arch/arm/mach-imx/gpc.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2011-2013 Freescale Semiconductor, Inc.
  * Copyright 2011 Linaro Ltd.
  *
  * The code contained herein is licensed under the GNU General Public
  * License. You may obtain a copy of the GNU General Public License
  * Version 2 or later at the following locations:
  *
  * http://www.opensource.org/licenses/gpl-license.html
  * http://www.gnu.org/copyleft/gpl.html
  */

 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/regulator/consumer.h>
 #include <linux/irqchip/arm-gic.h>
 #include "common.h"
 #include "hardware.h"

 #define GPC_CNTR		0x000
 #define GPC_IMR1		0x008
 #define GPC_PGC_GPU_PDN		0x260
 #define GPC_PGC_GPU_PUPSCR	0x264
 #define GPC_PGC_GPU_PDNSCR	0x268
 #define GPC_PGC_CPU_PDN		0x2a0
 #define GPC_PGC_CPU_PUPSCR	0x2a4
 #define GPC_PGC_CPU_PDNSCR	0x2a8
 #define GPC_PGC_SW2ISO_SHIFT	0x8
 #define GPC_PGC_SW_SHIFT	0x0

 #define IMR_NUM			4
 #define GPC_MAX_IRQS		(IMR_NUM * 32)

 #define GPU_VPU_PUP_REQ		BIT(1)
 #define GPU_VPU_PDN_REQ		BIT(0)

 #define GPC_CLK_MAX		6

 struct pu_domain {
 	struct generic_pm_domain base;
 	struct regulator *reg;
 	struct clk *clk[GPC_CLK_MAX];
 	int num_clks;
 };

 static void __iomem *gpc_base;
 static u32 gpc_wake_irqs[IMR_NUM];
 static u32 gpc_saved_imrs[IMR_NUM];

 void imx_gpc_set_arm_power_up_timing(u32 sw2iso, u32 sw)
 {
 	writel_relaxed((sw2iso << GPC_PGC_SW2ISO_SHIFT) |
 		(sw << GPC_PGC_SW_SHIFT), gpc_base + GPC_PGC_CPU_PUPSCR);
 }

 void imx_gpc_set_arm_power_down_timing(u32 sw2iso, u32 sw)
 {
 	writel_relaxed((sw2iso << GPC_PGC_SW2ISO_SHIFT) |
 		(sw << GPC_PGC_SW_SHIFT), gpc_base + GPC_PGC_CPU_PDNSCR);
 }

 void imx_gpc_set_arm_power_in_lpm(bool power_off)
 {
 	writel_relaxed(power_off, gpc_base + GPC_PGC_CPU_PDN);
 }

 void imx_gpc_pre_suspend(bool arm_power_off)
 {
 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
 	int i;

 	/* Tell GPC to power off ARM core when suspend */
 	if (arm_power_off)
 		imx_gpc_set_arm_power_in_lpm(arm_power_off);

 	for (i = 0; i < IMR_NUM; i++) {
 		gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
 		writel_relaxed(~gpc_wake_irqs[i], reg_imr1 + i * 4);
 	}
 }

 void imx_gpc_post_resume(void)
 {
 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
 	int i;

 	/* Keep ARM core powered on for other low-power modes */
 	imx_gpc_set_arm_power_in_lpm(false);

 	for (i = 0; i < IMR_NUM; i++)
 		writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
 }

 static int imx_gpc_irq_set_wake(struct irq_data *d, unsigned int on)
 {
 	unsigned int idx = d->hwirq / 32;
 	u32 mask;

 	mask = 1 << d->hwirq % 32;
 	gpc_wake_irqs[idx] = on ? gpc_wake_irqs[idx] | mask :
 				  gpc_wake_irqs[idx] & ~mask;

 	/*
 	 * Do *not* call into the parent, as the GIC doesn't have any
 	 * wake-up facility...
 	 */
 	return 0;
 }

 void imx_gpc_mask_all(void)
 {
 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
 	int i;

 	for (i = 0; i < IMR_NUM; i++) {
 		gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
 		writel_relaxed(~0, reg_imr1 + i * 4);
 	}

