From 7cca9b8b7c5bcc56d627851550840586a25aaa1b Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Fri, 23 Aug 2019 11:47:28 +0200 Subject: microblaze: Switch to standard restart handler The microblaze uses the legacy APIs to dig out a GPIO pin defined in the root of the device tree to issue a hard reset of the platform. Asserting a hard reset should be done using the standard DT-enabled and fully GPIO descriptor aware driver in drivers/power/reset/gpio-restart.c using the bindings from Documentation/devicetree/bindings/power/reset/gpio-restart.txt To achieve this, first make sure microblaze makes use of the standard kernel restart path utilizing do_kernel_restart() from . Put in some grace time and an emergency print if the restart does not properly assert. As this is basic platform functionality we patch the DTS file and defconfig in one go for a lockstep change. Cc: Arnd Bergmann Cc: Michal Simek Signed-off-by: Linus Walleij [ Michal: Move machine_restart back to reset.c ] Signed-off-by: Michal Simek --- arch/microblaze/boot/dts/system.dts | 16 +++++- arch/microblaze/configs/mmu_defconfig | 2 + arch/microblaze/configs/nommu_defconfig | 2 + arch/microblaze/kernel/reset.c | 87 +++++---------------------------- 4 files changed, 30 insertions(+), 77 deletions(-) (limited to 'arch') diff --git a/arch/microblaze/boot/dts/system.dts b/arch/microblaze/boot/dts/system.dts index 5a8a9d090c37..5b236527176e 100644 --- a/arch/microblaze/boot/dts/system.dts +++ b/arch/microblaze/boot/dts/system.dts @@ -18,7 +18,6 @@ #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"; @@ -281,6 +280,21 @@ gpios = <&LEDs_8Bit 7 1>; }; } ; + + gpio-restart { + compatible = "gpio-restart"; + /* + * FIXME: is this active low or active high? + * the current flag (1) indicates active low. + * delay measures are templates, should be adjusted + * to datasheet or trial-and-error with real hardware. + */ + gpios = <&LEDs_8Bit 2 1>; + active-delay = <100>; + inactive-delay = <10>; + wait-delay = <100>; + }; + RS232_Uart_1: serial@84000000 { clock-frequency = <125000000>; compatible = "xlnx,xps-uartlite-1.00.a"; diff --git a/arch/microblaze/configs/mmu_defconfig b/arch/microblaze/configs/mmu_defconfig index b83aff1e86cd..654edfdc7867 100644 --- a/arch/microblaze/configs/mmu_defconfig +++ b/arch/microblaze/configs/mmu_defconfig @@ -60,6 +60,8 @@ CONFIG_SPI_XILINX=y CONFIG_GPIOLIB=y CONFIG_GPIO_SYSFS=y CONFIG_GPIO_XILINX=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_GPIO_RESTART=y # CONFIG_HWMON is not set CONFIG_WATCHDOG=y CONFIG_XILINX_WATCHDOG=y diff --git a/arch/microblaze/configs/nommu_defconfig b/arch/microblaze/configs/nommu_defconfig index dc102eb65fca..377de39ccb8c 100644 --- a/arch/microblaze/configs/nommu_defconfig +++ b/arch/microblaze/configs/nommu_defconfig @@ -62,6 +62,8 @@ CONFIG_SPI_XILINX=y CONFIG_GPIOLIB=y CONFIG_GPIO_SYSFS=y CONFIG_GPIO_XILINX=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_GPIO_RESTART=y # CONFIG_HWMON is not set CONFIG_WATCHDOG=y CONFIG_XILINX_WATCHDOG=y diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c index fcbe1daf6316..5f4722908164 100644 --- a/arch/microblaze/kernel/reset.c +++ b/arch/microblaze/kernel/reset.c @@ -8,83 +8,9 @@ */ #include +#include #include - -/* Trigger specific functions */ -#ifdef CONFIG_GPIOLIB - -#include - -static int handle; /* reset pin handle */ -static unsigned int reset_val; - -static int of_platform_reset_gpio_probe(void) -{ - int ret; - handle = of_get_named_gpio(of_find_node_by_path("/"), - "hard-reset-gpios", 0); - - if (!gpio_is_valid(handle)) { - pr_info("Skipping unavailable RESET gpio %d (%s)\n", - handle, "reset"); - return -ENODEV; - } - - ret = gpio_request(handle, "reset"); - if (ret < 0) { - pr_info("GPIO pin is already allocated\n"); - return ret; - } - - /* get current setup value */ - reset_val = gpio_get_value(handle); - /* FIXME maybe worth to perform any action */ - pr_debug("Reset: Gpio output state: 0x%x\n", reset_val); - - /* Setup GPIO as output */ - ret = gpio_direction_output(handle, 0); - if (ret < 0) - goto err; - - /* Setup output direction */ - gpio_set_value(handle, 0); - - pr_info("RESET: Registered gpio device: %d, current val: %d\n", - handle, reset_val); - return 0; -err: - gpio_free(handle); - return ret; -} -device_initcall(of_platform_reset_gpio_probe); - - -static void gpio_system_reset(void) -{ - if (gpio_is_valid(handle)) - gpio_set_value(handle, 1 - reset_val); - else - pr_notice("Reset GPIO unavailable - halting!\n"); -} -#else -static void gpio_system_reset(void) -{ - pr_notice("No reset GPIO present - halting!\n"); -} - -void of_platform_reset_gpio_probe(void) -{ - return; -} -#endif - -void machine_restart(char *cmd) -{ - pr_notice("Machine restart...\n"); - gpio_system_reset(); - while (1) - ; -} +#include void machine_shutdown(void) { @@ -106,3 +32,12 @@ void machine_power_off(void) while (1) ; } + +void machine_restart(char *cmd) +{ + do_kernel_restart(cmd); + /* Give the restart hook 1 s to take us down */ + mdelay(1000); + pr_emerg("Reboot failed -- System halted\n"); + while (1); +} -- cgit v1.2.3