linux/drivers/gpio/gpio-bd71815.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Support to GPOs on ROHM BD71815
 * Copyright 2021 ROHM Semiconductors.
 * Author: Matti Vaittinen <[email protected]>
 *
 * Copyright 2014 Embest Technology Co. Ltd. Inc.
 * Author: [email protected]
 */

#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
/* For the BD71815 register definitions */
#include <linux/mfd/rohm-bd71815.h>

struct bd71815_gpio { … };

static int bd71815gpo_get(struct gpio_chip *chip, unsigned int offset)
{ … }

static void bd71815gpo_set(struct gpio_chip *chip, unsigned int offset,
			   int value)
{ … }

static int bd71815_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
				   unsigned long config)
{ … }

/* BD71815 GPIO is actually GPO */
static int bd71815gpo_direction_get(struct gpio_chip *gc, unsigned int offset)
{ … }

/* Template for GPIO chip */
static const struct gpio_chip bd71815gpo_chip = …;

#define BD71815_TWO_GPIOS …
#define BD71815_ONE_GPIO …

/*
 * Sigh. The BD71815 and BD71817 were originally designed to support two GPO
 * pins. At some point it was noticed the second GPO pin which is the E5 pin
 * located at the center of IC is hard to use on PCB (due to the location). It
 * was decided to not promote this second GPO and the pin is marked as GND in
 * the datasheet. The functionality is still there though! I guess driving a GPO
 * connected to the ground is a bad idea. Thus we do not support it by default.
 * OTOH - the original driver written by colleagues at Embest did support
 * controlling this second GPO. It is thus possible this is used in some of the
 * products.
 *
 * This driver does not by default support configuring this second GPO
 * but allows using it by providing the DT property
 * "rohm,enable-hidden-gpo".
 */
static int bd71815_init_valid_mask(struct gpio_chip *gc,
				   unsigned long *valid_mask,
				   unsigned int ngpios)
{ … }

static int gpo_bd71815_probe(struct platform_device *pdev)
{ … }

static struct platform_driver gpo_bd71815_driver = …;
module_platform_driver(…) …;

MODULE_ALIAS(…) …;
MODULE_AUTHOR(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;