 }

 void imx_gpc_restore_all(void)
 {
 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
 	int i;

 	for (i = 0; i < IMR_NUM; i++)
 		writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
 }

 void imx_gpc_hwirq_unmask(unsigned int hwirq)
 {
 	void __iomem *reg;
 	u32 val;

 	reg = gpc_base + GPC_IMR1 + hwirq / 32 * 4;
 	val = readl_relaxed(reg);
 	val &= ~(1 << hwirq % 32);
 	writel_relaxed(val, reg);
 }

 void imx_gpc_hwirq_mask(unsigned int hwirq)
 {
 	void __iomem *reg;
 	u32 val;

 	reg = gpc_base + GPC_IMR1 + hwirq / 32 * 4;
 	val = readl_relaxed(reg);
 	val |= 1 << (hwirq % 32);
 	writel_relaxed(val, reg);
 }

 static void imx_gpc_irq_unmask(struct irq_data *d)
 {
 	imx_gpc_hwirq_unmask(d->hwirq);
 	irq_chip_unmask_parent(d);
 }

 static void imx_gpc_irq_mask(struct irq_data *d)
 {
 	imx_gpc_hwirq_mask(d->hwirq);
 	irq_chip_mask_parent(d);
 }

 static struct irq_chip imx_gpc_chip = {
 	.name			= "GPC",
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_mask		= imx_gpc_irq_mask,
 	.irq_unmask		= imx_gpc_irq_unmask,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_wake		= imx_gpc_irq_set_wake,
 #ifdef CONFIG_SMP
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 #endif
 };

 static int imx_gpc_domain_xlate(struct irq_domain *domain,
 				struct device_node *controller,
 				const u32 *intspec,
 				unsigned int intsize,
 				unsigned long *out_hwirq,
 				unsigned int *out_type)
 {
 	if (domain->of_node != controller)
 		return -EINVAL;	/* Shouldn't happen, really... */
 	if (intsize != 3)
 		return -EINVAL;	/* Not GIC compliant */
 	if (intspec[0] != 0)
 		return -EINVAL;	/* No PPI should point to this domain */

 	*out_hwirq = intspec[1];
 	*out_type = intspec[2];
 	return 0;
 }

 static int imx_gpc_domain_alloc(struct irq_domain *domain,
 				  unsigned int irq,
 				  unsigned int nr_irqs, void *data)
 {
 	struct of_phandle_args *args = data;
 	struct of_phandle_args parent_args;
 	irq_hw_number_t hwirq;
 	int i;

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

 	hwirq = args->args[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_chip, NULL);

 	parent_args = *args;
 	parent_args.np = domain->parent->of_node;
 	return irq_domain_alloc_irqs_parent(domain, irq, nr_irqs, &parent_args);
 }

 static struct irq_domain_ops imx_gpc_domain_ops = {
 	.xlate	= imx_gpc_domain_xlate,
 	.alloc	= imx_gpc_domain_alloc,
 	.free	= irq_domain_free_irqs_common,
 };

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

 	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;
 	}

 	gpc_base = of_iomap(node, 0);
 	if (WARN_ON(!gpc_base))
 	        return -ENOMEM;

 	domain = irq_domain_add_hierarchy(parent_domain, 0, GPC_MAX_IRQS,
 					  node, &imx_gpc_domain_ops,
 					  NULL);
 	if (!domain) {
 		iounmap(gpc_base);
 		return -ENOMEM;
 	}

 	/* Initially mask all interrupts */
 	for (i = 0; i < IMR_NUM; i++)
 		writel_relaxed(~0, gpc_base + GPC_IMR1 + i * 4);

 	return 0;
 }

 /*
  * We cannot use the IRQCHIP_DECLARE macro that lives in
  * drivers/irqchip, so we're forced to roll our own. Not very nice.
  */
 OF_DECLARE_2(irqchip, imx_gpc, "fsl,imx6q-gpc", imx_gpc_init);

 void __init imx_gpc_check_dt(void)
 {
 	struct device_node *np;

