[PATCH v14 2/3] power-domain: rockchip: add power domain driver

[Caesar Wang <wxt@rock-chips.com>]

In order to meet high performance and low power requirements, a power
management unit is designed or saving power when RK3288 in low power
mode.
The RK3288 PMU is dedicated for managing the power ot the whole chip.

Signed-off-by: jinkun.hong <jinkun.hong@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
---

 arch/arm/mach-rockchip/Kconfig      |   1 +
 arch/arm/mach-rockchip/Makefile     |   1 +
 arch/arm/mach-rockchip/pm_domains.c | 506 ++++++++++++++++++++++++++++++++++++
 3 files changed, 508 insertions(+)
 create mode 100644 arch/arm/mach-rockchip/pm_domains.c

diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index ae4eb7c..578206b 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -15,6 +15,7 @@ config ARCH_ROCKCHIP
 	select ROCKCHIP_TIMER
 	select ARM_GLOBAL_TIMER
 	select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
+	select PM_GENERIC_DOMAINS if PM
 	help
 	  Support for Rockchip's Cortex-A9 Single-to-Quad-Core-SoCs
 	  containing the RK2928, RK30xx and RK31xx series.
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 5c3a9b2..9c902d3 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -1,5 +1,6 @@
 CFLAGS_platsmp.o := -march=armv7-a
 
 obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip.o
+obj-$(CONFIG_PM_GENERIC_DOMAINS) += pm_domains.o
 obj-$(CONFIG_PM_SLEEP) += pm.o sleep.o
 obj-$(CONFIG_SMP) += headsmp.o platsmp.o
diff --git a/arch/arm/mach-rockchip/pm_domains.c b/arch/arm/mach-rockchip/pm_domains.c
new file mode 100644
index 0000000..92d2569
--- /dev/null
+++ b/arch/arm/mach-rockchip/pm_domains.c
@@ -0,0 +1,506 @@
+/*
+ * Rockchip Generic power domain support.
+ *
+ * Copyright (c) 2014 ROCKCHIP, Co. Ltd.
+ *
+ * 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/pm_clock.h>
+#include <linux/pm_domain.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <dt-bindings/power-domain/rk3288.h>
+
+struct rockchip_domain_info {
+	int pwr_mask;
+	int status_mask;
+	int req_mask;
+	int idle_mask;
+	int ack_mask;
+};
+
+struct rockchip_pmu_info {
+	u32 pwr_offset;
+	u32 status_offset;
+	u32 req_offset;
+	u32 idle_offset;
+	u32 ack_offset;
+
+	u32 core_pwrcnt_offset;
+	u32 gpu_pwrcnt_offset;
+
+	unsigned int core_power_transition_time;
+	unsigned int gpu_power_transition_time;
+
+	int num_domains;
+	const struct rockchip_domain_info *domain_info;
+};
+
+struct rockchip_pm_domain {
+	struct generic_pm_domain genpd;
+	const struct rockchip_domain_info *info;
+	struct rockchip_pmu *pmu;
+	int num_clks;
+	struct clk *clks[];
+};
+
+struct rockchip_pmu {
+	struct device *dev;
+	struct regmap *regmap;
+	const struct rockchip_pmu_info *info;
+	struct mutex mutex; /* mutex lock for pmu */
+	struct genpd_onecell_data genpd_data;
+	struct generic_pm_domain *domains[];
+};
+
+#define to_rockchip_pd(gpd) container_of(gpd, struct rockchip_pm_domain, genpd)
+
+#define DOMAIN(pwr, status, req, idle, ack)	\
+{						\
+	.pwr_mask = BIT(pwr),			\
+	.status_mask = BIT(status),		\
+	.req_mask = BIT(req),			\
+	.idle_mask = BIT(idle),			\
+	.ack_mask = BIT(ack),			\
+}
+
+#define DOMAIN_RK3288(pwr, status, req)		\
+	DOMAIN(pwr, status, req, req, (req) + 16)
+
+static bool rockchip_pmu_domain_is_idle(struct rockchip_pm_domain *pd)
+{
+	struct rockchip_pmu *pmu = pd->pmu;
+	const struct rockchip_domain_info *pd_info = pd->info;
