drivers/gpio/gpio-twl6040.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-twl6040.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-twl6040.c
Extension
.c
Size
2862 bytes
Lines
119
Domain
Driver Families
Bucket
drivers/gpio
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+
/*
 * Access to GPOs on TWL6040 chip
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 *
 * Authors:
 *	Sergio Aguirre <saaguirre@ti.com>
 *	Peter Ujfalusi <peter.ujfalusi@ti.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/irq.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>
#include <linux/of.h>

#include <linux/mfd/twl6040.h>

static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
{
	struct twl6040 *twl6040 = gpiochip_get_data(chip);
	int ret = 0;

	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
	if (ret < 0)
		return ret;

	return !!(ret & BIT(offset));
}

static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
{
	return GPIO_LINE_DIRECTION_OUT;
}

static int twl6040gpo_set(struct gpio_chip *chip, unsigned int offset,
			  int value)
{
	struct twl6040 *twl6040 = gpiochip_get_data(chip);
	int ret;
	u8 gpoctl;

	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
	if (ret < 0)
		return ret;

	if (value)
		gpoctl = ret | BIT(offset);
	else
		gpoctl = ret & ~BIT(offset);

	return twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
}

static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned int offset,
				    int value)
{
	/* This only drives GPOs, and can't change direction */
	return twl6040gpo_set(chip, offset, value);
}

static struct gpio_chip twl6040gpo_chip = {
	.label			= "twl6040",
	.owner			= THIS_MODULE,
	.get			= twl6040gpo_get,
	.direction_output	= twl6040gpo_direction_out,
	.get_direction		= twl6040gpo_get_direction,
	.set			= twl6040gpo_set,
	.can_sleep		= true,
};

/*----------------------------------------------------------------------*/

static int gpo_twl6040_probe(struct platform_device *pdev)
{
	struct device *twl6040_core_dev = pdev->dev.parent;
	struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
	int ret;

	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));

	twl6040gpo_chip.base = -1;

	if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
		twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
	else

Annotation

Implementation Notes