[PATCH v18 3/4] soc: rockchip: power-domain: Add power domain driver

[Caesar Wang]

This driver is found on RK3288 SoCs.

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 of the whole chip.

PMU can work in the Low Power Mode by setting bit[0] of PMU_PWRMODE_CON
register. After setting the register, PMU would enter the Low Power mode.
In the low power mode, pmu will auto power on/off the specified power
domain, send idle req to specified power domain, shut down/up pll and
so on. All of above are configurable by setting corresponding registers.

Signed-off-by: jinkun.hong <jinkun.hong@xxxxxxxxxxxxxx>
Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>

---

Changes in v18:
- As Kevin suggestion, set pd->num_clks = 0 in
  rockchip_pm_remove_one_domain() ans add the mutex for protect
- assign the order in rk3288_pm_domains[] in pm-domain driver.

Changes in v17:
- (re)defining config for ROCKCHIP.

Changes in v16:
- the driver type from tristate to bool.
- Letter misspelled.
- As Ulf suggestion, remove #include <linux/clk-provider.h>,
  use "%pC" as the formatting string for the dev_dbg().
- As the Ulf suggestion, set the genpd->flags to assign the
  ->stop|start() callbacks.

Changes in v15:
- As the kevin suggestion, put the power-domain driver into driver/soc/vendor.
- As Heiko suggestion, Patch 1: binding doc, 2: binding-header, 3: driver,
  4: dts-changes.
- return -ENXIO --> return -ENODEV.

Changes in v14:
- does not need to set an owner,remove the "THIS_MODULE".

Changes in v13:
- Remove essential clocks from rk3288 PD_VIO domain Some clocks are essential
  for the system health and should not be turned down. However there is no owner
  for them so if they listed as belonging to power domain we'll try toggling them
  up and down during power domain.
- Device drivers expect their devices to be powered on before their
  probing code is invoked. To achieve that we should start with
  power domains powered on (we may turn them off later once all devices enable
  runtime powermanagment and go idle).
- This change switches Rockchip power domain driver to use updated
  device_attach and device_detach API.
- set the gpu/core power domain power delay time.
- fix enumerating PM clocks for devices.
- fix use after free We can't use clk after we did clk_put(clk).

Changes in v12:
- fix the title doamin->domain.
- updated device_attach and device_detach API,otherwise it will
  compile fail on next kernel.

Changes in v11:
- fix pm_genpd_init(&pd->genpd, NULL, false).

Changes in v10:
- this switches over domain infos to use masks instead of recomputing
  them each time and also gets rid of custom domain translator and
  uses standard onecell on.

Changes in v9:
- fix v8 changes as follows:
- This reconciles the v2 and v7 code so that we power domain have lists of clocks
  they trigger on and off during power transitions and independently from power
  domains clocks. We attach clocks to devices comprising power domain and prepare
  them so they are turn on and off by runtime PM.
- add rockchip_pm_add_one_domain() to control domains.
- add pd_start/pd_stop interface to control clocks.

Changes in v8:
- This reconciles the v2 and v7 code so that we power domain have
  lists of clocks they toggle on and off during power transitions
  and independently from power domains clocks we attach clocks to
  devices comprising power domain and prepare them so they are
  turn on and off by runtime PM.

Changes in v7:
 - Delete unused variables

Changes in v6:
- delete pmu_lock.
- modify dev_lock using mutex.
- pm_clk_resume(pd->dev) change to pm_clk_resume(ed->dev).
- pm_clk_suspend(pd->dev) change to pm_clk_suspend(ed->dev).
- add devm_kfree(pd->dev, de) in rockchip_pm_domain_detach_dev.

Changes in v5:
- delete idle_lock.
- add timeout in rockchip_pmu_set_idle_request().

Changes in v4:
- use list storage dev.

Changes in v3:
- change use pm_clk_resume() and pm_clk_suspend().

