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 * Units are in ms, if over the hardware able
253 * to support, fallback into software blink
254 */
255 period = *delay_on + *delay_off;
256
257 if (period > MT6323_MAX_PERIOD)
258 return -EINVAL;
259
260 /*
261 * LED subsystem requires a default user
262 * friendly blink pattern for the LED so using
263 * 1Hz duty cycle 50% here if without specific
264 * value delay_on and delay off being assigned.
265 */
266 if (!*delay_on && !*delay_off) {
267 *delay_on = 500;
268 *delay_off = 500;
269 }
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 led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
346 led->cdev.default_trigger = of_get_property(np,
347 "linux,default-trigger",
348 NULL);
349
350 state = of_get_property(np, "default-state", NULL);
351 if (state) {
352 if (!strcmp(state, "keep")) {
353 ret = mt6323_get_led_hw_brightness(cdev);
354 if (ret < 0)
355 return ret;
356 led->current_brightness = ret;
357 ret = 0;
358 } else if (!strcmp(state, "on")) {
359 ret =
360 mt6323_led_set_brightness(cdev, cdev->max_brightness);
361 } else {
362 ret = mt6323_led_set_brightness(cdev, LED_OFF);
363 }
364 }
365
366 return ret;
367 }
368
mt6323_led_probe(struct platform_device * pdev)369 static int mt6323_led_probe(struct platform_device *pdev)
370 {
371 struct device *dev = &pdev->dev;
372 struct device_node *np = pdev->dev.of_node;
373 struct device_node *child;
374 struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
375 struct mt6323_leds *leds;
376 struct mt6323_led *led;
377 int ret;
378 unsigned int status;
379 u32 reg;
380
381 leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
382 if (!leds)
383 return -ENOMEM;
384
385 platform_set_drvdata(pdev, leds);
386 leds->dev = dev;
387
388 /*
389 * leds->hw points to the underlying bus for the register
390 * controlled.
391 */
392 leds->hw = hw;
393 mutex_init(&leds->lock);
394
395 status = MT6323_RG_DRV_32K_CK_PDN;
396 ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
397 MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
398 if (ret < 0) {
399 dev_err(leds->dev,
400 "Failed to update MT6323_TOP_CKPDN0 Register\n");
401 return ret;
402 }
403
404 for_each_available_child_of_node(np, child) {
405 ret = of_property_read_u32(child, "reg", ®);
406 if (ret) {
407 dev_err(dev, "Failed to read led 'reg' property\n");
408 goto put_child_node;
409 }
410
411 if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
412 dev_err(dev, "Invalid led reg %u\n", reg);
413 ret = -EINVAL;
414 goto put_child_node;
415 }
416
417 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
418 if (!led) {
419 ret = -ENOMEM;
420 goto put_child_node;
421 }
422
423 leds->led[reg] = led;
424 leds->led[reg]->id = reg;
425 leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
426 leds->led[reg]->cdev.brightness_set_blocking =
427 mt6323_led_set_brightness;
428 leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
429 leds->led[reg]->cdev.brightness_get =
430 mt6323_get_led_hw_brightness;
431 leds->led[reg]->parent = leds;
432
433 ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
434 if (ret < 0) {
435 dev_err(leds->dev,
436 "Failed to LED set default from devicetree\n");
437 goto put_child_node;
438 }
439
440 ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
441 if (ret) {
442 dev_err(&pdev->dev, "Failed to register LED: %d\n",
443 ret);
444 goto put_child_node;
445 }
446 leds->led[reg]->cdev.dev->of_node = child;
447 }
448
449 return 0;
450
451 put_child_node:
452 of_node_put(child);
453 return ret;
454 }
455
mt6323_led_remove(struct platform_device * pdev)456 static int mt6323_led_remove(struct platform_device *pdev)
457 {
458 struct mt6323_leds *leds = platform_get_drvdata(pdev);
459 int i;
460
461 /* Turn the LEDs off on driver removal. */
462 for (i = 0 ; leds->led[i] ; i++)
463 mt6323_led_hw_off(&leds->led[i]->cdev);
464
465 regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
466 MT6323_RG_DRV_32K_CK_PDN_MASK,
467 MT6323_RG_DRV_32K_CK_PDN);
468
469 mutex_destroy(&leds->lock);
470
471 return 0;
472 }
473
474 static const struct of_device_id mt6323_led_dt_match[] = {
475 { .compatible = "mediatek,mt6323-led" },
476 {},
477 };
478 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
479
480 static struct platform_driver mt6323_led_driver = {
481 .probe = mt6323_led_probe,
482 .remove = mt6323_led_remove,
483 .driver = {
484 .name = "mt6323-led",
485 .of_match_table = mt6323_led_dt_match,
486 },
487 };
488
489 module_platform_driver(mt6323_led_driver);
490
491 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
492 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
493 MODULE_LICENSE("GPL");
494