drivers/leds/leds-ipaq-micro.c

Source file repositories/reference/linux-study-clean/drivers/leds/leds-ipaq-micro.c

File Facts

System
Linux kernel
Corpus path
drivers/leds/leds-ipaq-micro.c
Extension
.c
Size
3622 bytes
Lines
133
Domain
Driver Families
Bucket
drivers/leds
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * h3xxx atmel micro companion support, notification LED subdevice
 *
 * Author : Linus Walleij <linus.walleij@linaro.org>
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/ipaq-micro.h>
#include <linux/leds.h>

#define LED_YELLOW	0x00
#define LED_GREEN	0x01

#define LED_EN       (1 << 4) /* LED ON/OFF 0:off, 1:on                       */
#define LED_AUTOSTOP (1 << 5) /* LED ON/OFF auto stop set 0:disable, 1:enable */
#define LED_ALWAYS   (1 << 6) /* LED Interrupt Mask 0:No mask, 1:mask         */

static int micro_leds_brightness_set(struct led_classdev *led_cdev,
				      enum led_brightness value)
{
	struct ipaq_micro *micro = dev_get_drvdata(led_cdev->dev->parent->parent);
	/*
	 * In this message:
	 * Byte 0 = LED color: 0 = yellow, 1 = green
	 *          yellow LED is always ~30 blinks per minute
	 * Byte 1 = duration (flags?) appears to be ignored
	 * Byte 2 = green ontime in 1/10 sec (deciseconds)
	 *          1 = 1/10 second
	 *          0 = 256/10 second
	 * Byte 3 = green offtime in 1/10 sec (deciseconds)
	 *          1 = 1/10 second
	 *          0 = 256/10 seconds
	 */
	struct ipaq_micro_msg msg = {
		.id = MSG_NOTIFY_LED,
		.tx_len = 4,
	};

	msg.tx_data[0] = LED_GREEN;
	msg.tx_data[1] = 0;
	if (value) {
		msg.tx_data[2] = 0; /* Duty cycle 256 */
		msg.tx_data[3] = 1;
	} else {
		msg.tx_data[2] = 1;
		msg.tx_data[3] = 0; /* Duty cycle 256 */
	}
	return ipaq_micro_tx_msg_sync(micro, &msg);
}

/* Maximum duty cycle in ms 256/10 sec = 25600 ms */
#define IPAQ_LED_MAX_DUTY 25600

static int micro_leds_blink_set(struct led_classdev *led_cdev,
				unsigned long *delay_on,
				unsigned long *delay_off)
{
	struct ipaq_micro *micro = dev_get_drvdata(led_cdev->dev->parent->parent);
	/*
	 * In this message:
	 * Byte 0 = LED color: 0 = yellow, 1 = green
	 *          yellow LED is always ~30 blinks per minute
	 * Byte 1 = duration (flags?) appears to be ignored
	 * Byte 2 = green ontime in 1/10 sec (deciseconds)
	 *          1 = 1/10 second
	 *          0 = 256/10 second
	 * Byte 3 = green offtime in 1/10 sec (deciseconds)
	 *          1 = 1/10 second
	 *          0 = 256/10 seconds
	 */
	struct ipaq_micro_msg msg = {
		.id = MSG_NOTIFY_LED,
		.tx_len = 4,
	};

	msg.tx_data[0] = LED_GREEN;
	if (*delay_on > IPAQ_LED_MAX_DUTY ||
	    *delay_off > IPAQ_LED_MAX_DUTY)
		return -EINVAL;

	if (*delay_on == 0 && *delay_off == 0) {
		*delay_on = 100;
		*delay_off = 100;
	}

	msg.tx_data[1] = 0;
	if (*delay_on >= IPAQ_LED_MAX_DUTY)

Annotation

Implementation Notes