From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
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
<hisashi.nakamura.ak@xxxxxxxxxxx>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Hiep Cao Minh <cm-hiep@xxxxxxxxxxx>
Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
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),
--
2.7.0.rc3.207.g0ac5344
