microblaze: GPIO reset support

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

3 files changed, 139 insertions, 30 deletions

diff --git a/arch/microblaze/kernel/Makefile b/arch/microblaze/kernel/Makefile
index d487729683de..fddd0c403d40 100644
--- a/arch/microblaze/kernel/Makefile
+++ b/arch/microblaze/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y := head.o vmlinux.lds
 obj-y += exceptions.o \
         hw_exception_handler.o init_task.o intc.o irq.o of_device.o \
         of_platform.o process.o prom.o prom_parse.o ptrace.o \
-        setup.o signal.o sys_microblaze.o timer.o traps.o
+        setup.o signal.o sys_microblaze.o timer.o traps.o reset.o
 
 obj-y += cpu/
 
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)
+                ;
+}
diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index 8c1e0f4dcf18..367ad330148e 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -186,32 +186,3 @@ static int microblaze_debugfs_init(void)
 }
 arch_initcall(microblaze_debugfs_init);
 #endif
-
-void machine_restart(char *cmd)
-{
-        printk(KERN_NOTICE "Machine restart...\n");
-        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)
-                ;
-}