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

 /*
  * Copyright 2015-2017 Pengutronix, Lucas Stach <kernel@pengutronix.de>
  * Copyright 2011-2013 Freescale Semiconductor, Inc.
  *
  * 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/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>

 #define GPC_CNTR		0x000

 #define GPC_PGC_CTRL_OFFS	0x0
 #define GPC_PGC_PUPSCR_OFFS	0x4
 #define GPC_PGC_PDNSCR_OFFS	0x8
 #define GPC_PGC_SW2ISO_SHIFT	0x8
 #define GPC_PGC_SW_SHIFT	0x0

 #define GPC_PGC_PCI_PDN		0x200
 #define GPC_PGC_PCI_SR		0x20c

 #define GPC_PGC_GPU_PDN		0x260
 #define GPC_PGC_GPU_PUPSCR	0x264
 #define GPC_PGC_GPU_PDNSCR	0x268
 #define GPC_PGC_GPU_SR		0x26c

 #define GPC_PGC_DISP_PDN	0x240
 #define GPC_PGC_DISP_SR		0x24c

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

 #define GPC_CLK_MAX		6

 #define PGC_DOMAIN_FLAG_NO_PD		BIT(0)

 struct imx_pm_domain {
 	struct generic_pm_domain base;
 	struct regmap *regmap;
 	struct regulator *supply;
 	struct clk *clk[GPC_CLK_MAX];
 	int num_clks;
 	unsigned int reg_offs;
 	signed char cntr_pdn_bit;
 	unsigned int ipg_rate_mhz;
 };

 static inline struct imx_pm_domain *
 to_imx_pm_domain(struct generic_pm_domain *genpd)
 {
 	return container_of(genpd, struct imx_pm_domain, base);
 }

 static int imx6_pm_domain_power_off(struct generic_pm_domain *genpd)
 {
 	struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
 	int iso, iso2sw;
 	u32 val;

 	/* Read ISO and ISO2SW power down delays */
 	regmap_read(pd->regmap, pd->reg_offs + GPC_PGC_PDNSCR_OFFS, &val);
 	iso = val & 0x3f;
 	iso2sw = (val >> 8) & 0x3f;

 	/* Gate off domain when powered down */
 	regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_CTRL_OFFS,
 			   0x1, 0x1);

 	/* Request GPC to power down domain */
 	val = BIT(pd->cntr_pdn_bit);
 	regmap_update_bits(pd->regmap, GPC_CNTR, val, val);

 	/* Wait ISO + ISO2SW IPG clock cycles */
 	udelay(DIV_ROUND_UP(iso + iso2sw, pd->ipg_rate_mhz));

 	if (pd->supply)
 		regulator_disable(pd->supply);

 	return 0;
 }

 static int imx6_pm_domain_power_on(struct generic_pm_domain *genpd)
 {
 	struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
 	int i, ret;
 	u32 val, req;

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

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

 	/* Gate off domain when powered down */
 	regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_CTRL_OFFS,
 			   0x1, 0x1);

 	/* Request GPC to power up domain */
 	req = BIT(pd->cntr_pdn_bit + 1);
 	regmap_update_bits(pd->regmap, GPC_CNTR, req, req);

 	/* Wait for the PGC to handle the request */
 	ret = regmap_read_poll_timeout(pd->regmap, GPC_CNTR, val, !(val & req),
 				       1, 50);
 	if (ret)
 		pr_err("powerup request on domain %s timed out\n", genpd->name);

 	/* Wait for reset to propagate through peripherals */
 	usleep_range(5, 10);

