 int ret = 0;
353
354 led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
355 led->cdev.default_trigger = of_get_property(np,
356 "linux,default-trigger",
357 NULL);
358
359 state = of_get_property(np, "default-state", NULL);
360 if (state) {
361 if (!strcmp(state, "keep")) {
362 ret = mt6323_get_led_hw_brightness(cdev);
363 if (ret < 0)
364 return ret;
365 led->current_brightness = ret;
366 ret = 0;
367 } else if (!strcmp(state, "on")) {
368 ret =
369 mt6323_led_set_brightness(cdev, cdev->max_brightness);
370 } else {
371 ret = mt6323_led_set_brightness(cdev, LED_OFF);
372 }
373 }
374
375 return ret;
376 }
377
mt6323_led_probe(struct platform_device * pdev)378 static int mt6323_led_probe(struct platform_device *pdev)
379 {
380 struct device *dev = &pdev->dev;
381 struct device_node *np = pdev->dev.of_node;
382 struct device_node *child;
383 struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
384 struct mt6323_leds *leds;
385 struct mt6323_led *led;
386 int ret;
387 unsigned int status;
388 u32 reg;
389
390 leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
391 if (!leds)
392 return -ENOMEM;
393
394 platform_set_drvdata(pdev, leds);
395 leds->dev = dev;
396
397 /*
398 * leds->hw points to the underlying bus for the register
399 * controlled.
400 */
401 leds->hw = hw;
402 mutex_init(&leds->lock);
403
404 status = MT6323_RG_DRV_32K_CK_PDN;
405 ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
406 MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
407 if (ret < 0) {
408 dev_err(leds->dev,
409 "Failed to update MT6323_TOP_CKPDN0 Register\n");
410 return ret;
411 }
412
413 for_each_available_child_of_node(np, child) {
414 ret = of_property_read_u32(child, "reg", ®);
415 if (ret) {
416 dev_err(dev, "Failed to read led 'reg' property\n");
417 goto put_child_node;
418 }
419
420 if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
421 dev_err(dev, "Invalid led reg %u\n", reg);
422 ret = -EINVAL;
423 goto put_child_node;
424 }
425
426 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
427 if (!led) {
428 ret = -ENOMEM;
429 goto put_child_node;
430 }
431
432 leds->led[reg] = led;
433 leds->led[reg]->id = reg;
434 leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
435 leds->led[reg]->cdev.brightness_set_blocking =
436 mt6323_led_set_brightness;
437 leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
438 leds->led[reg]->cdev.brightness_get =
439 mt6323_get_led_hw_brightness;
440 leds->led[reg]->parent = leds;
441
442 ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
443 if (ret < 0) {
444 dev_err(leds->dev,
445 "Failed to LED set default from devicetree\n");
446 goto put_child_node;
447 }
448
449 ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
450 if (ret) {
451 dev_err(&pdev->dev, "Failed to register LED: %d\n",
452 ret);
453 goto put_child_node;
454 }
455 leds->led[reg]->cdev.dev->of_node = child;
456 }
457
458 return 0;
459
460 put_child_node:
461 of_node_put(child);
462 return ret;
463 }
464
mt6323_led_remove(struct platform_device * pdev)465 static int mt6323_led_remove(struct platform_device *pdev)
466 {
467 struct mt6323_leds *leds = platform_get_drvdata(pdev);
468 int i;
469
470 /* Turn the LEDs off on driver removal. */
471 for (i = 0 ; leds->led[i] ; i++)
472 mt6323_led_hw_off(&leds->led[i]->cdev);
473
474 regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
475 MT6323_RG_DRV_32K_CK_PDN_MASK,
476 MT6323_RG_DRV_32K_CK_PDN);
477
478 mutex_destroy(&leds->lock);
479
480 return 0;
481 }
482
483 static const struct of_device_id mt6323_led_dt_match[] = {
484 { .compatible = "mediatek,mt6323-led" },
485 {},
486 };
487 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
488
489 static struct platform_driver mt6323_led_driver = {
490 .probe = mt6323_led_probe,
491 .remove = mt6323_led_remove,
492 .driver = {
493 .name = "mt6323-led",
494 .of_match_table = mt6323_led_dt_match,
495 },
496 };
497
498 module_platform_driver(mt6323_led_driver);
499
500 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
501 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
502 MODULE_LICENSE("GPL");
503
