drivers/soc/imx/gpc-psci.c - linux-imx - Git at Google

 /*
  * Copyright (C) 2016 Freescale Semiconductor, Inc.
  * Copyright 2017 NXP
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
  * of the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/arm-smccc.h>
 #include <linux/clk.h>
 #include <linux/cpumask.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
 #include <linux/irqchip/arm-gic.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_domain.h>
 #include <soc/imx/fsl_sip.h>

 #define GPC_MAX_IRQS		(4 * 32)

 struct imx_gpc_pm_domain {
 	const char name[30];
 	struct device *dev;
 	struct generic_pm_domain pd;
 	u32 gpc_domain_id;
 	struct clk **clks;
 	unsigned int num_clks;
 	struct regulator *reg;
 };

 enum imx_gpc_pm_domain_state {
 	GPC_PD_STATE_OFF,
 	GPC_PD_STATE_ON,
 };

 #define to_imx_gpc_pm_domain(_genpd) container_of(_genpd, struct imx_gpc_pm_domain, pd)

 static DEFINE_SPINLOCK(gpc_psci_lock);
 static DEFINE_MUTEX(gpc_pd_mutex);

 /* USB1 port power domain */
 static bool usb1_on = false;

 static void imx_gpc_psci_irq_unmask(struct irq_data *d)
 {
 	struct arm_smccc_res res;

 	spin_lock(&gpc_psci_lock);
 	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_UNMASK, d->hwirq,
 		      0, 0, 0, 0, 0, &res);
 	spin_unlock(&gpc_psci_lock);

 	irq_chip_unmask_parent(d);
 }

 static void imx_gpc_psci_irq_mask(struct irq_data *d)
 {
 	struct arm_smccc_res res;

 	spin_lock(&gpc_psci_lock);
 	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_MASK, d->hwirq,
 		      0, 0, 0, 0, 0, &res);
 	spin_unlock(&gpc_psci_lock);

 	irq_chip_mask_parent(d);
 }
 static int imx_gpc_psci_irq_set_wake(struct irq_data *d, unsigned int on)
 {
 	struct arm_smccc_res res;

 	spin_lock(&gpc_psci_lock);
 	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_SET_WAKE, d->hwirq,
 		      on, 0, 0, 0, 0, &res);
 	spin_unlock(&gpc_psci_lock);

 	return 0;
 }

 static int imx_gpc_psci_irq_set_affinity(struct irq_data *d,
 					 const struct cpumask *dest, bool force)
 {
 	/* parse the cpu of irq affinity */
 	struct arm_smccc_res res;
 	int cpu = cpumask_any_and(dest, cpu_online_mask);

 	irq_chip_set_affinity_parent(d, dest, force);

 	spin_lock(&gpc_psci_lock);
 	arm_smccc_smc(FSL_SIP_GPC, 0x4, d->hwirq,
 		      cpu, 0, 0, 0, 0, &res);
 	spin_unlock(&gpc_psci_lock);

 	return 0;
 }

 static struct irq_chip imx_gpc_psci_chip = {
 	.name			= "GPC-PSCI",
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_mask		= imx_gpc_psci_irq_mask,
 	.irq_unmask		= imx_gpc_psci_irq_unmask,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_wake		= imx_gpc_psci_irq_set_wake,
 	.irq_set_affinity	= imx_gpc_psci_irq_set_affinity,
 };

 static int imx_gpc_psci_domain_translate(struct irq_domain *d,
 				    struct irq_fwspec *fwspec,
 				    unsigned long *hwirq,
 				    unsigned int *type)
 {
 	if (is_of_node(fwspec->fwnode)) {
 		if (fwspec->param_count != 3)
 			return -EINVAL;

 		/* No PPI should point to this domain */
 		if (fwspec->param[0] != 0)
 			return -EINVAL;

