368 lines
8.8 KiB
C
368 lines
8.8 KiB
C
/*
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* Timberdale FPGA GPIO driver
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* Copyright (c) 2009 Intel Corporation
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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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* 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, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/* Supports:
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* Timberdale FPGA GPIO
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*/
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#include <linux/module.h>
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#include <linux/gpio.h>
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#include <linux/platform_device.h>
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#include <linux/irq.h>
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#include <linux/io.h>
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#include <linux/timb_gpio.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#define DRIVER_NAME "timb-gpio"
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#define TGPIOVAL 0x00
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#define TGPIODIR 0x04
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#define TGPIO_IER 0x08
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#define TGPIO_ISR 0x0c
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#define TGPIO_IPR 0x10
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#define TGPIO_ICR 0x14
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#define TGPIO_FLR 0x18
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#define TGPIO_LVR 0x1c
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#define TGPIO_VER 0x20
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#define TGPIO_BFLR 0x24
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struct timbgpio {
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void __iomem *membase;
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spinlock_t lock; /* mutual exclusion */
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struct gpio_chip gpio;
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int irq_base;
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unsigned long last_ier;
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};
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static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
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unsigned offset, bool enabled)
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{
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struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
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u32 reg;
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spin_lock(&tgpio->lock);
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reg = ioread32(tgpio->membase + offset);
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if (enabled)
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reg |= (1 << index);
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else
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reg &= ~(1 << index);
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iowrite32(reg, tgpio->membase + offset);
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spin_unlock(&tgpio->lock);
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return 0;
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}
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static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
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{
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return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
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}
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static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
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{
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struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
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u32 value;
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value = ioread32(tgpio->membase + TGPIOVAL);
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return (value & (1 << nr)) ? 1 : 0;
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}
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static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
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unsigned nr, int val)
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{
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return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
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}
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static void timbgpio_gpio_set(struct gpio_chip *gpio,
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unsigned nr, int val)
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{
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timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
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}
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static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
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{
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struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
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if (tgpio->irq_base <= 0)
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return -EINVAL;
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return tgpio->irq_base + offset;
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}
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/*
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* GPIO IRQ
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*/
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static void timbgpio_irq_disable(struct irq_data *d)
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{
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struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
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int offset = d->irq - tgpio->irq_base;
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unsigned long flags;
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spin_lock_irqsave(&tgpio->lock, flags);
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tgpio->last_ier &= ~(1UL << offset);
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iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
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spin_unlock_irqrestore(&tgpio->lock, flags);
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}
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static void timbgpio_irq_enable(struct irq_data *d)
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{
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struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
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int offset = d->irq - tgpio->irq_base;
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unsigned long flags;
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spin_lock_irqsave(&tgpio->lock, flags);
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tgpio->last_ier |= 1UL << offset;
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iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
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spin_unlock_irqrestore(&tgpio->lock, flags);
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}
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static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
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{
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struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
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int offset = d->irq - tgpio->irq_base;
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unsigned long flags;
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u32 lvr, flr, bflr = 0;
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u32 ver;
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int ret = 0;
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if (offset < 0 || offset > tgpio->gpio.ngpio)
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return -EINVAL;
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ver = ioread32(tgpio->membase + TGPIO_VER);
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spin_lock_irqsave(&tgpio->lock, flags);
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lvr = ioread32(tgpio->membase + TGPIO_LVR);
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flr = ioread32(tgpio->membase + TGPIO_FLR);
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if (ver > 2)
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bflr = ioread32(tgpio->membase + TGPIO_BFLR);
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if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
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bflr &= ~(1 << offset);
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flr &= ~(1 << offset);
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if (trigger & IRQ_TYPE_LEVEL_HIGH)
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lvr |= 1 << offset;
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else
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lvr &= ~(1 << offset);
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}
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if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
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if (ver < 3) {
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ret = -EINVAL;
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goto out;
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} else {
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flr |= 1 << offset;
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bflr |= 1 << offset;
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}
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} else {
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bflr &= ~(1 << offset);
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flr |= 1 << offset;
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if (trigger & IRQ_TYPE_EDGE_FALLING)
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lvr &= ~(1 << offset);
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else
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lvr |= 1 << offset;
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}
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iowrite32(lvr, tgpio->membase + TGPIO_LVR);
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iowrite32(flr, tgpio->membase + TGPIO_FLR);
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if (ver > 2)
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iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
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iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
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out:
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spin_unlock_irqrestore(&tgpio->lock, flags);
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return ret;
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}
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static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
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{
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struct timbgpio *tgpio = irq_get_handler_data(irq);
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unsigned long ipr;
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int offset;
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desc->irq_data.chip->irq_ack(irq_get_irq_data(irq));
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ipr = ioread32(tgpio->membase + TGPIO_IPR);
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iowrite32(ipr, tgpio->membase + TGPIO_ICR);
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/*
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* Some versions of the hardware trash the IER register if more than
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* one interrupt is received simultaneously.
