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>
This commit is contained in:
Dom Cobley 2012-10-27 21:14:50 -06:00 committed by Stephen Warren
parent 526d239c30
commit 45e9d77a22

View File

@ -26,11 +26,13 @@
#include <mach/bcm2835_soc.h> #include <mach/bcm2835_soc.h>
#define PM_RSTC 0x1c #define PM_RSTC 0x1c
#define PM_RSTS 0x20
#define PM_WDOG 0x24 #define PM_WDOG 0x24
#define PM_PASSWORD 0x5a000000 #define PM_PASSWORD 0x5a000000
#define PM_RSTC_WRCFG_MASK 0x00000030 #define PM_RSTC_WRCFG_MASK 0x00000030
#define PM_RSTC_WRCFG_FULL_RESET 0x00000020 #define PM_RSTC_WRCFG_FULL_RESET 0x00000020
#define PM_RSTS_HADWRH_SET 0x00000040
static void __iomem *wdt_regs; static void __iomem *wdt_regs;
@ -67,6 +69,29 @@ static void bcm2835_restart(char mode, const char *cmd)
mdelay(1); 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 = { static struct map_desc io_map __initdata = {
.virtual = BCM2835_PERIPH_VIRT, .virtual = BCM2835_PERIPH_VIRT,
.pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS), .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
@ -84,6 +109,9 @@ static void __init bcm2835_init(void)
int ret; int ret;
bcm2835_setup_restart(); bcm2835_setup_restart();
if (wdt_regs)
pm_power_off = bcm2835_power_off;
bcm2835_init_clocks(); bcm2835_init_clocks();
ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,