drivers/soc/renesas/rcar-gen4-sysc.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * R-Car Gen4 SYSC Power management support
  *
  * Copyright (C) 2021 Renesas Electronics Corp.
  */

 #include <linux/bits.h>
 #include <linux/clk/renesas.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.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/types.h>

 #include "rcar-gen4-sysc.h"

 /* SYSC Common */
 #define SYSCSR		0x000	/* SYSC Status Register */
 #define SYSCPONSR(x)	(0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */
 #define SYSCPOFFSR(x)	(0x808 + ((x) * 0x4)) /* Power-OFF Status Register */
 #define SYSCISCR(x)	(0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */
 #define SYSCIER(x)	(0x820 + ((x) * 0x4)) /* Interrupt Enable Register */
 #define SYSCIMR(x)	(0x830 + ((x) * 0x4)) /* Interrupt Mask Register */

 /* Power Domain Registers */
 #define PDRSR(n)	(0x1000 + ((n) * 0x40))
 #define PDRONCR(n)	(0x1004 + ((n) * 0x40))
 #define PDROFFCR(n)	(0x1008 + ((n) * 0x40))
 #define PDRESR(n)	(0x100C + ((n) * 0x40))

 /* PWRON/PWROFF */
 #define PWRON_PWROFF		BIT(0)	/* Power-ON/OFF request */

 /* PDRESR */
 #define PDRESR_ERR		BIT(0)

 /* PDRSR */
 #define PDRSR_OFF		BIT(0)	/* Power-OFF state */
 #define PDRSR_ON		BIT(4)	/* Power-ON state */
 #define PDRSR_OFF_STATE		BIT(8)  /* Processing Power-OFF sequence */
 #define PDRSR_ON_STATE		BIT(12) /* Processing Power-ON sequence */

 #define SYSCSR_BUSY		GENMASK(1, 0)	/* All bit sets is not busy */

 #define SYSCSR_TIMEOUT		10000
 #define SYSCSR_DELAY_US		10

 #define PDRESR_RETRIES		1000
 #define PDRESR_DELAY_US		10

 #define SYSCISR_TIMEOUT		10000
 #define SYSCISR_DELAY_US	10

 #define RCAR_GEN4_PD_ALWAYS_ON	64
 #define NUM_DOMAINS_EACH_REG	BITS_PER_TYPE(u32)

 static void __iomem *rcar_gen4_sysc_base;
 static DEFINE_SPINLOCK(rcar_gen4_sysc_lock); /* SMP CPUs + I/O devices */

 static int rcar_gen4_sysc_pwr_on_off(u8 pdr, bool on)
 {
 	unsigned int reg_offs;
 	u32 val;
 	int ret;

 	if (on)
 		reg_offs = PDRONCR(pdr);
 	else
 		reg_offs = PDROFFCR(pdr);

 	/* Wait until SYSC is ready to accept a power request */
 	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCSR, val,
 					(val & SYSCSR_BUSY) == SYSCSR_BUSY,
 					SYSCSR_DELAY_US, SYSCSR_TIMEOUT);
 	if (ret < 0)
 		return -EAGAIN;

 	/* Submit power shutoff or power resume request */
 	iowrite32(PWRON_PWROFF, rcar_gen4_sysc_base + reg_offs);

 	return 0;
 }

 static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask)
 {
 	u32 val;
 	int ret;

 	iowrite32(isr_mask, rcar_gen4_sysc_base + SYSCISCR(reg_idx));

 	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
 					val, !(val & isr_mask),
 					SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
 	if (ret < 0) {
 		pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__);
 		return -EIO;
 	}

 	return 0;
 }

 static int rcar_gen4_sysc_power(u8 pdr, bool on)
 {
 	unsigned int isr_mask;
 	unsigned int reg_idx, bit_idx;
 	unsigned int status;
 	unsigned long flags;
 	int ret = 0;
 	u32 val;
 	int k;

 	spin_lock_irqsave(&rcar_gen4_sysc_lock, flags);

 	reg_idx = pdr / NUM_DOMAINS_EACH_REG;
 	bit_idx = pdr % NUM_DOMAINS_EACH_REG;

 	isr_mask = BIT(bit_idx);

 	/*
 	 * The interrupt source needs to be enabled, but masked, to prevent the
 	 * CPU from receiving it.
 	 */
 	iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIER(reg_idx)) | isr_mask,
 		  rcar_gen4_sysc_base + SYSCIER(reg_idx));
 	iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIMR(reg_idx)) | isr_mask,
 		  rcar_gen4_sysc_base + SYSCIMR(reg_idx));

 	ret = clear_irq_flags(reg_idx, isr_mask);
 	if (ret)
 		goto out;

