linux/drivers/gpio/gpio-74xx-mmio.c
Matti Vaittinen e42615ec23 gpio: Use new GPIO_LINE_DIRECTION
It's hard for occasional GPIO code reader/writer to know if values 0/1
equal to IN or OUT. Use defined GPIO_LINE_DIRECTION_IN and
GPIO_LINE_DIRECTION_OUT to help them out.

NOTE - for gpio-amd-fch and gpio-bd9571mwv:
This commit also changes the return value for direction get to equal 1
for direction INPUT. Prior this commit these drivers might have
returned some other positive value but 1 for INPUT.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-11-07 09:27:48 +01:00

150 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 74xx MMIO GPIO driver
*
* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#define MMIO_74XX_DIR_IN (0 << 8)
#define MMIO_74XX_DIR_OUT (1 << 8)
#define MMIO_74XX_BIT_CNT(x) ((x) & 0xff)
struct mmio_74xx_gpio_priv {
struct gpio_chip gc;
unsigned flags;
};
static const struct of_device_id mmio_74xx_gpio_ids[] = {
{
.compatible = "ti,741g125",
.data = (const void *)(MMIO_74XX_DIR_IN | 1),
},
{
.compatible = "ti,742g125",
.data = (const void *)(MMIO_74XX_DIR_IN | 2),
},
{
.compatible = "ti,74125",
.data = (const void *)(MMIO_74XX_DIR_IN | 4),
},
{
.compatible = "ti,74365",
.data = (const void *)(MMIO_74XX_DIR_IN | 6),
},
{
.compatible = "ti,74244",
.data = (const void *)(MMIO_74XX_DIR_IN | 8),
},
{
.compatible = "ti,741624",
.data = (const void *)(MMIO_74XX_DIR_IN | 16),
},
{
.compatible = "ti,741g74",
.data = (const void *)(MMIO_74XX_DIR_OUT | 1),
},
{
.compatible = "ti,7474",
.data = (const void *)(MMIO_74XX_DIR_OUT | 2),
},
{
.compatible = "ti,74175",
.data = (const void *)(MMIO_74XX_DIR_OUT | 4),
},
{
.compatible = "ti,74174",
.data = (const void *)(MMIO_74XX_DIR_OUT | 6),
},
{
.compatible = "ti,74273",
.data = (const void *)(MMIO_74XX_DIR_OUT | 8),
},
{
.compatible = "ti,7416374",
.data = (const void *)(MMIO_74XX_DIR_OUT | 16),
},
{ }
};
MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
{
struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
if (priv->flags & MMIO_74XX_DIR_OUT)
return GPIO_LINE_DIRECTION_OUT;
return GPIO_LINE_DIRECTION_IN;
}
static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
}
static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
if (priv->flags & MMIO_74XX_DIR_OUT) {
gc->set(gc, gpio, val);
return 0;
}
return -ENOTSUPP;
}
static int mmio_74xx_gpio_probe(struct platform_device *pdev)
{
struct mmio_74xx_gpio_priv *priv;
void __iomem *dat;
int err;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev);
dat = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(dat))
return PTR_ERR(dat);
err = bgpio_init(&priv->gc, &pdev->dev,
DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
dat, NULL, NULL, NULL, NULL, 0);
if (err)
return err;
priv->gc.direction_input = mmio_74xx_dir_in;
priv->gc.direction_output = mmio_74xx_dir_out;
priv->gc.get_direction = mmio_74xx_get_direction;
priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
priv->gc.owner = THIS_MODULE;
platform_set_drvdata(pdev, priv);
return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
}
static struct platform_driver mmio_74xx_gpio_driver = {
.driver = {
.name = "74xx-mmio-gpio",
.of_match_table = mmio_74xx_gpio_ids,
},
.probe = mmio_74xx_gpio_probe,
};
module_platform_driver(mmio_74xx_gpio_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("74xx MMIO GPIO driver");