pmdomain: Rename the genpd subsystem to pmdomain

It has been pointed out that naming a subsystem "genpd" isn't very
self-explanatory and the acronym itself that means Generic PM Domain, is
known only by a limited group of people.

In a way to improve the situation, let's rename the subsystem to pmdomain,
which ideally should indicate that this is about so called Power Domains or
"PM domains" as we often also use within the Linux Kernel terminology.

Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230912221127.487327-1-ulf.hansson@linaro.org

2 files changed, 169 insertions, 0 deletions

diff --git a/drivers/pmdomain/samsung/Makefile b/drivers/pmdomain/samsung/Makefile
new file mode 100644
index 000000000000..397aa5908c1d
--- /dev/null
+++ b/drivers/pmdomain/samsung/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_EXYNOS_PM_DOMAINS)		+= exynos-pm-domains.o
diff --git a/drivers/pmdomain/samsung/exynos-pm-domains.c b/drivers/pmdomain/samsung/exynos-pm-domains.c
new file mode 100644
index 000000000000..9b502e8751d1
--- /dev/null
+++ b/drivers/pmdomain/samsung/exynos-pm-domains.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// 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.
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pm_domain.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/pm_runtime.h>
+
+struct exynos_pm_domain_config {
+	/* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
+	u32 local_pwr_cfg;
+};
+
+/*
+ * Exynos specific wrapper around the generic power domain
+ */
+struct exynos_pm_domain {
+	void __iomem *base;
+	struct generic_pm_domain pd;
+	u32 local_pwr_cfg;
+};
+
+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;
+
+	pd = container_of(domain, struct exynos_pm_domain, pd);
+	base = pd->base;
+
+	pwr = power_on ? pd->local_pwr_cfg : 0;
+	writel_relaxed(pwr, base);
+
+	/* Wait max 1ms */
+	timeout = 10;
+
+	while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != 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);
+	}
+
+	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 const struct exynos_pm_domain_config exynos4210_cfg = {
+	.local_pwr_cfg		= 0x7,
+};
+
+static const struct exynos_pm_domain_config exynos5433_cfg = {
+	.local_pwr_cfg		= 0xf,
+};
+
+static const struct of_device_id exynos_pm_domain_of_match[] = {
+	{
+		.compatible = "samsung,exynos4210-pd",
+		.data = &exynos4210_cfg,
+	}, {
+		.compatible = "samsung,exynos5433-pd",
+		.data = &exynos5433_cfg,
+	},
+	{ },
+};
+
+static const char *exynos_get_domain_name(struct device_node *node)
+{
+	const char *name;
+
+	if (of_property_read_string(node, "label", &name) < 0)
+		name = kbasename(node->full_name);
+	return kstrdup_const(name, GFP_KERNEL);
+}
+
+static int exynos_pd_probe(struct platform_device *pdev)
+{
+	const struct exynos_pm_domain_config *pm_domain_cfg;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct of_phandle_args child, parent;
+	struct exynos_pm_domain *pd;
+	int on, ret;
+
+	pm_domain_cfg = of_device_get_match_data(dev);
+	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pd->pd.name = exynos_get_domain_name(np);
+	if (!pd->pd.name)
+		return -ENOMEM;
+
+	pd->base = of_iomap(np, 0);
+	if (!pd->base) {
+		kfree_const(pd->pd.name);
+		return -ENODEV;
+	}
+
+	pd->pd.power_off = exynos_pd_power_off;
+	pd->pd.power_on = exynos_pd_power_on;
+	pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg;
+
+	on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;
+
+	pm_genpd_init(&pd->pd, NULL, !on);
+	ret = of_genpd_add_provider_simple(np, &pd->pd);
+
+	if (ret == 0 && of_parse_phandle_with_args(np, "power-domains",
+				      "#power-domain-cells", 0, &parent) == 0) {
+		child.np = np;
+		child.args_count = 0;
+
+		if (of_genpd_add_subdomain(&parent, &child))
+			pr_warn("%pOF failed to add subdomain: %pOF\n",
+				parent.np, child.np);
+		else
+			pr_info("%pOF has as child subdomain: %pOF.\n",
+				parent.np, child.np);
+	}
+
+	pm_runtime_enable(dev);
+	return ret;
+}
+
+static struct platform_driver exynos_pd_driver = {
+	.probe	= exynos_pd_probe,
+	.driver	= {
+		.name		= "exynos-pd",
+		.of_match_table	= exynos_pm_domain_of_match,
+		.suppress_bind_attrs = true,
+	}
+};
+
+static __init int exynos4_pm_init_power_domain(void)
+{
+	return platform_driver_register(&exynos_pd_driver);
+}
+core_initcall(exynos4_pm_init_power_domain);