text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * Copyright (c) 2020 Collabora Ltd.
   */
  #include <linux/clk.h>
  #include <linux/clk-provider.h>
  #include <linux/init.h>
  #include <linux/io.h>
  #include <linux/iopoll.h>
  #include <linux/mfd/syscon.h>
  #include <linux/of_clk.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>
  #include <linux/soc/mediatek/infracfg.h>
  
  #include "mt8167-pm-domains.h"
  #include "mt8173-pm-domains.h"
  #include "mt8183-pm-domains.h"
  #include "mt8192-pm-domains.h"
  
  #define MTK_POLL_DELAY_US		10
  #define MTK_POLL_TIMEOUT		USEC_PER_SEC
  
  #define PWR_RST_B_BIT			BIT(0)
  #define PWR_ISO_BIT			BIT(1)
  #define PWR_ON_BIT			BIT(2)
  #define PWR_ON_2ND_BIT			BIT(3)
  #define PWR_CLK_DIS_BIT			BIT(4)
  #define PWR_SRAM_CLKISO_BIT		BIT(5)
  #define PWR_SRAM_ISOINT_B_BIT		BIT(6)
  
  struct scpsys_domain {
  	struct generic_pm_domain genpd;
  	const struct scpsys_domain_data *data;
  	struct scpsys *scpsys;
  	int num_clks;
  	struct clk_bulk_data *clks;
  	int num_subsys_clks;
  	struct clk_bulk_data *subsys_clks;
  	struct regmap *infracfg;
  	struct regmap *smi;
  	struct regulator *supply;
  };
  
  struct scpsys {
  	struct device *dev;
  	struct regmap *base;
  	const struct scpsys_soc_data *soc_data;
  	struct genpd_onecell_data pd_data;
  	struct generic_pm_domain *domains[];
  };
  
  #define to_scpsys_domain(gpd) container_of(gpd, struct scpsys_domain, genpd)
  
  static bool scpsys_domain_is_on(struct scpsys_domain *pd)
  {
  	struct scpsys *scpsys = pd->scpsys;
  	u32 status, status2;
  
  	regmap_read(scpsys->base, scpsys->soc_data->pwr_sta_offs, &status);
  	status &= pd->data->sta_mask;
  
  	regmap_read(scpsys->base, scpsys->soc_data->pwr_sta2nd_offs, &status2);
  	status2 &= pd->data->sta_mask;
  
  	/* A domain is on when both status bits are set. */
  	return status && status2;
  }
  
  static int scpsys_sram_enable(struct scpsys_domain *pd)
  {
  	u32 pdn_ack = pd->data->sram_pdn_ack_bits;
  	struct scpsys *scpsys = pd->scpsys;
  	unsigned int tmp;
  	int ret;
  
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, pd->data->sram_pdn_bits);
  
  	/* Either wait until SRAM_PDN_ACK all 1 or 0 */
  	ret = regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
  				       (tmp & pdn_ack) == 0, MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  	if (ret < 0)
  		return ret;
  
  	if (MTK_SCPD_CAPS(pd, MTK_SCPD_SRAM_ISO)) {
  		regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_SRAM_ISOINT_B_BIT);
  		udelay(1);
  		regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_SRAM_CLKISO_BIT);
  	}
  
  	return 0;
  }
  
  static int scpsys_sram_disable(struct scpsys_domain *pd)
  {
  	u32 pdn_ack = pd->data->sram_pdn_ack_bits;
  	struct scpsys *scpsys = pd->scpsys;
  	unsigned int tmp;
  
  	if (MTK_SCPD_CAPS(pd, MTK_SCPD_SRAM_ISO)) {
  		regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_SRAM_CLKISO_BIT);
  		udelay(1);
  		regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_SRAM_ISOINT_B_BIT);
  	}
  
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, pd->data->sram_pdn_bits);
  