+	unsigned int val;
+
+	regmap_read(pmu->regmap, pmu->info->idle_offset, &val);
+	return (val & pd_info->idle_mask) == pd_info->idle_mask;
+}
+
+static int rockchip_pmu_set_idle_request(struct rockchip_pm_domain *pd,
+					 bool idle)
+{
+	const struct rockchip_domain_info *pd_info = pd->info;
+	struct rockchip_pmu *pmu = pd->pmu;
+	unsigned int val;
+
+	regmap_update_bits(pmu->regmap, pmu->info->req_offset,
+			   pd_info->req_mask, idle ? -1U : 0);
+
+	dsb();
+
+	do {
+		regmap_read(pmu->regmap, pmu->info->ack_offset, &val);
+	} while ((val & pd_info->ack_mask) != (idle ? pd_info->ack_mask : 0));
+
+	while (rockchip_pmu_domain_is_idle(pd) != idle)
+		cpu_relax();
+
+	return 0;
+}
+
+static bool rockchip_pmu_domain_is_on(struct rockchip_pm_domain *pd)
+{
+	struct rockchip_pmu *pmu = pd->pmu;
+	unsigned int val;
+
+	regmap_read(pmu->regmap, pmu->info->status_offset, &val);
+
+	/* 1'b0: power on, 1'b1: power off */
+	return !(val & pd->info->status_mask);
+}
+
+static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
+					     bool on)
+{
+	struct rockchip_pmu *pmu = pd->pmu;
+
+	regmap_update_bits(pmu->regmap, pmu->info->pwr_offset,
+			   pd->info->pwr_mask, on ? 0 : -1U);
+
+	dsb();
+
+	while (rockchip_pmu_domain_is_on(pd) != on)
+		cpu_relax();
+}
+
+static int rockchip_pd_power(struct rockchip_pm_domain *pd, bool power_on)
+{
+	int i;
+
+	mutex_lock(&pd->pmu->mutex);
+
+	if (rockchip_pmu_domain_is_on(pd) != power_on) {
+		for (i = 0; i < pd->num_clks; i++)
+			clk_enable(pd->clks[i]);
+
+		if (!power_on) {
+			/* FIXME: add code to save AXI_QOS */
+
+			/* if powering down, idle request to NIU first */
+			rockchip_pmu_set_idle_request(pd, true);
+		}
+
+		rockchip_do_pmu_set_power_domain(pd, power_on);
+
+		if (power_on) {
+			/* if powering up, leave idle mode */
+			rockchip_pmu_set_idle_request(pd, false);
+
+			/* FIXME: add code to restore AXI_QOS */
+		}
+
+		for (i = pd->num_clks - 1; i >= 0; i--)
+			clk_disable(pd->clks[i]);
+	}
+
+	mutex_unlock(&pd->pmu->mutex);
+	return 0;
+}
+
+static int rockchip_pd_power_on(struct generic_pm_domain *domain)
+{
+	struct rockchip_pm_domain *pd = to_rockchip_pd(domain);
+
+	return rockchip_pd_power(pd, true);
+}
+
+static int rockchip_pd_power_off(struct generic_pm_domain *domain)
+{
+	struct rockchip_pm_domain *pd = to_rockchip_pd(domain);
+
+	return rockchip_pd_power(pd, false);
+}
+
+static int rockchip_pd_attach_dev(struct generic_pm_domain *genpd,
+				  struct device *dev)
+{
+	struct clk *clk;
+	int i;
+	int error;
+
+	dev_dbg(dev, "attaching to power domain '%s'\n", genpd->name);
+
+	error = pm_clk_create(dev);
+	if (error) {
+		dev_err(dev, "pm_clk_create failed %d\n", error);
+		return error;
+	}
+
+	i = 0;
+	while ((clk = of_clk_get(dev->of_node, i++)) && !IS_ERR(clk)) {
+		dev_dbg(dev, "adding clock '%s' to list of PM clocks\n",
+			__clk_get_name(clk));
+		error = pm_clk_add_clk(dev, clk);
+		clk_put(clk);
+		if (error) {
+			dev_err(dev, "pm_clk_add_clk failed %d\n", error);
+			pm_clk_destroy(dev);
+			return error;
+		}
+	}
+
+	return 0;
+}
+
+static void rockchip_pd_detach_dev(struct generic_pm_domain *genpd,
+				   struct device *dev)
+{
+	dev_dbg(dev, "detaching from power domain '%s'\n", genpd->name);
+
+	pm_clk_destroy(dev);
+}
+
+static int rockchip_pd_start_dev(struct device *dev)
+{
+	struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain);
+
