From d0f1c7ffaa32bdda2d413d2db41c51bbdd105834 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Sat, 15 Sep 2012 22:18:10 -0600 Subject: ARM: bcm2835: implement machine restart hook Implement the machine restart hook using the SoC's watchdog timer module. To support this, define a DT binding for the watchdog module, and add it to the device tree. The downstream rpi-split branch contains a full watchdog timer driver implementation, which also implements the restart hook. However, the restart function is largely separate from the watchdog driver, so for simplicity, the restart hook is implemented here directly in the main machine source file. Overall structure (separate setup/restart) functions derived from the picoxcell ARM support. Watchdog register IO sequence taken from code by Simon Arlott. Note that the watchdog module is not documented in BCM2835-ARM-Peripherals.pdf. Signed-off-by: Stephen Warren --- arch/arm/mach-bcm2835/bcm2835.c | 46 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'arch/arm/mach-bcm2835') diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index f6fea49..c4dd210 100644 --- a/arch/arm/mach-bcm2835/bcm2835.c +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -12,8 +12,10 @@ * GNU General Public License for more details. */ +#include #include #include +#include #include #include #include @@ -23,6 +25,48 @@ #include +#define PM_RSTC 0x1c +#define PM_WDOG 0x24 + +#define PM_PASSWORD 0x5a000000 +#define PM_RSTC_WRCFG_MASK 0x00000030 +#define PM_RSTC_WRCFG_FULL_RESET 0x00000020 + +static void __iomem *wdt_regs; + +/* + * The machine restart method can be called from an atomic context so we won't + * be able to ioremap the regs then. + */ +static void bcm2835_setup_restart(void) +{ + struct device_node *np = of_find_compatible_node(NULL, NULL, + "brcm,bcm2835-pm-wdt"); + if (WARN(!np, "unable to setup watchdog restart")) + return; + + wdt_regs = of_iomap(np, 0); + WARN(!wdt_regs, "failed to remap watchdog regs"); +} + +static void bcm2835_restart(char mode, const char *cmd) +{ + u32 val; + + if (!wdt_regs) + return; + + /* use a timeout of 10 ticks (~150us) */ + writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG); + val = readl_relaxed(wdt_regs + PM_RSTC); + val &= ~PM_RSTC_WRCFG_MASK; + val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET; + writel_relaxed(val, wdt_regs + PM_RSTC); + + /* No sleeping, possibly atomic. */ + mdelay(1); +} + static struct map_desc io_map __initdata = { .virtual = BCM2835_PERIPH_VIRT, .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS), @@ -39,6 +83,7 @@ void __init bcm2835_init(void) { int ret; + bcm2835_setup_restart(); bcm2835_init_clocks(); ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, @@ -60,5 +105,6 @@ DT_MACHINE_START(BCM2835, "BCM2835") .handle_irq = bcm2835_handle_irq, .init_machine = bcm2835_init, .timer = &bcm2835_timer, + .restart = bcm2835_restart, .dt_compat = bcm2835_compat MACHINE_END -- cgit v1.1 From 805504abdc73cfc745a5fee3d616cdb24bb2a68c Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Thu, 27 Sep 2012 21:54:21 -0600 Subject: ARM: bcm2835: enable GPIO/pinctrl Enable GPIO and pinctrl in Kconfig. Add required for gpiolib. Instantiate the BCM2835 GPIO module in bcm2835.dtsi. Add a pinctrl definition to bcm2835-rpi-b.dts that sets up all of the board's required pinmux configuration. GPIO aren't specified; that's left to gpio_request(). Signed-off-by: Stephen Warren Acked-by: Linus Walleij --- arch/arm/mach-bcm2835/include/mach/gpio.h | 1 + 1 file changed, 1 insertion(+) create mode 100644 arch/arm/mach-bcm2835/include/mach/gpio.h (limited to 'arch/arm/mach-bcm2835') diff --git a/arch/arm/mach-bcm2835/include/mach/gpio.h b/arch/arm/mach-bcm2835/include/mach/gpio.h new file mode 100644 index 0000000..40a8c17 --- /dev/null +++ b/arch/arm/mach-bcm2835/include/mach/gpio.h @@ -0,0 +1 @@ +/* empty */ -- cgit v1.1