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authorDom Cobley <popcornmix@gmail.com>2012-10-27 21:14:50 -0600
committerStephen Warren <swarren@wwwdotorg.org>2013-01-14 21:47:00 -0700
commit45e9d77a22b7b25373c7b8c0ea0b146168025360 (patch)
tree6874fbf713642b6f7979ff5edf7e9aad95d510ae /arch/arm/mach-bcm2835
parent526d239c301e6cb7fe6657642c43d6c524590745 (diff)
ARM: bcm2835: add a pm_power_off implementation
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 <popcornmix@gmail.com> [swarren: Various non-semantic rework for upstreaming] Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Diffstat (limited to 'arch/arm/mach-bcm2835')
-rw-r--r--arch/arm/mach-bcm2835/bcm2835.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c
index f0d739f4b7a3..c867d0e8cf7c 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,