 		*hwirq = fwspec->param[1];
 		*type = fwspec->param[2];
 		return 0;
 	}

 	return -EINVAL;
 }

 static int imx_gpc_psci_domain_alloc(struct irq_domain *domain,
 				  unsigned int irq,
 				  unsigned int nr_irqs, void *data)
 {
 	struct irq_fwspec *fwspec = data;
 	struct irq_fwspec parent_fwspec;
 	irq_hw_number_t hwirq;
 	int i;

 	if (fwspec->param_count != 3)
 		return -EINVAL;	/* Not GIC compliant */
 	if (fwspec->param[0] != 0)
 		return -EINVAL;	/* No PPI should point to this domain */

 	hwirq = fwspec->param[1];
 	if (hwirq >= GPC_MAX_IRQS)
 		return -EINVAL;	/* Can't deal with this */

 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_set_hwirq_and_chip(domain, irq + i, hwirq + i,
 					      &imx_gpc_psci_chip, NULL);

 	parent_fwspec = *fwspec;
 	parent_fwspec.fwnode = domain->parent->fwnode;

 	return irq_domain_alloc_irqs_parent(domain, irq, nr_irqs,
 					    &parent_fwspec);
 }

 static struct irq_domain_ops imx_gpc_psci_domain_ops = {
 	.translate = imx_gpc_psci_domain_translate,
 	.alloc	= imx_gpc_psci_domain_alloc,
 	.free	= irq_domain_free_irqs_common,
 };

 static int __init imx_gpc_psci_init(struct device_node *node,
 			       struct device_node *parent)
 {
 	struct irq_domain *parent_domain, *domain;

 	if (!parent) {
 		pr_err("%s: no parent, giving up\n", node->full_name);
 		return -ENODEV;
 	}

 	parent_domain = irq_find_host(parent);
 	if (!parent_domain) {
 		pr_err("%s: unable to obtain parent domain\n", node->full_name);
 		return -ENXIO;
 	}

 	domain = irq_domain_add_hierarchy(parent_domain, 0, GPC_MAX_IRQS,
 					  node, &imx_gpc_psci_domain_ops,
 					  NULL);
 	if (!domain)
 		return -ENOMEM;

 	return 0;
 }
 IRQCHIP_DECLARE(imx_gpc_psci, "fsl,imx8mq-gpc", imx_gpc_psci_init);

 static int imx_gpc_pd_power_on(struct generic_pm_domain *domain)
 {
 	struct imx_gpc_pm_domain *pd = to_imx_gpc_pm_domain(domain);
 	struct arm_smccc_res res;
 	int index, ret = 0;

 	if (usb1_on && pd->gpc_domain_id == 3)
 		return 0;

 	/* power on the external supply */
 	if (pd->reg) {
 		ret = regulator_enable(pd->reg);
 		if (ret) {
 			dev_warn(pd->dev, "failed to power up the reg%d\n", ret);
 			return ret;
 		}
 	}

 	/* enable the necessary clks needed by the power domain */
 	if (pd->num_clks) {
 		for (index = 0; index < pd->num_clks; index++)
 			clk_prepare_enable(pd->clks[index]);
 	}

 	mutex_lock(&gpc_pd_mutex);
 	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_PM_DOMAIN, pd->gpc_domain_id,
 		      GPC_PD_STATE_ON, 0, 0, 0, 0, &res);
 	mutex_unlock(&gpc_pd_mutex);

 	if (pd->gpc_domain_id == 3)
 		usb1_on = true;

 	return 0;
 }

 static int imx_gpc_pd_power_off(struct generic_pm_domain *domain)
 {
 	struct imx_gpc_pm_domain *pd = to_imx_gpc_pm_domain(domain);
 	struct arm_smccc_res res;
 	int index, ret = 0;

 	if (pd->gpc_domain_id == 3)
 		return 0;

 	mutex_lock(&gpc_pd_mutex);
 	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_PM_DOMAIN, pd->gpc_domain_id,
 		      GPC_PD_STATE_OFF, 0, 0, 0, 0, &res);
 	mutex_unlock(&gpc_pd_mutex);

