Commit a14f9b82 authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Peter Maydell

hw/misc/exynos4210_pmu: Add support for system poweroff

On all Exynos-based boards, the system powers down itself by driving
PS_HOLD signal low - eight bit in PS_HOLD_CONTROL register of PMU.
Handle writing to respective PMU register to fix power off failure:

    reboot: Power down
    Unable to poweroff system
    shutdown: 31 output lines suppressed due to ratelimiting
    Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000

    CPU: 0 PID: 1 Comm: shutdown Not tainted 4.11.0-rc8 #846
    Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
    [<c031050c>] (unwind_backtrace) from [<c030ba6c>] (show_stack+0x10/0x14)
    [<c030ba6c>] (show_stack) from [<c05b2800>] (dump_stack+0x88/0x9c)
    [<c05b2800>] (dump_stack) from [<c03d3140>] (panic+0xdc/0x268)
    [<c03d3140>] (panic) from [<c0343614>] (do_exit+0xa90/0xab4)
    [<c0343614>] (do_exit) from [<c035f2dc>] (SyS_reboot+0x164/0x1d0)
    [<c035f2dc>] (SyS_reboot) from [<c0307c80>] (ret_fast_syscall+0x0/0x3c)

Additionally the initial value of PS_HOLD has to be changed because
recent Linux kernel (v4.12-rc1) uses regmap cache for this access.
When the register is kept at reset value, the kernel will not issue a
write to it.  Usually the bootloader sets the eight bit of PS_HOLD high
so mimic its existence here.
Signed-off-by: 's avatarKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: 's avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: 's avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: 's avatarPeter Maydell <peter.maydell@linaro.org>
parent 5f7f22ff
......@@ -26,6 +26,7 @@
#include "qemu/osdep.h"
#include "hw/sysbus.h"
#include "sysemu/sysemu.h"
#ifndef DEBUG_PMU
#define DEBUG_PMU 0
......@@ -350,7 +351,11 @@ static const Exynos4210PmuReg exynos4210_pmu_regs[] = {
{"PAD_RETENTION_MMCB_OPTION", PAD_RETENTION_MMCB_OPTION, 0x00000000},
{"PAD_RETENTION_EBIA_OPTION", PAD_RETENTION_EBIA_OPTION, 0x00000000},
{"PAD_RETENTION_EBIB_OPTION", PAD_RETENTION_EBIB_OPTION, 0x00000000},
{"PS_HOLD_CONTROL", PS_HOLD_CONTROL, 0x00005200},
/*
* PS_HOLD_CONTROL: reset value and manually toggle high the DATA bit.
* DATA bit high, set usually by bootloader, keeps system on.
*/
{"PS_HOLD_CONTROL", PS_HOLD_CONTROL, 0x00005200 | BIT(8)},
{"XUSBXTI_CONFIGURATION", XUSBXTI_CONFIGURATION, 0x00000001},
{"XUSBXTI_STATUS", XUSBXTI_STATUS, 0x00000001},
{"XUSBXTI_DURATION", XUSBXTI_DURATION, 0xFFF00000},
......@@ -397,6 +402,12 @@ typedef struct Exynos4210PmuState {
uint32_t reg[PMU_NUM_OF_REGISTERS];
} Exynos4210PmuState;
static void exynos4210_pmu_poweroff(void)
{
PRINT_DEBUG("QEMU PMU: PS_HOLD bit down, powering off\n");
qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
}
static uint64_t exynos4210_pmu_read(void *opaque, hwaddr offset,
unsigned size)
{
......@@ -428,6 +439,13 @@ static void exynos4210_pmu_write(void *opaque, hwaddr offset,
PRINT_DEBUG_EXTEND("%s <0x%04x> <- 0x%04x\n", reg_p->name,
(uint32_t)offset, (uint32_t)val);
s->reg[i] = val;
if ((offset == PS_HOLD_CONTROL) && ((val & BIT(8)) == 0)) {
/*
* We are interested only in setting data bit
* of PS_HOLD_CONTROL register to indicate power off request.
*/
exynos4210_pmu_poweroff();
}
return;
}
reg_p++;
......
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