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

 	return 0;
 }

 static int imx_pgc_get_clocks(struct device *dev, struct imx_pm_domain *domain)
 {
 	int i, ret;

 	for (i = 0; ; i++) {
 		struct clk *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);
 			ret = -EINVAL;
 			goto clk_err;
 		}
 		domain->clk[i] = clk;
 	}
 	domain->num_clks = i;

 	return 0;

 clk_err:
 	while (i--)
 		clk_put(domain->clk[i]);

 	return ret;
 }

 static void imx_pgc_put_clocks(struct imx_pm_domain *domain)
 {
 	int i;

 	for (i = domain->num_clks - 1; i >= 0; i--)
 		clk_put(domain->clk[i]);
 }

 static int imx_pgc_parse_dt(struct device *dev, struct imx_pm_domain *domain)
 {
 	/* try to get the domain supply regulator */
 	domain->supply = devm_regulator_get_optional(dev, "power");
 	if (IS_ERR(domain->supply)) {
 		if (PTR_ERR(domain->supply) == -ENODEV)
 			domain->supply = NULL;
 		else
 			return PTR_ERR(domain->supply);
 	}

 	/* try to get all clocks needed for reset propagation */
 	return imx_pgc_get_clocks(dev, domain);
 }

 static int imx_pgc_power_domain_probe(struct platform_device *pdev)
 {
 	struct imx_pm_domain *domain = pdev->dev.platform_data;
 	struct device *dev = &pdev->dev;
 	int ret;

 	/* if this PD is associated with a DT node try to parse it */
 	if (dev->of_node) {
 		ret = imx_pgc_parse_dt(dev, domain);
 		if (ret)
 			return ret;
 	}

 	/* initially power on the domain */
 	if (domain->base.power_on)
 		domain->base.power_on(&domain->base);

 	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
 		pm_genpd_init(&domain->base, NULL, false);
 		ret = of_genpd_add_provider_simple(dev->of_node, &domain->base);
 		if (ret)
 			goto genpd_err;
 	}

 	device_link_add(dev, dev->parent, DL_FLAG_AUTOREMOVE_CONSUMER);

 	return 0;

 genpd_err:
 	pm_genpd_remove(&domain->base);
 	imx_pgc_put_clocks(domain);

 	return ret;
 }

 static int imx_pgc_power_domain_remove(struct platform_device *pdev)
 {
 	struct imx_pm_domain *domain = pdev->dev.platform_data;

 	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
 		of_genpd_del_provider(pdev->dev.of_node);
 		pm_genpd_remove(&domain->base);
 		imx_pgc_put_clocks(domain);
 	}

 	return 0;
 }

 static const struct platform_device_id imx_pgc_power_domain_id[] = {
 	{ "imx-pgc-power-domain"},
 	{ },
 };

 static struct platform_driver imx_pgc_power_domain_driver = {
 	.driver = {
 		.name = "imx-pgc-pd",
 	},
 	.probe = imx_pgc_power_domain_probe,
 	.remove = imx_pgc_power_domain_remove,
 	.id_table = imx_pgc_power_domain_id,
 };
 builtin_platform_driver(imx_pgc_power_domain_driver)

 #define GPC_PGC_DOMAIN_ARM	0
 #define GPC_PGC_DOMAIN_PU	1
 #define GPC_PGC_DOMAIN_DISPLAY	2

 static struct genpd_power_state imx6_pm_domain_pu_state = {
 	.power_off_latency_ns = 25000,
 	.power_on_latency_ns = 2000000,
 };

 static struct imx_pm_domain imx_gpc_domains[] = {
 	{
 		.base = {
 			.name = "ARM",
 			.flags = GENPD_FLAG_ALWAYS_ON,
 		},
 	}, {
 		.base = {
 			.name = "PU",
 			.power_off = imx6_pm_domain_power_off,
 			.power_on = imx6_pm_domain_power_on,
 			.states = &imx6_pm_domain_pu_state,
 			.state_count = 1,
 		},
 		.reg_offs = 0x260,
 		.cntr_pdn_bit = 0,
 	}, {
 		.base = {
 			.name = "DISPLAY",
 			.power_off = imx6_pm_domain_power_off,
 			.power_on = imx6_pm_domain_power_on,
 		},
 		.reg_offs = 0x240,
 		.cntr_pdn_bit = 4,
 	}, {
 		.base = {
 			.name = "PCI",
 			.power_off = imx6_pm_domain_power_off,
 			.power_on = imx6_pm_domain_power_on,
 		},
 		.reg_offs = 0x200,
 		.cntr_pdn_bit = 6,
 	},
 };

