1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for LEDs connected to the Intel Cherry Trail Whiskey Cove PMIC
4 *
5 * Copyright 2019 Yauhen Kharuzhy <jekhor@gmail.com>
6 * Copyright 2023 Hans de Goede <hansg@kernel.org>
7 *
8 * Register info comes from the Lenovo Yoga Book Android opensource code
9 * available from Lenovo. File lenovo_yb1_x90f_l_osc_201803.7z path in the 7z:
10 * YB1_source_code/kernel/cht/drivers/misc/charger_gp_led.c
11 */
12
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/mfd/intel_soc_pmic.h>
16#include <linux/module.h>
17#include <linux/mod_devicetable.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/suspend.h>
21
22#define CHT_WC_LED1_CTRL		0x5e1f
23#define CHT_WC_LED1_FSM			0x5e20
24#define CHT_WC_LED1_PWM			0x5e21
25
26#define CHT_WC_LED2_CTRL		0x4fdf
27#define CHT_WC_LED2_FSM			0x4fe0
28#define CHT_WC_LED2_PWM			0x4fe1
29
30#define CHT_WC_LED1_SWCTL		BIT(0)		/* HW or SW control of charging led */
31#define CHT_WC_LED1_ON			BIT(1)
32
33#define CHT_WC_LED2_ON			BIT(0)
34#define CHT_WC_LED_I_MA2_5		(2 << 2)	/* LED current limit */
35#define CHT_WC_LED_I_MASK		GENMASK(3, 2)	/* LED current limit mask */
36
37#define CHT_WC_LED_F_1_4_HZ		(0 << 4)
38#define CHT_WC_LED_F_1_2_HZ		(1 << 4)
39#define CHT_WC_LED_F_1_HZ		(2 << 4)
40#define CHT_WC_LED_F_2_HZ		(3 << 4)
41#define CHT_WC_LED_F_MASK		GENMASK(5, 4)
42
43#define CHT_WC_LED_EFF_OFF		(0 << 1)
44#define CHT_WC_LED_EFF_ON		(1 << 1)
45#define CHT_WC_LED_EFF_BLINKING		(2 << 1)
46#define CHT_WC_LED_EFF_BREATHING	(3 << 1)
47#define CHT_WC_LED_EFF_MASK		GENMASK(2, 1)
48
49#define CHT_WC_LED_COUNT		2
50
51struct cht_wc_led_regs {
52	/* Register addresses */
53	u16 ctrl;
54	u16 fsm;
55	u16 pwm;
56	/* Mask + values for turning the LED on/off */
57	u8 on_off_mask;
58	u8 on_val;
59	u8 off_val;
60};
61
62struct cht_wc_led_saved_regs {
63	unsigned int ctrl;
64	unsigned int fsm;
65	unsigned int pwm;
66};
67
68struct cht_wc_led {
69	struct led_classdev cdev;
70	const struct cht_wc_led_regs *regs;
71	struct regmap *regmap;
72	struct mutex mutex;
73	struct cht_wc_led_saved_regs saved_regs;
74};
75
76struct cht_wc_leds {
77	struct cht_wc_led leds[CHT_WC_LED_COUNT];
78	/* Saved LED1 initial register values */
79	struct cht_wc_led_saved_regs led1_initial_regs;
80};
81
82static const struct cht_wc_led_regs cht_wc_led_regs[CHT_WC_LED_COUNT] = {
83	{
84		.ctrl		= CHT_WC_LED1_CTRL,
85		.fsm		= CHT_WC_LED1_FSM,
86		.pwm		= CHT_WC_LED1_PWM,
87		.on_off_mask	= CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
88		.on_val		= CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
89		.off_val	= CHT_WC_LED1_SWCTL,
90	},
91	{
92		.ctrl		= CHT_WC_LED2_CTRL,
93		.fsm		= CHT_WC_LED2_FSM,
94		.pwm		= CHT_WC_LED2_PWM,
95		.on_off_mask	= CHT_WC_LED2_ON,
96		.on_val		= CHT_WC_LED2_ON,
97		.off_val	= 0,
98	},
99};
100
101static const char * const cht_wc_leds_names[CHT_WC_LED_COUNT] = {
102	"platform::" LED_FUNCTION_CHARGING,
103	"platform::" LED_FUNCTION_INDICATOR,
104};
105
106static int cht_wc_leds_brightness_set(struct led_classdev *cdev,
107				      enum led_brightness value)
108{
109	struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
110	int ret;
111
112	mutex_lock(&led->mutex);
113
114	if (!value) {
115		ret = regmap_update_bits(led->regmap, led->regs->ctrl,
116					 led->regs->on_off_mask, led->regs->off_val);
117		if (ret < 0) {
118			dev_err(cdev->dev, "Failed to turn off: %d\n", ret);
119			goto out;
120		}
121
122		/* Disable HW blinking */
123		ret = regmap_update_bits(led->regmap, led->regs->fsm,
124					 CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
125		if (ret < 0)
126			dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
127	} else {
128		ret = regmap_write(led->regmap, led->regs->pwm, value);
129		if (ret < 0) {
130			dev_err(cdev->dev, "Failed to set brightness: %d\n", ret);
131			goto out;
132		}
133
134		ret = regmap_update_bits(led->regmap, led->regs->ctrl,
135					 led->regs->on_off_mask, led->regs->on_val);
