Initial import

1 files changed, 356 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
new file mode 100644
index 000000000..61243d177
--- /dev/null
+++ b/drivers/gpio/gpio-xilinx.c
@@ -0,0 +1,356 @@
+/*
+ * Xilinx gpio driver for xps/axi_gpio IP.
+ *
+ * Copyright 2008 - 2013 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/bitops.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+/* Register Offset Definitions */
+#define XGPIO_DATA_OFFSET   (0x0)	/* Data register  */
+#define XGPIO_TRI_OFFSET    (0x4)	/* I/O direction register  */
+
+#define XGPIO_CHANNEL_OFFSET	0x8
+
+/* Read/Write access to the GPIO registers */
+#if defined(CONFIG_ARCH_ZYNQ) || defined(CONFIG_X86)
+# define xgpio_readreg(offset)		readl(offset)
+# define xgpio_writereg(offset, val)	writel(val, offset)
+#else
+# define xgpio_readreg(offset)		__raw_readl(offset)
+# define xgpio_writereg(offset, val)	__raw_writel(val, offset)
+#endif
+
+/**
+ * struct xgpio_instance - Stores information about GPIO device
+ * @mmchip: OF GPIO chip for memory mapped banks
+ * @gpio_state: GPIO state shadow register
+ * @gpio_dir: GPIO direction shadow register
+ * @gpio_lock: Lock used for synchronization
+ * @inited: True if the port has been inited
+ */
+struct xgpio_instance {
+	struct of_mm_gpio_chip mmchip;
+	unsigned int gpio_width[2];
+	u32 gpio_state[2];
+	u32 gpio_dir[2];
+	spinlock_t gpio_lock[2];
+};
+
+static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
+{
+	if (gpio >= chip->gpio_width[0])
+		return 1;
+
+	return 0;
+}
+
+static inline int xgpio_regoffset(struct xgpio_instance *chip, int gpio)
+{
+	if (xgpio_index(chip, gpio))
+		return XGPIO_CHANNEL_OFFSET;
+
+	return 0;
+}
+
+static inline int xgpio_offset(struct xgpio_instance *chip, int gpio)
+{
+	if (xgpio_index(chip, gpio))
+		return gpio - chip->gpio_width[0];
+
+	return gpio;
+}
+
+/**
+ * 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.
+ *
+ * Return:
+ * 0 if direction of GPIO signals is set as input otherwise it
+ * returns negative error value.
+ */
+static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	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);
+	u32 val;
+
+	val = xgpio_readreg(mm_gc->regs + XGPIO_DATA_OFFSET +
+			    xgpio_regoffset(chip, gpio));
+
+	return !!(val & BIT(xgpio_offset(chip, gpio)));
+}
+
+/**
+ * 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);
+	int index =  xgpio_index(chip, gpio);
+	int offset =  xgpio_offset(chip, gpio);
+
+	spin_lock_irqsave(&chip->gpio_lock[index], flags);
+
+	/* Write to GPIO signal and set its direction to output */
+	if (val)
+		chip->gpio_state[index] |= BIT(offset);
+	else
+		chip->gpio_state[index] &= ~BIT(offset);
+
+	xgpio_writereg(mm_gc->regs + XGPIO_DATA_OFFSET +
+		       xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
+
+	spin_unlock_irqrestore(&chip->gpio_lock[index], 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.
+ *
+ * Return:
+ * 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);
+	int index =  xgpio_index(chip, gpio);
+	int offset =  xgpio_offset(chip, gpio);
+
+	spin_lock_irqsave(&chip->gpio_lock[index], flags);
+
+	/* Set the GPIO bit in shadow register and set direction as input */
+	chip->gpio_dir[index] |= BIT(offset);
+	xgpio_writereg(mm_gc->regs + XGPIO_TRI_OFFSET +
+		       xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
+
+	spin_unlock_irqrestore(&chip->gpio_lock[index], 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.