+	dev_dbg(dev, "starting device in power domain '%s'\n", genpd->name);
+
+	return pm_clk_resume(dev);
+}
+
+static int rockchip_pd_stop_dev(struct device *dev)
+{
+	struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain);
+
+	dev_dbg(dev, "stopping device in power domain '%s'\n", genpd->name);
+
+	return pm_clk_suspend(dev);
+}
+
+static int rockchip_pm_add_one_domain(struct rockchip_pmu *pmu,
+				      struct device_node *node)
+{
+	const struct rockchip_domain_info *pd_info;
+	struct rockchip_pm_domain *pd;
+	struct clk *clk;
+	int clk_cnt;
+	int i;
+	u32 id;
+	int error;
+
+	error = of_property_read_u32(node, "reg", &id);
+	if (error) {
+		dev_err(pmu->dev,
+			"%s: failed to retrieve domain id (reg): %d\n",
+			node->name, error);
+		return -EINVAL;
+	}
+
+	if (id >= pmu->info->num_domains) {
+		dev_err(pmu->dev, "%s: invalid domain id %d\n",
+			node->name, id);
+		return -EINVAL;
+	}
+
+	pd_info = &pmu->info->domain_info[id];
+	if (!pd_info) {
+		dev_err(pmu->dev, "%s: undefined domain id %d\n",
+			node->name, id);
+		return -EINVAL;
+	}
+
+	clk_cnt = of_count_phandle_with_args(node, "clocks", "#clock-cells");
+	pd = devm_kzalloc(pmu->dev,
+			  sizeof(*pd) + clk_cnt * sizeof(pd->clks[0]),
+			  GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pd->info = pd_info;
+	pd->pmu = pmu;
+
+	for (i = 0; i < clk_cnt; i++) {
+		clk = of_clk_get(node, i);
+		if (IS_ERR(clk)) {
+			error = PTR_ERR(clk);
+			dev_err(pmu->dev,
+				"%s: failed to get clk %s (index %d): %d\n",
+				node->name, __clk_get_name(clk), i, error);
+			goto err_out;
+		}
+
+		error = clk_prepare(clk);
+		if (error) {
+			dev_err(pmu->dev,
+				"%s: failed to prepare clk %s (index %d): %d\n",
+				node->name, __clk_get_name(clk), i, error);
+			clk_put(clk);
+			goto err_out;
+		}
+
+		pd->clks[pd->num_clks++] = clk;
+
+		dev_dbg(pmu->dev, "added clock '%s' to domain '%s'\n",
+			__clk_get_name(clk), node->name);
+	}
+
+	error = rockchip_pd_power(pd, true);
+	if (error) {
+		dev_err(pmu->dev,
+			"failed to power on domain '%s': %d\n",
+			node->name, error);
+		goto err_out;
+	}
+
+	pd->genpd.name = node->name;
+	pd->genpd.power_off = rockchip_pd_power_off;
+	pd->genpd.power_on = rockchip_pd_power_on;
+	pd->genpd.attach_dev = rockchip_pd_attach_dev;
+	pd->genpd.detach_dev = rockchip_pd_detach_dev;
+	pd->genpd.dev_ops.start = rockchip_pd_start_dev;
+	pd->genpd.dev_ops.stop = rockchip_pd_stop_dev;
+	pm_genpd_init(&pd->genpd, NULL, false);
+
+	pmu->genpd_data.domains[id] = &pd->genpd;
+	return 0;
+
+err_out:
+	while (--i >= 0) {
+		clk_unprepare(pd->clks[i]);
+		clk_put(pd->clks[i]);
+	}
+	return error;
+}
+
+static void rockchip_pm_remove_one_domain(struct rockchip_pm_domain *pd)
+{
+	int i;
+
+	for (i = 0; i < pd->num_clks; i++) {
+		clk_unprepare(pd->clks[i]);
+		clk_put(pd->clks[i]);
+	}
+
+	/* devm will free our memory */
+}
+
+static void rockchip_pm_domain_cleanup(struct rockchip_pmu *pmu)
+{
+	struct generic_pm_domain *genpd;
+	struct rockchip_pm_domain *pd;
+	int i;
+
+	for (i = 0; i < pmu->genpd_data.num_domains; i++) {
+		genpd = pmu->genpd_data.domains[i];
+		if (genpd) {
+			pd = to_rockchip_pd(genpd);
+			rockchip_pm_remove_one_domain(pd);
+		}
+	}
+
+	/* devm will free our memory */
+}
+
+static void rockchip_configure_pd_cnt(struct rockchip_pmu *pmu,
+				      u32 domain_reg_offset,
+				      unsigned int count)
+{
+	/* First configure domain power down transition count ... */