 	/* power off the external supply */
 	if (pd->reg) {
 		ret = regulator_disable(pd->reg);
 		if (ret) {
 			dev_warn(pd->dev, "failed to power off the reg%d\n", ret);
 			return ret;
 		}
 	}

 	/* disable the necessary clks when power domain on finished */
 	if (pd->num_clks) {
 		for (index = 0; index < pd->num_clks; index++)
 			clk_disable_unprepare(pd->clks[index]);
 	}

 	return ret;
 };

 static int imx8m_pd_clk_init(struct device_node *np,
 			     struct imx_gpc_pm_domain *domain)
 {
 	struct property *pp;
 	struct clk **clks;
 	int index;

 	pp = of_find_property(np, "clocks", NULL);
 	if (pp)
 		domain->num_clks = pp->length / 8;
 	else
 		domain->num_clks = 0;

 	if (domain->num_clks) {
 		clks = kcalloc(domain->num_clks, sizeof(*clks), GFP_KERNEL);
 		if (!clks) {
 			domain->num_clks = 0;
 			domain->clks = NULL;
 			return -ENOMEM;
 		}

 		domain->clks = clks;
 	}

 	for (index = 0; index < domain->num_clks; index++) {
 		clks[index] = of_clk_get(np, index);
 		if (IS_ERR(clks[index])) {
 			for (index = 0; index < domain->num_clks; index++) {
 				if (!IS_ERR(clks[index]))
 					clk_put(clks[index]);
 			}

 			domain->num_clks = 0;
 			domain->clks = NULL;
 			kfree(clks);
 			pr_warn("imx8m domain clock init failed\n");
 			return -ENODEV;
 		}
 	}

 	return 0;
 }

 static int imx8m_add_subdomain(struct device_node *parent,
 			       struct generic_pm_domain *parent_pd)
 {
 	struct device_node *child_node;
 	struct imx_gpc_pm_domain *child_domain;
 	int ret = 0;

 	/* add each of the child domain of parent */
 	for_each_child_of_node(parent, child_node) {
 		if (!of_device_is_available(child_node))
 			continue;

 		child_domain = kzalloc(sizeof(*child_domain), GFP_KERNEL);
 		if (!child_domain)
 			return -ENOMEM;

 		ret = of_property_read_string(child_node, "domain-name",
 					      &child_domain->pd.name);
 		if (ret)
 			goto exit;

 		ret = of_property_read_u32(child_node, "domain-id",
 					   &child_domain->gpc_domain_id);
 		if (ret)
 			goto exit;

 		child_domain->pd.power_off = imx_gpc_pd_power_off;
 		child_domain->pd.power_on = imx_gpc_pd_power_on;
 		/* no reg for subdomains */
 		child_domain->reg = NULL;

 		imx8m_pd_clk_init(child_node, child_domain);

 		/* power domains as off at boot */
 		pm_genpd_init(&child_domain->pd, NULL, true);

 		/* add subdomain of parent power domain */
 		pm_genpd_add_subdomain(parent_pd, &child_domain->pd);

 		ret = of_genpd_add_provider_simple(child_node,
 						 &child_domain->pd);
 		if (ret)
 			pr_err("failed to add subdomain\n");
 	}

 	return 0;
 exit:
 	kfree(child_domain);
 	return ret;
 };

 static int imx_gpc_pm_domain_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct imx_gpc_pm_domain *imx_pm_domain;
 	int ret = 0;

 	if (!np) {
 		dev_err(dev, "power domain device tree node not found\n");
 		return -ENODEV;
 	}

 	imx_pm_domain = devm_kzalloc(dev, sizeof(*imx_pm_domain), GFP_KERNEL);
 	if (!imx_pm_domain)
 		return -ENOMEM;
 	imx_pm_domain->dev = dev;