 	/* Submit power shutoff or resume request until it was accepted */
 	for (k = 0; k < PDRESR_RETRIES; k++) {
 		ret = rcar_gen4_sysc_pwr_on_off(pdr, on);
 		if (ret)
 			goto out;

 		status = ioread32(rcar_gen4_sysc_base + PDRESR(pdr));
 		if (!(status & PDRESR_ERR))
 			break;

 		udelay(PDRESR_DELAY_US);
 	}

 	if (k == PDRESR_RETRIES) {
 		ret = -EIO;
 		goto out;
 	}

 	/* Wait until the power shutoff or resume request has completed * */
 	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
 					val, (val & isr_mask),
 					SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
 	if (ret < 0) {
 		ret = -EIO;
 		goto out;
 	}

 	/* Clear interrupt flags */
 	ret = clear_irq_flags(reg_idx, isr_mask);
 	if (ret)
 		goto out;

  out:
 	spin_unlock_irqrestore(&rcar_gen4_sysc_lock, flags);

 	pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
 		 pdr, ioread32(rcar_gen4_sysc_base + SYSCISCR(reg_idx)), ret);
 	return ret;
 }

 static bool rcar_gen4_sysc_power_is_off(u8 pdr)
 {
 	unsigned int st;

 	st = ioread32(rcar_gen4_sysc_base + PDRSR(pdr));

 	if (st & PDRSR_OFF)
 		return true;

 	return false;
 }

 struct rcar_gen4_sysc_pd {
 	struct generic_pm_domain genpd;
 	u8 pdr;
 	unsigned int flags;
 	char name[];
 };

 static inline struct rcar_gen4_sysc_pd *to_rcar_gen4_pd(struct generic_pm_domain *d)
 {
 	return container_of(d, struct rcar_gen4_sysc_pd, genpd);
 }

 static int rcar_gen4_sysc_pd_power_off(struct generic_pm_domain *genpd)
 {
 	struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);

 	pr_debug("%s: %s\n", __func__, genpd->name);
 	return rcar_gen4_sysc_power(pd->pdr, false);
 }

 static int rcar_gen4_sysc_pd_power_on(struct generic_pm_domain *genpd)
 {
 	struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);

 	pr_debug("%s: %s\n", __func__, genpd->name);
 	return rcar_gen4_sysc_power(pd->pdr, true);
 }

 static int __init rcar_gen4_sysc_pd_setup(struct rcar_gen4_sysc_pd *pd)
 {
 	struct generic_pm_domain *genpd = &pd->genpd;
 	const char *name = pd->genpd.name;
 	int error;

 	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");
 		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 	} 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");
 		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 	} else if (pd->flags & PD_NO_CR) {
 		/*
 		 * This domain cannot be turned off.
 		 */
 		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
 	}

 	if (!(pd->flags & (PD_CPU | PD_SCU))) {
 		/* Enable Clock Domain for I/O devices */
 		genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
 		genpd->attach_dev = cpg_mssr_attach_dev;
 		genpd->detach_dev = cpg_mssr_detach_dev;
 	}

 	genpd->power_off = rcar_gen4_sysc_pd_power_off;
 	genpd->power_on = rcar_gen4_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_gen4_sysc_power_is_off(pd->pdr)) {
 		pr_debug("%s: %s is already powered\n", __func__, genpd->name);
 		goto finalize;
 	}

 	rcar_gen4_sysc_power(pd->pdr, true);

 finalize:
 	error = pm_genpd_init(genpd, &simple_qos_governor, false);
 	if (error)
 		pr_err("Failed to init PM domain %s: %d\n", name, error);

 	return error;
 }

 static const struct of_device_id rcar_gen4_sysc_matches[] __initconst = {
 #ifdef CONFIG_SYSC_R8A779A0
 	{ .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info },
 #endif
 #ifdef CONFIG_SYSC_R8A779F0
 	{ .compatible = "renesas,r8a779f0-sysc", .data = &r8a779f0_sysc_info },
 #endif
 #ifdef CONFIG_SYSC_R8A779G0
 	{ .compatible = "renesas,r8a779g0-sysc", .data = &r8a779g0_sysc_info },
 #endif
 	{ /* sentinel */ }
 };

