/*
* linux/drivers/gpio/gpio-mb86s7x.c
*
* Copyright (C) 2015 Fujitsu Semiconductor Limited
* Copyright (C) 2015 Linaro Ltd.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/io.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/of_device.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
/*
* Only first 8bits of a register correspond to each pin,
* so there are 4 registers for 32 pins.
*/
#define PDR(x) (0x0 + x / 8 * 4)
#define DDR(x) (0x10 + x / 8 * 4)
#define PFR(x) (0x20 + x / 8 * 4)
#define OFFSET(x) BIT((x) % 8)
struct mb86s70_gpio_chip {
struct gpio_chip gc;
void __iomem *base;
struct clk *clk;
spinlock_t lock;
};
static inline struct mb86s70_gpio_chip *chip_to_mb86s70(struct gpio_chip *gc)
{
return container_of(gc, struct mb86s70_gpio_chip, gc);
}
static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
unsigned long flags;
u32 val;
spin_lock_irqsave(&gchip->lock, flags);
val = readl(gchip->base + PFR(gpio));
if (!(val & OFFSET(gpio))) {
spin_unlock_irqrestore(&gchip->lock, flags);
return -EINVAL;
}
val &= ~OFFSET(gpio);
writel(val, gchip->base + PFR(gpio));
spin_unlock_irqrestore(&gchip->lock, flags);
return 0;
}
static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
unsigned long flags;
u32 val;
spin_lock_irqsave(&gchip->lock, flags);
val = readl(gchip->base + PFR(gpio));
val |= OFFSET(gpio);
writel(val, gchip->base + PFR(gpio));
spin_unlock_irqrestore(&gchip->lock, flags);
}
static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
unsigned long flags;
unsigned char val;
spin_lock_irqsave(&gchip->lock, flags);
val = readl(gchip->base + DDR(gpio));
val &= ~OFFSET(gpio);
writel(val, gchip->base + DDR(gpio));
spin_unlock_irqrestore(&gchip->lock, flags);
return 0;
}
static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
unsigned gpio, int value)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
unsigned long flags;
unsigned char val;
spin_lock_irqsave(&gchip->lock, flags);
val = readl(gchip->base + PDR(gpio));
if (value)
val |= OFFSET(gpio);
else
val &= ~OFFSET(gpio);
writel(val, gchip->base + PDR(gpio));
val = readl(gchip->base + DDR(gpio));
val |= OFFSET(gpio);
writel(val, gchip->base + DDR(gpio));
spin_unlock_irqrestore(&gchip->lock, flags);
return 0;
}
static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
}
static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
{
struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
unsigned long flags;
unsigned char val;
spin_lock_irqsave(&gchip->lock, flags);
val = readl(gchip->base + PDR(gpio));
if (value)
val |= OFFSET(gpio);
else
val &= ~OFFSET(gpio);
writel(val, gchip->base + PDR(gpio));
spin_unlock_irqrestore(&gchip->lock, flags);
}
static int mb86s70_gpio_probe(struct platform_device *pdev)
{
struct mb86s70_gpio_chip *gchip;
struct resource *res;
int ret;
gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
if (gchip == NULL)
return -ENOMEM;
platform_set_drvdata(pdev, gchip);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
gchip->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(gchip->base))
return PTR_ERR(gchip->base);
gchip->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(gchip->clk))
return PTR_ERR(gchip->clk);
clk_prepare_enable(gchip->clk);
spin_lock_init(&gchip->lock);
gchip->gc.direction_output = mb86s70_gpio_direction_output;
gchip->gc.direction_input = mb86s70_gpio_direction_input;
gchip->gc.request = mb86s70_gpio_request;
gchip->gc.free = mb86s70_gpio_free;
gchip->gc.get = mb86s70_gpio_get;
gchip->gc.set = mb86s70_gpio_set;
gchip->gc.label = dev_name(&pdev->dev);
gchip->gc.ngpio = 32;
gchip->gc.owner = THIS_MODULE;
gchip->gc.dev = &pdev->dev;
gchip->gc.base = -1;
platform_set_drvdata(pdev, gchip);
ret = gpiochip_add(&gchip->gc);
if (ret) {
dev_err(&pdev->dev, "couldn't register gpio driver\n");
clk_disable_unprepare(gchip->clk);
}
return ret;
}
static int mb86s70_gpio_remove(struct platform_device *pdev)
{
struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
gpiochip_remove(&gchip->gc);
clk_disable_unprepare(gchip->clk);
return 0;
}
static const struct of_device_id mb86s70_gpio_dt_ids[] = {
{ .compatible = "fujitsu,mb86s70-gpio" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
static struct platform_driver mb86s70_gpio_driver = {
.driver = {
.name = "mb86s70-gpio",
.of_match_table = mb86s70_gpio_dt_ids,
},
.probe = mb86s70_gpio_probe,
.remove = mb86s70_gpio_remove,
};
static int __init mb86s70_gpio_init(void)
{
return platform_driver_register(&mb86s70_gpio_driver);
}
module_init(mb86s70_gpio_init);
MODULE_DESCRIPTION("MB86S7x GPIO Driver");
MODULE_ALIAS("platform:mb86s70-gpio");
MODULE_LICENSE("GPL");
