![Linus Walleij](/assets/img/avatar_default.png)
This is a GPIO driver, include only <linux/gpio/driver.h>. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
432 lines
11 KiB
C
432 lines
11 KiB
C
/*
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* Copyright (C) 2008, 2009 Provigent Ltd.
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*
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* Author: Baruch Siach <baruch@tkos.co.il>
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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 version 2 as
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* published by the Free Software Foundation.
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*
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* Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
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*
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* Data sheet: ARM DDI 0190B, September 2000
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*/
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#include <linux/spinlock.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/irqchip/chained_irq.h>
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#include <linux/bitops.h>
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#include <linux/gpio/driver.h>
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#include <linux/device.h>
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#include <linux/amba/bus.h>
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#include <linux/slab.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/pm.h>
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#define GPIODIR 0x400
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#define GPIOIS 0x404
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#define GPIOIBE 0x408
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#define GPIOIEV 0x40C
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#define GPIOIE 0x410
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#define GPIORIS 0x414
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#define GPIOMIS 0x418
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#define GPIOIC 0x41C
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#define PL061_GPIO_NR 8
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#ifdef CONFIG_PM
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struct pl061_context_save_regs {
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u8 gpio_data;
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u8 gpio_dir;
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u8 gpio_is;
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u8 gpio_ibe;
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u8 gpio_iev;
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u8 gpio_ie;
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};
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#endif
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struct pl061 {
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raw_spinlock_t lock;
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void __iomem *base;
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struct gpio_chip gc;
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int parent_irq;
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#ifdef CONFIG_PM
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struct pl061_context_save_regs csave_regs;
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#endif
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};
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static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
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{
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struct pl061 *pl061 = gpiochip_get_data(gc);
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return !(readb(pl061->base + GPIODIR) & BIT(offset));
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}
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static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
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{
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struct pl061 *pl061 = gpiochip_get_data(gc);
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unsigned long flags;
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unsigned char gpiodir;
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raw_spin_lock_irqsave(&pl061->lock, flags);
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gpiodir = readb(pl061->base + GPIODIR);
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gpiodir &= ~(BIT(offset));
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writeb(gpiodir, pl061->base + GPIODIR);
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raw_spin_unlock_irqrestore(&pl061->lock, flags);
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return 0;
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}
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static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
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int value)
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{
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struct pl061 *pl061 = gpiochip_get_data(gc);
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unsigned long flags;
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unsigned char gpiodir;
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raw_spin_lock_irqsave(&pl061->lock, flags);
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writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
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gpiodir = readb(pl061->base + GPIODIR);
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gpiodir |= BIT(offset);
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writeb(gpiodir, pl061->base + GPIODIR);
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/*
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* gpio value is set again, because pl061 doesn't allow to set value of
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* a gpio pin before configuring it in OUT mode.
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*/
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writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
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raw_spin_unlock_irqrestore(&pl061->lock, flags);
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return 0;
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}
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static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
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{
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struct pl061 *pl061 = gpiochip_get_data(gc);
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return !!readb(pl061->base + (BIT(offset + 2)));
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}
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static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
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{
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struct pl061 *pl061 = gpiochip_get_data(gc);
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writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
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}
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static int pl061_irq_type(struct irq_data *d, unsigned trigger)
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{
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struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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int offset = irqd_to_hwirq(d);
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unsigned long flags;
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u8 gpiois, gpioibe, gpioiev;
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u8 bit = BIT(offset);
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if (offset < 0 || offset >= PL061_GPIO_NR)
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return -EINVAL;
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if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
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(trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
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{
