GPIO: add new Xilinx driver for powerpc (0bcb6069) · Commits · 戴 / test

drivers/gpio/Kconfig

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		@@ -65,6 +65,14 @@ config GPIO_SYSFS

		# put expanders in the right section, in alphabetical order

		comment "Memory mapped GPIO expanders:"

		config GPIO_XILINX
		bool "Xilinx GPIO support"
		depends on PPC_OF
		help
		Say yes here to support the Xilinx FPGA GPIO device

		comment "I2C GPIO expanders:"

		config GPIO_MAX732X

drivers/gpio/Makefile

+1 −0

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		@@ -10,4 +10,5 @@ obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
		obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
		obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
		obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o
		obj-$(CONFIG_GPIO_XILINX) += xilinx_gpio.o
		obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o

drivers/gpio/xilinx_gpio.c

0 → 100644

+235 −0

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		/*
		* Xilinx gpio driver
		*
		* Copyright 2008 Xilinx, Inc.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2
		* as published by the Free Software Foundation.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		*/

		#include <linux/init.h>
		#include <linux/errno.h>
		#include <linux/of_device.h>
		#include <linux/of_platform.h>
		#include <linux/of_gpio.h>
		#include <linux/io.h>
		#include <linux/gpio.h>

		/* Register Offset Definitions */
		#define XGPIO_DATA_OFFSET (0x0) /* Data register */
		#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */

		struct xgpio_instance {
		struct of_mm_gpio_chip mmchip;
		u32 gpio_state; /* GPIO state shadow register */
		u32 gpio_dir; /* GPIO direction shadow register */
		spinlock_t gpio_lock; /* Lock used for synchronization */
		};

		/**
		* xgpio_get - Read the specified signal of the GPIO device.
		* @gc: Pointer to gpio_chip device structure.
		* @gpio: GPIO signal number.
		*
		* This function reads the specified signal of the GPIO device. It returns 0 if
		* the signal clear, 1 if signal is set or negative value on error.
		*/
		static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
		{
		struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

		return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1;
		}

		/**
		* xgpio_set - Write the specified signal of the GPIO device.
		* @gc: Pointer to gpio_chip device structure.
		* @gpio: GPIO signal number.
		* @val: Value to be written to specified signal.
		*
		* This function writes the specified value in to the specified signal of the
		* GPIO device.
		*/
		static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
		{
		unsigned long flags;
		struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
		struct xgpio_instance *chip =
		container_of(mm_gc, struct xgpio_instance, mmchip);

		spin_lock_irqsave(&chip->gpio_lock, flags);

		/* Write to GPIO signal and set its direction to output */
		if (val)
		chip->gpio_state \|= 1 << gpio;
		else
		chip->gpio_state &= ~(1 << gpio);
		out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);

		spin_unlock_irqrestore(&chip->gpio_lock, flags);
		}

		/**
		* xgpio_dir_in - Set the direction of the specified GPIO signal as input.
		* @gc: Pointer to gpio_chip device structure.
		* @gpio: GPIO signal number.
		*
		* This function sets the direction of specified GPIO signal as input.
		* It returns 0 if direction of GPIO signals is set as input otherwise it
		* returns negative error value.
		*/
		static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
		{
		unsigned long flags;
		struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
		struct xgpio_instance *chip =
		container_of(mm_gc, struct xgpio_instance, mmchip);

		spin_lock_irqsave(&chip->gpio_lock, flags);

		/* Set the GPIO bit in shadow register and set direction as input */
		chip->gpio_dir \|= (1 << gpio);
		out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);

		spin_unlock_irqrestore(&chip->gpio_lock, flags);

		return 0;
		}

		/**
		* xgpio_dir_out - Set the direction of the specified GPIO signal as output.
		* @gc: Pointer to gpio_chip device structure.
		* @gpio: GPIO signal number.
		* @val: Value to be written to specified signal.
		*
		* This function sets the direction of specified GPIO signal as output. If all
		* GPIO signals of GPIO chip is configured as input then it returns
		* error otherwise it returns 0.
		*/
		static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
		{
		unsigned long flags;
		struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
		struct xgpio_instance *chip =
		container_of(mm_gc, struct xgpio_instance, mmchip);

		spin_lock_irqsave(&chip->gpio_lock, flags);

