microblaze: GPIO reset support

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

arch/microblaze/include/asm/setup.h

@@ -35,6 +35,8 @@ extern void mmu_reset(void);
 extern void early_console_reg_tlb_alloc(unsigned int addr);
 #   endif /* CONFIG_MMU */
 
+extern void of_platform_reset_gpio_probe(void);
+
 void time_init(void);
 void init_IRQ(void);
 void machine_early_init(const char *cmdline, unsigned int ram,

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/
 

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)
+		;
+}

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)
-		;
-}

arch/microblaze/platform/generic/system.dts

@@ -32,6 +32,7 @@
 	#address-cells = <1>;
 	#size-cells = <1>;
 	compatible = "xlnx,microblaze";
+	hard-reset-gpios = <&LEDs_8Bit 2 1>;
 	model = "testing";
 	DDR2_SDRAM: memory@90000000 {
 		device_type = "memory";
@@ -261,6 +262,33 @@
 			xlnx,is-dual = <0x0>;
 			xlnx,tri-default = <0xffffffff>;
 			xlnx,tri-default-2 = <0xffffffff>;
+			#gpio-cells = <2>;
+			gpio-controller;
+		} ;
+
+		gpio-leds {
+			compatible = "gpio-leds";
+
+			heartbeat {
+				label = "Heartbeat";
+				gpios = <&LEDs_8Bit 4 1>;
+				linux,default-trigger = "heartbeat";
+			};
+
+			yellow {
+				label = "Yellow";
+				gpios = <&LEDs_8Bit 5 1>;
+			};
+
+			red {
+				label = "Red";
+				gpios = <&LEDs_8Bit 6 1>;
+			};
+
+			green {
+				label = "Green";
+				gpios = <&LEDs_8Bit 7 1>;
+			};
 		} ;
 		RS232_Uart_1: serial@84000000 {
 			clock-frequency = <125000000>;

arch/microblaze/platform/platform.c

@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/of_platform.h>
 #include <asm/prom.h>
+#include <asm/setup.h>
 
 static struct of_device_id xilinx_of_bus_ids[] __initdata = {
 	{ .compatible = "simple-bus", },
@@ -26,6 +27,7 @@ static struct of_device_id xilinx_of_bus_ids[] __initdata = {
 static int __init microblaze_device_probe(void)
 {
 	of_platform_bus_probe(NULL, xilinx_of_bus_ids, NULL);
+	of_platform_reset_gpio_probe();
 	return 0;
 }
 device_initcall(microblaze_device_probe);