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dev_err(gc->parent,
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"trying to configure line %d for both level and edge "
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"detection, choose one!\n",
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offset);
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return -EINVAL;
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}
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raw_spin_lock_irqsave(&pl061->lock, flags);
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gpioiev = readb(pl061->base + GPIOIEV);
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gpiois = readb(pl061->base + GPIOIS);
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gpioibe = readb(pl061->base + GPIOIBE);
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if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
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bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;
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/* Disable edge detection */
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gpioibe &= ~bit;
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/* Enable level detection */
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gpiois |= bit;
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/* Select polarity */
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if (polarity)
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gpioiev |= bit;
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else
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gpioiev &= ~bit;
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irq_set_handler_locked(d, handle_level_irq);
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dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
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offset,
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polarity ? "HIGH" : "LOW");
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} else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
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/* Disable level detection */
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gpiois &= ~bit;
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/* Select both edges, setting this makes GPIOEV be ignored */
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gpioibe |= bit;
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irq_set_handler_locked(d, handle_edge_irq);
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dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
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} else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
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(trigger & IRQ_TYPE_EDGE_FALLING)) {
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bool rising = trigger & IRQ_TYPE_EDGE_RISING;
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/* Disable level detection */
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gpiois &= ~bit;
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/* Clear detection on both edges */
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gpioibe &= ~bit;
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/* Select edge */
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if (rising)
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gpioiev |= bit;
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else
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gpioiev &= ~bit;
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irq_set_handler_locked(d, handle_edge_irq);
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dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
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offset,
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rising ? "RISING" : "FALLING");
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} else {
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/* No trigger: disable everything */
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gpiois &= ~bit;
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gpioibe &= ~bit;
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gpioiev &= ~bit;
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irq_set_handler_locked(d, handle_bad_irq);
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dev_warn(gc->parent, "no trigger selected for line %d\n",
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offset);
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}
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writeb(gpiois, pl061->base + GPIOIS);
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writeb(gpioibe, pl061->base + GPIOIBE);
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writeb(gpioiev, pl061->base + GPIOIEV);
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raw_spin_unlock_irqrestore(&pl061->lock, flags);
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return 0;
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}
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static void pl061_irq_handler(struct irq_desc *desc)
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{
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unsigned long pending;
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int offset;
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struct gpio_chip *gc = irq_desc_get_handler_data(desc);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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struct irq_chip *irqchip = irq_desc_get_chip(desc);
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chained_irq_enter(irqchip, desc);
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pending = readb(pl061->base + GPIOMIS);
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if (pending) {
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for_each_set_bit(offset, &pending, PL061_GPIO_NR)
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generic_handle_irq(irq_find_mapping(gc->irq.domain,
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offset));
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}
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chained_irq_exit(irqchip, desc);
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}
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static void pl061_irq_mask(struct irq_data *d)
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{
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struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
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u8 gpioie;
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raw_spin_lock(&pl061->lock);
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gpioie = readb(pl061->base + GPIOIE) & ~mask;
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writeb(gpioie, pl061->base + GPIOIE);
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raw_spin_unlock(&pl061->lock);
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}
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static void pl061_irq_unmask(struct irq_data *d)
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{
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struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
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u8 gpioie;
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raw_spin_lock(&pl061->lock);
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gpioie = readb(pl061->base + GPIOIE) | mask;
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writeb(gpioie, pl061->base + GPIOIE);
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raw_spin_unlock(&pl061->lock);
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}
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/**
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* pl061_irq_ack() - ACK an edge IRQ
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* @d: IRQ data for this IRQ
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*
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* This gets called from the edge IRQ handler to ACK the edge IRQ
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* in the GPIOIC (interrupt-clear) register. For level IRQs this is
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* not needed: these go away when the level signal goes away.
