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// SPDX-License-Identifier: GPL-2.0-only
/*
* PPC4xx gpio driver
*
* Copyright (c) 2008 Harris Corporation
* Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
* Copyright (c) MontaVista Software, Inc. 2008.
*
* Author: Steve Falco <sfalco@harris.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/gpio/driver.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#define GPIO_MASK(gpio) (0x80000000 >> (gpio))
#define GPIO_MASK2(gpio) (0xc0000000 >> ((gpio) * 2))
/* Physical GPIO register layout */
struct ppc4xx_gpio {
__be32 or;
__be32 tcr;
__be32 osrl;
__be32 osrh;
__be32 tsrl;
__be32 tsrh;
__be32 odr;
__be32 ir;
__be32 rr1;
__be32 rr2;
__be32 rr3;
__be32 reserved1;
__be32 isr1l;
__be32 isr1h;
__be32 isr2l;
__be32 isr2h;
__be32 isr3l;
__be32 isr3h;
};
struct ppc4xx_gpio_chip {
struct gpio_chip gc;
void __iomem *regs;
spinlock_t lock;
};
/*
* GPIO LIB API implementation for GPIOs
*
* There are a maximum of 32 gpios in each gpio controller.
*/
static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = chip->regs;
return !!(in_be32(®s->ir) & GPIO_MASK(gpio));
}
static inline void
__ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = chip->regs;
if (val)
setbits32(®s->or, GPIO_MASK(gpio));
else
clrbits32(®s->or, GPIO_MASK(gpio));
}
static int ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__ppc4xx_gpio_set(gc, gpio, val);
spin_unlock_irqrestore(&chip->lock, flags);
pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
return 0;
}
static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = chip->regs;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
/* Disable open-drain function */
clrbits32(®s->odr, GPIO_MASK(gpio));
/* Float the pin */
clrbits32(®s->tcr, GPIO_MASK(gpio));
/* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
if (gpio < 16) {
clrbits32(®s->osrl, GPIO_MASK2(gpio));
clrbits32(®s->tsrl, GPIO_MASK2(gpio));
} else {
clrbits32(®s->osrh, GPIO_MASK2(gpio));
clrbits32(®s->tsrh, GPIO_MASK2(gpio));
}
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int
ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = chip->regs;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
/* First set initial value */
__ppc4xx_gpio_set(gc, gpio, val);
/* Disable open-drain function */
clrbits32(®s->odr, GPIO_MASK(gpio));
/* Drive the pin */
setbits32(®s->tcr, GPIO_MASK(gpio));
/* Bits 0-15 use TSRL, bits 16-31 use TSRH */
if (gpio < 16) {
clrbits32(®s->osrl, GPIO_MASK2(gpio));
clrbits32(®s->tsrl, GPIO_MASK2(gpio));
} else {
clrbits32(®s->osrh, GPIO_MASK2(gpio));
clrbits32(®s->tsrh, GPIO_MASK2(gpio));
}
spin_unlock_irqrestore(&chip->lock, flags);
pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
return 0;
}
static int ppc4xx_gpio_probe(struct platform_device *ofdev)
{
struct device *dev = &ofdev->dev;
struct device_node *np = dev->of_node;
struct ppc4xx_gpio_chip *chip;
struct gpio_chip *gc;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
spin_lock_init(&chip->lock);
gc = &chip->gc;
gc->base = -1;
gc->ngpio = 32;
gc->direction_input = ppc4xx_gpio_dir_in;
gc->direction_output = ppc4xx_gpio_dir_out;
gc->get = ppc4xx_gpio_get;
gc->set = ppc4xx_gpio_set;
gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
if (!gc->label)
return -ENOMEM;
chip->regs = devm_of_iomap(dev, np, 0, NULL);
if (IS_ERR(chip->regs))
return PTR_ERR(chip->regs);
return devm_gpiochip_add_data(dev, gc, chip);
}
static const struct of_device_id ppc4xx_gpio_match[] = {
{
.compatible = "ibm,ppc4xx-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, ppc4xx_gpio_match);
static struct platform_driver ppc4xx_gpio_driver = {
.probe = ppc4xx_gpio_probe,
.driver = {
.name = "ppc4xx-gpio",
.of_match_table = ppc4xx_gpio_match,
},
};
static int __init ppc4xx_gpio_init(void)
{
return platform_driver_register(&ppc4xx_gpio_driver);
}
arch_initcall(ppc4xx_gpio_init);
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