 	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpc");
 	if (WARN_ON(!np ||
 		    !of_find_property(np, "interrupt-controller", NULL)))
 		pr_warn("Outdated DT detected, system is about to crash!!!\n");
 }

 #ifdef CONFIG_PM_GENERIC_DOMAINS

 static void _imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
 {
 	int iso, iso2sw;
 	u32 val;

 	/* Read ISO and ISO2SW power down delays */
 	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PDNSCR);
 	iso = val & 0x3f;
 	iso2sw = (val >> 8) & 0x3f;

 	/* Gate off PU domain when GPU/VPU when powered down */
 	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);

 	/* Request GPC to power down GPU/VPU */
 	val = readl_relaxed(gpc_base + GPC_CNTR);
 	val |= GPU_VPU_PDN_REQ;
 	writel_relaxed(val, gpc_base + GPC_CNTR);

 	/* Wait ISO + ISO2SW IPG clock cycles */
 	ndelay((iso + iso2sw) * 1000 / 66);
 }

 static int imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
 {
 	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);

 	_imx6q_pm_pu_power_off(genpd);

 	if (pu->reg)
 		regulator_disable(pu->reg);

 	return 0;
 }

 static int imx6q_pm_pu_power_on(struct generic_pm_domain *genpd)
 {
 	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
 	int i, ret, sw, sw2iso;
 	u32 val;

 	if (pu->reg)
 		ret = regulator_enable(pu->reg);
 	if (pu->reg && ret) {
 		pr_err("%s: failed to enable regulator: %d\n", __func__, ret);
 		return ret;
 	}

 	/* Enable reset clocks for all devices in the PU domain */
 	for (i = 0; i < pu->num_clks; i++)
 		clk_prepare_enable(pu->clk[i]);

 	/* Gate off PU domain when GPU/VPU when powered down */
 	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);

 	/* Read ISO and ISO2SW power down delays */
 	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PUPSCR);
 	sw = val & 0x3f;
 	sw2iso = (val >> 8) & 0x3f;

 	/* Request GPC to power up GPU/VPU */
 	val = readl_relaxed(gpc_base + GPC_CNTR);
 	val |= GPU_VPU_PUP_REQ;
 	writel_relaxed(val, gpc_base + GPC_CNTR);

 	/* Wait ISO + ISO2SW IPG clock cycles */
 	ndelay((sw + sw2iso) * 1000 / 66);

 	/* Disable reset clocks for all devices in the PU domain */
 	for (i = 0; i < pu->num_clks; i++)
 		clk_disable_unprepare(pu->clk[i]);

 	return 0;
 }

 static struct generic_pm_domain imx6q_arm_domain = {
 	.name = "ARM",
 };

 static struct pu_domain imx6q_pu_domain = {
 	.base = {
 		.name = "PU",
 		.power_off = imx6q_pm_pu_power_off,
 		.power_on = imx6q_pm_pu_power_on,
 		.power_off_latency_ns = 25000,
 		.power_on_latency_ns = 2000000,
 	},
 };

 static struct generic_pm_domain imx6sl_display_domain = {
 	.name = "DISPLAY",
 };

 static struct generic_pm_domain *imx_gpc_domains[] = {
 	&imx6q_arm_domain,
 	&imx6q_pu_domain.base,
 	&imx6sl_display_domain,
 };

 static struct genpd_onecell_data imx_gpc_onecell_data = {
 	.domains = imx_gpc_domains,
 	.num_domains = ARRAY_SIZE(imx_gpc_domains),
 };

 static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
 {
 	struct clk *clk;
 	bool is_off;
 	int i;

 	imx6q_pu_domain.reg = pu_reg;

 	for (i = 0; ; i++) {
 		clk = of_clk_get(dev->of_node, i);
 		if (IS_ERR(clk))
 			break;
 		if (i >= GPC_CLK_MAX) {
 			dev_err(dev, "more than %d clocks\n", GPC_CLK_MAX);
 			goto clk_err;
 		}
 		imx6q_pu_domain.clk[i] = clk;
 	}
 	imx6q_pu_domain.num_clks = i;