 	ret = of_property_read_string(np, "domain-name", &imx_pm_domain->pd.name);
 	if (ret) {
 		dev_err(dev, "get domain name failed\n");
 		return -EINVAL;
 	}

 	ret = of_property_read_u32(np, "domain-id", &imx_pm_domain->gpc_domain_id);
 	if (ret) {
 		dev_err(dev, "get domain id failed\n");
 		return -EINVAL;
 	}

 	imx_pm_domain->reg = devm_regulator_get_optional(dev, "power");
 	if (IS_ERR(imx_pm_domain->reg)) {
 		if (PTR_ERR(imx_pm_domain->reg) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;

 		imx_pm_domain->reg = NULL;
 	}

 	imx8m_pd_clk_init(np, imx_pm_domain);

 	imx_pm_domain->pd.power_off = imx_gpc_pd_power_off;
 	imx_pm_domain->pd.power_on = imx_gpc_pd_power_on;
 	/* all power domains as off at boot */
 	pm_genpd_init(&imx_pm_domain->pd, NULL, true);

 	ret = of_genpd_add_provider_simple(np,
 				 &imx_pm_domain->pd);

 	/* add subdomain */
 	ret = imx8m_add_subdomain(np, &imx_pm_domain->pd);
 	if (ret)
 		dev_warn(dev, "please check the child power domain init\n");

 	return 0;
 }

 static const struct of_device_id imx_gpc_pm_domain_ids[] = {
 	{.compatible = "fsl,imx8mq-pm-domain"},
 	{.compatible = "fsl,imx8mm-pm-domain"},
 	{},
 };

 static struct platform_driver imx_gpc_pm_domain_driver = {
 	.driver = {
 		.name	= "imx8m_gpc_pm_domain",
 		.owner	= THIS_MODULE,
 		.of_match_table = imx_gpc_pm_domain_ids,
 	},
 	.probe = imx_gpc_pm_domain_probe,
 };

 module_platform_driver(imx_gpc_pm_domain_driver);

 MODULE_AUTHOR("NXP");
 MODULE_DESCRIPTION("NXP i.MX8M GPC power domain driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (C) 2016 Freescale Semiconductor, Inc.
	* Copyright 2017 NXP
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version 2
	* of the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/arm-smccc.h>
	#include <linux/clk.h>
	#include <linux/cpumask.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/irqchip.h>
	#include <linux/irqchip/arm-gic.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>
	#include <linux/pm_domain.h>
	#include <soc/imx/fsl_sip.h>

	#define GPC_MAX_IRQS (4 * 32)

	struct imx_gpc_pm_domain {
	const char name[30];
	struct device *dev;
	struct generic_pm_domain pd;
	u32 gpc_domain_id;
	struct clk **clks;
	unsigned int num_clks;
	struct regulator *reg;
	};

	enum imx_gpc_pm_domain_state {
	GPC_PD_STATE_OFF,
	GPC_PD_STATE_ON,
	};

	#define to_imx_gpc_pm_domain(_genpd) container_of(_genpd, struct imx_gpc_pm_domain, pd)

	static DEFINE_SPINLOCK(gpc_psci_lock);
	static DEFINE_MUTEX(gpc_pd_mutex);

	/* USB1 port power domain */
	static bool usb1_on = false;

	static void imx_gpc_psci_irq_unmask(struct irq_data *d)
	{
	struct arm_smccc_res res;

	spin_lock(&gpc_psci_lock);
	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_UNMASK, d->hwirq,
	0, 0, 0, 0, 0, &res);
	spin_unlock(&gpc_psci_lock);

	irq_chip_unmask_parent(d);
	}

	static void imx_gpc_psci_irq_mask(struct irq_data *d)
	{
	struct arm_smccc_res res;

	spin_lock(&gpc_psci_lock);
	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_MASK, d->hwirq,
	0, 0, 0, 0, 0, &res);
	spin_unlock(&gpc_psci_lock);

