1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/soc/renesas/rmobile-sysc.c b/drivers/soc/renesas/rmobile-sysc.c
new file mode 100644
index 000000000..204e61351
--- /dev/null
+++ b/drivers/soc/renesas/rmobile-sysc.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * rmobile power management support
+ *
+ * Copyright (C) 2012  Renesas Solutions Corp.
+ * Copyright (C) 2012  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ * Copyright (C) 2014  Glider bvba
+ *
+ * based on pm-sh7372.c
+ *  Copyright (C) 2011 Magnus Damm
+ */
+#include <linux/clk/renesas.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/pm.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+
+#include <asm/io.h>
+
+/* SYSC */
+#define SPDCR		0x08	/* SYS Power Down Control Register */
+#define SWUCR		0x14	/* SYS Wakeup Control Register */
+#define PSTR		0x80	/* Power Status Register */
+
+#define PSTR_RETRIES	100
+#define PSTR_DELAY_US	10
+
+struct rmobile_pm_domain {
+	struct generic_pm_domain genpd;
+	struct dev_power_governor *gov;
+	int (*suspend)(void);
+	void __iomem *base;
+	unsigned int bit_shift;
+};
+
+static inline
+struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
+{
+	return container_of(d, struct rmobile_pm_domain, genpd);
+}
+
+static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
+{
+	struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
+	unsigned int mask = BIT(rmobile_pd->bit_shift);
+
+	if (rmobile_pd->suspend) {
+		int ret = rmobile_pd->suspend();
+
+		if (ret)
+			return ret;
+	}
+
+	if (readl(rmobile_pd->base + PSTR) & mask) {
+		unsigned int retry_count;
+		writel(mask, rmobile_pd->base + SPDCR);
+
+		for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
+			if (!(readl(rmobile_pd->base + SPDCR) & mask))
+				break;
+			cpu_relax();
+		}
+	}
+
+	pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask,
+		 readl(rmobile_pd->base + PSTR));
+
+	return 0;
+}
+
+static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd)
+{
+	unsigned int mask = BIT(rmobile_pd->bit_shift);
+	unsigned int retry_count;
+	int ret = 0;
+
+	if (readl(rmobile_pd->base + PSTR) & mask)
+		return ret;
+
+	writel(mask, rmobile_pd->base + SWUCR);
+
+	for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
+		if (!(readl(rmobile_pd->base + SWUCR) & mask))
+			break;
+		if (retry_count > PSTR_RETRIES)
+			udelay(PSTR_DELAY_US);
+		else
+			cpu_relax();
+	}
+	if (!retry_count)
+		ret = -EIO;
+
+	pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
+		 rmobile_pd->genpd.name, mask,
+		 readl(rmobile_pd->base + PSTR));
+
+	return ret;
+}
+
+static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
+{
+	return __rmobile_pd_power_up(to_rmobile_pd(genpd));
+}
+
+static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
+{
+	struct generic_pm_domain *genpd = &rmobile_pd->genpd;
+	struct dev_power_governor *gov = rmobile_pd->gov;
+
+	genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
+	genpd->attach_dev = cpg_mstp_attach_dev;
+	genpd->detach_dev = cpg_mstp_detach_dev;
+
+	if (!(genpd->flags & GENPD_FLAG_ALWAYS_ON)) {
+		genpd->power_off = rmobile_pd_power_down;
+		genpd->power_on = rmobile_pd_power_up;
+		__rmobile_pd_power_up(rmobile_pd);
+	}
+
+	pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
+}
+
+static int rmobile_pd_suspend_console(void)
+{
+	/*
+	 * Serial consoles make use of SCIF hardware located in this domain,
+	 * hence keep the power domain on if "no_console_suspend" is set.