 	is_off = IS_ENABLED(CONFIG_PM);
 	if (is_off) {
 		_imx6q_pm_pu_power_off(&imx6q_pu_domain.base);
 	} else {
 		/*
 		 * Enable power if compiled without CONFIG_PM in case the
 		 * bootloader disabled it.
 		 */
 		imx6q_pm_pu_power_on(&imx6q_pu_domain.base);
 	}

 	pm_genpd_init(&imx6q_pu_domain.base, NULL, is_off);
 	return of_genpd_add_provider_onecell(dev->of_node,
 					     &imx_gpc_onecell_data);

 clk_err:
 	while (i--)
 		clk_put(imx6q_pu_domain.clk[i]);
 	return -EINVAL;
 }

 #else
 static inline int imx_gpc_genpd_init(struct device *dev, struct regulator *reg)
 {
 	return 0;
 }
 #endif /* CONFIG_PM_GENERIC_DOMAINS */

 static int imx_gpc_probe(struct platform_device *pdev)
 {
 	struct regulator *pu_reg;
 	int ret;

 	pu_reg = devm_regulator_get_optional(&pdev->dev, "pu");
 	if (PTR_ERR(pu_reg) == -ENODEV)
 		pu_reg = NULL;
 	if (IS_ERR(pu_reg)) {
 		ret = PTR_ERR(pu_reg);
 		dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
 		return ret;
 	}

 	return imx_gpc_genpd_init(&pdev->dev, pu_reg);
 }

 static const struct of_device_id imx_gpc_dt_ids[] = {
 	{ .compatible = "fsl,imx6q-gpc" },
 	{ .compatible = "fsl,imx6sl-gpc" },
 	{ }
 };

 static struct platform_driver imx_gpc_driver = {
 	.driver = {
 		.name = "imx-gpc",
 		.owner = THIS_MODULE,
 		.of_match_table = imx_gpc_dt_ids,
 	},
 	.probe = imx_gpc_probe,
 };

 static int __init imx_pgc_init(void)
 {
 	return platform_driver_register(&imx_gpc_driver);
 }
 subsys_initcall(imx_pgc_init);
	/*
	* Copyright 2011-2013 Freescale Semiconductor, Inc.
	* Copyright 2011 Linaro Ltd.
	*
	* The code contained herein is licensed under the GNU General Public
	* License. You may obtain a copy of the GNU General Public License
	* Version 2 or later at the following locations:
	*
	* http://www.opensource.org/licenses/gpl-license.html
	* http://www.gnu.org/copyleft/gpl.html
	*/

	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/platform_device.h>
	#include <linux/pm_domain.h>
	#include <linux/regulator/consumer.h>
	#include <linux/irqchip/arm-gic.h>
	#include "common.h"
	#include "hardware.h"

	#define GPC_CNTR 0x000
	#define GPC_IMR1 0x008
	#define GPC_PGC_GPU_PDN 0x260
	#define GPC_PGC_GPU_PUPSCR 0x264
	#define GPC_PGC_GPU_PDNSCR 0x268
	#define GPC_PGC_CPU_PDN 0x2a0
	#define GPC_PGC_CPU_PUPSCR 0x2a4
	#define GPC_PGC_CPU_PDNSCR 0x2a8
	#define GPC_PGC_SW2ISO_SHIFT 0x8
	#define GPC_PGC_SW_SHIFT 0x0

	#define IMR_NUM 4
	#define GPC_MAX_IRQS (IMR_NUM * 32)

	#define GPU_VPU_PUP_REQ BIT(1)
	#define GPU_VPU_PDN_REQ BIT(0)