	irq_chip_mask_parent(d);
	}
	static int imx_gpc_psci_irq_set_wake(struct irq_data *d, unsigned int on)
	{
	struct arm_smccc_res res;

	spin_lock(&gpc_psci_lock);
	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_SET_WAKE, d->hwirq,
	on, 0, 0, 0, 0, &res);
	spin_unlock(&gpc_psci_lock);

	return 0;
	}

	static int imx_gpc_psci_irq_set_affinity(struct irq_data *d,
	const struct cpumask *dest, bool force)
	{
	/* parse the cpu of irq affinity */
	struct arm_smccc_res res;
	int cpu = cpumask_any_and(dest, cpu_online_mask);

	irq_chip_set_affinity_parent(d, dest, force);

	spin_lock(&gpc_psci_lock);
	arm_smccc_smc(FSL_SIP_GPC, 0x4, d->hwirq,
	cpu, 0, 0, 0, 0, &res);
	spin_unlock(&gpc_psci_lock);

	return 0;
	}

	static struct irq_chip imx_gpc_psci_chip = {
	.name = "GPC-PSCI",
	.irq_eoi = irq_chip_eoi_parent,
	.irq_mask = imx_gpc_psci_irq_mask,
	.irq_unmask = imx_gpc_psci_irq_unmask,
	.irq_retrigger = irq_chip_retrigger_hierarchy,
	.irq_set_wake = imx_gpc_psci_irq_set_wake,
	.irq_set_affinity = imx_gpc_psci_irq_set_affinity,
	};

	static int imx_gpc_psci_domain_translate(struct irq_domain *d,
	struct irq_fwspec *fwspec,
	unsigned long *hwirq,
	unsigned int *type)
	{
	if (is_of_node(fwspec->fwnode)) {
	if (fwspec->param_count != 3)
	return -EINVAL;

	/* No PPI should point to this domain */
	if (fwspec->param[0] != 0)
	return -EINVAL;

	*hwirq = fwspec->param[1];
	*type = fwspec->param[2];
	return 0;
	}

	return -EINVAL;
	}

	static int imx_gpc_psci_domain_alloc(struct irq_domain *domain,
	unsigned int irq,
	unsigned int nr_irqs, void *data)
	{
	struct irq_fwspec *fwspec = data;
	struct irq_fwspec parent_fwspec;
	irq_hw_number_t hwirq;
	int i;

	if (fwspec->param_count != 3)
	return -EINVAL; /* Not GIC compliant */
	if (fwspec->param[0] != 0)
	return -EINVAL; /* No PPI should point to this domain */

	hwirq = fwspec->param[1];
	if (hwirq >= GPC_MAX_IRQS)
	return -EINVAL; /* Can't deal with this */

	for (i = 0; i < nr_irqs; i++)
	irq_domain_set_hwirq_and_chip(domain, irq + i, hwirq + i,
	&imx_gpc_psci_chip, NULL);

	parent_fwspec = *fwspec;
	parent_fwspec.fwnode = domain->parent->fwnode;

	return irq_domain_alloc_irqs_parent(domain, irq, nr_irqs,
	&parent_fwspec);
	}

	static struct irq_domain_ops imx_gpc_psci_domain_ops = {
	.translate = imx_gpc_psci_domain_translate,
	.alloc = imx_gpc_psci_domain_alloc,
	.free = irq_domain_free_irqs_common,
	};

	static int __init imx_gpc_psci_init(struct device_node *node,
	struct device_node *parent)
	{
	struct irq_domain parent_domain, domain;

	if (!parent) {
	pr_err("%s: no parent, giving up\n", node->full_name);
	return -ENODEV;
	}

	parent_domain = irq_find_host(parent);
	if (!parent_domain) {
	pr_err("%s: unable to obtain parent domain\n", node->full_name);
	return -ENXIO;
	}