 struct imx_gpc_dt_data {
 	int num_domains;
 	bool err009619_present;
 	bool err006287_present;
 };

 static const struct imx_gpc_dt_data imx6q_dt_data = {
 	.num_domains = 2,
 	.err009619_present = false,
 	.err006287_present = false,
 };

 static const struct imx_gpc_dt_data imx6qp_dt_data = {
 	.num_domains = 2,
 	.err009619_present = true,
 	.err006287_present = false,
 };

 static const struct imx_gpc_dt_data imx6sl_dt_data = {
 	.num_domains = 3,
 	.err009619_present = false,
 	.err006287_present = true,
 };

 static const struct imx_gpc_dt_data imx6sx_dt_data = {
 	.num_domains = 4,
 	.err009619_present = false,
 	.err006287_present = false,
 };

 static const struct of_device_id imx_gpc_dt_ids[] = {
 	{ .compatible = "fsl,imx6q-gpc", .data = &imx6q_dt_data },
 	{ .compatible = "fsl,imx6qp-gpc", .data = &imx6qp_dt_data },
 	{ .compatible = "fsl,imx6sl-gpc", .data = &imx6sl_dt_data },
 	{ .compatible = "fsl,imx6sx-gpc", .data = &imx6sx_dt_data },
 	{ }
 };

 static const struct regmap_range yes_ranges[] = {
 	regmap_reg_range(GPC_CNTR, GPC_CNTR),
 	regmap_reg_range(GPC_PGC_PCI_PDN, GPC_PGC_PCI_SR),
 	regmap_reg_range(GPC_PGC_GPU_PDN, GPC_PGC_GPU_SR),
 	regmap_reg_range(GPC_PGC_DISP_PDN, GPC_PGC_DISP_SR),
 };

 static const struct regmap_access_table access_table = {
 	.yes_ranges	= yes_ranges,
 	.n_yes_ranges	= ARRAY_SIZE(yes_ranges),
 };

 static const struct regmap_config imx_gpc_regmap_config = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.reg_stride = 4,
 	.rd_table = &access_table,
 	.wr_table = &access_table,
 	.max_register = 0x2ac,
 	.fast_io = true,
 };

 static struct generic_pm_domain *imx_gpc_onecell_domains[] = {
 	&imx_gpc_domains[0].base,
 	&imx_gpc_domains[1].base,
 };

 static struct genpd_onecell_data imx_gpc_onecell_data = {
 	.domains = imx_gpc_onecell_domains,
 	.num_domains = 2,
 };

 static int imx_gpc_old_dt_init(struct device *dev, struct regmap *regmap,
 			       unsigned int num_domains)
 {
 	struct imx_pm_domain *domain;
 	int i, ret;

 	for (i = 0; i < num_domains; i++) {
 		domain = &imx_gpc_domains[i];
 		domain->regmap = regmap;
 		domain->ipg_rate_mhz = 66;

 		if (i == 1) {
 			domain->supply = devm_regulator_get(dev, "pu");
 			if (IS_ERR(domain->supply))
 				return PTR_ERR(domain->supply);

 			ret = imx_pgc_get_clocks(dev, domain);
 			if (ret)
 				goto clk_err;

 			domain->base.power_on(&domain->base);
 		}
 	}

 	for (i = 0; i < num_domains; i++)
 		pm_genpd_init(&imx_gpc_domains[i].base, NULL, false);

 	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
 		ret = of_genpd_add_provider_onecell(dev->of_node,
 						    &imx_gpc_onecell_data);
 		if (ret)
 			goto genpd_err;
 	}

 	return 0;

 genpd_err:
 	for (i = 0; i < num_domains; i++)
 		pm_genpd_remove(&imx_gpc_domains[i].base);
 	imx_pgc_put_clocks(&imx_gpc_domains[GPC_PGC_DOMAIN_PU]);
 clk_err:
 	return ret;
 }

 static int imx_gpc_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *of_id =
 			of_match_device(imx_gpc_dt_ids, &pdev->dev);
 	const struct imx_gpc_dt_data *of_id_data = of_id->data;
 	struct device_node *pgc_node;
 	struct regmap *regmap;
 	struct resource *res;
 	void __iomem *base;
 	int ret;

