drivers/gpio/gpio-sl28cpld.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-sl28cpld.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-sl28cpld.c
Extension
.c
Size
3946 bytes
Lines
161
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-only
/*
 * sl28cpld GPIO driver
 *
 * Copyright 2020 Michael Walle <michael@walle.cc>
 */

#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/regmap.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* GPIO flavor */
#define GPIO_REG_DIR	0x00
#define GPIO_REG_OUT	0x01
#define GPIO_REG_IN	0x02
#define GPIO_REG_IE	0x03
#define GPIO_REG_IP	0x04

/* input-only flavor */
#define GPI_REG_IN	0x00

/* output-only flavor */
#define GPO_REG_OUT	0x00

enum sl28cpld_gpio_type {
	SL28CPLD_GPIO = 1,
	SL28CPLD_GPI,
	SL28CPLD_GPO,
};

static const struct regmap_irq sl28cpld_gpio_irqs[] = {
	REGMAP_IRQ_REG_LINE(0, 8),
	REGMAP_IRQ_REG_LINE(1, 8),
	REGMAP_IRQ_REG_LINE(2, 8),
	REGMAP_IRQ_REG_LINE(3, 8),
	REGMAP_IRQ_REG_LINE(4, 8),
	REGMAP_IRQ_REG_LINE(5, 8),
	REGMAP_IRQ_REG_LINE(6, 8),
	REGMAP_IRQ_REG_LINE(7, 8),
};

static int sl28cpld_gpio_irq_init(struct platform_device *pdev,
				  unsigned int base,
				  struct gpio_regmap_config *config)
{
	struct regmap_irq_chip_data *irq_data;
	struct regmap_irq_chip *irq_chip;
	struct device *dev = &pdev->dev;
	int irq, ret;

	if (!device_property_read_bool(dev, "interrupt-controller"))
		return 0;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
	if (!irq_chip)
		return -ENOMEM;

	irq_chip->name = "sl28cpld-gpio-irq";
	irq_chip->irqs = sl28cpld_gpio_irqs;
	irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
	irq_chip->num_regs = 1;
	irq_chip->status_base = base + GPIO_REG_IP;
	irq_chip->unmask_base = base + GPIO_REG_IE;
	irq_chip->ack_base = base + GPIO_REG_IP;

	ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
					      config->regmap, irq,
					      IRQF_SHARED | IRQF_ONESHOT,
					      0, irq_chip, &irq_data);
	if (ret)
		return ret;

	config->irq_domain = regmap_irq_get_domain(irq_data);

	return 0;
}

static int sl28cpld_gpio_probe(struct platform_device *pdev)
{
	struct gpio_regmap_config config = {0};

Annotation

Implementation Notes