ARM: rockchip: convert to regmap and use pmu syscon if available

The pmu register space is - like the GRF - shared by quite some peripherals.
On the rk3188 and rk3288 even parts of the pinctrl are living there.
Therefore we normally shouldn't map it a second time when the syscon
does this already.

Therefore convert the cpu power-domain handling to access the pmu via a
regmap and at first try to get it via the syscon interface.
Getting this syscon will only fail if the pmu node does not have the
"syscon" compatible and thus does not get shared with other drivers.

In this case we map it like before and create the necessary regmap on
top of it.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/mach-rockchip/platsmp.c

@@ -19,6 +19,8 @@
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
 
 #include <asm/cacheflush.h>
 #include <asm/cp15.h>
@@ -37,23 +39,42 @@ static int ncores;
 
 #define PMU_PWRDN_SCU		4
 
-static void __iomem *pmu_base_addr;
+static struct regmap *pmu;
 
-static inline bool pmu_power_domain_is_on(int pd)
+static int pmu_power_domain_is_on(int pd)
 {
-	return !(readl_relaxed(pmu_base_addr + PMU_PWRDN_ST) & BIT(pd));
+	u32 val;
+	int ret;
+
+	ret = regmap_read(pmu, PMU_PWRDN_ST, &val);
+	if (ret < 0)
+		return ret;
+
+	return !(val & BIT(pd));
 }
 
-static void pmu_set_power_domain(int pd, bool on)
+static int pmu_set_power_domain(int pd, bool on)
 {
-	u32 val = readl_relaxed(pmu_base_addr + PMU_PWRDN_CON);
-	if (on)
-		val &= ~BIT(pd);
-	else
-		val |=  BIT(pd);
-	writel(val, pmu_base_addr + PMU_PWRDN_CON);
+	u32 val = (on) ? 0 : BIT(pd);
+	int ret;
 
-	while (pmu_power_domain_is_on(pd) != on) { }
+	ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
+	if (ret < 0) {
+		pr_err("%s: could not update power domain\n", __func__);
+		return ret;
+	}
+
+	ret = -1;
+	while (ret != on) {
+		ret = pmu_power_domain_is_on(pd);
+		if (ret < 0) {
+			pr_err("%s: could not read power domain state\n",
+				 __func__);
+			return ret;
+		}
+	}
+
+	return 0;
 }
 
 /*
@@ -63,7 +84,7 @@ static void pmu_set_power_domain(int pd, bool on)
 static int __cpuinit rockchip_boot_secondary(unsigned int cpu,
 					     struct task_struct *idle)
 {
-	if (!sram_base_addr || !pmu_base_addr) {
+	if (!sram_base_addr || !pmu) {
 		pr_err("%s: sram or pmu missing for cpu boot\n", __func__);
 		return -ENXIO;
 	}
@@ -75,9 +96,7 @@ static int __cpuinit rockchip_boot_secondary(unsigned int cpu,
 	}
 
 	/* start the core */
-	pmu_set_power_domain(0 + cpu, true);
-
-	return 0;
+	return pmu_set_power_domain(0 + cpu, true);
 }
 
 /**
@@ -125,6 +144,48 @@ static int __init rockchip_smp_prepare_sram(struct device_node *node)
 	return 0;
 }
 
+static struct regmap_config rockchip_pmu_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static int __init rockchip_smp_prepare_pmu(void)
+{
+	struct device_node *node;
+	void __iomem *pmu_base;
+
+	pmu = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu");
+	if (!IS_ERR(pmu))
+		return 0;
+
+	/* fallback, create our own regmap for the pmu area */
+	pmu = NULL;
+	node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
+	if (!node) {
+		pr_err("%s: could not find pmu dt node\n", __func__);
+		return -ENODEV;
+	}
+
+	pmu_base = of_iomap(node, 0);
+	if (!pmu_base) {
+		pr_err("%s: could not map pmu registers\n", __func__);
+		return -ENOMEM;
+	}
+
+	pmu = regmap_init_mmio(NULL, pmu_base, &rockchip_pmu_regmap_config);
+	if (IS_ERR(pmu)) {
+		int ret = PTR_ERR(pmu);
+
+		iounmap(pmu_base);
+		pmu = NULL;
+		pr_err("%s: regmap init failed\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
 static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
 {
 	struct device_node *node;
@@ -151,17 +212,8 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
 	if (rockchip_smp_prepare_sram(node))
 		return;
 
-	node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
-	if (!node) {
-		pr_err("%s: could not find pmu dt node\n", __func__);
+	if (rockchip_smp_prepare_pmu())
 		return;
-	}
-
-	pmu_base_addr = of_iomap(node, 0);
-	if (!pmu_base_addr) {
-		pr_err("%s: could not map pmu registers\n", __func__);
-		return;
-	}
 
 	/* enable the SCU power domain */
 	pmu_set_power_domain(PMU_PWRDN_SCU, true);