 	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");

 	/* bail out if DT too old and doesn't provide the necessary info */
 	if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells") &&
 	    !pgc_node)
 		return 0;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(base))
 		return PTR_ERR(base);

 	regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
 					   &imx_gpc_regmap_config);
 	if (IS_ERR(regmap)) {
 		ret = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "failed to init regmap: %d\n",
 			ret);
 		return ret;
 	}

 	/* Disable PU power down in normal operation if ERR009619 is present */
 	if (of_id_data->err009619_present)
 		imx_gpc_domains[GPC_PGC_DOMAIN_PU].base.flags |=
 				GENPD_FLAG_ALWAYS_ON;

 	/* Keep DISP always on if ERR006287 is present */
 	if (of_id_data->err006287_present)
 		imx_gpc_domains[GPC_PGC_DOMAIN_DISPLAY].base.flags |=
 				GENPD_FLAG_ALWAYS_ON;

 	if (!pgc_node) {
 		ret = imx_gpc_old_dt_init(&pdev->dev, regmap,
 					  of_id_data->num_domains);
 		if (ret)
 			return ret;
 	} else {
 		struct imx_pm_domain *domain;
 		struct platform_device *pd_pdev;
 		struct device_node *np;
 		struct clk *ipg_clk;
 		unsigned int ipg_rate_mhz;
 		int domain_index;

 		ipg_clk = devm_clk_get(&pdev->dev, "ipg");
 		if (IS_ERR(ipg_clk))
 			return PTR_ERR(ipg_clk);
 		ipg_rate_mhz = clk_get_rate(ipg_clk) / 1000000;

 		for_each_child_of_node(pgc_node, np) {
 			ret = of_property_read_u32(np, "reg", &domain_index);
 			if (ret) {
 				of_node_put(np);
 				return ret;
 			}
 			if (domain_index >= of_id_data->num_domains)
 				continue;

 			pd_pdev = platform_device_alloc("imx-pgc-power-domain",
 							domain_index);
 			if (!pd_pdev) {
 				of_node_put(np);
 				return -ENOMEM;
 			}

 			ret = platform_device_add_data(pd_pdev,
 						       &imx_gpc_domains[domain_index],
 						       sizeof(imx_gpc_domains[domain_index]));
 			if (ret) {
 				platform_device_put(pd_pdev);
 				of_node_put(np);
 				return ret;
 			}
 			domain = pd_pdev->dev.platform_data;
 			domain->regmap = regmap;
 			domain->ipg_rate_mhz = ipg_rate_mhz;

 			pd_pdev->dev.parent = &pdev->dev;
 			pd_pdev->dev.of_node = np;

 			ret = platform_device_add(pd_pdev);
 			if (ret) {
 				platform_device_put(pd_pdev);
 				of_node_put(np);
 				return ret;
 			}
 		}
 	}

 	return 0;
 }

 static int imx_gpc_remove(struct platform_device *pdev)
 {
 	struct device_node *pgc_node;
 	int ret;

 	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");

 	/* bail out if DT too old and doesn't provide the necessary info */
 	if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells") &&
 	    !pgc_node)
 		return 0;

 	/*
 	 * If the old DT binding is used the toplevel driver needs to
 	 * de-register the power domains
 	 */
 	if (!pgc_node) {
 		of_genpd_del_provider(pdev->dev.of_node);

 		ret = pm_genpd_remove(&imx_gpc_domains[GPC_PGC_DOMAIN_PU].base);
 		if (ret)
 			return ret;
 		imx_pgc_put_clocks(&imx_gpc_domains[GPC_PGC_DOMAIN_PU]);