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*/
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static void pl061_irq_ack(struct irq_data *d)
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{
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struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
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raw_spin_lock(&pl061->lock);
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writeb(mask, pl061->base + GPIOIC);
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raw_spin_unlock(&pl061->lock);
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}
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static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
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{
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struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
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struct pl061 *pl061 = gpiochip_get_data(gc);
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return irq_set_irq_wake(pl061->parent_irq, state);
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}
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static struct irq_chip pl061_irqchip = {
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.name = "pl061",
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.irq_ack = pl061_irq_ack,
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.irq_mask = pl061_irq_mask,
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.irq_unmask = pl061_irq_unmask,
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.irq_set_type = pl061_irq_type,
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.irq_set_wake = pl061_irq_set_wake,
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};
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static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
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{
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struct device *dev = &adev->dev;
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struct pl061 *pl061;
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int ret, irq;
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pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
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if (pl061 == NULL)
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return -ENOMEM;
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pl061->base = devm_ioremap_resource(dev, &adev->res);
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if (IS_ERR(pl061->base))
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return PTR_ERR(pl061->base);
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raw_spin_lock_init(&pl061->lock);
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if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
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pl061->gc.request = gpiochip_generic_request;
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pl061->gc.free = gpiochip_generic_free;
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}
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pl061->gc.base = -1;
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pl061->gc.get_direction = pl061_get_direction;
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pl061->gc.direction_input = pl061_direction_input;
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pl061->gc.direction_output = pl061_direction_output;
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pl061->gc.get = pl061_get_value;
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pl061->gc.set = pl061_set_value;
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pl061->gc.ngpio = PL061_GPIO_NR;
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pl061->gc.label = dev_name(dev);
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pl061->gc.parent = dev;
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pl061->gc.owner = THIS_MODULE;
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ret = gpiochip_add_data(&pl061->gc, pl061);
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if (ret)
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return ret;
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/*
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* irq_chip support
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*/
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writeb(0, pl061->base + GPIOIE); /* disable irqs */
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irq = adev->irq[0];
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if (irq < 0) {
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dev_err(&adev->dev, "invalid IRQ\n");
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return -ENODEV;
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}
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pl061->parent_irq = irq;
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ret = gpiochip_irqchip_add(&pl061->gc, &pl061_irqchip,
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0, handle_bad_irq,
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IRQ_TYPE_NONE);
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if (ret) {
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dev_info(&adev->dev, "could not add irqchip\n");
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return ret;
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}
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gpiochip_set_chained_irqchip(&pl061->gc, &pl061_irqchip,
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irq, pl061_irq_handler);
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amba_set_drvdata(adev, pl061);
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dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
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&adev->res.start);
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return 0;
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}
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#ifdef CONFIG_PM
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static int pl061_suspend(struct device *dev)
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{
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struct pl061 *pl061 = dev_get_drvdata(dev);
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int offset;
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pl061->csave_regs.gpio_data = 0;
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pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
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pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
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pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
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pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
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pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);
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for (offset = 0; offset < PL061_GPIO_NR; offset++) {
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if (pl061->csave_regs.gpio_dir & (BIT(offset)))
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pl061->csave_regs.gpio_data |=
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pl061_get_value(&pl061->gc, offset) << offset;
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}
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return 0;
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}
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static int pl061_resume(struct device *dev)
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{
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struct pl061 *pl061 = dev_get_drvdata(dev);
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int offset;
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for (offset = 0; offset < PL061_GPIO_NR; offset++) {
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if (pl061->csave_regs.gpio_dir & (BIT(offset)))
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pl061_direction_output(&pl061->gc, offset,
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pl061->csave_regs.gpio_data &
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(BIT(offset)));
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else
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pl061_direction_input(&pl061->gc, offset);
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}
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writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
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writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
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writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
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writeb(pl061->csave_regs.gpio_ie, pl061->base + GPIOIE);
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return 0;
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}
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static const struct dev_pm_ops pl061_dev_pm_ops = {
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.suspend = pl061_suspend,
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.resume = pl061_resume,
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.freeze = pl061_suspend,
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.restore = pl061_resume,
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};
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#endif
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static const struct amba_id pl061_ids[] = {
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{
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.id = 0x00041061,
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.mask = 0x000fffff,
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},
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{ 0, 0 },
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};
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static struct amba_driver pl061_gpio_driver = {
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.drv = {
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.name = "pl061_gpio",
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#ifdef CONFIG_PM
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.pm = &pl061_dev_pm_ops,
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#endif
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},
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.id_table = pl061_ids,
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.probe = pl061_probe,
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};
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static int __init pl061_gpio_init(void)
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{
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return amba_driver_register(&pl061_gpio_driver);
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}
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device_initcall(pl061_gpio_init);
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