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 10 enum { 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 17 struct 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 24 static 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 29 static 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 33 static 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 37 static 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 65 static 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 } 117 118 static struct platform_driver a500_ec_leds_driver = { 119 .driver = { 120 .name = "acer-a500-iconia-leds", 121 }, 122 .probe = a500_ec_leds_probe, 123 }; 124 module_platform_driver(a500_ec_leds_driver); 125 126 MODULE_DESCRIPTION("LED driver for Acer Iconia Tab A500 Power Button"); 127 MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>"); 128 MODULE_ALIAS("platform:acer-a500-iconia-leds"); 129 MODULE_LICENSE("GPL"); 130