 struct rcar_gen4_pm_domains {
 	struct genpd_onecell_data onecell_data;
 	struct generic_pm_domain *domains[RCAR_GEN4_PD_ALWAYS_ON + 1];
 };

 static struct genpd_onecell_data *rcar_gen4_sysc_onecell_data;

 static int __init rcar_gen4_sysc_pd_init(void)
 {
 	const struct rcar_gen4_sysc_info *info;
 	const struct of_device_id *match;
 	struct rcar_gen4_pm_domains *domains;
 	struct device_node *np;
 	void __iomem *base;
 	unsigned int i;
 	int error;

 	np = of_find_matching_node_and_match(NULL, rcar_gen4_sysc_matches, &match);
 	if (!np)
 		return -ENODEV;

 	info = match->data;

 	base = of_iomap(np, 0);
 	if (!base) {
 		pr_warn("%pOF: Cannot map regs\n", np);
 		error = -ENOMEM;
 		goto out_put;
 	}

 	rcar_gen4_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);
 	rcar_gen4_sysc_onecell_data = &domains->onecell_data;

 	for (i = 0; i < info->num_areas; i++) {
 		const struct rcar_gen4_sysc_area *area = &info->areas[i];
 		struct rcar_gen4_sysc_pd *pd;
 		size_t n;

 		if (!area->name) {
 			/* Skip NULLified area */
 			continue;
 		}

 		n = strlen(area->name) + 1;
 		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
 		if (!pd) {
 			error = -ENOMEM;
 			goto out_put;
 		}

 		memcpy(pd->name, area->name, n);
 		pd->genpd.name = pd->name;
 		pd->pdr = area->pdr;
 		pd->flags = area->flags;

 		error = rcar_gen4_sysc_pd_setup(pd);
 		if (error)
 			goto out_put;

 		domains->domains[area->pdr] = &pd->genpd;

 		if (area->parent < 0)
 			continue;

 		error = pm_genpd_add_subdomain(domains->domains[area->parent],
 					       &pd->genpd);
 		if (error) {
 			pr_warn("Failed to add PM subdomain %s to parent %u\n",
 				area->name, area->parent);
 			goto out_put;
 		}
 	}

 	error = of_genpd_add_provider_onecell(np, &domains->onecell_data);

 out_put:
 	of_node_put(np);
 	return error;
 }
 early_initcall(rcar_gen4_sysc_pd_init);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* R-Car Gen4 SYSC Power management support
	*
	* Copyright (C) 2021 Renesas Electronics Corp.
	*/

	#include <linux/bits.h>
	#include <linux/clk/renesas.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/iopoll.h>
	#include <linux/kernel.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/types.h>

	#include "rcar-gen4-sysc.h"

	/* SYSC Common */
	#define SYSCSR 0x000 /* SYSC Status Register */
	#define SYSCPONSR(x) (0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */
	#define SYSCPOFFSR(x) (0x808 + ((x) * 0x4)) /* Power-OFF Status Register */
	#define SYSCISCR(x) (0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */
	#define SYSCIER(x) (0x820 + ((x) * 0x4)) /* Interrupt Enable Register */
	#define SYSCIMR(x) (0x830 + ((x) * 0x4)) /* Interrupt Mask Register */

	/* Power Domain Registers */
	#define PDRSR(n) (0x1000 + ((n) * 0x40))
	#define PDRONCR(n) (0x1004 + ((n) * 0x40))
	#define PDROFFCR(n) (0x1008 + ((n) * 0x40))
	#define PDRESR(n) (0x100C + ((n) * 0x40))

	/* PWRON/PWROFF */
	#define PWRON_PWROFF BIT(0) /* Power-ON/OFF request */

	/* PDRESR */
	#define PDRESR_ERR BIT(0)

	/* PDRSR */
	#define PDRSR_OFF BIT(0) /* Power-OFF state */
	#define PDRSR_ON BIT(4) /* Power-ON state */
	#define PDRSR_OFF_STATE BIT(8) /* Processing Power-OFF sequence */
	#define PDRSR_ON_STATE BIT(12) /* Processing Power-ON sequence */

