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	This is a GPIO driver so it should definately include <linux/gpio/driver.h>. We want to get rid of <linux/of_gpio.h> but that will take a bit longer. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
		
			
				
	
	
		
			372 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			372 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2013 Altera Corporation
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 * Based on gpio-mpc8xxx.c
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/gpio/driver.h>
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#include <linux/of_gpio.h> /* For of_mm_gpio_chip */
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#include <linux/platform_device.h>
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#define ALTERA_GPIO_MAX_NGPIO		32
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#define ALTERA_GPIO_DATA		0x0
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#define ALTERA_GPIO_DIR			0x4
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#define ALTERA_GPIO_IRQ_MASK		0x8
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#define ALTERA_GPIO_EDGE_CAP		0xc
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/**
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* struct altera_gpio_chip
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* @mmchip		: memory mapped chip structure.
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* @gpio_lock		: synchronization lock so that new irq/set/get requests
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			  will be blocked until the current one completes.
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* @interrupt_trigger	: specifies the hardware configured IRQ trigger type
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			  (rising, falling, both, high)
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* @mapped_irq		: kernel mapped irq number.
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*/
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struct altera_gpio_chip {
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	struct of_mm_gpio_chip mmchip;
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	raw_spinlock_t gpio_lock;
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	int interrupt_trigger;
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	int mapped_irq;
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};
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static void altera_gpio_irq_unmask(struct irq_data *d)
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{
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	struct altera_gpio_chip *altera_gc;
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	struct of_mm_gpio_chip *mm_gc;
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	unsigned long flags;
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	u32 intmask;
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	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
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	mm_gc = &altera_gc->mmchip;
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	raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
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	intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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	/* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
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	intmask |= BIT(irqd_to_hwirq(d));
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	writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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	raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
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}
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static void altera_gpio_irq_mask(struct irq_data *d)
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{
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	struct altera_gpio_chip *altera_gc;
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	struct of_mm_gpio_chip *mm_gc;
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	unsigned long flags;
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	u32 intmask;
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	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
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	mm_gc = &altera_gc->mmchip;
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	raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
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	intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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	/* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
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	intmask &= ~BIT(irqd_to_hwirq(d));
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	writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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	raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
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}
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/**
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 * This controller's IRQ type is synthesized in hardware, so this function
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 * just checks if the requested set_type matches the synthesized IRQ type
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 */
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static int altera_gpio_irq_set_type(struct irq_data *d,
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				   unsigned int type)
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{
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	struct altera_gpio_chip *altera_gc;
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	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
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	if (type == IRQ_TYPE_NONE) {
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		irq_set_handler_locked(d, handle_bad_irq);
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		return 0;
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	}
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	if (type == altera_gc->interrupt_trigger) {
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		if (type == IRQ_TYPE_LEVEL_HIGH)
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			irq_set_handler_locked(d, handle_level_irq);
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		else
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			irq_set_handler_locked(d, handle_simple_irq);
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		return 0;
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	}
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	irq_set_handler_locked(d, handle_bad_irq);
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	return -EINVAL;
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}
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static unsigned int altera_gpio_irq_startup(struct irq_data *d)
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{
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	altera_gpio_irq_unmask(d);
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	return 0;
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}
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static struct irq_chip altera_irq_chip = {
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	.name		= "altera-gpio",
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	.irq_mask	= altera_gpio_irq_mask,
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	.irq_unmask	= altera_gpio_irq_unmask,
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	.irq_set_type	= altera_gpio_irq_set_type,
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	.irq_startup	= altera_gpio_irq_startup,
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	.irq_shutdown	= altera_gpio_irq_mask,
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};
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static int altera_gpio_get(struct gpio_chip *gc, unsigned offset)
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{
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	struct of_mm_gpio_chip *mm_gc;
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	mm_gc = to_of_mm_gpio_chip(gc);
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	return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset));
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}
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static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
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{
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	struct of_mm_gpio_chip *mm_gc;
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	struct altera_gpio_chip *chip;
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	unsigned long flags;
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	unsigned int data_reg;
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	mm_gc = to_of_mm_gpio_chip(gc);
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	chip = gpiochip_get_data(gc);
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	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
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	data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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	if (value)
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		data_reg |= BIT(offset);
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	else
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		data_reg &= ~BIT(offset);
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	writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
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	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
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}
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static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
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{
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	struct of_mm_gpio_chip *mm_gc;
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	struct altera_gpio_chip *chip;
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	unsigned long flags;
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	unsigned int gpio_ddr;
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	mm_gc = to_of_mm_gpio_chip(gc);
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	chip = gpiochip_get_data(gc);
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	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
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	/* Set pin as input, assumes software controlled IP */
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	gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
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	gpio_ddr &= ~BIT(offset);
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	writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
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	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
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	return 0;
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}
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static int altera_gpio_direction_output(struct gpio_chip *gc,
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		unsigned offset, int value)
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{
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	struct of_mm_gpio_chip *mm_gc;
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	struct altera_gpio_chip *chip;
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	unsigned long flags;
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	unsigned int data_reg, gpio_ddr;
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	mm_gc = to_of_mm_gpio_chip(gc);
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	chip = gpiochip_get_data(gc);
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	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
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	/* Sets the GPIO value */
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	data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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	if (value)
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		data_reg |= BIT(offset);