+ *
+ * Return:
+ * 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);
+	int index =  xgpio_index(chip, gpio);
+	int offset =  xgpio_offset(chip, gpio);
+
+	spin_lock_irqsave(&chip->gpio_lock[index], flags);
+
+	/* Write state of GPIO signal */
+	if (val)
+		chip->gpio_state[index] |= BIT(offset);
+	else
+		chip->gpio_state[index] &= ~BIT(offset);
+	xgpio_writereg(mm_gc->regs + XGPIO_DATA_OFFSET +
+			xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
+
+	/* Clear the GPIO bit in shadow register and set direction as output */
+	chip->gpio_dir[index] &= ~BIT(offset);
+	xgpio_writereg(mm_gc->regs + XGPIO_TRI_OFFSET +
+			xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
+
+	spin_unlock_irqrestore(&chip->gpio_lock[index], 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);
+
+	xgpio_writereg(mm_gc->regs + XGPIO_DATA_OFFSET,	chip->gpio_state[0]);
+	xgpio_writereg(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir[0]);
+
+	if (!chip->gpio_width[1])
+		return;
+
+	xgpio_writereg(mm_gc->regs + XGPIO_DATA_OFFSET + XGPIO_TRI_OFFSET,
+		       chip->gpio_state[1]);
+	xgpio_writereg(mm_gc->regs + XGPIO_TRI_OFFSET + XGPIO_TRI_OFFSET,
+		       chip->gpio_dir[1]);
+}
+
+/**
+ * xgpio_remove - Remove method for the GPIO device.
+ * @pdev: pointer to the platform device
+ *
+ * This function remove gpiochips and frees all the allocated resources.
+ */
+static int xgpio_remove(struct platform_device *pdev)
+{
+	struct xgpio_instance *chip = platform_get_drvdata(pdev);
+
+	of_mm_gpiochip_remove(&chip->mmchip);
+
+	return 0;
+}
+
+/**
+ * xgpio_of_probe - Probe method for the GPIO device.
+ * @pdev: pointer to the platform device
+ *
+ * Return:
+ * It returns 0, if the driver is bound to the GPIO device, or
+ * a negative value if there is an error.
+ */
+static int xgpio_probe(struct platform_device *pdev)
+{
+	struct xgpio_instance *chip;
+	int status = 0;
+	struct device_node *np = pdev->dev.of_node;
+	u32 is_dual;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, chip);
+
+	/* Update GPIO state shadow register with default value */
+	of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state[0]);
+
+	/* Update GPIO direction shadow register with default value */
+	if (of_property_read_u32(np, "xlnx,tri-default", &chip->gpio_dir[0]))
+		chip->gpio_dir[0] = 0xFFFFFFFF;
+
+	/*
+	 * Check device node and parent device node for device width
+	 * and assume default width of 32
+	 */
+	if (of_property_read_u32(np, "xlnx,gpio-width", &chip->gpio_width[0]))
+		chip->gpio_width[0] = 32;
+
+	spin_lock_init(&chip->gpio_lock[0]);
+
+	if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
+		is_dual = 0;
+
+	if (is_dual) {
+		/* Update GPIO state shadow register with default value */
+		of_property_read_u32(np, "xlnx,dout-default-2",
+				     &chip->gpio_state[1]);
+
+		/* Update GPIO direction shadow register with default value */
+		if (of_property_read_u32(np, "xlnx,tri-default-2",
+					 &chip->gpio_dir[1]))
+			chip->gpio_dir[1] = 0xFFFFFFFF;
+
+		/*
+		 * Check device node and parent device node for device width
+		 * and assume default width of 32
+		 */
+		if (of_property_read_u32(np, "xlnx,gpio2-width",
+					 &chip->gpio_width[1]))
+			chip->gpio_width[1] = 32;
+
+		spin_lock_init(&chip->gpio_lock[1]);
+	}
+
+	chip->mmchip.gc.ngpio = chip->gpio_width[0] + chip->gpio_width[1];
+	chip->mmchip.gc.dev = &pdev->dev;
+	chip->mmchip.gc.direction_input = xgpio_dir_in;
+	chip->mmchip.gc.direction_output = xgpio_dir_out;
+	chip->mmchip.gc.get = xgpio_get;
+	chip->mmchip.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) {
+		pr_err("%s: error in probe function with status %d\n",
+		       np->full_name, status);
+		return status;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id xgpio_of_match[] = {
+	{ .compatible = "xlnx,xps-gpio-1.00.a", },
+	{ /* end of list */ },
+};
+
+MODULE_DEVICE_TABLE(of, xgpio_of_match);
+
+static struct platform_driver xgpio_plat_driver = {
+	.probe		= xgpio_probe,
+	.remove		= xgpio_remove,
+	.driver		= {
+			.name = "gpio-xilinx",
+			.of_match_table	= xgpio_of_match,
+	},
+};
+
+static int __init xgpio_init(void)
+{
+	return platform_driver_register(&xgpio_plat_driver);
+}
+
+subsys_initcall(xgpio_init);
+
+static void __exit xgpio_exit(void)
+{
+	platform_driver_unregister(&xgpio_plat_driver);
+}
+module_exit(xgpio_exit);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("Xilinx GPIO driver");
+MODULE_LICENSE("GPL");