136		if (ret < 0)
137			dev_err(cdev->dev, "Failed to turn on: %d\n", ret);
138	}
139out:
140	mutex_unlock(&led->mutex);
141	return ret;
142}
143
144static enum led_brightness cht_wc_leds_brightness_get(struct led_classdev *cdev)
145{
146	struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
147	unsigned int val;
148	int ret;
149
150	mutex_lock(&led->mutex);
151
152	ret = regmap_read(led->regmap, led->regs->ctrl, &val);
153	if (ret < 0) {
154		dev_err(cdev->dev, "Failed to read LED CTRL reg: %d\n", ret);
155		ret = 0;
156		goto done;
157	}
158
159	val &= led->regs->on_off_mask;
160	if (val != led->regs->on_val) {
161		ret = 0;
162		goto done;
163	}
164
165	ret = regmap_read(led->regmap, led->regs->pwm, &val);
166	if (ret < 0) {
167		dev_err(cdev->dev, "Failed to read LED PWM reg: %d\n", ret);
168		ret = 0;
169		goto done;
170	}
171
172	ret = val;
173done:
174	mutex_unlock(&led->mutex);
175
176	return ret;
177}
178
179/* Return blinking period for given CTRL reg value */
180static unsigned long cht_wc_leds_get_period(int ctrl)
181{
182	ctrl &= CHT_WC_LED_F_MASK;
183
184	switch (ctrl) {
185	case CHT_WC_LED_F_1_4_HZ:
186		return 1000 * 4;
187	case CHT_WC_LED_F_1_2_HZ:
188		return 1000 * 2;
189	case CHT_WC_LED_F_1_HZ:
190		return 1000;
191	case CHT_WC_LED_F_2_HZ:
192		return 1000 / 2;
193	}
194
195	return 0;
196}
197
198/*
199 * Find suitable hardware blink mode for given period.
200 * period < 750 ms - select 2 HZ
201 * 750 ms <= period < 1500 ms - select 1 HZ
202 * 1500 ms <= period < 3000 ms - select 1/2 HZ
203 * 3000 ms <= period < 5000 ms - select 1/4 HZ
204 * 5000 ms <= period - return -1
205 */
206static int cht_wc_leds_find_freq(unsigned long period)
207{
208	if (period < 750)
209		return CHT_WC_LED_F_2_HZ;
210	else if (period < 1500)
211		return CHT_WC_LED_F_1_HZ;
212	else if (period < 3000)
213		return CHT_WC_LED_F_1_2_HZ;
214	else if (period < 5000)
215		return CHT_WC_LED_F_1_4_HZ;
216	else
217		return -1;
218}
219
220static int cht_wc_leds_set_effect(struct led_classdev *cdev,
221				  unsigned long *delay_on,
222				  unsigned long *delay_off,
223				  u8 effect)
224{
225	struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
226	int ctrl, ret;
227
228	mutex_lock(&led->mutex);
229
230	/* Blink with 1 Hz as default if nothing specified */
231	if (!*delay_on && !*delay_off)
232		*delay_on = *delay_off = 500;
233
234	ctrl = cht_wc_leds_find_freq(*delay_on + *delay_off);
235	if (ctrl < 0) {
236		/* Disable HW blinking */
237		ret = regmap_update_bits(led->regmap, led->regs->fsm,
238					 CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
239		if (ret < 0)
240			dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
241
242		/* Fallback to software timer */
243		*delay_on = *delay_off = 0;
244		ret = -EINVAL;
245		goto done;
246	}
247
248	ret = regmap_update_bits(led->regmap, led->regs->fsm,
249				 CHT_WC_LED_EFF_MASK, effect);
250	if (ret < 0)
251		dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
252
253	/* Set the frequency and make sure the LED is on */
254	ret = regmap_update_bits(led->regmap, led->regs->ctrl,
255				 CHT_WC_LED_F_MASK | led->regs->on_off_mask,
256				 ctrl | led->regs->on_val);
257	if (ret < 0)
258		dev_err(cdev->dev, "Failed to update LED CTRL reg: %d\n", ret);
259
260	*delay_off = *delay_on = cht_wc_leds_get_period(ctrl) / 2;
261
262done:
263	mutex_unlock(&led->mutex);
264
265	return ret;
266}
267
268static int cht_wc_leds_blink_set(struct led_classdev *cdev,
269				 unsigned long *delay_on,
270				 unsigned long *delay_off)
271{
272	u8 effect = CHT_WC_LED_EFF_BLINKING;
273
274	/*
275	 * The desired default behavior of LED1 / the charge LED is breathing
276	 * while charging and on/solid when full. Since triggers cannot select
277	 * breathing, blink_set() gets called when charging. Use slow breathing
278	 * when the default "charging-blink-full-solid" trigger is used to
279	 * achieve the desired default behavior.