	#define GPC_CLK_MAX 6

	struct pu_domain {
	struct generic_pm_domain base;
	struct regulator *reg;
	struct clk *clk[GPC_CLK_MAX];
	int num_clks;
	};

	static void __iomem *gpc_base;
	static u32 gpc_wake_irqs[IMR_NUM];
	static u32 gpc_saved_imrs[IMR_NUM];

	void imx_gpc_set_arm_power_up_timing(u32 sw2iso, u32 sw)
	{
	writel_relaxed((sw2iso << GPC_PGC_SW2ISO_SHIFT) \|
	(sw << GPC_PGC_SW_SHIFT), gpc_base + GPC_PGC_CPU_PUPSCR);
	}

	void imx_gpc_set_arm_power_down_timing(u32 sw2iso, u32 sw)
	{
	writel_relaxed((sw2iso << GPC_PGC_SW2ISO_SHIFT) \|
	(sw << GPC_PGC_SW_SHIFT), gpc_base + GPC_PGC_CPU_PDNSCR);
	}

	void imx_gpc_set_arm_power_in_lpm(bool power_off)
	{
	writel_relaxed(power_off, gpc_base + GPC_PGC_CPU_PDN);
	}

	void imx_gpc_pre_suspend(bool arm_power_off)
	{
	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
	int i;

	/* Tell GPC to power off ARM core when suspend */
	if (arm_power_off)
	imx_gpc_set_arm_power_in_lpm(arm_power_off);

	for (i = 0; i < IMR_NUM; i++) {
	gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
	writel_relaxed(~gpc_wake_irqs[i], reg_imr1 + i * 4);
	}
	}

	void imx_gpc_post_resume(void)
	{
	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
	int i;

	/* Keep ARM core powered on for other low-power modes */
	imx_gpc_set_arm_power_in_lpm(false);

	for (i = 0; i < IMR_NUM; i++)
	writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
	}

	static int imx_gpc_irq_set_wake(struct irq_data *d, unsigned int on)
	{
	unsigned int idx = d->hwirq / 32;
	u32 mask;

	mask = 1 << d->hwirq % 32;
	gpc_wake_irqs[idx] = on ? gpc_wake_irqs[idx] \| mask :
	gpc_wake_irqs[idx] & ~mask;

	/*
	* Do not call into the parent, as the GIC doesn't have any
	* wake-up facility...
	*/
	return 0;
	}

	void imx_gpc_mask_all(void)
	{
	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
	int i;

	for (i = 0; i < IMR_NUM; i++) {
	gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
	writel_relaxed(~0, reg_imr1 + i * 4);
	}

	}

	void imx_gpc_restore_all(void)
	{
	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
	int i;

	for (i = 0; i < IMR_NUM; i++)
	writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
	}

	void imx_gpc_hwirq_unmask(unsigned int hwirq)
	{
	void __iomem *reg;
	u32 val;

	reg = gpc_base + GPC_IMR1 + hwirq / 32 * 4;
	val = readl_relaxed(reg);
	val &= ~(1 << hwirq % 32);
	writel_relaxed(val, reg);
	}

	void imx_gpc_hwirq_mask(unsigned int hwirq)
	{
	void __iomem *reg;
	u32 val;

	reg = gpc_base + GPC_IMR1 + hwirq / 32 * 4;
	val = readl_relaxed(reg);
	val \|= 1 << (hwirq % 32);
	writel_relaxed(val, reg);
	}

	static void imx_gpc_irq_unmask(struct irq_data *d)
	{
	imx_gpc_hwirq_unmask(d->hwirq);
	irq_chip_unmask_parent(d);
	}

	static void imx_gpc_irq_mask(struct irq_data *d)
	{
	imx_gpc_hwirq_mask(d->hwirq);
	irq_chip_mask_parent(d);
	}

	static struct irq_chip imx_gpc_chip = {
	.name = "GPC",
	.irq_eoi = irq_chip_eoi_parent,
	.irq_mask = imx_gpc_irq_mask,
	.irq_unmask = imx_gpc_irq_unmask,
	.irq_retrigger = irq_chip_retrigger_hierarchy,
	.irq_set_wake = imx_gpc_irq_set_wake,
	#ifdef CONFIG_SMP
	.irq_set_affinity = irq_chip_set_affinity_parent,
	#endif
	};

	static int imx_gpc_domain_xlate(struct irq_domain *domain,
	struct device_node *controller,
	const u32 *intspec,
	unsigned int intsize,
	unsigned long *out_hwirq,
	unsigned int *out_type)
	{
	if (domain->of_node != controller)
	return -EINVAL; /* Shouldn't happen, really... */
	if (intsize != 3)
	return -EINVAL; /* Not GIC compliant */
	if (intspec[0] != 0)
	return -EINVAL; /* No PPI should point to this domain */

