From 10f778a97845e8b10af8878af99c9cfe6c31baf9 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 5 Dec 2016 11:39:38 +0100 Subject: [PATCH] ARM: shmobile: apmu: Add debug resource reset for secondary CPU boot In debug mode (MD21=1), reset requests derived from power-shutoff to the AP-system CPU cores must be enabled before the AP-system CPU cores resume from power-shutoff for the first time. Else resume may fail, causing the system to hang during boot. As setting these bits is a no-op in normal mode, there's no need to check the actual state of MD21 first. Inspired by CPU-specific patches in the BSP by Hisashi Nakamura . Signed-off-by: Geert Uytterhoeven Tested-by: Hiep Cao Minh Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/platsmp-apmu.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c b/arch/arm/mach-shmobile/platsmp-apmu.c index 933f9b902405..7e4ca6788be5 100644 --- a/arch/arm/mach-shmobile/platsmp-apmu.c +++ b/arch/arm/mach-shmobile/platsmp-apmu.c @@ -35,12 +35,18 @@ static struct { #define PSTR_OFFS 0x40 /* Power Status Register */ #define CPUNCR_OFFS(n) (0x100 + (0x10 * (n))) /* CPUn Power Status Control Register */ +#define DBGRCR_OFFS 0x180 /* Debug Resource Reset Control Reg. */ /* Power Status Register */ #define CPUNST(r, n) (((r) >> (n * 4)) & 3) /* CPUn Status Bit */ #define CPUST_RUN 0 /* Run Mode */ #define CPUST_STANDBY 3 /* CoreStandby Mode */ +/* Debug Resource Reset Control Register */ +#define DBGCPUREN BIT(24) /* CPU Other Reset Request Enable */ +#define DBGCPUNREN(n) BIT((n) + 20) /* CPUn Reset Request Enable */ +#define DBGCPUPREN BIT(19) /* CPU Peripheral Reset Req. Enable */ + static int __maybe_unused apmu_power_on(void __iomem *p, int bit) { /* request power on */ @@ -84,6 +90,8 @@ static int __maybe_unused apmu_wrap(int cpu, int (*fn)(void __iomem *p, int cpu) #ifdef CONFIG_SMP static void apmu_init_cpu(struct resource *res, int cpu, int bit) { + u32 x; + if ((cpu >= ARRAY_SIZE(apmu_cpus)) || apmu_cpus[cpu].iomem) return; @@ -91,6 +99,11 @@ static void apmu_init_cpu(struct resource *res, int cpu, int bit) apmu_cpus[cpu].bit = bit; pr_debug("apmu ioremap %d %d %pr\n", cpu, bit, res); + + /* Setup for debug mode */ + x = readl(apmu_cpus[cpu].iomem + DBGRCR_OFFS); + x |= DBGCPUREN | DBGCPUNREN(bit) | DBGCPUPREN; + writel(x, apmu_cpus[cpu].iomem + DBGRCR_OFFS); } static void apmu_parse_cfg(void (*fn)(struct resource *res, int cpu, int bit),