 		ret = pm_genpd_remove(&imx_gpc_domains[GPC_PGC_DOMAIN_ARM].base);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 static struct platform_driver imx_gpc_driver = {
 	.driver = {
 		.name = "imx-gpc",
 		.of_match_table = imx_gpc_dt_ids,
 	},
 	.probe = imx_gpc_probe,
 	.remove = imx_gpc_remove,
 };
 builtin_platform_driver(imx_gpc_driver)
	/*
	* Copyright 2015-2017 Pengutronix, Lucas Stach <kernel@pengutronix.de>
	* Copyright 2011-2013 Freescale Semiconductor, Inc.
	*
	* 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/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/pm_domain.h>
	#include <linux/regmap.h>
	#include <linux/regulator/consumer.h>

	#define GPC_CNTR 0x000

	#define GPC_PGC_CTRL_OFFS 0x0
	#define GPC_PGC_PUPSCR_OFFS 0x4
	#define GPC_PGC_PDNSCR_OFFS 0x8
	#define GPC_PGC_SW2ISO_SHIFT 0x8
	#define GPC_PGC_SW_SHIFT 0x0

	#define GPC_PGC_PCI_PDN 0x200
	#define GPC_PGC_PCI_SR 0x20c

	#define GPC_PGC_GPU_PDN 0x260
	#define GPC_PGC_GPU_PUPSCR 0x264
	#define GPC_PGC_GPU_PDNSCR 0x268
	#define GPC_PGC_GPU_SR 0x26c

	#define GPC_PGC_DISP_PDN 0x240
	#define GPC_PGC_DISP_SR 0x24c

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

	#define GPC_CLK_MAX 6

	#define PGC_DOMAIN_FLAG_NO_PD BIT(0)

	struct imx_pm_domain {
	struct generic_pm_domain base;
	struct regmap *regmap;
	struct regulator *supply;
	struct clk *clk[GPC_CLK_MAX];
	int num_clks;
	unsigned int reg_offs;
	signed char cntr_pdn_bit;
	unsigned int ipg_rate_mhz;
	};

	static inline struct imx_pm_domain *
	to_imx_pm_domain(struct generic_pm_domain *genpd)
	{
	return container_of(genpd, struct imx_pm_domain, base);
	}

	static int imx6_pm_domain_power_off(struct generic_pm_domain *genpd)
	{
	struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
	int iso, iso2sw;
	u32 val;

	/* Read ISO and ISO2SW power down delays */
	regmap_read(pd->regmap, pd->reg_offs + GPC_PGC_PDNSCR_OFFS, &val);
	iso = val & 0x3f;
	iso2sw = (val >> 8) & 0x3f;

	/* Gate off domain when powered down */
	regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_CTRL_OFFS,
	0x1, 0x1);

	/* Request GPC to power down domain */
	val = BIT(pd->cntr_pdn_bit);
	regmap_update_bits(pd->regmap, GPC_CNTR, val, val);

	/* Wait ISO + ISO2SW IPG clock cycles */
	udelay(DIV_ROUND_UP(iso + iso2sw, pd->ipg_rate_mhz));

	if (pd->supply)
	regulator_disable(pd->supply);

	return 0;
	}

	static int imx6_pm_domain_power_on(struct generic_pm_domain *genpd)
	{
	struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
	int i, ret;
	u32 val, req;

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

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

	/* Gate off domain when powered down */
	regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_CTRL_OFFS,
	0x1, 0x1);

	/* Request GPC to power up domain */
	req = BIT(pd->cntr_pdn_bit + 1);
	regmap_update_bits(pd->regmap, GPC_CNTR, req, req);

	/* Wait for the PGC to handle the request */
	ret = regmap_read_poll_timeout(pd->regmap, GPC_CNTR, val, !(val & req),
	1, 50);
	if (ret)
	pr_err("powerup request on domain %s timed out\n", genpd->name);

	/* Wait for reset to propagate through peripherals */
	usleep_range(5, 10);

