microblaze: GPIO reset support

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 138 insertions, 0 deletions

diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
new file mode 100644
index 000000000000..ce74a6f436e3
--- /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)
+		;
+}