1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2019 Christian Mauderer <oss@c-mauderer.de>
6  * - one LED is controlled by a single byte on MOSI
7  * - the value of the byte gives the brightness between two values (lowest to
9  * - no return value is necessary (no MISO signal)
11  * The value for minimum and maximum brightness depends on the device
15  * - "ubnt,acb-spi-led": Microcontroller (SONiX 8F26E611LA) based device used
19  *   * Mode: 00 -> set brightness between 0x00 (min) and 0x3F (max)
20  *   * Mode: 01 -> pulsing pattern (min -> max -> min) with an interval. From
24  *   * Mode: 10 -> same as 01 but with only a ramp from min to max. Again a
26  *   * Mode: 11 -> blinking (off -> 25% -> off -> 25% -> ...) with a period of
41 	/* SPI byte that will be send to switch the LED to maximum brightness */
59 	{ .compatible = "ubnt,acb-spi-led", .data = &ubnt_acb_spi_led_cdef },
66 					    enum led_brightness brightness)  in spi_byte_brightness_set_blocking()  argument
72 	value = (u8) brightness + led->cdef->off_value;  in spi_byte_brightness_set_blocking()
74 	mutex_lock(&led->mutex);  in spi_byte_brightness_set_blocking()
75 	ret = spi_write(led->spi, &value, sizeof(value));  in spi_byte_brightness_set_blocking()
76 	mutex_unlock(&led->mutex);  in spi_byte_brightness_set_blocking()
84 	struct device *dev = &spi->dev;  in spi_byte_probe()
86 	const char *name = "leds-spi-byte::";  in spi_byte_probe()
91 		dev_err(dev, "Device must have exactly one LED sub-node.");  in spi_byte_probe()
92 		return -EINVAL;  in spi_byte_probe()
98 		return -ENOMEM;  in spi_byte_probe()
101 	strlcpy(led->name, name, sizeof(led->name));  in spi_byte_probe()
102 	led->spi = spi;  in spi_byte_probe()
103 	mutex_init(&led->mutex);  in spi_byte_probe()
104 	led->cdef = device_get_match_data(dev);  in spi_byte_probe()
105 	led->ldev.name = led->name;  in spi_byte_probe()
106 	led->ldev.brightness = LED_OFF;  in spi_byte_probe()
107 	led->ldev.max_brightness = led->cdef->max_value - led->cdef->off_value;  in spi_byte_probe()
108 	led->ldev.brightness_set_blocking = spi_byte_brightness_set_blocking;  in spi_byte_probe()
110 	state = of_get_property(child, "default-state", NULL);  in spi_byte_probe()
113 			led->ldev.brightness = led->ldev.max_brightness;  in spi_byte_probe()
116 			dev_err(dev, "default-state can only be 'on' or 'off'");  in spi_byte_probe()
117 			return -EINVAL;  in spi_byte_probe()
120 	spi_byte_brightness_set_blocking(&led->ldev,  in spi_byte_probe()
121 					 led->ldev.brightness);  in spi_byte_probe()
123 	ret = devm_led_classdev_register(&spi->dev, &led->ldev);  in spi_byte_probe()
125 		mutex_destroy(&led->mutex);  in spi_byte_probe()
137 	mutex_destroy(&led->mutex);  in spi_byte_remove()
151 MODULE_AUTHOR("Christian Mauderer <oss@c-mauderer.de>");
154 MODULE_ALIAS("spi:leds-spi-byte");