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Commit 10f778a9 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Simon Horman
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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
<hisashi.nakamura.ak@renesas.com>.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: default avatarHiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
parent 460d4117

arch/arm/mach-shmobile/platsmp-apmu.c

+13 −0
Original line number Diff line number Diff line
@@ -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),