	domain = irq_domain_add_hierarchy(parent_domain, 0, GPC_MAX_IRQS,
	node, &imx_gpc_psci_domain_ops,
	NULL);
	if (!domain)
	return -ENOMEM;

	return 0;
	}
	IRQCHIP_DECLARE(imx_gpc_psci, "fsl,imx8mq-gpc", imx_gpc_psci_init);

	static int imx_gpc_pd_power_on(struct generic_pm_domain *domain)
	{
	struct imx_gpc_pm_domain *pd = to_imx_gpc_pm_domain(domain);
	struct arm_smccc_res res;
	int index, ret = 0;

	if (usb1_on && pd->gpc_domain_id == 3)
	return 0;

	/* power on the external supply */
	if (pd->reg) {
	ret = regulator_enable(pd->reg);
	if (ret) {
	dev_warn(pd->dev, "failed to power up the reg%d\n", ret);
	return ret;
	}
	}

	/* enable the necessary clks needed by the power domain */
	if (pd->num_clks) {
	for (index = 0; index < pd->num_clks; index++)
	clk_prepare_enable(pd->clks[index]);
	}

	mutex_lock(&gpc_pd_mutex);
	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_PM_DOMAIN, pd->gpc_domain_id,
	GPC_PD_STATE_ON, 0, 0, 0, 0, &res);
	mutex_unlock(&gpc_pd_mutex);

	if (pd->gpc_domain_id == 3)
	usb1_on = true;

	return 0;
	}

	static int imx_gpc_pd_power_off(struct generic_pm_domain *domain)
	{
	struct imx_gpc_pm_domain *pd = to_imx_gpc_pm_domain(domain);
	struct arm_smccc_res res;
	int index, ret = 0;

	if (pd->gpc_domain_id == 3)
	return 0;

	mutex_lock(&gpc_pd_mutex);
	arm_smccc_smc(FSL_SIP_GPC, FSL_SIP_CONFIG_GPC_PM_DOMAIN, pd->gpc_domain_id,
	GPC_PD_STATE_OFF, 0, 0, 0, 0, &res);
	mutex_unlock(&gpc_pd_mutex);

	/* power off the external supply */
	if (pd->reg) {
	ret = regulator_disable(pd->reg);
	if (ret) {
	dev_warn(pd->dev, "failed to power off the reg%d\n", ret);
	return ret;
	}
	}

	/* disable the necessary clks when power domain on finished */
	if (pd->num_clks) {
	for (index = 0; index < pd->num_clks; index++)
	clk_disable_unprepare(pd->clks[index]);
	}

	return ret;
	};

	static int imx8m_pd_clk_init(struct device_node *np,
	struct imx_gpc_pm_domain *domain)
	{
	struct property *pp;
	struct clk **clks;
	int index;

	pp = of_find_property(np, "clocks", NULL);
	if (pp)
	domain->num_clks = pp->length / 8;
	else
	domain->num_clks = 0;

	if (domain->num_clks) {
	clks = kcalloc(domain->num_clks, sizeof(*clks), GFP_KERNEL);
	if (!clks) {
	domain->num_clks = 0;
	domain->clks = NULL;
	return -ENOMEM;
	}

	domain->clks = clks;
	}

	for (index = 0; index < domain->num_clks; index++) {
	clks[index] = of_clk_get(np, index);
	if (IS_ERR(clks[index])) {
	for (index = 0; index < domain->num_clks; index++) {
	if (!IS_ERR(clks[index]))
	clk_put(clks[index]);
	}

	domain->num_clks = 0;
	domain->clks = NULL;
	kfree(clks);
	pr_warn("imx8m domain clock init failed\n");
	return -ENODEV;
	}
	}

	return 0;
	}

	static int imx8m_add_subdomain(struct device_node *parent,
	struct generic_pm_domain *parent_pd)
	{
	struct device_node *child_node;
	struct imx_gpc_pm_domain *child_domain;
	int ret = 0;

