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	gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips
Add a driver to use GPIO pins available on several AMD south bridges (currently only AMD 8111 is supported). Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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					 3 changed files with 259 additions and 0 deletions
				
			
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			@ -466,6 +466,18 @@ config GPIO_BT8XX
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	  If unsure, say N.
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config GPIO_AMD8111
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	tristate "AMD 8111 GPIO driver"
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	depends on PCI
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	help
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	  The AMD 8111 south bridge contains 32 GPIO pins which can be used.
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	  Note, that usually system firmware/ACPI handles GPIO pins on their
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	  own and users might easily break their systems with uncarefull usage
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	  of this driver!
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	  If unsure, say N
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config GPIO_LANGWELL
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	bool "Intel Langwell/Penwell GPIO support"
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	depends on PCI && X86
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			@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_74X164)	+= gpio-74x164.o
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obj-$(CONFIG_GPIO_AB8500)	+= gpio-ab8500.o
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obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
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obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
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obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
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obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
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obj-$(CONFIG_GPIO_CS5535)	+= gpio-cs5535.o
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obj-$(CONFIG_GPIO_DA9052)	+= gpio-da9052.o
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										246
									
								
								drivers/gpio/gpio-amd8111.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										246
									
								
								drivers/gpio/gpio-amd8111.c
									
									
									
									
									