+	regmap_write(pmu->regmap, domain_reg_offset, count);
+	/* ... and then power up count. */
+	regmap_write(pmu->regmap, domain_reg_offset + 4, count);
+}
+
+static int rockchip_pm_domain_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *node;
+	struct rockchip_pmu *pmu;
+	const struct of_device_id *match;
+	const struct rockchip_pmu_info *pmu_info;
+	int error;
+
+	if (!np) {
+		dev_err(dev, "device tree node not found\n");
+		return -ENXIO;
+	}
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match || !match->data) {
+		dev_err(dev, "missing pmu data\n");
+		return -EINVAL;
+	}
+
+	pmu_info = match->data;
+
+	pmu = devm_kzalloc(dev,
+			   sizeof(*pmu) +
+				pmu_info->num_domains * sizeof(pmu->domains[0]),
+			   GFP_KERNEL);
+	if (!pmu)
+		return -ENOMEM;
+
+	pmu->dev = &pdev->dev;
+	mutex_init(&pmu->mutex);
+
+	pmu->info = pmu_info;
+
+	pmu->genpd_data.domains = pmu->domains;
+	pmu->genpd_data.num_domains = pmu_info->num_domains;
+
+	node = of_parse_phandle(np, "rockchip,pmu", 0);
+	pmu->regmap = syscon_node_to_regmap(node);
+	of_node_put(node);
+	if (IS_ERR(pmu->regmap)) {
+		error = PTR_ERR(pmu->regmap);
+		dev_err(dev, "failed to get PMU regmap: %d\n", error);
+		return error;
+	}
+
+	/*
+	 * Configure power up and down transition delays for core
+	 * and GPU domains.
+	 */
+	rockchip_configure_pd_cnt(pmu, pmu_info->core_pwrcnt_offset,
+				  pmu_info->core_power_transition_time);
+	rockchip_configure_pd_cnt(pmu, pmu_info->gpu_pwrcnt_offset,
+				  pmu_info->gpu_power_transition_time);
+
+	error = -ENXIO;
+
+	for_each_available_child_of_node(np, node) {
+		error = rockchip_pm_add_one_domain(pmu, node);
+		if (error) {
+			dev_err(dev, "failed to handle node %s: %d\n",
+				node->name, error);
+			goto err_out;
+		}
+	}
+
+	if (error) {
+		dev_dbg(dev, "no power domains defined\n");
+		goto err_out;
+	}
+
+	of_genpd_add_provider_onecell(np, &pmu->genpd_data);
+
+	return 0;
+
+err_out:
+	rockchip_pm_domain_cleanup(pmu);
+	return error;
+}
+
+static const struct rockchip_domain_info rk3288_pm_domains[] = {
+	[RK3288_PD_GPU]		= DOMAIN_RK3288(9, 9, 2),
+	[RK3288_PD_VIO]		= DOMAIN_RK3288(7, 7, 4),
+	[RK3288_PD_VIDEO]	= DOMAIN_RK3288(8, 8, 3),
+	[RK3288_PD_HEVC]	= DOMAIN_RK3288(14, 10, 9),
+};
+
+static const struct rockchip_pmu_info rk3288_pmu = {
+	.pwr_offset = 0x08,
+	.status_offset = 0x0c,
+	.req_offset = 0x10,
+	.idle_offset = 0x14,
+	.ack_offset = 0x14,
+
+	.core_pwrcnt_offset = 0x34,
+	.gpu_pwrcnt_offset = 0x3c,
+
+	.core_power_transition_time = 24, /* 1us */
+	.gpu_power_transition_time = 24, /* 1us */
+
+	.num_domains = ARRAY_SIZE(rk3288_pm_domains),
+	.domain_info = rk3288_pm_domains,
+};
+
+static const struct of_device_id rockchip_pm_domain_dt_match[] = {
+	{
+		.compatible = "rockchip,rk3288-power-controller",
+		.data = (void *)&rk3288_pmu,
+	},
+	{ /* sentinel */ },
+};
+
+static struct platform_driver rockchip_pm_domain_driver = {
+	.probe = rockchip_pm_domain_probe,
+	.driver = {
+		.name   = "rockchip-pm-domain",
+		.of_match_table = rockchip_pm_domain_dt_match,
+		/*
+		 * We can't forcibly eject devices form power domain,
+		 * so we can't really remove power domains once they
+		 * were added.
+		 */
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init rockchip_pm_domain_drv_register(void)
+{
+	return platform_driver_register(&rockchip_pm_domain_driver);
+}
+postcore_initcall(rockchip_pm_domain_drv_register);
-- 
1.9.1