1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
new file mode 100644
index 000000000000..79dbc770895f
--- /dev/null
+++ b/drivers/soc/renesas/rcar-sysc.c
@@ -0,0 +1,401 @@
+/*
+ * R-Car SYSC Power management support
+ *
+ * Copyright (C) 2014  Magnus Damm
+ * Copyright (C) 2015-2016 Glider bvba
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/clk/renesas.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/of_address.h>
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/soc/renesas/rcar-sysc.h>
+
+#include "rcar-sysc.h"
+
+/* SYSC Common */
+#define SYSCSR			0x00	/* SYSC Status Register */
+#define SYSCISR			0x04	/* Interrupt Status Register */
+#define SYSCISCR		0x08	/* Interrupt Status Clear Register */
+#define SYSCIER			0x0c	/* Interrupt Enable Register */
+#define SYSCIMR			0x10	/* Interrupt Mask Register */
+
+/* SYSC Status Register */
+#define SYSCSR_PONENB		1	/* Ready for power resume requests */
+#define SYSCSR_POFFENB		0	/* Ready for power shutoff requests */
+
+/*
+ * Power Control Register Offsets inside the register block for each domain
+ * Note: The "CR" registers for ARM cores exist on H1 only
+ *	 Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
+ *	 Use PSCI on R-Car Gen3
+ */
+#define PWRSR_OFFS		0x00	/* Power Status Register */
+#define PWROFFCR_OFFS		0x04	/* Power Shutoff Control Register */
+#define PWROFFSR_OFFS		0x08	/* Power Shutoff Status Register */
+#define PWRONCR_OFFS		0x0c	/* Power Resume Control Register */
+#define PWRONSR_OFFS		0x10	/* Power Resume Status Register */
+#define PWRER_OFFS		0x14	/* Power Shutoff/Resume Error */
+
+
+#define SYSCSR_RETRIES		100
+#define SYSCSR_DELAY_US		1
+
+#define PWRER_RETRIES		100
+#define PWRER_DELAY_US		1
+
+#define SYSCISR_RETRIES		1000
+#define SYSCISR_DELAY_US	1
+
+#define RCAR_PD_ALWAYS_ON	32	/* Always-on power area */
+
+static void __iomem *rcar_sysc_base;
+static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
+
+static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
+{
+	unsigned int sr_bit, reg_offs;
+	int k;
+
+	if (on) {
+		sr_bit = SYSCSR_PONENB;
+		reg_offs = PWRONCR_OFFS;
+	} else {
+		sr_bit = SYSCSR_POFFENB;
+		reg_offs = PWROFFCR_OFFS;
+	}
+
+	/* Wait until SYSC is ready to accept a power request */
+	for (k = 0; k < SYSCSR_RETRIES; k++) {
+		if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
+			break;
+		udelay(SYSCSR_DELAY_US);
+	}
+
+	if (k == SYSCSR_RETRIES)
+		return -EAGAIN;
+
+	/* Submit power shutoff or power resume request */
+	iowrite32(BIT(sysc_ch->chan_bit),
+		  rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
+
+	return 0;
+}
+
+static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
+{
+	unsigned int isr_mask = BIT(sysc_ch->isr_bit);
+	unsigned int chan_mask = BIT(sysc_ch->chan_bit);
+	unsigned int status;
+	unsigned long flags;
+	int ret = 0;
+	int k;
+
+	spin_lock_irqsave(&rcar_sysc_lock, flags);
+
+	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+	/* Submit power shutoff or resume request until it was accepted */
+	for (k = 0; k < PWRER_RETRIES; k++) {
+		ret = rcar_sysc_pwr_on_off(sysc_ch, on);
+		if (ret)
+			goto out;
+
+		status = ioread32(rcar_sysc_base +
+				  sysc_ch->chan_offs + PWRER_OFFS);
