1
linux/drivers/gpio/gpio-amd-fch.c

193 lines
4.9 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0+
/*
* GPIO driver for the AMD G series FCH (eg. GX-412TC)
*
* Copyright (C) 2018 metux IT consult
* Author: Enrico Weigelt, metux IT consult <info@metux.net>
*
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/platform_data/gpio/gpio-amd-fch.h>
#include <linux/spinlock.h>
#define AMD_FCH_MMIO_BASE 0xFED80000
#define AMD_FCH_GPIO_BANK0_BASE 0x1500
#define AMD_FCH_GPIO_SIZE 0x0300
#define AMD_FCH_GPIO_FLAG_DIRECTION BIT(23)
#define AMD_FCH_GPIO_FLAG_WRITE BIT(22)
#define AMD_FCH_GPIO_FLAG_READ BIT(16)
static const struct resource amd_fch_gpio_iores =
DEFINE_RES_MEM_NAMED(
AMD_FCH_MMIO_BASE + AMD_FCH_GPIO_BANK0_BASE,
AMD_FCH_GPIO_SIZE,
"amd-fch-gpio-iomem");
struct amd_fch_gpio_priv {
struct gpio_chip gc;
void __iomem *base;
struct amd_fch_gpio_pdata *pdata;
spinlock_t lock;
};
static void __iomem *amd_fch_gpio_addr(struct amd_fch_gpio_priv *priv,
unsigned int gpio)
{
return priv->base + priv->pdata->gpio_reg[gpio]*sizeof(u32);
}
static int amd_fch_gpio_direction_input(struct gpio_chip *gc,
unsigned int offset)
{
unsigned long flags;
struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
void __iomem *ptr = amd_fch_gpio_addr(priv, offset);
spin_lock_irqsave(&priv->lock, flags);
writel_relaxed(readl_relaxed(ptr) & ~AMD_FCH_GPIO_FLAG_DIRECTION, ptr);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int amd_fch_gpio_direction_output(struct gpio_chip *gc,
unsigned int gpio, int value)
{
unsigned long flags;
struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
u32 val;
spin_lock_irqsave(&priv->lock, flags);
val = readl_relaxed(ptr);
if (value)
val |= AMD_FCH_GPIO_FLAG_WRITE;
else
val &= ~AMD_FCH_GPIO_FLAG_WRITE;
writel_relaxed(val | AMD_FCH_GPIO_FLAG_DIRECTION, ptr);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int amd_fch_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
{
int ret;
unsigned long flags;
struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
spin_lock_irqsave(&priv->lock, flags);
ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_DIRECTION);
spin_unlock_irqrestore(&priv->lock, flags);
return ret ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
}
static void amd_fch_gpio_set(struct gpio_chip *gc,
unsigned int gpio, int value)
{
unsigned long flags;
struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
u32 mask;
spin_lock_irqsave(&priv->lock, flags);
mask = readl_relaxed(ptr);
if (value)
mask |= AMD_FCH_GPIO_FLAG_WRITE;
else
mask &= ~AMD_FCH_GPIO_FLAG_WRITE;
writel_relaxed(mask, ptr);
spin_unlock_irqrestore(&priv->lock, flags);
}
static int amd_fch_gpio_get(struct gpio_chip *gc,
unsigned int offset)
{
unsigned long flags;
int ret;
struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
void __iomem *ptr = amd_fch_gpio_addr(priv, offset);
spin_lock_irqsave(&priv->lock, flags);
ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_READ);
spin_unlock_irqrestore(&priv->lock, flags);
return ret;
}
static int amd_fch_gpio_request(struct gpio_chip *chip,
unsigned int gpio_pin)
{
return 0;
}
static int amd_fch_gpio_probe(struct platform_device *pdev)
{
struct amd_fch_gpio_priv *priv;
struct amd_fch_gpio_pdata *pdata;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "no platform_data\n");
return -ENOENT;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->pdata = pdata;
priv->gc.owner = THIS_MODULE;
priv->gc.parent = &pdev->dev;
priv->gc.label = dev_name(&pdev->dev);
priv->gc.ngpio = priv->pdata->gpio_num;
priv->gc.names = priv->pdata->gpio_names;
priv->gc.base = -1;
priv->gc.request = amd_fch_gpio_request;
priv->gc.direction_input = amd_fch_gpio_direction_input;
priv->gc.direction_output = amd_fch_gpio_direction_output;
priv->gc.get_direction = amd_fch_gpio_get_direction;
priv->gc.get = amd_fch_gpio_get;
priv->gc.set = amd_fch_gpio_set;
spin_lock_init(&priv->lock);
priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
platform_set_drvdata(pdev, priv);
return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
}
static struct platform_driver amd_fch_gpio_driver = {
.driver = {
.name = AMD_FCH_GPIO_DRIVER_NAME,
},
.probe = amd_fch_gpio_probe,
};
module_platform_driver(amd_fch_gpio_driver);
MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>");
MODULE_DESCRIPTION("AMD G-series FCH GPIO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" AMD_FCH_GPIO_DRIVER_NAME);