ARM: EXYNOS: Move pm_domains driver to drivers/soc/samsung

Exynos PM domains driver does not have mach-specific dependencies so it
can be safely moved out of arm/mach-exynos to drivers/soc. This in
future will allow re-using it on ARM64 boards.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>

2 files changed, 224 insertions, 0 deletions

diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
index f64ac4d80564..8aead5835def 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_EXYNOS_PMU)	+= exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
 					exynos5250-pmu.o exynos5420-pmu.o
+obj-$(CONFIG_PM_GENERIC_DOMAINS) += pm_domains.o
diff --git a/drivers/soc/samsung/pm_domains.c b/drivers/soc/samsung/pm_domains.c
new file mode 100644
index 000000000000..875a2bab64f6
--- /dev/null
+++ b/drivers/soc/samsung/pm_domains.c
@@ -0,0 +1,223 @@
+/*
+ * Exynos Generic power domain support.
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Implementation of Exynos specific power domain control which is used in
+ * conjunction with runtime-pm. Support for both device-tree and non-device-tree
+ * based power domain support is included.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/pm_domain.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/sched.h>
+
+#define INT_LOCAL_PWR_EN	0x7
+#define MAX_CLK_PER_DOMAIN	4
+
+/*
+ * Exynos specific wrapper around the generic power domain
+ */
+struct exynos_pm_domain {
+	void __iomem *base;
+	char const *name;
+	bool is_off;
+	struct generic_pm_domain pd;
+	struct clk *oscclk;
+	struct clk *clk[MAX_CLK_PER_DOMAIN];
+	struct clk *pclk[MAX_CLK_PER_DOMAIN];
+	struct clk *asb_clk[MAX_CLK_PER_DOMAIN];
+};
+
+static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
+{
+	struct exynos_pm_domain *pd;
+	void __iomem *base;
+	u32 timeout, pwr;
+	char *op;
+	int i;
+
+	pd = container_of(domain, struct exynos_pm_domain, pd);
+	base = pd->base;
+
+	for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+		if (IS_ERR(pd->asb_clk[i]))
+			break;
+		clk_prepare_enable(pd->asb_clk[i]);
+	}
+
+	/* Set oscclk before powering off a domain*/
+	if (!power_on) {
+		for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+			if (IS_ERR(pd->clk[i]))
+				break;
+			pd->pclk[i] = clk_get_parent(pd->clk[i]);
+			if (clk_set_parent(pd->clk[i], pd->oscclk))
+				pr_err("%s: error setting oscclk as parent to clock %d\n",
+						pd->name, i);
+		}
+	}
+
+	pwr = power_on ? INT_LOCAL_PWR_EN : 0;
+	__raw_writel(pwr, base);
+
+	/* Wait max 1ms */
+	timeout = 10;
+
+	while ((__raw_readl(base + 0x4) & INT_LOCAL_PWR_EN) != pwr) {
+		if (!timeout) {
+			op = (power_on) ? "enable" : "disable";
+			pr_err("Power domain %s %s failed\n", domain->name, op);
+			return -ETIMEDOUT;
+		}
+		timeout--;
+		cpu_relax();
+		usleep_range(80, 100);
+	}
+
+	/* Restore clocks after powering on a domain*/
+	if (power_on) {
+		for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+			if (IS_ERR(pd->clk[i]))
+				break;
+
+			if (IS_ERR(pd->pclk[i]))
+				continue; /* Skip on first power up */
+			if (clk_set_parent(pd->clk[i], pd->pclk[i]))
+				pr_err("%s: error setting parent to clock%d\n",
+						pd->name, i);
+		}
+	}
+
+	for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+		if (IS_ERR(pd->asb_clk[i]))
+			break;
+		clk_disable_unprepare(pd->asb_clk[i]);
+	}
+
+	return 0;
+}
+
+static int exynos_pd_power_on(struct generic_pm_domain *domain)
+{
+	return exynos_pd_power(domain, true);
+}
+
+static int exynos_pd_power_off(struct generic_pm_domain *domain)
+{
+	return exynos_pd_power(domain, false);
+}
+
+static __init int exynos4_pm_init_power_domain(void)
+{
+	struct device_node *np;
+
+	for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
+		struct exynos_pm_domain *pd;
+		int on, i;
+
+		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+		if (!pd) {
+			pr_err("%s: failed to allocate memory for domain\n",
+					__func__);
+			of_node_put(np);
+			return -ENOMEM;
+		}
+		pd->pd.name = kstrdup_const(strrchr(np->full_name, '/') + 1,
+					    GFP_KERNEL);
+		if (!pd->pd.name) {
+			kfree(pd);
+			of_node_put(np);
+			return -ENOMEM;
+		}
+
+		pd->name = pd->pd.name;
+		pd->base = of_iomap(np, 0);
+		if (!pd->base) {
+			pr_warn("%s: failed to map memory\n", __func__);
+			kfree_const(pd->pd.name);
+			kfree(pd);
+			continue;
+		}
+
+		pd->pd.power_off = exynos_pd_power_off;
+		pd->pd.power_on = exynos_pd_power_on;
+
+		for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+			char clk_name[8];
+
+			snprintf(clk_name, sizeof(clk_name), "asb%d", i);
+			pd->asb_clk[i] = of_clk_get_by_name(np, clk_name);
+			if (IS_ERR(pd->asb_clk[i]))
+				break;
+		}
+
+		pd->oscclk = of_clk_get_by_name(np, "oscclk");
+		if (IS_ERR(pd->oscclk))
+			goto no_clk;
+
+		for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
+			char clk_name[8];
+
+			snprintf(clk_name, sizeof(clk_name), "clk%d", i);
+			pd->clk[i] = of_clk_get_by_name(np, clk_name);
+			if (IS_ERR(pd->clk[i]))
+				break;
+			/*
+			 * Skip setting parent on first power up.
+			 * The parent at this time may not be useful at all.
+			 */
+			pd->pclk[i] = ERR_PTR(-EINVAL);
+		}
+
+		if (IS_ERR(pd->clk[0]))
+			clk_put(pd->oscclk);
+
+no_clk:
+		on = __raw_readl(pd->base + 0x4) & INT_LOCAL_PWR_EN;
+
+		pm_genpd_init(&pd->pd, NULL, !on);
+		of_genpd_add_provider_simple(np, &pd->pd);
+	}
+
+	/* Assign the child power domains to their parents */
+	for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
+		struct generic_pm_domain *child_domain, *parent_domain;
+		struct of_phandle_args args;
+
+		args.np = np;
+		args.args_count = 0;
+		child_domain = of_genpd_get_from_provider(&args);
+		if (IS_ERR(child_domain))
+			continue;
+
+		if (of_parse_phandle_with_args(np, "power-domains",
+					 "#power-domain-cells", 0, &args) != 0)
+			continue;
+
+		parent_domain = of_genpd_get_from_provider(&args);
+		if (IS_ERR(parent_domain))
+			continue;
+
+		if (pm_genpd_add_subdomain(parent_domain, child_domain))
+			pr_warn("%s failed to add subdomain: %s\n",
+				parent_domain->name, child_domain->name);
+		else
+			pr_info("%s has as child subdomain: %s.\n",
+				parent_domain->name, child_domain->name);
+	}
+
+	return 0;
+}
+core_initcall(exynos4_pm_init_power_domain);