+		if (!(status & chan_mask))
+			break;
+
+		udelay(PWRER_DELAY_US);
+	}
+
+	if (k == PWRER_RETRIES) {
+		ret = -EIO;
+		goto out;
+	}
+
+	/* Wait until the power shutoff or resume request has completed * */
+	for (k = 0; k < SYSCISR_RETRIES; k++) {
+		if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
+			break;
+		udelay(SYSCISR_DELAY_US);
+	}
+
+	if (k == SYSCISR_RETRIES)
+		ret = -EIO;
+
+	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+ out:
+	spin_unlock_irqrestore(&rcar_sysc_lock, flags);
+
+	pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
+		 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
+	return ret;
+}
+
+int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_power(sysc_ch, false);
+}
+
+int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_power(sysc_ch, true);
+}
+
+static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
+{
+	unsigned int st;
+
+	st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
+	if (st & BIT(sysc_ch->chan_bit))
+		return true;
+
+	return false;
+}
+
+void __iomem *rcar_sysc_init(phys_addr_t base)
+{
+	rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
+	if (!rcar_sysc_base)
+		panic("unable to ioremap R-Car SYSC hardware block\n");
+
+	return rcar_sysc_base;
+}
+
+struct rcar_sysc_pd {
+	struct generic_pm_domain genpd;
+	struct rcar_sysc_ch ch;
+	unsigned int flags;
+	char name[0];
+};
+
+static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
+{
+	return container_of(d, struct rcar_sysc_pd, genpd);
+}
+
+static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
+{
+	struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
+
+	pr_debug("%s: %s\n", __func__, genpd->name);
+
+	if (pd->flags & PD_NO_CR) {
+		pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
+		return -EBUSY;
+	}
+
+	if (pd->flags & PD_BUSY) {
+		pr_debug("%s: %s busy\n", __func__, genpd->name);
+		return -EBUSY;
+	}
+
+	return rcar_sysc_power_down(&pd->ch);
+}
+
+static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd)
+{
+	struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
+
+	pr_debug("%s: %s\n", __func__, genpd->name);
+
+	if (pd->flags & PD_NO_CR) {
+		pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
+		return 0;
+	}
+
+	return rcar_sysc_power_up(&pd->ch);
+}
+
+static bool has_cpg_mstp;
+
+static void __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
+{
+	struct generic_pm_domain *genpd = &pd->genpd;
+	const char *name = pd->genpd.name;
+	struct dev_power_governor *gov = &simple_qos_governor;
+
+	if (pd->flags & PD_CPU) {
+		/*
+		 * This domain contains a CPU core and therefore it should
+		 * only be turned off if the CPU is not in use.
+		 */
+		pr_debug("PM domain %s contains %s\n", name, "CPU");
+		pd->flags |= PD_BUSY;
+		gov = &pm_domain_always_on_gov;
+	} else if (pd->flags & PD_SCU) {
+		/*
+		 * This domain contains an SCU and cache-controller, and
+		 * therefore it should only be turned off if the CPU cores are
+		 * not in use.
+		 */
+		pr_debug("PM domain %s contains %s\n", name, "SCU");
+		pd->flags |= PD_BUSY;
+		gov = &pm_domain_always_on_gov;
+	} else if (pd->flags & PD_NO_CR) {
+		/*
+		 * This domain cannot be turned off.