+	 */
+	return console_suspend_enabled ? 0 : -EBUSY;
+}
+
+enum pd_types {
+	PD_NORMAL,
+	PD_CPU,
+	PD_CONSOLE,
+	PD_DEBUG,
+	PD_MEMCTL,
+};
+
+#define MAX_NUM_SPECIAL_PDS	16
+
+static struct special_pd {
+	struct device_node *pd;
+	enum pd_types type;
+} special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
+
+static unsigned int num_special_pds __initdata;
+
+static const struct of_device_id special_ids[] __initconst = {
+	{ .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
+	{ .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
+	{ .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
+	{ .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
+	{ /* sentinel */ },
+};
+
+static void __init add_special_pd(struct device_node *np, enum pd_types type)
+{
+	unsigned int i;
+	struct device_node *pd;
+
+	pd = of_parse_phandle(np, "power-domains", 0);
+	if (!pd)
+		return;
+
+	for (i = 0; i < num_special_pds; i++)
+		if (pd == special_pds[i].pd && type == special_pds[i].type) {
+			of_node_put(pd);
+			return;
+		}
+
+	if (num_special_pds == ARRAY_SIZE(special_pds)) {
+		pr_warn("Too many special PM domains\n");
+		of_node_put(pd);
+		return;
+	}
+
+	pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
+
+	special_pds[num_special_pds].pd = pd;
+	special_pds[num_special_pds].type = type;
+	num_special_pds++;
+}
+
+static void __init get_special_pds(void)
+{
+	struct device_node *np;
+	const struct of_device_id *id;
+
+	/* PM domains containing CPUs */
+	for_each_of_cpu_node(np)
+		add_special_pd(np, PD_CPU);
+
+	/* PM domain containing console */
+	if (of_stdout)
+		add_special_pd(of_stdout, PD_CONSOLE);
+
+	/* PM domains containing other special devices */
+	for_each_matching_node_and_match(np, special_ids, &id)
+		add_special_pd(np, (enum pd_types)id->data);
+}
+
+static void __init put_special_pds(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_special_pds; i++)
+		of_node_put(special_pds[i].pd);
+}
+
+static enum pd_types __init pd_type(const struct device_node *pd)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_special_pds; i++)
+		if (pd == special_pds[i].pd)
+			return special_pds[i].type;
+
+	return PD_NORMAL;
+}
+
+static void __init rmobile_setup_pm_domain(struct device_node *np,
+					   struct rmobile_pm_domain *pd)
+{
+	const char *name = pd->genpd.name;
+
+	switch (pd_type(np)) {
+	case PD_CPU:
+		/*
+		 * This domain contains the CPU core and therefore it should
+		 * only be turned off if the CPU is not in use.
+		 */
+		pr_debug("PM domain %s contains CPU\n", name);
+		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
+		break;
+
+	case PD_CONSOLE:
+		pr_debug("PM domain %s contains serial console\n", name);
+		pd->gov = &pm_domain_always_on_gov;
+		pd->suspend = rmobile_pd_suspend_console;
+		break;
+
+	case PD_DEBUG:
+		/*
+		 * This domain contains the Coresight-ETM hardware block and
+		 * therefore it should only be turned off if the debug module
+		 * is not in use.
+		 */
+		pr_debug("PM domain %s contains Coresight-ETM\n", name);
+		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
+		break;
+
+	case PD_MEMCTL:
+		/*
+		 * This domain contains a memory-controller and therefore it
+		 * should only be turned off if memory is not in use.
+		 */
+		pr_debug("PM domain %s contains MEMCTL\n", name);
+		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
+		break;
+
+	case PD_NORMAL:
+		if (pd->bit_shift == ~0) {
+			/* Top-level always-on domain */
+			pr_debug("PM domain %s is always-on domain\n", name);
+			pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
+		}
+		break;
+	}
+
+	rmobile_init_pm_domain(pd);
+}
+
+static int __init rmobile_add_pm_domains(void __iomem *base,
+					 struct device_node *parent,
+					 struct generic_pm_domain *genpd_parent)
+{
+	struct device_node *np;
+
+	for_each_child_of_node(parent, np) {
+		struct rmobile_pm_domain *pd;
+		u32 idx = ~0;
+
+		if (of_property_read_u32(np, "reg", &idx)) {
+			/* always-on domain */
+		}
+
+		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+		if (!pd) {
+			of_node_put(np);
+			return -ENOMEM;
+		}
+
+		pd->genpd.name = np->name;
+		pd->base = base;
+		pd->bit_shift = idx;
+
+		rmobile_setup_pm_domain(np, pd);
+		if (genpd_parent)
+			pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
+		of_genpd_add_provider_simple(np, &pd->genpd);
+
+		rmobile_add_pm_domains(base, np, &pd->genpd);
+	}
+	return 0;
+}
+
+static int __init rmobile_init_pm_domains(void)
+{
+	struct device_node *np, *pmd;
+	bool scanned = false;
+	void __iomem *base;
+	int ret = 0;
+
+	for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
+		base = of_iomap(np, 0);
+		if (!base) {
+			pr_warn("%pOF cannot map reg 0\n", np);
+			continue;
+		}
+
+		pmd = of_get_child_by_name(np, "pm-domains");
+		if (!pmd) {
+			iounmap(base);
+			pr_warn("%pOF lacks pm-domains node\n", np);
+			continue;
+		}
+
+		if (!scanned) {
+			/* Find PM domains containing special blocks */
+			get_special_pds();
+			scanned = true;
+		}
+
+		ret = rmobile_add_pm_domains(base, pmd, NULL);
+		of_node_put(pmd);
+		if (ret) {
+			of_node_put(np);
+			break;
+		}
+
+		fwnode_dev_initialized(&np->fwnode, true);
+	}
+
+	put_special_pds();
+
+	return ret;
+}
+
+core_initcall(rmobile_init_pm_domains);