	*out_hwirq = intspec[1];
	*out_type = intspec[2];
	return 0;
	}

	static int imx_gpc_domain_alloc(struct irq_domain *domain,
	unsigned int irq,
	unsigned int nr_irqs, void *data)
	{
	struct of_phandle_args *args = data;
	struct of_phandle_args parent_args;
	irq_hw_number_t hwirq;
	int i;

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

	hwirq = args->args[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_chip, NULL);

	parent_args = *args;
	parent_args.np = domain->parent->of_node;
	return irq_domain_alloc_irqs_parent(domain, irq, nr_irqs, &parent_args);
	}

	static struct irq_domain_ops imx_gpc_domain_ops = {
	.xlate = imx_gpc_domain_xlate,
	.alloc = imx_gpc_domain_alloc,
	.free = irq_domain_free_irqs_common,
	};

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

	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;
	}

	gpc_base = of_iomap(node, 0);
	if (WARN_ON(!gpc_base))
	return -ENOMEM;

	domain = irq_domain_add_hierarchy(parent_domain, 0, GPC_MAX_IRQS,
	node, &imx_gpc_domain_ops,
	NULL);
	if (!domain) {
	iounmap(gpc_base);
	return -ENOMEM;
	}

	/* Initially mask all interrupts */
	for (i = 0; i < IMR_NUM; i++)
	writel_relaxed(~0, gpc_base + GPC_IMR1 + i * 4);

	return 0;
	}

	/*
	* We cannot use the IRQCHIP_DECLARE macro that lives in
	* drivers/irqchip, so we're forced to roll our own. Not very nice.
	*/
	OF_DECLARE_2(irqchip, imx_gpc, "fsl,imx6q-gpc", imx_gpc_init);

	void __init imx_gpc_check_dt(void)
	{
	struct device_node *np;

	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpc");
	if (WARN_ON(!np \|\|
	!of_find_property(np, "interrupt-controller", NULL)))
	pr_warn("Outdated DT detected, system is about to crash!!!\n");
	}

	#ifdef CONFIG_PM_GENERIC_DOMAINS

	static void _imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
	{
	int iso, iso2sw;
	u32 val;

	/* Read ISO and ISO2SW power down delays */
	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PDNSCR);
	iso = val & 0x3f;
	iso2sw = (val >> 8) & 0x3f;

	/* Gate off PU domain when GPU/VPU when powered down */
	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);

	/* Request GPC to power down GPU/VPU */
	val = readl_relaxed(gpc_base + GPC_CNTR);
	val \|= GPU_VPU_PDN_REQ;
	writel_relaxed(val, gpc_base + GPC_CNTR);

	/* Wait ISO + ISO2SW IPG clock cycles */
	ndelay((iso + iso2sw) * 1000 / 66);
	}

	static int imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
	{
	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);

	_imx6q_pm_pu_power_off(genpd);

	if (pu->reg)
	regulator_disable(pu->reg);

	return 0;
	}

	static int imx6q_pm_pu_power_on(struct generic_pm_domain *genpd)
	{
	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
	int i, ret, sw, sw2iso;
	u32 val;

	if (pu->reg)
	ret = regulator_enable(pu->reg);
	if (pu->reg && ret) {
	pr_err("%s: failed to enable regulator: %d\n", __func__, ret);
	return ret;
	}

	/* Enable reset clocks for all devices in the PU domain */
	for (i = 0; i < pu->num_clks; i++)
	clk_prepare_enable(pu->clk[i]);

	/* Gate off PU domain when GPU/VPU when powered down */
	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);

	/* Read ISO and ISO2SW power down delays */
	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PUPSCR);
	sw = val & 0x3f;
	sw2iso = (val >> 8) & 0x3f;