+		 */
+		pd->flags |= PD_BUSY;
+		gov = &pm_domain_always_on_gov;
+	}
+
+	if (!(pd->flags & (PD_CPU | PD_SCU))) {
+		/* Enable Clock Domain for I/O devices */
+		genpd->flags = GENPD_FLAG_PM_CLK;
+		if (has_cpg_mstp) {
+			genpd->attach_dev = cpg_mstp_attach_dev;
+			genpd->detach_dev = cpg_mstp_detach_dev;
+		} else {
+			genpd->attach_dev = cpg_mssr_attach_dev;
+			genpd->detach_dev = cpg_mssr_detach_dev;
+		}
+	}
+
+	genpd->power_off = rcar_sysc_pd_power_off;
+	genpd->power_on = rcar_sysc_pd_power_on;
+
+	if (pd->flags & (PD_CPU | PD_NO_CR)) {
+		/* Skip CPUs (handled by SMP code) and areas without control */
+		pr_debug("%s: Not touching %s\n", __func__, genpd->name);
+		goto finalize;
+	}
+
+	if (!rcar_sysc_power_is_off(&pd->ch)) {
+		pr_debug("%s: %s is already powered\n", __func__, genpd->name);
+		goto finalize;
+	}
+
+	rcar_sysc_power_up(&pd->ch);
+
+finalize:
+	pm_genpd_init(genpd, gov, false);
+}
+
+static const struct of_device_id rcar_sysc_matches[] = {
+#ifdef CONFIG_ARCH_R8A7779
+	{ .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7790
+	{ .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7791
+	{ .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7793
+	/* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
+	{ .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7794
+	{ .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
+#endif
+#ifdef CONFIG_ARCH_R8A7795
+	{ .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
+#endif
+	{ /* sentinel */ }
+};
+
+struct rcar_pm_domains {
+	struct genpd_onecell_data onecell_data;
+	struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
+};
+
+static int __init rcar_sysc_pd_init(void)
+{
+	const struct rcar_sysc_info *info;
+	const struct of_device_id *match;
+	struct rcar_pm_domains *domains;
+	struct device_node *np;
+	u32 syscier, syscimr;
+	void __iomem *base;
+	unsigned int i;
+	int error;
+
+	np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
+	if (!np)
+		return -ENODEV;
+
+	info = match->data;
+
+	has_cpg_mstp = of_find_compatible_node(NULL, NULL,
+					       "renesas,cpg-mstp-clocks");
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		pr_warn("%s: Cannot map regs\n", np->full_name);
+		error = -ENOMEM;
+		goto out_put;
+	}
+
+	rcar_sysc_base = base;
+
+	domains = kzalloc(sizeof(*domains), GFP_KERNEL);
+	if (!domains) {
+		error = -ENOMEM;
+		goto out_put;
+	}
+
+	domains->onecell_data.domains = domains->domains;
+	domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
+
+	for (i = 0, syscier = 0; i < info->num_areas; i++)
+		syscier |= BIT(info->areas[i].isr_bit);
+
+	/*
+	 * Mask all interrupt sources to prevent the CPU from receiving them.
+	 * Make sure not to clear reserved bits that were set before.
+	 */
+	syscimr = ioread32(base + SYSCIMR);
+	syscimr |= syscier;
+	pr_debug("%s: syscimr = 0x%08x\n", np->full_name, syscimr);
+	iowrite32(syscimr, base + SYSCIMR);
+
+	/*
+	 * SYSC needs all interrupt sources enabled to control power.
+	 */
+	pr_debug("%s: syscier = 0x%08x\n", np->full_name, syscier);
+	iowrite32(syscier, base + SYSCIER);
+
+	for (i = 0; i < info->num_areas; i++) {
+		const struct rcar_sysc_area *area = &info->areas[i];
+		struct rcar_sysc_pd *pd;
+
+		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
+		if (!pd) {
+			error = -ENOMEM;
+			goto out_put;
+		}
+
+		strcpy(pd->name, area->name);
+		pd->genpd.name = pd->name;
+		pd->ch.chan_offs = area->chan_offs;
+		pd->ch.chan_bit = area->chan_bit;
+		pd->ch.isr_bit = area->isr_bit;
+		pd->flags = area->flags;
+
+		rcar_sysc_pd_setup(pd);
+		if (area->parent >= 0)
+			pm_genpd_add_subdomain(domains->domains[area->parent],
+					       &pd->genpd);
+
+		domains->domains[area->isr_bit] = &pd->genpd;
+	}
+
+	of_genpd_add_provider_onecell(np, &domains->onecell_data);
+
+out_put:
+	of_node_put(np);
+	return error;
+}
+early_initcall(rcar_sysc_pd_init);