[PATCH] ARM: bcm2835: add a pm_power_off implementation
From: Stephen Warren <hidden>
Date: 2012-12-05 03:22:59
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
From: Dom Cobley <redacted> Add a pm_power_off function that resets the SoC, and indicates to bootcode.bin not to boot. Should allow a lower power 'off' state, even if it's not really off. This is commit 48efdd2 "Add a pm_power_off function that resets us, ..." downstream. Signed-off-by: Dom Cobley <redacted> [swarren: Various non-semantic rework for upstreaming] Signed-off-by: Stephen Warren <redacted> --- This is for 3.9; just posting early! arch/arm/mach-bcm2835/bcm2835.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c
index f0d739f..c867d0e 100644
--- a/arch/arm/mach-bcm2835/bcm2835.c
+++ b/arch/arm/mach-bcm2835/bcm2835.c@@ -26,11 +26,13 @@ #include <mach/bcm2835_soc.h> #define PM_RSTC 0x1c +#define PM_RSTS 0x20 #define PM_WDOG 0x24 #define PM_PASSWORD 0x5a000000 #define PM_RSTC_WRCFG_MASK 0x00000030 #define PM_RSTC_WRCFG_FULL_RESET 0x00000020 +#define PM_RSTS_HADWRH_SET 0x00000040 static void __iomem *wdt_regs;
@@ -67,6 +69,29 @@ static void bcm2835_restart(char mode, const char *cmd) mdelay(1); } +/* + * We can't really power off, but if we do the normal reset scheme, and + * indicate to bootcode.bin not to reboot, then most of the chip will be + * powered off. + */ +static void bcm2835_power_off(void) +{ + u32 val; + + /* + * We set the watchdog hard reset bit here to distinguish this reset + * from the normal (full) reset. bootcode.bin will not reboot after a + * hard reset. + */ + val = readl_relaxed(wdt_regs + PM_RSTS); + val &= ~PM_RSTC_WRCFG_MASK; + val |= PM_PASSWORD | PM_RSTS_HADWRH_SET; + writel_relaxed(val, wdt_regs + PM_RSTS); + + /* Continue with normal reset mechanism */ + bcm2835_restart(0, ""); +} + static struct map_desc io_map __initdata = { .virtual = BCM2835_PERIPH_VIRT, .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
@@ -84,6 +109,9 @@ static void __init bcm2835_init(void) int ret; bcm2835_setup_restart(); + if (wdt_regs) + pm_power_off = bcm2835_power_off; + bcm2835_init_clocks(); ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
--
1.7.10.4