Changes in v2:
- remove the "pd->pd.of_node = np".

 drivers/soc/Kconfig               |   1 +
 drivers/soc/Makefile              |   1 +
 drivers/soc/rockchip/Kconfig      |  14 ++
 drivers/soc/rockchip/Makefile     |   4 +
 drivers/soc/rockchip/pm_domains.c | 490 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 510 insertions(+)
 create mode 100644 drivers/soc/rockchip/Kconfig
 create mode 100644 drivers/soc/rockchip/Makefile
 create mode 100644 drivers/soc/rockchip/pm_domains.c

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 96ddecb..ecb1a6c 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -2,6 +2,7 @@ menu "SOC (System On Chip) specific Drivers"
 
 source "drivers/soc/mediatek/Kconfig"
 source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/rockchip/Kconfig"
 source "drivers/soc/sunxi/Kconfig"
 source "drivers/soc/ti/Kconfig"
 source "drivers/soc/versatile/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 0b12d77..c2b485f 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_MACH_DOVE)		+= dove/
 obj-$(CONFIG_ARCH_MEDIATEK)	+= mediatek/
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
+obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/
 obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
 obj-$(CONFIG_SOC_TI)		+= ti/
diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
new file mode 100644
index 0000000..6ee0399
--- /dev/null
+++ b/drivers/soc/rockchip/Kconfig
@@ -0,0 +1,14 @@
+#
+# Rockchip Soc drivers
+#
+config ROCKCHIP_PM_DOMAINS
+        bool "Rockchip generic power domain"
+        depends on PM
+        select PM_GENERIC_DOMAINS
+        help
+          Say y here to enable power domain support.
+          In order to meet high performance and low power requirements, a power
+          management unit is designed or saving power when RK3288 in low power
+          mode. The RK3288 PMU is dedicated for managing the power of the whole chip.
+
+          If unsure, say N.
diff --git a/drivers/soc/rockchip/Makefile b/drivers/soc/rockchip/Makefile
new file mode 100644
index 0000000..3d73d06
--- /dev/null
+++ b/drivers/soc/rockchip/Makefile
@@ -0,0 +1,4 @@
+#
+# Rockchip Soc drivers
+#
+obj-$(CONFIG_ROCKCHIP_PM_DOMAINS) += pm_domains.o
diff --git a/drivers/soc/rockchip/pm_domains.c b/drivers/soc/rockchip/pm_domains.c
new file mode 100644
index 0000000..e8984a6
--- /dev/null
+++ b/drivers/soc/rockchip/pm_domains.c
@@ -0,0 +1,490 @@
+/*
+ * Rockchip Generic power domain support.
+ *
+ * Copyright (c) 2015 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/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 '%pC' to list of PM clocks\n", 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_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 %pC (index %d): %d\n",
+				node->name, clk, i, error);
+			goto err_out;
+		}
+
+		error = clk_prepare(clk);
+		if (error) {
+			dev_err(pmu->dev,
+				"%s: failed to prepare clk %pC (index %d): %d\n",
+				node->name, clk, i, error);
+			clk_put(clk);
+			goto err_out;
+		}
+
+		pd->clks[pd->num_clks++] = clk;
+
+		dev_dbg(pmu->dev, "added clock '%pC' to domain '%s'\n",
+			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.flags = GENPD_FLAG_PM_CLK;
+	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]);
+	}
+
+	/* protect the zeroing of pm->num_clks */
+	mutex_lock(&pd->pmu->mutex);
+	pd->num_clks = 0;
+	mutex_unlock(&pd->pmu->mutex);
+
+	/* 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 device *parent;
+	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 -ENODEV;
+	}
+
+	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;
+
+	parent = dev->parent;
+	if (!parent) {
+		dev_err(dev, "no parent for syscon devices\n");
+		return -ENODEV;
+	}
+
+	pmu->regmap = syscon_node_to_regmap(parent->of_node);
+
+	/*
+	 * 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 = -ENODEV;
+
+	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_VIO]		= DOMAIN_RK3288(7, 7, 4),
+	[RK3288_PD_HEVC]	= DOMAIN_RK3288(14, 10, 9),
+	[RK3288_PD_VIDEO]	= DOMAIN_RK3288(8, 8, 3),
+	[RK3288_PD_GPU]		= DOMAIN_RK3288(9, 9, 2),
+};
+
+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

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