	/* add each of the child domain of parent */
	for_each_child_of_node(parent, child_node) {
	if (!of_device_is_available(child_node))
	continue;

	child_domain = kzalloc(sizeof(*child_domain), GFP_KERNEL);
	if (!child_domain)
	return -ENOMEM;

	ret = of_property_read_string(child_node, "domain-name",
	&child_domain->pd.name);
	if (ret)
	goto exit;

	ret = of_property_read_u32(child_node, "domain-id",
	&child_domain->gpc_domain_id);
	if (ret)
	goto exit;

	child_domain->pd.power_off = imx_gpc_pd_power_off;
	child_domain->pd.power_on = imx_gpc_pd_power_on;
	/* no reg for subdomains */
	child_domain->reg = NULL;

	imx8m_pd_clk_init(child_node, child_domain);

	/* power domains as off at boot */
	pm_genpd_init(&child_domain->pd, NULL, true);

	/* add subdomain of parent power domain */
	pm_genpd_add_subdomain(parent_pd, &child_domain->pd);

	ret = of_genpd_add_provider_simple(child_node,
	&child_domain->pd);
	if (ret)
	pr_err("failed to add subdomain\n");
	}

	return 0;
	exit:
	kfree(child_domain);
	return ret;
	};

	static int imx_gpc_pm_domain_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct imx_gpc_pm_domain *imx_pm_domain;
	int ret = 0;

	if (!np) {
	dev_err(dev, "power domain device tree node not found\n");
	return -ENODEV;
	}

	imx_pm_domain = devm_kzalloc(dev, sizeof(*imx_pm_domain), GFP_KERNEL);
	if (!imx_pm_domain)
	return -ENOMEM;
	imx_pm_domain->dev = dev;

	ret = of_property_read_string(np, "domain-name", &imx_pm_domain->pd.name);
	if (ret) {
	dev_err(dev, "get domain name failed\n");
	return -EINVAL;
	}

	ret = of_property_read_u32(np, "domain-id", &imx_pm_domain->gpc_domain_id);
	if (ret) {
	dev_err(dev, "get domain id failed\n");
	return -EINVAL;
	}

	imx_pm_domain->reg = devm_regulator_get_optional(dev, "power");
	if (IS_ERR(imx_pm_domain->reg)) {
	if (PTR_ERR(imx_pm_domain->reg) == -EPROBE_DEFER)
	return -EPROBE_DEFER;

	imx_pm_domain->reg = NULL;
	}

	imx8m_pd_clk_init(np, imx_pm_domain);

	imx_pm_domain->pd.power_off = imx_gpc_pd_power_off;
	imx_pm_domain->pd.power_on = imx_gpc_pd_power_on;
	/* all power domains as off at boot */
	pm_genpd_init(&imx_pm_domain->pd, NULL, true);

	ret = of_genpd_add_provider_simple(np,
	&imx_pm_domain->pd);

	/* add subdomain */
	ret = imx8m_add_subdomain(np, &imx_pm_domain->pd);
	if (ret)
	dev_warn(dev, "please check the child power domain init\n");

	return 0;
	}

	static const struct of_device_id imx_gpc_pm_domain_ids[] = {
	{.compatible = "fsl,imx8mq-pm-domain"},
	{.compatible = "fsl,imx8mm-pm-domain"},
	{},
	};

	static struct platform_driver imx_gpc_pm_domain_driver = {
	.driver = {
	.name = "imx8m_gpc_pm_domain",
	.owner = THIS_MODULE,
	.of_match_table = imx_gpc_pm_domain_ids,
	},
	.probe = imx_gpc_pm_domain_probe,
	};

	module_platform_driver(imx_gpc_pm_domain_driver);

	MODULE_AUTHOR("NXP");
	MODULE_DESCRIPTION("NXP i.MX8M GPC power domain driver");
	MODULE_LICENSE("GPL v2");