1// SPDX-License-Identifier: GPL-2.0+
  2
  3#include <linux/leds.h>
  4#include <linux/module.h>
  5#include <linux/platform_device.h>
  6#include <linux/regmap.h>
  7
  8#define A500_EC_LED_DELAY_USEC	(100 * 1000)
  9
 10enum {
 11	REG_RESET_LEDS = 0x40,
 12	REG_POWER_LED_ON = 0x42,
 13	REG_CHARGE_LED_ON = 0x43,
 14	REG_ANDROID_LEDS_OFF = 0x5a,
 15};
 16
 17struct a500_led {
 18	struct led_classdev cdev;
 19	const struct reg_sequence *enable_seq;
 20	struct a500_led *other;
 21	struct regmap *rmap;
 22};
 23
 24static const struct reg_sequence a500_ec_leds_reset_seq[] = {
 25	REG_SEQ(REG_RESET_LEDS, 0x0, A500_EC_LED_DELAY_USEC),
 26	REG_SEQ(REG_ANDROID_LEDS_OFF, 0x0, A500_EC_LED_DELAY_USEC),
 27};
 28
 29static const struct reg_sequence a500_ec_white_led_enable_seq[] = {
 30	REG_SEQ(REG_POWER_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
 31};
 32
 33static const struct reg_sequence a500_ec_orange_led_enable_seq[] = {
 34	REG_SEQ(REG_CHARGE_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
 35};
 36
 37static int a500_ec_led_brightness_set(struct led_classdev *led_cdev,
 38				      enum led_brightness value)
 39{
 40	struct a500_led *led = container_of(led_cdev, struct a500_led, cdev);
 41	struct reg_sequence control_seq[2];
 42	unsigned int num_regs = 1;
 43
 44	if (value) {
 45		control_seq[0] = led->enable_seq[0];
 46	} else {
 47		/*
 48		 * There is no separate controls which can disable LEDs
 49		 * individually, there is only RESET_LEDS command that turns
 50		 * off both LEDs.
 51		 *
 52		 * RESET_LEDS turns off both LEDs, thus restore other LED if
 53		 * it's turned ON.
 54		 */
 55		if (led->other->cdev.brightness)
 56			num_regs = 2;
 57
 58		control_seq[0] = a500_ec_leds_reset_seq[0];
 59		control_seq[1] = led->other->enable_seq[0];
 60	}
 61
 62	return regmap_multi_reg_write(led->rmap, control_seq, num_regs);
 63}
 64
 65static int a500_ec_leds_probe(struct platform_device *pdev)
 66{
 67	struct a500_led *white_led, *orange_led;
 68	struct regmap *rmap;
 69	int err;
 70
 71	rmap = dev_get_regmap(pdev->dev.parent, "KB930");
 72	if (!rmap)
 73		return -EINVAL;
 74
 75	/* reset and turn off LEDs */
 76	regmap_multi_reg_write(rmap, a500_ec_leds_reset_seq, 2);
 77
 78	white_led = devm_kzalloc(&pdev->dev, sizeof(*white_led), GFP_KERNEL);
 79	if (!white_led)
 80		return -ENOMEM;
 81
 82	white_led->cdev.name = "power:white";
 83	white_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
 84	white_led->cdev.flags = LED_CORE_SUSPENDRESUME;
 85	white_led->cdev.max_brightness = 1;
 86	white_led->enable_seq = a500_ec_white_led_enable_seq;
 87	white_led->rmap = rmap;
 88
 89	orange_led = devm_kzalloc(&pdev->dev, sizeof(*orange_led), GFP_KERNEL);
 90	if (!orange_led)
 91		return -ENOMEM;
 92
 93	orange_led->cdev.name = "power:orange";
 94	orange_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
 95	orange_led->cdev.flags = LED_CORE_SUSPENDRESUME;
 96	orange_led->cdev.max_brightness = 1;
 97	orange_led->enable_seq = a500_ec_orange_led_enable_seq;
 98	orange_led->rmap = rmap;
 99
100	white_led->other = orange_led;
101	orange_led->other = white_led;
102
103	err = devm_led_classdev_register(&pdev->dev, &white_led->cdev);
104	if (err) {
105		dev_err(&pdev->dev, "failed to register white LED\n");
106		return err;
107	}
108
109	err = devm_led_classdev_register(&pdev->dev, &orange_led->cdev);
110	if (err) {
111		dev_err(&pdev->dev, "failed to register orange LED\n");
112		return err;
113	}
114
115	return 0;
116}
117
118static struct platform_driver a500_ec_leds_driver = {
119	.driver = {
120		.name = "acer-a500-iconia-leds",
121	},
122	.probe = a500_ec_leds_probe,
123};
124module_platform_driver(a500_ec_leds_driver);
125
126MODULE_DESCRIPTION("LED driver for Acer Iconia Tab A500 Power Button");
127MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
128MODULE_ALIAS("platform:acer-a500-iconia-leds");
129MODULE_LICENSE("GPL");