[RFC PATCH 3/4] sunxi: psci: refactor register access to separate functions

[Sam Edwards]

This is to prepare for R528, which does not have the typical
"CPUCFG" block; it has a "CPUX" block which provides these
same functions but is organized differently.

Moving the hardware-access bits to their own functions separates the
logic from the hardware so we can reuse the same logic.

Signed-off-by: Sam Edwards <CFSworks at gmail.com>
---
 arch/arm/cpu/armv7/sunxi/psci.c | 66 +++++++++++++++++++++++----------
 1 file changed, 47 insertions(+), 19 deletions(-)

diff --git a/arch/arm/cpu/armv7/sunxi/psci.c b/arch/arm/cpu/armv7/sunxi/psci.c
index e6b73ebf2b..d9a9d73881 100644
--- a/arch/arm/cpu/armv7/sunxi/psci.c
+++ b/arch/arm/cpu/armv7/sunxi/psci.c
@@ -114,7 +114,7 @@ static void __secure sunxi_power_switch(u32 *clamp, u32 *pwroff, bool on,
 	}
 }
 
-static void __secure sunxi_set_entry_address(void *entry)
+static void __secure sunxi_cpu_set_entry(int __always_unused cpu, void *entry)
 {
 	/* secondary core entry address is programmed differently on R40 */
 	if (IS_ENABLED(CONFIG_MACH_SUN8I_R40)) {
@@ -154,30 +154,60 @@ static void __secure sunxi_cpu_set_power(int cpu, bool on)
 	}
 }
 
-void __secure sunxi_cpu_power_off(u32 cpuid)
+static void __secure sunxi_cpu_set_reset(int cpu, bool reset)
+{
+	struct sunxi_cpucfg_reg *cpucfg =
+		(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
+
+	writel(reset ? 0b00 : 0b11, &cpucfg->cpu[cpu].rst);
+}
+
+static void __secure sunxi_cpu_set_locking(int cpu, bool lock)
 {
 	struct sunxi_cpucfg_reg *cpucfg =
 		(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
+
+	if (lock)
+		clrbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+	else
+		setbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+}
+
+static bool __secure sunxi_cpu_poll_wfi(int cpu)
+{
+	struct sunxi_cpucfg_reg *cpucfg =
+		(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
+
+	return !!(readl(&cpucfg->cpu[cpu].status) & BIT(2));
+}
+
+static void __secure sunxi_cpu_invalidate_cache(int cpu)
+{
+	struct sunxi_cpucfg_reg *cpucfg =
+		(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
+
+	clrbits_le32(&cpucfg->gen_ctrl, BIT(cpu));
+}
+
+void __secure sunxi_cpu_power_off(u32 cpuid)
+{
 	u32 cpu = cpuid & 0x3;
 
 	/* Wait for the core to enter WFI */
-	while (1) {
-		if (readl(&cpucfg->cpu[cpu].status) & BIT(2))
-			break;
+	while (!sunxi_cpu_poll_wfi(cpu))
 		__mdelay(1);
-	}
 
 	/* Assert reset on target CPU */
-	writel(0, &cpucfg->cpu[cpu].rst);
+	sunxi_cpu_set_reset(cpu, true);
 
 	/* Lock CPU (Disable external debug access) */
-	clrbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+	sunxi_cpu_set_locking(cpu, true);
 
 	/* Power down CPU */
 	sunxi_cpu_set_power(cpuid, false);
 
-	/* Unlock CPU (Disable external debug access) */
-	setbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+	/* Unlock CPU (Reenable external debug access) */
+	sunxi_cpu_set_locking(cpu, false);
 }
 
 static u32 __secure cp15_read_scr(void)
@@ -234,33 +264,31 @@ out:
 int __secure psci_cpu_on(u32 __always_unused unused, u32 mpidr, u32 pc,
 			 u32 context_id)
 {
-	struct sunxi_cpucfg_reg *cpucfg =
-		(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
 	u32 cpu = (mpidr & 0x3);
 
 	/* store target PC and context id */
 	psci_save(cpu, pc, context_id);
 
 	/* Set secondary core power on PC */
-	sunxi_set_entry_address(&psci_cpu_entry);
+	sunxi_cpu_set_entry(cpu, &psci_cpu_entry);
 
 	/* Assert reset on target CPU */
-	writel(0, &cpucfg->cpu[cpu].rst);
+	sunxi_cpu_set_reset(cpu, true);
 
 	/* Invalidate L1 cache */
-	clrbits_le32(&cpucfg->gen_ctrl, BIT(cpu));
+	sunxi_cpu_invalidate_cache(cpu);
 
 	/* Lock CPU (Disable external debug access) */
-	clrbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+	sunxi_cpu_set_locking(cpu, true);
 
 	/* Power up target CPU */
 	sunxi_cpu_set_power(cpu, true);
 
 	/* De-assert reset on target CPU */
-	writel(BIT(1) | BIT(0), &cpucfg->cpu[cpu].rst);
+	sunxi_cpu_set_reset(cpu, false);
 
-	/* Unlock CPU (Disable external debug access) */
-	setbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
+	/* Unlock CPU (Reenable external debug access) */
+	sunxi_cpu_set_locking(cpu, false);
 
 	return ARM_PSCI_RET_SUCCESS;
 }
-- 
2.39.2