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*/
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iowrite32(0, tgpio->membase + TGPIO_IER);
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for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
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generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
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iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
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}
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static struct irq_chip timbgpio_irqchip = {
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.name = "GPIO",
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.irq_enable = timbgpio_irq_enable,
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.irq_disable = timbgpio_irq_disable,
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.irq_set_type = timbgpio_irq_type,
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};
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static int timbgpio_probe(struct platform_device *pdev)
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{
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int err, i;
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struct gpio_chip *gc;
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struct timbgpio *tgpio;
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struct resource *iomem;
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struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
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int irq = platform_get_irq(pdev, 0);
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if (!pdata || pdata->nr_pins > 32) {
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err = -EINVAL;
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goto err_mem;
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}
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iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!iomem) {
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err = -EINVAL;
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goto err_mem;
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}
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tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
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if (!tgpio) {
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err = -EINVAL;
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goto err_mem;
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}
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tgpio->irq_base = pdata->irq_base;
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spin_lock_init(&tgpio->lock);
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if (!request_mem_region(iomem->start, resource_size(iomem),
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DRIVER_NAME)) {
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err = -EBUSY;
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goto err_request;
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}
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tgpio->membase = ioremap(iomem->start, resource_size(iomem));
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if (!tgpio->membase) {
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err = -ENOMEM;
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goto err_ioremap;
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}
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gc = &tgpio->gpio;
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gc->label = dev_name(&pdev->dev);
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gc->owner = THIS_MODULE;
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gc->dev = &pdev->dev;
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gc->direction_input = timbgpio_gpio_direction_input;
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gc->get = timbgpio_gpio_get;
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gc->direction_output = timbgpio_gpio_direction_output;
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gc->set = timbgpio_gpio_set;
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gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
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gc->dbg_show = NULL;
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gc->base = pdata->gpio_base;
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gc->ngpio = pdata->nr_pins;
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gc->can_sleep = 0;
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err = gpiochip_add(gc);
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if (err)
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goto err_chipadd;
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platform_set_drvdata(pdev, tgpio);
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/* make sure to disable interrupts */
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iowrite32(0x0, tgpio->membase + TGPIO_IER);
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if (irq < 0 || tgpio->irq_base <= 0)
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return 0;
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for (i = 0; i < pdata->nr_pins; i++) {
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irq_set_chip_and_handler_name(tgpio->irq_base + i,
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&timbgpio_irqchip, handle_simple_irq, "mux");
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irq_set_chip_data(tgpio->irq_base + i, tgpio);
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#ifdef CONFIG_ARM
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set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
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#endif
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}
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irq_set_handler_data(irq, tgpio);
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irq_set_chained_handler(irq, timbgpio_irq);
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return 0;
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err_chipadd:
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iounmap(tgpio->membase);
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err_ioremap:
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release_mem_region(iomem->start, resource_size(iomem));
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err_request:
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kfree(tgpio);
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err_mem:
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printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);
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return err;
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}
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static int timbgpio_remove(struct platform_device *pdev)
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{
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int err;
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struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
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struct timbgpio *tgpio = platform_get_drvdata(pdev);
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struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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int irq = platform_get_irq(pdev, 0);
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if (irq >= 0 && tgpio->irq_base > 0) {
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int i;
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for (i = 0; i < pdata->nr_pins; i++) {
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irq_set_chip(tgpio->irq_base + i, NULL);
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irq_set_chip_data(tgpio->irq_base + i, NULL);
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}
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irq_set_handler(irq, NULL);
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irq_set_handler_data(irq, NULL);
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}
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err = gpiochip_remove(&tgpio->gpio);
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if (err)
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printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
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iounmap(tgpio->membase);
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release_mem_region(iomem->start, resource_size(iomem));
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kfree(tgpio);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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static struct platform_driver timbgpio_platform_driver = {
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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.probe = timbgpio_probe,
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.remove = timbgpio_remove,
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};
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/*--------------------------------------------------------------------------*/
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module_platform_driver(timbgpio_platform_driver);
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MODULE_DESCRIPTION("Timberdale GPIO driver");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Mocean Laboratories");
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MODULE_ALIAS("platform:"DRIVER_NAME);
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