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

	return 0;
	}

	static int imx_pgc_get_clocks(struct device dev, struct imx_pm_domain domain)
	{
	int i, ret;

	for (i = 0; ; i++) {
	struct clk *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);
	ret = -EINVAL;
	goto clk_err;
	}
	domain->clk[i] = clk;
	}
	domain->num_clks = i;

	return 0;

	clk_err:
	while (i--)
	clk_put(domain->clk[i]);

	return ret;
	}

	static void imx_pgc_put_clocks(struct imx_pm_domain *domain)
	{
	int i;

	for (i = domain->num_clks - 1; i >= 0; i--)
	clk_put(domain->clk[i]);
	}

	static int imx_pgc_parse_dt(struct device dev, struct imx_pm_domain domain)
	{
	/* try to get the domain supply regulator */
	domain->supply = devm_regulator_get_optional(dev, "power");
	if (IS_ERR(domain->supply)) {
	if (PTR_ERR(domain->supply) == -ENODEV)
	domain->supply = NULL;
	else
	return PTR_ERR(domain->supply);
	}

	/* try to get all clocks needed for reset propagation */
	return imx_pgc_get_clocks(dev, domain);
	}

	static int imx_pgc_power_domain_probe(struct platform_device *pdev)
	{
	struct imx_pm_domain *domain = pdev->dev.platform_data;
	struct device *dev = &pdev->dev;
	int ret;

	/* if this PD is associated with a DT node try to parse it */
	if (dev->of_node) {
	ret = imx_pgc_parse_dt(dev, domain);
	if (ret)
	return ret;
	}

	/* initially power on the domain */
	if (domain->base.power_on)
	domain->base.power_on(&domain->base);

	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
	pm_genpd_init(&domain->base, NULL, false);
	ret = of_genpd_add_provider_simple(dev->of_node, &domain->base);
	if (ret)
	goto genpd_err;
	}

	device_link_add(dev, dev->parent, DL_FLAG_AUTOREMOVE_CONSUMER);

	return 0;

	genpd_err:
	pm_genpd_remove(&domain->base);
	imx_pgc_put_clocks(domain);

	return ret;
	}

	static int imx_pgc_power_domain_remove(struct platform_device *pdev)
	{
	struct imx_pm_domain *domain = pdev->dev.platform_data;

	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
	of_genpd_del_provider(pdev->dev.of_node);
	pm_genpd_remove(&domain->base);
	imx_pgc_put_clocks(domain);
	}

	return 0;
	}

	static const struct platform_device_id imx_pgc_power_domain_id[] = {
	{ "imx-pgc-power-domain"},
	{ },
	};

	static struct platform_driver imx_pgc_power_domain_driver = {
	.driver = {
	.name = "imx-pgc-pd",
	},
	.probe = imx_pgc_power_domain_probe,
	.remove = imx_pgc_power_domain_remove,
	.id_table = imx_pgc_power_domain_id,
	};
	builtin_platform_driver(imx_pgc_power_domain_driver)

	#define GPC_PGC_DOMAIN_ARM 0
	#define GPC_PGC_DOMAIN_PU 1
	#define GPC_PGC_DOMAIN_DISPLAY 2

	static struct genpd_power_state imx6_pm_domain_pu_state = {
	.power_off_latency_ns = 25000,
	.power_on_latency_ns = 2000000,
	};

	static struct imx_pm_domain imx_gpc_domains[] = {
	{
	.base = {
	.name = "ARM",
	.flags = GENPD_FLAG_ALWAYS_ON,
	},
	}, {
	.base = {
	.name = "PU",
	.power_off = imx6_pm_domain_power_off,
	.power_on = imx6_pm_domain_power_on,
	.states = &imx6_pm_domain_pu_state,
	.state_count = 1,
	},
	.reg_offs = 0x260,
	.cntr_pdn_bit = 0,
	}, {
	.base = {
	.name = "DISPLAY",
	.power_off = imx6_pm_domain_power_off,
	.power_on = imx6_pm_domain_power_on,
	},
	.reg_offs = 0x240,
	.cntr_pdn_bit = 4,
	}, {
	.base = {
	.name = "PCI",
	.power_off = imx6_pm_domain_power_off,
	.power_on = imx6_pm_domain_power_on,
	},
	.reg_offs = 0x200,
	.cntr_pdn_bit = 6,
	},
	};