	#define SYSCSR_BUSY GENMASK(1, 0) /* All bit sets is not busy */

	#define SYSCSR_TIMEOUT 10000
	#define SYSCSR_DELAY_US 10

	#define PDRESR_RETRIES 1000
	#define PDRESR_DELAY_US 10

	#define SYSCISR_TIMEOUT 10000
	#define SYSCISR_DELAY_US 10

	#define RCAR_GEN4_PD_ALWAYS_ON 64
	#define NUM_DOMAINS_EACH_REG BITS_PER_TYPE(u32)

	static void __iomem *rcar_gen4_sysc_base;
	static DEFINE_SPINLOCK(rcar_gen4_sysc_lock); /* SMP CPUs + I/O devices */

	static int rcar_gen4_sysc_pwr_on_off(u8 pdr, bool on)
	{
	unsigned int reg_offs;
	u32 val;
	int ret;

	if (on)
	reg_offs = PDRONCR(pdr);
	else
	reg_offs = PDROFFCR(pdr);

	/* Wait until SYSC is ready to accept a power request */
	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCSR, val,
	(val & SYSCSR_BUSY) == SYSCSR_BUSY,
	SYSCSR_DELAY_US, SYSCSR_TIMEOUT);
	if (ret < 0)
	return -EAGAIN;

	/* Submit power shutoff or power resume request */
	iowrite32(PWRON_PWROFF, rcar_gen4_sysc_base + reg_offs);

	return 0;
	}

	static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask)
	{
	u32 val;
	int ret;

	iowrite32(isr_mask, rcar_gen4_sysc_base + SYSCISCR(reg_idx));

	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
	val, !(val & isr_mask),
	SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
	if (ret < 0) {
	pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__);
	return -EIO;
	}

	return 0;
	}

	static int rcar_gen4_sysc_power(u8 pdr, bool on)
	{
	unsigned int isr_mask;
	unsigned int reg_idx, bit_idx;
	unsigned int status;
	unsigned long flags;
	int ret = 0;
	u32 val;
	int k;

	spin_lock_irqsave(&rcar_gen4_sysc_lock, flags);

	reg_idx = pdr / NUM_DOMAINS_EACH_REG;
	bit_idx = pdr % NUM_DOMAINS_EACH_REG;

	isr_mask = BIT(bit_idx);

	/*
	* The interrupt source needs to be enabled, but masked, to prevent the
	* CPU from receiving it.
	*/
	iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIER(reg_idx)) \| isr_mask,
	rcar_gen4_sysc_base + SYSCIER(reg_idx));
	iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIMR(reg_idx)) \| isr_mask,
	rcar_gen4_sysc_base + SYSCIMR(reg_idx));

	ret = clear_irq_flags(reg_idx, isr_mask);
	if (ret)
	goto out;

	/* Submit power shutoff or resume request until it was accepted */
	for (k = 0; k < PDRESR_RETRIES; k++) {
	ret = rcar_gen4_sysc_pwr_on_off(pdr, on);
	if (ret)
	goto out;

	status = ioread32(rcar_gen4_sysc_base + PDRESR(pdr));
	if (!(status & PDRESR_ERR))
	break;

	udelay(PDRESR_DELAY_US);
	}

	if (k == PDRESR_RETRIES) {
	ret = -EIO;
	goto out;
	}

	/* Wait until the power shutoff or resume request has completed * */
	ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx),
	val, (val & isr_mask),
	SYSCISR_DELAY_US, SYSCISR_TIMEOUT);
	if (ret < 0) {
	ret = -EIO;
	goto out;
	}

	/* Clear interrupt flags */
	ret = clear_irq_flags(reg_idx, isr_mask);
	if (ret)
	goto out;

	out:
	spin_unlock_irqrestore(&rcar_gen4_sysc_lock, flags);

	pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
	pdr, ioread32(rcar_gen4_sysc_base + SYSCISCR(reg_idx)), ret);
	return ret;
	}

	static bool rcar_gen4_sysc_power_is_off(u8 pdr)
	{
	unsigned int st;

	st = ioread32(rcar_gen4_sysc_base + PDRSR(pdr));

	if (st & PDRSR_OFF)
	return true;

	return false;
	}

	struct rcar_gen4_sysc_pd {
	struct generic_pm_domain genpd;
	u8 pdr;
	unsigned int flags;
	char name[];
	};

	static inline struct rcar_gen4_sysc_pd to_rcar_gen4_pd(struct generic_pm_domain d)
	{
	return container_of(d, struct rcar_gen4_sysc_pd, genpd);
	}

	static int rcar_gen4_sysc_pd_power_off(struct generic_pm_domain *genpd)
	{
	struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);

	pr_debug("%s: %s\n", __func__, genpd->name);
	return rcar_gen4_sysc_power(pd->pdr, false);
	}

	static int rcar_gen4_sysc_pd_power_on(struct generic_pm_domain *genpd)
	{
	struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd);

	pr_debug("%s: %s\n", __func__, genpd->name);
	return rcar_gen4_sysc_power(pd->pdr, true);
	}

	static int __init rcar_gen4_sysc_pd_setup(struct rcar_gen4_sysc_pd *pd)
	{
	struct generic_pm_domain *genpd = &pd->genpd;
	const char *name = pd->genpd.name;
	int error;

