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// SPDX-License-Identifier: GPL-2.0-only
/*
* PPC44x 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/io.h>
#include <linux/of.h>
#include <linux/gpio/generic.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) % 16) * 2))
/* Physical GPIO register layout */
struct ppc44x_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 ppc44x_gpio_chip {
struct gpio_generic_chip chip;
void __iomem *regs;
};
static inline void ppc44x_clrbits32(void __iomem *addr, u32 mask)
{
u32 val = ioread32be(addr);
val &= ~mask;
iowrite32be(val, addr);
}
static inline void ppc44x_setbits32(void __iomem *addr, u32 mask)
{
u32 val = ioread32be(addr);
val |= mask;
iowrite32be(val, addr);
}
/*
* GPIO LIB API implementation for GPIOs
*
* There are a maximum of 32 gpios in each gpio controller.
*/
static inline void
__ppc44x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct ppc44x_gpio_chip *chip = gpiochip_get_data(gc);
struct gpio_generic_chip *gen_gc = &chip->chip;
if (val)
gen_gc->sdata |= GPIO_MASK(gpio);
else
gen_gc->sdata &= ~GPIO_MASK(gpio);
gpio_generic_write_reg(gen_gc, gen_gc->reg_set, gen_gc->sdata);
}
static int ppc44x_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct ppc44x_gpio_chip *chip = gpiochip_get_data(gc);
struct gpio_generic_chip *gen_gc = &chip->chip;
struct ppc44x_gpio __iomem *regs = chip->regs;
guard(gpio_generic_lock_irqsave)(gen_gc);
/* Disable open-drain function */
ppc44x_clrbits32(®s->odr, GPIO_MASK(gpio));
/* Float the pin */
ppc44x_clrbits32(®s->tcr, GPIO_MASK(gpio));
gen_gc->sdir &= ~GPIO_MASK(gpio);
/* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
if (gpio < 16) {
ppc44x_clrbits32(®s->osrl, GPIO_MASK2(gpio));
ppc44x_clrbits32(®s->tsrl, GPIO_MASK2(gpio));
} else {
ppc44x_clrbits32(®s->osrh, GPIO_MASK2(gpio));
ppc44x_clrbits32(®s->tsrh, GPIO_MASK2(gpio));
}
return 0;
}
static int
ppc44x_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct ppc44x_gpio_chip *chip = gpiochip_get_data(gc);
struct gpio_generic_chip *gen_gc = &chip->chip;
struct ppc44x_gpio __iomem *regs = chip->regs;
guard(gpio_generic_lock_irqsave)(gen_gc);
/* First set initial value */
__ppc44x_gpio_set(gc, gpio, val);
/* Disable open-drain function */
ppc44x_clrbits32(®s->odr, GPIO_MASK(gpio));
/* Drive the pin */
ppc44x_setbits32(®s->tcr, GPIO_MASK(gpio));
gen_gc->sdir |= GPIO_MASK(gpio);
/* Bits 0-15 use TSRL, bits 16-31 use TSRH */
if (gpio < 16) {
ppc44x_clrbits32(®s->osrl, GPIO_MASK2(gpio));
ppc44x_clrbits32(®s->tsrl, GPIO_MASK2(gpio));
} else {
ppc44x_clrbits32(®s->osrh, GPIO_MASK2(gpio));
ppc44x_clrbits32(®s->tsrh, GPIO_MASK2(gpio));
}
pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
return 0;
}
static int ppc44x_gpio_probe(struct platform_device *ofdev)
{
struct device *dev = &ofdev->dev;
struct ppc44x_gpio __iomem *regs;
struct ppc44x_gpio_chip *chip;
struct gpio_generic_chip_config config;
struct gpio_chip *gc;
int ret;
regs = devm_platform_ioremap_resource(ofdev, 0);
if (IS_ERR(regs))
return PTR_ERR(regs);
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->regs = regs;
config = (struct gpio_generic_chip_config) {
.dev = dev,
.sz = 4,
.dat = ®s->ir,
.set = ®s->or,
.dirout = ®s->tcr,
.flags = GPIO_GENERIC_BIG_ENDIAN |
GPIO_GENERIC_BIG_ENDIAN_BYTE_ORDER,
};
ret = gpio_generic_chip_init(&chip->chip, &config);
if (ret)
return ret;
gc = &chip->chip.gc;
gc->label = dev_name(dev);
gc->parent = dev;
gc->direction_input = ppc44x_gpio_dir_in;
gc->direction_output = ppc44x_gpio_dir_out;
return devm_gpiochip_add_data(dev, gc, chip);
}
static const struct of_device_id ppc44x_gpio_match[] = {
{
.compatible = "ibm,ppc4xx-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, ppc44x_gpio_match);
static struct platform_driver ppc44x_gpio_driver = {
.probe = ppc44x_gpio_probe,
.driver = {
.name = "ppc44x-gpio",
.of_match_table = ppc44x_gpio_match,
},
};
MODULE_DESCRIPTION("PPC44x gpio driver");
MODULE_LICENSE("GPL");
module_platform_driver(ppc44x_gpio_driver);
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