		/* Write state of GPIO signal */
		if (val)
		chip->gpio_state \|= 1 << gpio;
		else
		chip->gpio_state &= ~(1 << gpio);
		out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);

		/* Clear the GPIO bit in shadow register and set direction as output */
		chip->gpio_dir &= (~(1 << gpio));
		out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);

		spin_unlock_irqrestore(&chip->gpio_lock, flags);

		return 0;
		}

		/**
		* xgpio_save_regs - Set initial values of GPIO pins
		* @mm_gc: pointer to memory mapped GPIO chip structure
		*/
		static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
		{
		struct xgpio_instance *chip =
		container_of(mm_gc, struct xgpio_instance, mmchip);

		out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
		out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
		}

		/**
		* xgpio_of_probe - Probe method for the GPIO device.
		* @np: pointer to device tree node
		*
		* This function probes the GPIO device in the device tree. It initializes the
		* driver data structure. It returns 0, if the driver is bound to the GPIO
		* device, or a negative value if there is an error.
		*/
		static int __devinit xgpio_of_probe(struct device_node *np)
		{
		struct xgpio_instance *chip;
		struct of_gpio_chip *ofchip;
		int status = 0;
		const u32 *tree_info;

		chip = kzalloc(sizeof(*chip), GFP_KERNEL);
		if (!chip)
		return -ENOMEM;
		ofchip = &chip->mmchip.of_gc;

		/* Update GPIO state shadow register with default value */
		tree_info = of_get_property(np, "xlnx,dout-default", NULL);
		if (tree_info)
		chip->gpio_state = *tree_info;

		/* Update GPIO direction shadow register with default value */
		chip->gpio_dir = 0xFFFFFFFF; /* By default, all pins are inputs */
		tree_info = of_get_property(np, "xlnx,tri-default", NULL);
		if (tree_info)
		chip->gpio_dir = *tree_info;

		/* Check device node and parent device node for device width */
		ofchip->gc.ngpio = 32; /* By default assume full GPIO controller */
		tree_info = of_get_property(np, "xlnx,gpio-width", NULL);
		if (!tree_info)
		tree_info = of_get_property(np->parent,
		"xlnx,gpio-width", NULL);
		if (tree_info)
		ofchip->gc.ngpio = *tree_info;

		spin_lock_init(&chip->gpio_lock);

		ofchip->gpio_cells = 2;
		ofchip->gc.direction_input = xgpio_dir_in;
		ofchip->gc.direction_output = xgpio_dir_out;
		ofchip->gc.get = xgpio_get;
		ofchip->gc.set = xgpio_set;

		chip->mmchip.save_regs = xgpio_save_regs;

		/* Call the OF gpio helper to setup and register the GPIO device */
		status = of_mm_gpiochip_add(np, &chip->mmchip);
		if (status) {
		kfree(chip);
		pr_err("%s: error in probe function with status %d\n",
		np->full_name, status);
		return status;
		}
		pr_info("XGpio: %s: registered\n", np->full_name);
		return 0;
		}

		static struct of_device_id xgpio_of_match[] __devinitdata = {
		{ .compatible = "xlnx,xps-gpio-1.00.a", },
		{ /* end of list */ },
		};

		static int __init xgpio_init(void)
		{
		struct device_node *np;

		for_each_matching_node(np, xgpio_of_match)
		xgpio_of_probe(np);

		return 0;
		}

		/* Make sure we get initialized before anyone else tries to use us */
		subsys_initcall(xgpio_init);
		/* No exit call at the moment as we cannot unregister of GPIO chips */

		MODULE_AUTHOR("Xilinx, Inc.");
		MODULE_DESCRIPTION("Xilinx GPIO driver");
		MODULE_LICENSE("GPL");

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