linux-stable/drivers/gpio/gpio-twl6040.c
Linus Walleij 4bef8bf20b gpio: twl6040: Use bitops
It's nice to use BIT() macros rather than open coding the same.
It's good practice as sometimes people use BIT(31) and forget
that the constant must be cast unsigned long.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-10 08:49:14 +02:00

112 lines
2.6 KiB
C

// 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 = dev_get_drvdata(chip->parent->parent);
int ret = 0;
ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
if (ret < 0)
return ret;
return !!(ret & BIT(offset));
}
static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
int value)
{
/* This only drives GPOs, and can't change direction */
return 0;
}
static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
int ret;
u8 gpoctl;
ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
if (ret < 0)
return;
if (value)
gpoctl = ret | BIT(offset);
else
gpoctl = ret & ~BIT(offset);
twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
}
static struct gpio_chip twl6040gpo_chip = {
.label = "twl6040",
.owner = THIS_MODULE,
.get = twl6040gpo_get,
.direction_output = twl6040gpo_direction_out,
.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;
twl6040gpo_chip.base = -1;
if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
else
twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
twl6040gpo_chip.parent = &pdev->dev;
#ifdef CONFIG_OF_GPIO
twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
#endif
ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
if (ret < 0) {
dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
twl6040gpo_chip.ngpio = 0;
}
return ret;
}
/* Note: this hardware lives inside an I2C-based multi-function device. */
MODULE_ALIAS("platform:twl6040-gpo");
static struct platform_driver gpo_twl6040_driver = {
.driver = {
.name = "twl6040-gpo",
},
.probe = gpo_twl6040_probe,
};
module_platform_driver(gpo_twl6040_driver);
MODULE_AUTHOR("Texas Instruments, Inc.");
MODULE_DESCRIPTION("GPO interface for TWL6040");
MODULE_LICENSE("GPL");