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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 14:50:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 14:50:57 -0700
commitc7c8518498e82591d7784452f5674c3aeb4d079c (patch)
tree790ff7e6b6741daf32ec686b9a302b957b07c0f4 /drivers/gpio/gpio-xilinx.c
parentece236ce2fad9c27a6fd2530f899289025194bce (diff)
parent591567a5ea25852f20b7ef2953f6f72020121199 (diff)
Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6
* 'gpio/next' of git://git.secretlab.ca/git/linux-2.6: (61 commits) gpio/mxc/mxs: fix build error introduced by the irq_gc_ack() renaming mcp23s08: add i2c support mcp23s08: isolate spi specific parts mcp23s08: get rid of setup/teardown callbacks gpio/tegra: dt: add binding for gpio polarity mcp23s08: remove unused work queue gpio/da9052: remove a redundant assignment for gpio->da9052 gpio/mxc: add device tree probe support ARM: mxc: use ARCH_NR_GPIOS to define gpio number gpio/mxc: get rid of the uses of cpu_is_mx() gpio/mxc: add missing initialization of basic_mmio_gpio shadow variables gpio: Move mpc5200 gpio driver to drivers/gpio GPIO: DA9052 GPIO module v3 gpio/tegra: Use engineering names in DT compatible property of/gpio: Add new method for getting gpios under different property names gpio/dt: Refine GPIO device tree binding gpio/ml-ioh: fix off-by-one for displaying variable i in dev_err gpio/pca953x: Deprecate meaningless device-tree bindings gpio/pca953x: Remove dynamic platform data pointer gpio/pca953x: Fix IRQ support. ...
Diffstat (limited to 'drivers/gpio/gpio-xilinx.c')
-rw-r--r--drivers/gpio/gpio-xilinx.c233
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
new file mode 100644
index 000000000000..846fbd5e31bf
--- /dev/null
+++ b/drivers/gpio/gpio-xilinx.c
@@ -0,0 +1,233 @@
+/*
+ * 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>
+#include <linux/slab.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;
+ int status = 0;
+ const u32 *tree_info;
+
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ /* Update GPIO state shadow register with default value */
+ tree_info = of_get_property(np, "xlnx,dout-default", NULL);
+ if (tree_info)
+ chip->gpio_state = be32_to_cpup(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 = be32_to_cpup(tree_info);
+
+ /* Check device node and parent device node for device width */
+ chip->mmchip.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)
+ chip->mmchip.gc.ngpio = be32_to_cpup(tree_info);
+
+ spin_lock_init(&chip->gpio_lock);
+
+ 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) {
+ 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");