aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/86xx/gef_gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/platforms/86xx/gef_gpio.c')
-rw-r--r--arch/powerpc/platforms/86xx/gef_gpio.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/86xx/gef_gpio.c b/arch/powerpc/platforms/86xx/gef_gpio.c
new file mode 100644
index 00000000000..85b2800f4cb
--- /dev/null
+++ b/arch/powerpc/platforms/86xx/gef_gpio.c
@@ -0,0 +1,143 @@
+/*
+ * Driver for GE Fanuc's FPGA based GPIO pins
+ *
+ * Author: Martyn Welch <martyn.welch@gefanuc.com>
+ *
+ * 2008 (c) GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+/* TODO
+ *
+ * Configuration of output modes (totem-pole/open-drain)
+ * Interrupt configuration - interrupts are always generated the FPGA relies on
+ * the I/O interrupt controllers mask to stop them propergating
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+
+#define GEF_GPIO_DIRECT 0x00
+#define GEF_GPIO_IN 0x04
+#define GEF_GPIO_OUT 0x08
+#define GEF_GPIO_TRIG 0x0C
+#define GEF_GPIO_POLAR_A 0x10
+#define GEF_GPIO_POLAR_B 0x14
+#define GEF_GPIO_INT_STAT 0x18
+#define GEF_GPIO_OVERRUN 0x1C
+#define GEF_GPIO_MODE 0x20
+
+#define NUM_GPIO 19
+
+static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value)
+{
+ unsigned int data;
+
+ data = ioread32be(reg);
+ /* value: 0=low; 1=high */
+ if (value & 0x1)
+ data = data | (0x1 << offset);
+ else
+ data = data & ~(0x1 << offset);
+
+ iowrite32be(data, reg);
+}
+
+
+static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+ unsigned int data;
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+ data = data | (0x1 << offset);
+ iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+ return 0;
+}
+
+static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+ unsigned int data;
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+ /* Set direction before switching to input */
+ _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+ data = data & ~(0x1 << offset);
+ iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+ return 0;
+}
+
+static int gef_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ unsigned int data;
+ int state = 0;
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+ data = ioread32be(mmchip->regs + GEF_GPIO_IN);
+ state = (int)((data >> offset) & 0x1);
+
+ return state;
+}
+
+static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+ _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+}
+
+static int __init gef_gpio_init(void)
+{
+ struct device_node *np;
+
+ for_each_compatible_node(np, NULL, "gef,sbc610-gpio") {
+ int retval;
+ struct of_mm_gpio_chip *gef_gpio_chip;
+
+ pr_debug("%s: Initialising GEF GPIO\n", np->full_name);
+
+ /* Allocate chip structure */
+ gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL);
+ if (!gef_gpio_chip) {
+ pr_err("%s: Unable to allocate structure\n",
+ np->full_name);
+ continue;
+ }
+
+ /* Setup pointers to chip functions */
+ gef_gpio_chip->of_gc.gpio_cells = 2;
+ gef_gpio_chip->of_gc.gc.ngpio = NUM_GPIO;
+ gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in;
+ gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out;
+ gef_gpio_chip->of_gc.gc.get = gef_gpio_get;
+ gef_gpio_chip->of_gc.gc.set = gef_gpio_set;
+
+ /* This function adds a memory mapped GPIO chip */
+ retval = of_mm_gpiochip_add(np, gef_gpio_chip);
+ if (retval) {
+ kfree(gef_gpio_chip);
+ pr_err("%s: Unable to add GPIO\n", np->full_name);
+ }
+ }
+
+ return 0;
+};
+arch_initcall(gef_gpio_init);
+
+MODULE_DESCRIPTION("GE Fanuc I/O FPGA GPIO driver");
+MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com");
+MODULE_LICENSE("GPL");