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/*
* Copyright (C) 2013 Altera Corporation
* Based on gpio-mpc8xxx.c
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/io.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#define ALTERA_GPIO_MAX_NGPIO 32
#define ALTERA_GPIO_DATA 0x0
#define ALTERA_GPIO_DIR 0x4
#define ALTERA_GPIO_IRQ_MASK 0x8
#define ALTERA_GPIO_EDGE_CAP 0xc
/**
* struct altera_gpio_chip
* @mmchip : memory mapped chip structure.
* @gpio_lock : synchronization lock so that new irq/set/get requests
will be blocked until the current one completes.
* @interrupt_trigger : specifies the hardware configured IRQ trigger type
(rising, falling, both, high)
* @mapped_irq : kernel mapped irq number.
*/
struct altera_gpio_chip {
struct of_mm_gpio_chip mmchip;
spinlock_t gpio_lock;
int interrupt_trigger;
int mapped_irq;
};
static void altera_gpio_irq_unmask(struct irq_data *d)
{
struct altera_gpio_chip *altera_gc;
struct of_mm_gpio_chip *mm_gc;
unsigned long flags;
u32 intmask;
altera_gc = irq_data_get_irq_chip_data(d);
mm_gc = &altera_gc->mmchip;
spin_lock_irqsave(&altera_gc->gpio_lock, flags);
intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
/* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
intmask |= BIT(irqd_to_hwirq(d));
writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
}
static void altera_gpio_irq_mask(struct irq_data *d)
{
struct altera_gpio_chip *altera_gc;
struct of_mm_gpio_chip *mm_gc;
unsigned long flags;
u32 intmask;
altera_gc = irq_data_get_irq_chip_data(d);
mm_gc = &altera_gc->mmchip;
spin_lock_irqsave(&altera_gc->gpio_lock, flags);
intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
/* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
intmask &= ~BIT(irqd_to_hwirq(d));
writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
}
/**
* This controller's IRQ type is synthesized in hardware, so this function
* just checks if the requested set_type matches the synthesized IRQ type
*/
static int altera_gpio_irq_set_type(struct irq_data *d,
unsigned int type)
{
struct altera_gpio_chip *altera_gc;
altera_gc = irq_data_get_irq_chip_data(d);
if (type == IRQ_TYPE_NONE)
return 0;
if (type == IRQ_TYPE_LEVEL_HIGH &&
altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH)
return 0;
if (type == IRQ_TYPE_EDGE_RISING &&
altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_RISING)
return 0;
if (type == IRQ_TYPE_EDGE_FALLING &&
altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_FALLING)
return 0;
if (type == IRQ_TYPE_EDGE_BOTH &&
altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_BOTH)
return 0;
return -EINVAL;
}
static unsigned int altera_gpio_irq_startup(struct irq_data *d) {
altera_gpio_irq_unmask(d);
return 0;
}
static struct irq_chip altera_irq_chip = {
.name = "altera-gpio",
.irq_mask = altera_gpio_irq_mask,
.irq_unmask = altera_gpio_irq_unmask,
.irq_set_type = altera_gpio_irq_set_type,
.irq_startup = altera_gpio_irq_startup,
.irq_shutdown = altera_gpio_irq_mask,
};
static int altera_gpio_get(struct gpio_chip *gc, unsigned offset)
{
struct of_mm_gpio_chip *mm_gc;
mm_gc = to_of_mm_gpio_chip(gc);
return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset));
}
static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
{
struct of_mm_gpio_chip *mm_gc;
struct altera_gpio_chip *chip;
unsigned long flags;
unsigned int data_reg;
mm_gc = to_of_mm_gpio_chip(gc);
chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
spin_lock_irqsave(&chip->gpio_lock, flags);
data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
if (value)
data_reg |= BIT(offset);
else
data_reg &= ~BIT(offset);
writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
}
static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
struct of_mm_gpio_chip *mm_gc;
struct altera_gpio_chip *chip;
unsigned long flags;
unsigned int gpio_ddr;
mm_gc = to_of_mm_gpio_chip(gc);
chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
spin_lock_irqsave(&chip->gpio_lock, flags);
/* Set pin as input, assumes software controlled IP */
gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
gpio_ddr &= ~BIT(offset);
writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
return 0;
}
static int altera_gpio_direction_output(struct gpio_chip *gc,
unsigned offset, int value)
{
struct of_mm_gpio_chip *mm_gc;
struct altera_gpio_chip *chip;
unsigned long flags;
unsigned int data_reg, gpio_ddr;
mm_gc = to_of_mm_gpio_chip(gc);
chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
spin_lock_irqsave(&chip->gpio_lock, flags);
/* Sets the GPIO value */
data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
if (value)
data_reg |= BIT(offset);
else
data_reg &= ~BIT(offset);
writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
/* Set pin as output, assumes software controlled IP */
gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
gpio_ddr |= BIT(offset);
writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
spin_unlock_irqrestore(&chip->gpio_lock, flags);
return 0;
}
static void altera_gpio_irq_edge_handler(unsigned int irq,
struct irq_desc *desc)
{
struct altera_gpio_chip *altera_gc;
struct irq_chip *chip;
struct of_mm_gpio_chip *mm_gc;
struct irq_domain *irqdomain;
unsigned long status;
int i;
altera_gc = irq_desc_get_handler_data(desc);
chip = irq_desc_get_chip(desc);
mm_gc = &altera_gc->mmchip;
irqdomain = altera_gc->mmchip.gc.irqdomain;
chained_irq_enter(chip, desc);
while ((status =
(readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) &
readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) {
writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
generic_handle_irq(irq_find_mapping(irqdomain, i));
}
}
chained_irq_exit(chip, desc);
}
static void altera_gpio_irq_leveL_high_handler(unsigned int irq,
struct irq_desc *desc)
{
struct altera_gpio_chip *altera_gc;
struct irq_chip *chip;
struct of_mm_gpio_chip *mm_gc;
struct irq_domain *irqdomain;
unsigned long status;
int i;
altera_gc = irq_desc_get_handler_data(desc);
chip = irq_desc_get_chip(desc);
mm_gc = &altera_gc->mmchip;
irqdomain = altera_gc->mmchip.gc.irqdomain;
chained_irq_enter(chip, desc);
status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
generic_handle_irq(irq_find_mapping(irqdomain, i));
}
chained_irq_exit(chip, desc);
}
static int altera_gpio_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
int reg, ret;
struct altera_gpio_chip *altera_gc;
altera_gc = devm_kzalloc
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