	struct imx_gpc_dt_data {
	int num_domains;
	bool err009619_present;
	bool err006287_present;
	};

	static const struct imx_gpc_dt_data imx6q_dt_data = {
	.num_domains = 2,
	.err009619_present = false,
	.err006287_present = false,
	};

	static const struct imx_gpc_dt_data imx6qp_dt_data = {
	.num_domains = 2,
	.err009619_present = true,
	.err006287_present = false,
	};

	static const struct imx_gpc_dt_data imx6sl_dt_data = {
	.num_domains = 3,
	.err009619_present = false,
	.err006287_present = true,
	};

	static const struct imx_gpc_dt_data imx6sx_dt_data = {
	.num_domains = 4,
	.err009619_present = false,
	.err006287_present = false,
	};

	static const struct of_device_id imx_gpc_dt_ids[] = {
	{ .compatible = "fsl,imx6q-gpc", .data = &imx6q_dt_data },
	{ .compatible = "fsl,imx6qp-gpc", .data = &imx6qp_dt_data },
	{ .compatible = "fsl,imx6sl-gpc", .data = &imx6sl_dt_data },
	{ .compatible = "fsl,imx6sx-gpc", .data = &imx6sx_dt_data },
	{ }
	};

	static const struct regmap_range yes_ranges[] = {
	regmap_reg_range(GPC_CNTR, GPC_CNTR),
	regmap_reg_range(GPC_PGC_PCI_PDN, GPC_PGC_PCI_SR),
	regmap_reg_range(GPC_PGC_GPU_PDN, GPC_PGC_GPU_SR),
	regmap_reg_range(GPC_PGC_DISP_PDN, GPC_PGC_DISP_SR),
	};

	static const struct regmap_access_table access_table = {
	.yes_ranges = yes_ranges,
	.n_yes_ranges = ARRAY_SIZE(yes_ranges),
	};

	static const struct regmap_config imx_gpc_regmap_config = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.rd_table = &access_table,
	.wr_table = &access_table,
	.max_register = 0x2ac,
	.fast_io = true,
	};

	static struct generic_pm_domain *imx_gpc_onecell_domains[] = {
	&imx_gpc_domains[0].base,
	&imx_gpc_domains[1].base,
	};

	static struct genpd_onecell_data imx_gpc_onecell_data = {
	.domains = imx_gpc_onecell_domains,
	.num_domains = 2,
	};

	static int imx_gpc_old_dt_init(struct device dev, struct regmap regmap,
	unsigned int num_domains)
	{
	struct imx_pm_domain *domain;
	int i, ret;

	for (i = 0; i < num_domains; i++) {
	domain = &imx_gpc_domains[i];
	domain->regmap = regmap;
	domain->ipg_rate_mhz = 66;

	if (i == 1) {
	domain->supply = devm_regulator_get(dev, "pu");
	if (IS_ERR(domain->supply))
	return PTR_ERR(domain->supply);

	ret = imx_pgc_get_clocks(dev, domain);
	if (ret)
	goto clk_err;

	domain->base.power_on(&domain->base);
	}
	}

	for (i = 0; i < num_domains; i++)
	pm_genpd_init(&imx_gpc_domains[i].base, NULL, false);

	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
	ret = of_genpd_add_provider_onecell(dev->of_node,
	&imx_gpc_onecell_data);
	if (ret)
	goto genpd_err;
	}

	return 0;

	genpd_err:
	for (i = 0; i < num_domains; i++)
	pm_genpd_remove(&imx_gpc_domains[i].base);
	imx_pgc_put_clocks(&imx_gpc_domains[GPC_PGC_DOMAIN_PU]);
	clk_err:
	return ret;
	}

	static int imx_gpc_probe(struct platform_device *pdev)
	{
	const struct of_device_id *of_id =
	of_match_device(imx_gpc_dt_ids, &pdev->dev);
	const struct imx_gpc_dt_data *of_id_data = of_id->data;
	struct device_node *pgc_node;
	struct regmap *regmap;
	struct resource *res;
	void __iomem *base;
	int ret;