	/* Request GPC to power up GPU/VPU */
	val = readl_relaxed(gpc_base + GPC_CNTR);
	val \|= GPU_VPU_PUP_REQ;
	writel_relaxed(val, gpc_base + GPC_CNTR);

	/* Wait ISO + ISO2SW IPG clock cycles */
	ndelay((sw + sw2iso) * 1000 / 66);

	/* Disable reset clocks for all devices in the PU domain */
	for (i = 0; i < pu->num_clks; i++)
	clk_disable_unprepare(pu->clk[i]);

	return 0;
	}

	static struct generic_pm_domain imx6q_arm_domain = {
	.name = "ARM",
	};

	static struct pu_domain imx6q_pu_domain = {
	.base = {
	.name = "PU",
	.power_off = imx6q_pm_pu_power_off,
	.power_on = imx6q_pm_pu_power_on,
	.power_off_latency_ns = 25000,
	.power_on_latency_ns = 2000000,
	},
	};

	static struct generic_pm_domain imx6sl_display_domain = {
	.name = "DISPLAY",
	};

	static struct generic_pm_domain *imx_gpc_domains[] = {
	&imx6q_arm_domain,
	&imx6q_pu_domain.base,
	&imx6sl_display_domain,
	};

	static struct genpd_onecell_data imx_gpc_onecell_data = {
	.domains = imx_gpc_domains,
	.num_domains = ARRAY_SIZE(imx_gpc_domains),
	};

	static int imx_gpc_genpd_init(struct device dev, struct regulator pu_reg)
	{
	struct clk *clk;
	bool is_off;
	int i;

	imx6q_pu_domain.reg = pu_reg;

	for (i = 0; ; i++) {
	clk = of_clk_get(dev->of_node, i);
	if (IS_ERR(clk))
	break;
	if (i >= GPC_CLK_MAX) {
	dev_err(dev, "more than %d clocks\n", GPC_CLK_MAX);
	goto clk_err;
	}
	imx6q_pu_domain.clk[i] = clk;
	}
	imx6q_pu_domain.num_clks = i;

	is_off = IS_ENABLED(CONFIG_PM);
	if (is_off) {
	_imx6q_pm_pu_power_off(&imx6q_pu_domain.base);
	} else {
	/*
	* Enable power if compiled without CONFIG_PM in case the
	* bootloader disabled it.
	*/
	imx6q_pm_pu_power_on(&imx6q_pu_domain.base);
	}

	pm_genpd_init(&imx6q_pu_domain.base, NULL, is_off);
	return of_genpd_add_provider_onecell(dev->of_node,
	&imx_gpc_onecell_data);

	clk_err:
	while (i--)
	clk_put(imx6q_pu_domain.clk[i]);
	return -EINVAL;
	}

	#else
	static inline int imx_gpc_genpd_init(struct device dev, struct regulator reg)
	{
	return 0;
	}
	#endif /* CONFIG_PM_GENERIC_DOMAINS */

	static int imx_gpc_probe(struct platform_device *pdev)
	{
	struct regulator *pu_reg;
	int ret;

	pu_reg = devm_regulator_get_optional(&pdev->dev, "pu");
	if (PTR_ERR(pu_reg) == -ENODEV)
	pu_reg = NULL;
	if (IS_ERR(pu_reg)) {
	ret = PTR_ERR(pu_reg);
	dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
	return ret;
	}

	return imx_gpc_genpd_init(&pdev->dev, pu_reg);
	}

	static const struct of_device_id imx_gpc_dt_ids[] = {
	{ .compatible = "fsl,imx6q-gpc" },
	{ .compatible = "fsl,imx6sl-gpc" },
	{ }
	};

	static struct platform_driver imx_gpc_driver = {
	.driver = {
	.name = "imx-gpc",
	.owner = THIS_MODULE,
	.of_match_table = imx_gpc_dt_ids,
	},
	.probe = imx_gpc_probe,
	};

	static int __init imx_pgc_init(void)
	{
	return platform_driver_register(&imx_gpc_driver);
	}
	subsys_initcall(imx_pgc_init);