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	else
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		data_reg &= ~BIT(offset);
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	writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
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	/* Set pin as output, assumes software controlled IP */
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	gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
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	gpio_ddr |= BIT(offset);
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	writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
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	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
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	return 0;
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}
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static void altera_gpio_irq_edge_handler(struct irq_desc *desc)
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{
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	struct altera_gpio_chip *altera_gc;
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	struct irq_chip *chip;
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	struct of_mm_gpio_chip *mm_gc;
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	struct irq_domain *irqdomain;
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	unsigned long status;
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	int i;
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	altera_gc = gpiochip_get_data(irq_desc_get_handler_data(desc));
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	chip = irq_desc_get_chip(desc);
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	mm_gc = &altera_gc->mmchip;
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	irqdomain = altera_gc->mmchip.gc.irq.domain;
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	chained_irq_enter(chip, desc);
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	while ((status =
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	      (readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) &
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	      readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) {
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		writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
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		for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
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			generic_handle_irq(irq_find_mapping(irqdomain, i));
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		}
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	}
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	chained_irq_exit(chip, desc);
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}
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static void altera_gpio_irq_leveL_high_handler(struct irq_desc *desc)
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{
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	struct altera_gpio_chip *altera_gc;
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	struct irq_chip *chip;
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	struct of_mm_gpio_chip *mm_gc;
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	struct irq_domain *irqdomain;
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	unsigned long status;
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	int i;
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	altera_gc = gpiochip_get_data(irq_desc_get_handler_data(desc));
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	chip = irq_desc_get_chip(desc);
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	mm_gc = &altera_gc->mmchip;
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	irqdomain = altera_gc->mmchip.gc.irq.domain;
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	chained_irq_enter(chip, desc);
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	status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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	status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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	for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
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		generic_handle_irq(irq_find_mapping(irqdomain, i));
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	}
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	chained_irq_exit(chip, desc);
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}
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static int altera_gpio_probe(struct platform_device *pdev)
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{
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	struct device_node *node = pdev->dev.of_node;
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	int reg, ret;
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	struct altera_gpio_chip *altera_gc;
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	altera_gc = devm_kzalloc(&pdev->dev, sizeof(*altera_gc), GFP_KERNEL);
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	if (!altera_gc)
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		return -ENOMEM;
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	raw_spin_lock_init(&altera_gc->gpio_lock);
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	if (of_property_read_u32(node, "altr,ngpio", ®))
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		/* By default assume maximum ngpio */
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		altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
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	else
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		altera_gc->mmchip.gc.ngpio = reg;
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	if (altera_gc->mmchip.gc.ngpio > ALTERA_GPIO_MAX_NGPIO) {
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		dev_warn(&pdev->dev,
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			"ngpio is greater than %d, defaulting to %d\n",
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			ALTERA_GPIO_MAX_NGPIO, ALTERA_GPIO_MAX_NGPIO);
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		altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
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	}
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	altera_gc->mmchip.gc.direction_input	= altera_gpio_direction_input;
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	altera_gc->mmchip.gc.direction_output	= altera_gpio_direction_output;
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	altera_gc->mmchip.gc.get		= altera_gpio_get;
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	altera_gc->mmchip.gc.set		= altera_gpio_set;
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	altera_gc->mmchip.gc.owner		= THIS_MODULE;
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	altera_gc->mmchip.gc.parent		= &pdev->dev;
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	ret = of_mm_gpiochip_add_data(node, &altera_gc->mmchip, altera_gc);
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	if (ret) {
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		dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n");
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		return ret;
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	}
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	platform_set_drvdata(pdev, altera_gc);
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	altera_gc->mapped_irq = platform_get_irq(pdev, 0);
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	if (altera_gc->mapped_irq < 0)
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		goto skip_irq;
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	if (of_property_read_u32(node, "altr,interrupt-type", ®)) {
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		ret = -EINVAL;
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		dev_err(&pdev->dev,
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			"altr,interrupt-type value not set in device tree\n");
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		goto teardown;
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	}
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	altera_gc->interrupt_trigger = reg;
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	ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0,
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		handle_bad_irq, IRQ_TYPE_NONE);
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	if (ret) {
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		dev_err(&pdev->dev, "could not add irqchip\n");
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		goto teardown;
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	}
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	gpiochip_set_chained_irqchip(&altera_gc->mmchip.gc,
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		&altera_irq_chip,
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		altera_gc->mapped_irq,
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		altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH ?
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		altera_gpio_irq_leveL_high_handler :
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		altera_gpio_irq_edge_handler);
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skip_irq:
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	return 0;
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teardown:
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	of_mm_gpiochip_remove(&altera_gc->mmchip);
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	pr_err("%pOF: registration failed with status %d\n",
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		node, ret);
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	return ret;
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}
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static int altera_gpio_remove(struct platform_device *pdev)
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{
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	struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev);
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	of_mm_gpiochip_remove(&altera_gc->mmchip);
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	return 0;
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}
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static const struct of_device_id altera_gpio_of_match[] = {
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	{ .compatible = "altr,pio-1.0", },
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	{},
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};
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MODULE_DEVICE_TABLE(of, altera_gpio_of_match);
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static struct platform_driver altera_gpio_driver = {
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	.driver = {
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		.name	= "altera_gpio",
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		.of_match_table = of_match_ptr(altera_gpio_of_match),
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	},
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	.probe		= altera_gpio_probe,
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	.remove		= altera_gpio_remove,
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};
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static int __init altera_gpio_init(void)
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{
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	return platform_driver_register(&altera_gpio_driver);
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}
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subsys_initcall(altera_gpio_init);
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static void __exit altera_gpio_exit(void)
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{
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	platform_driver_unregister(&altera_gpio_driver);
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}
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module_exit(altera_gpio_exit);
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MODULE_AUTHOR("Tien Hock Loh <thloh@altera.com>");
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MODULE_DESCRIPTION("Altera GPIO driver");
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MODULE_LICENSE("GPL");
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