microblaze: GPIO reset support
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
new file mode 100644
index 0000000..ce74a6f
--- /dev/null
+++ b/arch/microblaze/kernel/reset.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2009 PetaLogix
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/of_platform.h>
+#include <asm/prom.h>
+
+/* Trigger specific functions */
+#ifdef CONFIG_GPIOLIB
+
+#include <linux/of_gpio.h>
+
+static int handle; /* reset pin handle */
+
+static int of_reset_gpio_handle(void)
+{
+ int ret; /* variable which stored handle reset gpio pin */
+ struct device_node *root; /* root node */
+ struct device_node *gpio; /* gpio node */
+ struct of_gpio_chip *of_gc = NULL;
+ enum of_gpio_flags flags ;
+ const void *gpio_spec;
+
+ /* find out root node */
+ root = of_find_node_by_path("/");
+
+ /* give me handle for gpio node to be possible allocate pin */
+ ret = of_parse_phandles_with_args(root, "hard-reset-gpios",
+ "#gpio-cells", 0, &gpio, &gpio_spec);
+ if (ret) {
+ pr_debug("%s: can't parse gpios property\n", __func__);
+ goto err0;
+ }
+
+ of_gc = gpio->data;
+ if (!of_gc) {
+ pr_debug("%s: gpio controller %s isn't registered\n",
+ root->full_name, gpio->full_name);
+ ret = -ENODEV;
+ goto err1;
+ }
+
+ ret = of_gc->xlate(of_gc, root, gpio_spec, &flags);
+ if (ret < 0)
+ goto err1;
+
+ ret += of_gc->gc.base;
+err1:
+ of_node_put(gpio);
+err0:
+ pr_debug("%s exited with status %d\n", __func__, ret);
+ return ret;
+}
+
+void of_platform_reset_gpio_probe(void)
+{
+ int ret;
+ handle = of_reset_gpio_handle();
+
+ if (!gpio_is_valid(handle)) {
+ printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
+ handle, "reset");
+ }
+
+ ret = gpio_request(handle, "reset");
+ if (ret < 0) {
+ printk(KERN_INFO "GPIO pin is already allocated\n");
+ return;
+ }
+
+ /* get current setup value */
+ ret = gpio_get_value(handle);
+ /* FIXME maybe worth to perform any action */
+ pr_debug("Reset: Gpio output state: 0x%x\n", ret);
+
+ /* Setup GPIO as output */
+ ret = gpio_direction_output(handle, 0);
+ if (ret < 0)
+ goto err;
+
+ /* Setup output direction */
+ gpio_set_value(handle, 0);
+
+ printk(KERN_INFO "Registered reset device: %d\n", handle);
+ return;
+err:
+ gpio_free(handle);
+ return;
+}
+
+
+static void gpio_system_reset(void)
+{
+ gpio_set_value(handle, 1);
+}
+#else
+#define gpio_system_reset() do {} while (0)
+void of_platform_reset_gpio_probe(void)
+{
+ return;
+}
+#endif
+
+void machine_restart(char *cmd)
+{
+ printk(KERN_NOTICE "Machine restart...\n");
+ gpio_system_reset();
+ dump_stack();
+ while (1)
+ ;
+}
+
+void machine_shutdown(void)
+{
+ printk(KERN_NOTICE "Machine shutdown...\n");
+ while (1)
+ ;
+}
+
+void machine_halt(void)
+{
+ printk(KERN_NOTICE "Machine halt...\n");
+ while (1)
+ ;
+}
+
+void machine_power_off(void)
+{
+ printk(KERN_NOTICE "Machine power off...\n");
+ while (1)
+ ;
+}