280	 */
281	if (cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
282		*delay_on = *delay_off = 1000;
283		effect = CHT_WC_LED_EFF_BREATHING;
284	}
285
286	return cht_wc_leds_set_effect(cdev, delay_on, delay_off, effect);
287}
288
289static int cht_wc_leds_pattern_set(struct led_classdev *cdev,
290				   struct led_pattern *pattern,
291				   u32 len, int repeat)
292{
293	unsigned long delay_off, delay_on;
294
295	if (repeat > 0 || len != 2 ||
296	    pattern[0].brightness != 0 || pattern[1].brightness != 1 ||
297	    pattern[0].delta_t != pattern[1].delta_t ||
298	    (pattern[0].delta_t != 250 && pattern[0].delta_t != 500 &&
299	     pattern[0].delta_t != 1000 && pattern[0].delta_t != 2000))
300		return -EINVAL;
301
302	delay_off = pattern[0].delta_t;
303	delay_on  = pattern[1].delta_t;
304
305	return cht_wc_leds_set_effect(cdev, &delay_on, &delay_off, CHT_WC_LED_EFF_BREATHING);
306}
307
308static int cht_wc_leds_pattern_clear(struct led_classdev *cdev)
309{
310	return cht_wc_leds_brightness_set(cdev, 0);
311}
312
313static int cht_wc_led_save_regs(struct cht_wc_led *led,
314				struct cht_wc_led_saved_regs *saved_regs)
315{
316	int ret;
317
318	ret = regmap_read(led->regmap, led->regs->ctrl, &saved_regs->ctrl);
319	if (ret < 0)
320		return ret;
321
322	ret = regmap_read(led->regmap, led->regs->fsm, &saved_regs->fsm);
323	if (ret < 0)
324		return ret;
325
326	return regmap_read(led->regmap, led->regs->pwm, &saved_regs->pwm);
327}
328
329static void cht_wc_led_restore_regs(struct cht_wc_led *led,
330				    const struct cht_wc_led_saved_regs *saved_regs)
331{
332	regmap_write(led->regmap, led->regs->ctrl, saved_regs->ctrl);
333	regmap_write(led->regmap, led->regs->fsm, saved_regs->fsm);
334	regmap_write(led->regmap, led->regs->pwm, saved_regs->pwm);
335}
336
337static int cht_wc_leds_probe(struct platform_device *pdev)
338{
339	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
340	struct cht_wc_leds *leds;
341	int ret;
342	int i;
343
344	/*
345	 * On the Lenovo Yoga Tab 3 the LED1 driver output is actually
346	 * connected to a haptic feedback motor rather then a LED.
347	 * So do not register a LED classdev there (LED2 is unused).
348	 */
349	if (pmic->cht_wc_model == INTEL_CHT_WC_LENOVO_YT3_X90)
350		return -ENODEV;
351
352	leds = devm_kzalloc(&pdev->dev, sizeof(*leds), GFP_KERNEL);
353	if (!leds)
354		return -ENOMEM;
355
356	/*
357	 * LED1 might be in hw-controlled mode when this driver gets loaded; and
358	 * since the PMIC is always powered by the battery any changes made are
359	 * permanent. Save LED1 regs to restore them on remove() or shutdown().