	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");

	/* bail out if DT too old and doesn't provide the necessary info */
	if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells") &&
	!pgc_node)
	return 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base))
	return PTR_ERR(base);

	regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
	&imx_gpc_regmap_config);
	if (IS_ERR(regmap)) {
	ret = PTR_ERR(regmap);
	dev_err(&pdev->dev, "failed to init regmap: %d\n",
	ret);
	return ret;
	}

	/* Disable PU power down in normal operation if ERR009619 is present */
	if (of_id_data->err009619_present)
	imx_gpc_domains[GPC_PGC_DOMAIN_PU].base.flags \|=
	GENPD_FLAG_ALWAYS_ON;

	/* Keep DISP always on if ERR006287 is present */
	if (of_id_data->err006287_present)
	imx_gpc_domains[GPC_PGC_DOMAIN_DISPLAY].base.flags \|=
	GENPD_FLAG_ALWAYS_ON;

	if (!pgc_node) {
	ret = imx_gpc_old_dt_init(&pdev->dev, regmap,
	of_id_data->num_domains);
	if (ret)
	return ret;
	} else {
	struct imx_pm_domain *domain;
	struct platform_device *pd_pdev;
	struct device_node *np;
	struct clk *ipg_clk;
	unsigned int ipg_rate_mhz;
	int domain_index;

	ipg_clk = devm_clk_get(&pdev->dev, "ipg");
	if (IS_ERR(ipg_clk))
	return PTR_ERR(ipg_clk);
	ipg_rate_mhz = clk_get_rate(ipg_clk) / 1000000;

	for_each_child_of_node(pgc_node, np) {
	ret = of_property_read_u32(np, "reg", &domain_index);
	if (ret) {
	of_node_put(np);
	return ret;
	}
	if (domain_index >= of_id_data->num_domains)
	continue;

	pd_pdev = platform_device_alloc("imx-pgc-power-domain",
	domain_index);
	if (!pd_pdev) {
	of_node_put(np);
	return -ENOMEM;
	}

	ret = platform_device_add_data(pd_pdev,
	&imx_gpc_domains[domain_index],
	sizeof(imx_gpc_domains[domain_index]));
	if (ret) {
	platform_device_put(pd_pdev);
	of_node_put(np);
	return ret;
	}
	domain = pd_pdev->dev.platform_data;
	domain->regmap = regmap;
	domain->ipg_rate_mhz = ipg_rate_mhz;

	pd_pdev->dev.parent = &pdev->dev;
	pd_pdev->dev.of_node = np;

	ret = platform_device_add(pd_pdev);
	if (ret) {
	platform_device_put(pd_pdev);
	of_node_put(np);
	return ret;
	}
	}
	}

	return 0;
	}

	static int imx_gpc_remove(struct platform_device *pdev)
	{
	struct device_node *pgc_node;
	int ret;

	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");

	/* bail out if DT too old and doesn't provide the necessary info */
	if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells") &&
	!pgc_node)
	return 0;

	/*
	* If the old DT binding is used the toplevel driver needs to
	* de-register the power domains
	*/
	if (!pgc_node) {
	of_genpd_del_provider(pdev->dev.of_node);

	ret = pm_genpd_remove(&imx_gpc_domains[GPC_PGC_DOMAIN_PU].base);
	if (ret)
	return ret;
	imx_pgc_put_clocks(&imx_gpc_domains[GPC_PGC_DOMAIN_PU]);

	ret = pm_genpd_remove(&imx_gpc_domains[GPC_PGC_DOMAIN_ARM].base);
	if (ret)
	return ret;
	}

	return 0;
	}

	static struct platform_driver imx_gpc_driver = {
	.driver = {
	.name = "imx-gpc",
	.of_match_table = imx_gpc_dt_ids,
	},
	.probe = imx_gpc_probe,
	.remove = imx_gpc_remove,
	};
	builtin_platform_driver(imx_gpc_driver)