										Normal file
									
								
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			@ -0,0 +1,246 @@
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/*
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 * GPIO driver for AMD 8111 south bridges
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 *
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 * Copyright (c) 2012 Dmitry Eremin-Solenikov
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 *
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 * Based on the AMD RNG driver:
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 * Copyright 2005 (c) MontaVista Software, Inc.
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 * with the majority of the code coming from:
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 *
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 * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
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 * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
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 *
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 * derived from
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 *
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 * Hardware driver for the AMD 768 Random Number Generator (RNG)
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 * (c) Copyright 2001 Red Hat Inc
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 *
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 * derived from
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 *
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 * Hardware driver for Intel i810 Random Number Generator (RNG)
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 * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
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 * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
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 *
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 * This file is licensed under  the terms of the GNU General Public
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 * License version 2. This program is licensed "as is" without any
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 * warranty of any kind, whether express or implied.
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 */
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/gpio.h>
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#include <linux/pci.h>
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#include <linux/spinlock.h>
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#define PMBASE_OFFSET 0xb0
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#define PMBASE_SIZE   0x30
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#define AMD_REG_GPIO(i) (0x10 + (i))
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#define AMD_GPIO_LTCH_STS	0x40 /* Latch status, w1 */
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#define AMD_GPIO_RTIN		0x20 /* Real Time in, ro */
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#define AMD_GPIO_DEBOUNCE	0x10 /* Debounce, rw */
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#define AMD_GPIO_MODE_MASK	0x0c /* Pin Mode Select, rw */
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#define AMD_GPIO_MODE_IN	0x00
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#define AMD_GPIO_MODE_OUT	0x04
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/* Enable alternative (e.g. clkout, IRQ, etc) function of the pin */
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#define AMD_GPIO_MODE_ALTFN	0x08 /* Or 0x09 */
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#define AMD_GPIO_X_MASK		0x03 /* In/Out specific, rw */
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#define AMD_GPIO_X_IN_ACTIVEHI	0x01 /* Active High */
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#define AMD_GPIO_X_IN_LATCH	0x02 /* Latched version is selected */
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#define AMD_GPIO_X_OUT_LOW	0x00
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#define AMD_GPIO_X_OUT_HI	0x01
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#define AMD_GPIO_X_OUT_CLK0	0x02
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#define AMD_GPIO_X_OUT_CLK1	0x03
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/*
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 * Data for PCI driver interface
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 *
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 * This data only exists for exporting the supported
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 * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
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 * register a pci_driver, because someone else might one day
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 * want to register another driver on the same PCI id.
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 */
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static DEFINE_PCI_DEVICE_TABLE(pci_tbl) = {
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	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS), 0 },
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	{ 0, },	/* terminate list */
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};
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MODULE_DEVICE_TABLE(pci, pci_tbl);
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struct amd_gpio {
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	struct gpio_chip	chip;
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	u32			pmbase;
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	void __iomem		*pm;
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	struct pci_dev		*pdev;
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	spinlock_t		lock; /* guards hw registers and orig table */
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	u8			orig[32];
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};
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#define to_agp(chip)	container_of(chip, struct amd_gpio, chip)
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static int amd_gpio_request(struct gpio_chip *chip, unsigned offset)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	agp->orig[offset] = ioread8(agp->pm + AMD_REG_GPIO(offset)) &
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		(AMD_GPIO_DEBOUNCE | AMD_GPIO_MODE_MASK | AMD_GPIO_X_MASK);
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	dev_dbg(&agp->pdev->dev, "Requested gpio %d, data %x\n", offset, agp->orig[offset]);
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	return 0;
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}
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static void amd_gpio_free(struct gpio_chip *chip, unsigned offset)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	dev_dbg(&agp->pdev->dev, "Freed gpio %d, data %x\n", offset, agp->orig[offset]);
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	iowrite8(agp->orig[offset], agp->pm + AMD_REG_GPIO(offset));
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}
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static void amd_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	u8 temp;
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	unsigned long flags;
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	spin_lock_irqsave(&agp->lock, flags);
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	temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
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	temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
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	iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
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	spin_unlock_irqrestore(&agp->lock, flags);
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	dev_dbg(&agp->pdev->dev, "Setting gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
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}
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static int amd_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	u8 temp;
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	temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
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	dev_dbg(&agp->pdev->dev, "Getting gpio %d, reg=%02x\n", offset, temp);
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	return (temp & AMD_GPIO_RTIN) ? 1 : 0;
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}
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static int amd_gpio_dirout(struct gpio_chip *chip, unsigned offset, int value)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	u8 temp;
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	unsigned long flags;
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	spin_lock_irqsave(&agp->lock, flags);
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	temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
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	temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
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	iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
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	spin_unlock_irqrestore(&agp->lock, flags);
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	dev_dbg(&agp->pdev->dev, "Dirout gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
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	return 0;
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}
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static int amd_gpio_dirin(struct gpio_chip *chip, unsigned offset)
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{
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	struct amd_gpio *agp = to_agp(chip);
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	u8 temp;
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	unsigned long flags;
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	spin_lock_irqsave(&agp->lock, flags);
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	temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
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	temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_IN;
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	iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
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	spin_unlock_irqrestore(&agp->lock, flags);
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	dev_dbg(&agp->pdev->dev, "Dirin gpio %d, reg=%02x\n", offset, temp);
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	return 0;
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}
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static struct amd_gpio gp = {
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	.chip = {
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		.label		= "AMD GPIO",
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		.owner		= THIS_MODULE,
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		.base		= -1,
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		.ngpio		= 32,
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		.request	= amd_gpio_request,
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		.free		= amd_gpio_free,
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		.set		= amd_gpio_set,
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		.get		= amd_gpio_get,
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		.direction_output = amd_gpio_dirout,
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		.direction_input = amd_gpio_dirin,
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	},
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};
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static int __init amd_gpio_init(void)
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{
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	int err = -ENODEV;
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	struct pci_dev *pdev = NULL;
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	const struct pci_device_id *ent;
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	/* We look for our device - AMD South Bridge
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	 * I don't know about a system with two such bridges,
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	 * so we can assume that there is max. one device.
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	 *
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	 * We can't use plain pci_driver mechanism,
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	 * as the device is really a multiple function device,
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	 * main driver that binds to the pci_device is an smbus
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	 * driver and have to find & bind to the device this way.
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	 */
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	for_each_pci_dev(pdev) {
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		ent = pci_match_id(pci_tbl, pdev);
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		if (ent)
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			goto found;
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	}
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	/* Device not found. */
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	goto out;
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found:
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	err = pci_read_config_dword(pdev, 0x58, &gp.pmbase);
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	if (err)
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		goto out;
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	err = -EIO;
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	gp.pmbase &= 0x0000FF00;
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	if (gp.pmbase == 0)
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		goto out;
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	if (!request_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE, "AMD GPIO")) {
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		dev_err(&pdev->dev, "AMD GPIO region 0x%x already in use!\n",
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			gp.pmbase + PMBASE_OFFSET);
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		err = -EBUSY;
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		goto out;
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	}
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	gp.pm = ioport_map(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
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	gp.pdev = pdev;
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	gp.chip.dev = &pdev->dev;
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	spin_lock_init(&gp.lock);
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	printk(KERN_INFO "AMD-8111 GPIO detected\n");
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	err = gpiochip_add(&gp.chip);
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	if (err) {
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		printk(KERN_ERR "GPIO registering failed (%d)\n",
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		       err);
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		release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
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		goto out;
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	}
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out:
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	return err;
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}
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static void __exit amd_gpio_exit(void)
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{
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	int err = gpiochip_remove(&gp.chip);
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	WARN_ON(err);
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	ioport_unmap(gp.pm);
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	release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
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}
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module_init(amd_gpio_init);
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module_exit(amd_gpio_exit);
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MODULE_AUTHOR("The Linux Kernel team");
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MODULE_DESCRIPTION("GPIO driver for AMD chipsets");
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MODULE_LICENSE("GPL");
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