360	 */
361	leds->leds[0].regs = &cht_wc_led_regs[0];
362	leds->leds[0].regmap = pmic->regmap;
363	ret = cht_wc_led_save_regs(&leds->leds[0], &leds->led1_initial_regs);
364	if (ret < 0)
365		return ret;
366
367	/* Set LED1 default trigger based on machine model */
368	switch (pmic->cht_wc_model) {
369	case INTEL_CHT_WC_GPD_WIN_POCKET:
370		leds->leds[0].cdev.default_trigger = "max170xx_battery-charging-blink-full-solid";
371		break;
372	case INTEL_CHT_WC_XIAOMI_MIPAD2:
373		leds->leds[0].cdev.default_trigger = "bq27520-0-charging-blink-full-solid";
374		break;
375	case INTEL_CHT_WC_LENOVO_YOGABOOK1:
376		leds->leds[0].cdev.default_trigger = "bq27542-0-charging-blink-full-solid";
377		break;
378	default:
379		dev_warn(&pdev->dev, "Unknown model, no default charging trigger\n");
380		break;
381	}
382
383	for (i = 0; i < CHT_WC_LED_COUNT; i++) {
384		struct cht_wc_led *led = &leds->leds[i];
385
386		led->regs = &cht_wc_led_regs[i];
387		led->regmap = pmic->regmap;
388		mutex_init(&led->mutex);
389		led->cdev.name = cht_wc_leds_names[i];
390		led->cdev.brightness_set_blocking = cht_wc_leds_brightness_set;
391		led->cdev.brightness_get = cht_wc_leds_brightness_get;
392		led->cdev.blink_set = cht_wc_leds_blink_set;
393		led->cdev.pattern_set = cht_wc_leds_pattern_set;
394		led->cdev.pattern_clear = cht_wc_leds_pattern_clear;
395		led->cdev.max_brightness = 255;
396
397		ret = led_classdev_register(&pdev->dev, &led->cdev);
398		if (ret < 0)
399			return ret;
400	}
401
402	platform_set_drvdata(pdev, leds);
403	return 0;
404}
405
406static void cht_wc_leds_remove(struct platform_device *pdev)
407{
408	struct cht_wc_leds *leds = platform_get_drvdata(pdev);
409	int i;
410
411	for (i = 0; i < CHT_WC_LED_COUNT; i++)
412		led_classdev_unregister(&leds->leds[i].cdev);
413
414	/* Restore LED1 regs if hw-control was active else leave LED1 off */
415	if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
416		cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
417}
418
419static void cht_wc_leds_disable(struct platform_device *pdev)
420{
421	struct cht_wc_leds *leds = platform_get_drvdata(pdev);
422	int i;
423
424	for (i = 0; i < CHT_WC_LED_COUNT; i++)
425		cht_wc_leds_brightness_set(&leds->leds[i].cdev, 0);
426
427	/* Restore LED1 regs if hw-control was active else leave LED1 off */
428	if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
429		cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
430}
431
432/* On suspend save current settings and turn LEDs off */
433static int cht_wc_leds_suspend(struct device *dev)
434{
435	struct cht_wc_leds *leds = dev_get_drvdata(dev);
436	int i, ret;
437
438	for (i = 0; i < CHT_WC_LED_COUNT; i++) {
439		ret = cht_wc_led_save_regs(&leds->leds[i], &leds->leds[i].saved_regs);
440		if (ret < 0)
441			return ret;
442	}
443
444	cht_wc_leds_disable(to_platform_device(dev));
445	return 0;
446}
447
448/* On resume restore the saved settings */
449static int cht_wc_leds_resume(struct device *dev)
450{
451	struct cht_wc_leds *leds = dev_get_drvdata(dev);
452	int i;
453
454	for (i = 0; i < CHT_WC_LED_COUNT; i++)
455		cht_wc_led_restore_regs(&leds->leds[i], &leds->leds[i].saved_regs);
456
457	return 0;
458}
459
460static DEFINE_SIMPLE_DEV_PM_OPS(cht_wc_leds_pm, cht_wc_leds_suspend, cht_wc_leds_resume);
461
462static struct platform_driver cht_wc_leds_driver = {
463	.probe = cht_wc_leds_probe,
464	.remove_new = cht_wc_leds_remove,
465	.shutdown = cht_wc_leds_disable,
466	.driver = {
467		.name = "cht_wcove_leds",
468		.pm = pm_sleep_ptr(&cht_wc_leds_pm),
469	},
470};
471module_platform_driver(cht_wc_leds_driver);
472
473MODULE_ALIAS("platform:cht_wcove_leds");
474MODULE_DESCRIPTION("Intel Cherry Trail Whiskey Cove PMIC LEDs driver");
475MODULE_AUTHOR("Yauhen Kharuzhy <jekhor@gmail.com>");
476MODULE_LICENSE("GPL");
477