	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");
	genpd->flags \|= GENPD_FLAG_ALWAYS_ON;
	} 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");
	genpd->flags \|= GENPD_FLAG_ALWAYS_ON;
	} else if (pd->flags & PD_NO_CR) {
	/*
	* This domain cannot be turned off.
	*/
	genpd->flags \|= GENPD_FLAG_ALWAYS_ON;
	}

	if (!(pd->flags & (PD_CPU \| PD_SCU))) {
	/* Enable Clock Domain for I/O devices */
	genpd->flags \|= GENPD_FLAG_PM_CLK \| GENPD_FLAG_ACTIVE_WAKEUP;
	genpd->attach_dev = cpg_mssr_attach_dev;
	genpd->detach_dev = cpg_mssr_detach_dev;
	}

	genpd->power_off = rcar_gen4_sysc_pd_power_off;
	genpd->power_on = rcar_gen4_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_gen4_sysc_power_is_off(pd->pdr)) {
	pr_debug("%s: %s is already powered\n", __func__, genpd->name);
	goto finalize;
	}

	rcar_gen4_sysc_power(pd->pdr, true);

	finalize:
	error = pm_genpd_init(genpd, &simple_qos_governor, false);
	if (error)
	pr_err("Failed to init PM domain %s: %d\n", name, error);

	return error;
	}

	static const struct of_device_id rcar_gen4_sysc_matches[] __initconst = {
	#ifdef CONFIG_SYSC_R8A779A0
	{ .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info },
	#endif
	#ifdef CONFIG_SYSC_R8A779F0
	{ .compatible = "renesas,r8a779f0-sysc", .data = &r8a779f0_sysc_info },
	#endif
	#ifdef CONFIG_SYSC_R8A779G0
	{ .compatible = "renesas,r8a779g0-sysc", .data = &r8a779g0_sysc_info },
	#endif
	{ /* sentinel */ }
	};

	struct rcar_gen4_pm_domains {
	struct genpd_onecell_data onecell_data;
	struct generic_pm_domain *domains[RCAR_GEN4_PD_ALWAYS_ON + 1];
	};

	static struct genpd_onecell_data *rcar_gen4_sysc_onecell_data;

	static int __init rcar_gen4_sysc_pd_init(void)
	{
	const struct rcar_gen4_sysc_info *info;
	const struct of_device_id *match;
	struct rcar_gen4_pm_domains *domains;
	struct device_node *np;
	void __iomem *base;
	unsigned int i;
	int error;

	np = of_find_matching_node_and_match(NULL, rcar_gen4_sysc_matches, &match);
	if (!np)
	return -ENODEV;

	info = match->data;

	base = of_iomap(np, 0);
	if (!base) {
	pr_warn("%pOF: Cannot map regs\n", np);
	error = -ENOMEM;
	goto out_put;
	}

	rcar_gen4_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);
	rcar_gen4_sysc_onecell_data = &domains->onecell_data;

	for (i = 0; i < info->num_areas; i++) {
	const struct rcar_gen4_sysc_area *area = &info->areas[i];
	struct rcar_gen4_sysc_pd *pd;
	size_t n;

	if (!area->name) {
	/* Skip NULLified area */
	continue;
	}

	n = strlen(area->name) + 1;
	pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
	if (!pd) {
	error = -ENOMEM;
	goto out_put;
	}

	memcpy(pd->name, area->name, n);
	pd->genpd.name = pd->name;
	pd->pdr = area->pdr;
	pd->flags = area->flags;

	error = rcar_gen4_sysc_pd_setup(pd);
	if (error)
	goto out_put;

	domains->domains[area->pdr] = &pd->genpd;

	if (area->parent < 0)
	continue;

	error = pm_genpd_add_subdomain(domains->domains[area->parent],
	&pd->genpd);
	if (error) {
	pr_warn("Failed to add PM subdomain %s to parent %u\n",
	area->name, area->parent);
	goto out_put;
	}
	}

	error = of_genpd_add_provider_onecell(np, &domains->onecell_data);

	out_put:
	of_node_put(np);
	return error;
	}
	early_initcall(rcar_gen4_sysc_pd_init);