From d0f1c7ffaa32bdda2d413d2db41c51bbdd105834 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Sat, 15 Sep 2012 22:18:10 -0600 Subject: [PATCH 1/2] 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 --- .../watchdog/brcm,bcm2835-pm-wdog.txt | 13 ++++++ arch/arm/boot/dts/bcm2835.dtsi | 5 ++ arch/arm/mach-bcm2835/bcm2835.c | 46 +++++++++++++++++++ 3 files changed, 64 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt new file mode 100644 index 000000000000..d209366b4a69 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm2835-pm-wdog.txt @@ -0,0 +1,13 @@ +BCM2835 Watchdog timer + +Required properties: + +- compatible : should be "brcm,bcm2835-pm-wdt" +- reg : Specifies base physical address and size of the registers. + +Example: + +watchdog { + compatible = "brcm,bcm2835-pm-wdt"; + reg = <0x7e100000 0x28>; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index 0b619398532c..5c5cbafed191 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -29,6 +29,11 @@ #interrupt-cells = <2>; }; + watchdog { + compatible = "brcm,bcm2835-pm-wdt"; + reg = <0x7e100000 0x28>; + }; + uart@20201000 { compatible = "brcm,bcm2835-pl011", "arm,pl011", "arm,primecell"; reg = <0x7e201000 0x1000>; diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index f6fea4933571..c4dd210f4db1 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 From 805504abdc73cfc745a5fee3d616cdb24bb2a68c Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Thu, 27 Sep 2012 21:54:21 -0600 Subject: [PATCH 2/2] 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/Kconfig | 5 ++++- arch/arm/boot/dts/bcm2835-rpi-b.dts | 15 +++++++++++++++ arch/arm/boot/dts/bcm2835.dtsi | 23 +++++++++++++++++++++++ arch/arm/mach-bcm2835/include/mach/gpio.h | 1 + 4 files changed, 43 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mach-bcm2835/include/mach/gpio.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 73067efd4845..7cce11a1849e 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -336,7 +336,7 @@ config ARCH_AT91 config ARCH_BCM2835 bool "Broadcom BCM2835 family" - select ARCH_WANT_OPTIONAL_GPIOLIB + select ARCH_REQUIRE_GPIOLIB select ARM_AMBA select ARM_ERRATA_411920 select ARM_TIMER_SP804 @@ -344,7 +344,10 @@ config ARCH_BCM2835 select COMMON_CLK select CPU_V6 select GENERIC_CLOCKEVENTS + select GENERIC_GPIO select MULTI_IRQ_HANDLER + select PINCTRL + select PINCTRL_BCM2835 select SPARSE_IRQ select USE_OF help diff --git a/arch/arm/boot/dts/bcm2835-rpi-b.dts b/arch/arm/boot/dts/bcm2835-rpi-b.dts index 7dd860f83f96..9b72054a0bc0 100644 --- a/arch/arm/boot/dts/bcm2835-rpi-b.dts +++ b/arch/arm/boot/dts/bcm2835-rpi-b.dts @@ -10,3 +10,18 @@ reg = <0 0x10000000>; }; }; + +&gpio { + pinctrl-names = "default"; + pinctrl-0 = <&alt0 &alt3>; + + alt0: alt0 { + brcm,pins = <0 1 2 3 4 5 6 7 8 9 10 11 14 15 40 45>; + brcm,function = <4>; /* alt0 */ + }; + + alt3: alt3 { + brcm,pins = <48 49 50 51 52 53>; + brcm,function = <7>; /* alt3 */ + }; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index 5c5cbafed191..8917550fd1bb 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -40,5 +40,28 @@ interrupts = <2 25>; clock-frequency = <3000000>; }; + + gpio: gpio { + compatible = "brcm,bcm2835-gpio"; + reg = <0x7e200000 0xb4>; + /* + * The GPIO IP block is designed for 3 banks of GPIOs. + * Each bank has a GPIO interrupt for itself. + * There is an overall "any bank" interrupt. + * In order, these are GIC interrupts 17, 18, 19, 20. + * Since the BCM2835 only has 2 banks, the 2nd bank + * interrupt output appears to be mirrored onto the + * 3rd bank's interrupt signal. + * So, a bank0 interrupt shows up on 17, 20, and + * a bank1 interrupt shows up on 18, 19, 20! + */ + interrupts = <2 17>, <2 18>, <2 19>, <2 20>; + + gpio-controller; + #gpio-cells = <2>; + + interrupt-controller; + #interrupt-cells = <2>; + }; }; }; 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 000000000000..40a8c178f10d --- /dev/null +++ b/arch/arm/mach-bcm2835/include/mach/gpio.h @@ -0,0 +1 @@ +/* empty */