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/*
* 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>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio/driver.h>
#include <linux/types.h>
#include <linux/slab.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 of_mm_gpio_chip mm_gc;
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 of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct ppc4xx_gpio __iomem *regs = mm_gc->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 of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
if (val)
setbits32(®s->or, GPIO_MASK(gpio));
else
clrbits32(®s->or, GPIO_MASK(gpio));
}
static void
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);
}
static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = mm_gc->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 of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
struct ppc4xx_gpio __iomem *regs = mm_gc->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 __init ppc4xx_add_gpiochips(void)
{
struct device_node *np;
for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {
int ret;
struct ppc4xx_gpio_chip *ppc4xx_gc;
struct of_mm_gpio_chip *mm_gc;
struct gpio_chip *gc;
ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);
if (!ppc4xx_gc) {
ret = -ENOMEM;
goto err;
}
spin_lock_init(&ppc4xx_gc->lock);
mm_gc = &ppc4xx_gc->mm_gc;
gc = &mm_gc->gc;
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;
ret = of_mm_gpiochip_add_data(np, mm_gc, ppc4xx_gc);
if (ret)
goto err;
continue;
err:
pr_err("%s: registration failed with status %d\n",
np->full_name, ret);
kfree(ppc4xx_gc);
/* try others anyway */
}
return 0;
}
arch_initcall(ppc4xx_add_gpiochips);
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