  	/* Either wait until SRAM_PDN_ACK all 1 or 0 */
  	return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
  					(tmp & pdn_ack) == pdn_ack, MTK_POLL_DELAY_US,
  					MTK_POLL_TIMEOUT);
  }
  
  static int _scpsys_bus_protect_enable(const struct scpsys_bus_prot_data *bpd, struct regmap *regmap)
  {
  	int i, ret;
  
  	for (i = 0; i < SPM_MAX_BUS_PROT_DATA; i++) {
  		u32 val, mask = bpd[i].bus_prot_mask;
  
  		if (!mask)
  			break;
  
  		if (bpd[i].bus_prot_reg_update)
  			regmap_set_bits(regmap, bpd[i].bus_prot_set, mask);
  		else
  			regmap_write(regmap, bpd[i].bus_prot_set, mask);
  
  		ret = regmap_read_poll_timeout(regmap, bpd[i].bus_prot_sta,
  					       val, (val & mask) == mask,
  					       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  		if (ret)
  			return ret;
  	}
  
  	return 0;
  }
  
  static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
  {
  	int ret;
  
  	ret = _scpsys_bus_protect_enable(pd->data->bp_infracfg, pd->infracfg);
  	if (ret)
  		return ret;
  
  	return _scpsys_bus_protect_enable(pd->data->bp_smi, pd->smi);
  }
  
  static int _scpsys_bus_protect_disable(const struct scpsys_bus_prot_data *bpd,
  				       struct regmap *regmap)
  {
  	int i, ret;
  
  	for (i = SPM_MAX_BUS_PROT_DATA - 1; i >= 0; i--) {
  		u32 val, mask = bpd[i].bus_prot_mask;
  
  		if (!mask)
  			continue;
  
  		if (bpd[i].bus_prot_reg_update)
  			regmap_clear_bits(regmap, bpd[i].bus_prot_clr, mask);
  		else
  			regmap_write(regmap, bpd[i].bus_prot_clr, mask);
  
  		if (bpd[i].ignore_clr_ack)
  			continue;
  
  		ret = regmap_read_poll_timeout(regmap, bpd[i].bus_prot_sta,
  					       val, !(val & mask),
  					       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  		if (ret)
  			return ret;
  	}
  
  	return 0;
  }
  
  static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
  {
  	int ret;
  
  	ret = _scpsys_bus_protect_disable(pd->data->bp_smi, pd->smi);
  	if (ret)
  		return ret;
  
  	return _scpsys_bus_protect_disable(pd->data->bp_infracfg, pd->infracfg);
  }
  
  static int scpsys_regulator_enable(struct regulator *supply)
  {
  	return supply ? regulator_enable(supply) : 0;
  }
  
  static int scpsys_regulator_disable(struct regulator *supply)
  {
  	return supply ? regulator_disable(supply) : 0;
  }
  
  static int scpsys_power_on(struct generic_pm_domain *genpd)
  {
  	struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
  	struct scpsys *scpsys = pd->scpsys;
  	bool tmp;
  	int ret;
  
  	ret = scpsys_regulator_enable(pd->supply);
  	if (ret)
  		return ret;
  
  	ret = clk_bulk_prepare_enable(pd->num_clks, pd->clks);
  	if (ret)
  		goto err_reg;
  
  	/* subsys power on */
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_2ND_BIT);
  
  	/* wait until PWR_ACK = 1 */
  	ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp, MTK_POLL_DELAY_US,
  				 MTK_POLL_TIMEOUT);
  	if (ret < 0)
  		goto err_pwr_ack;
  
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_CLK_DIS_BIT);
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ISO_BIT);
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
  
  	ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
  	if (ret)
  		goto err_pwr_ack;
  
  	ret = scpsys_sram_enable(pd);
  	if (ret < 0)
  		goto err_disable_subsys_clks;
  
  	ret = scpsys_bus_protect_disable(pd);
  	if (ret < 0)
  		goto err_disable_sram;
  
  	return 0;
  
  err_disable_sram:
  	scpsys_sram_disable(pd);
  err_disable_subsys_clks:
  	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
  err_pwr_ack:
  	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
  err_reg:
  	scpsys_regulator_disable(pd->supply);
  	return ret;
  }
  
  static int scpsys_power_off(struct generic_pm_domain *genpd)
  {
  	struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
  	struct scpsys *scpsys = pd->scpsys;
  	bool tmp;
  	int ret;
  
  	ret = scpsys_bus_protect_enable(pd);
  	if (ret < 0)
  		return ret;
  
  	ret = scpsys_sram_disable(pd);
  	if (ret < 0)
  		return ret;
  
  	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
  
  	/* subsys power off */
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ISO_BIT);
  	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_CLK_DIS_BIT);
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_2ND_BIT);
  	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
  
  	/* wait until PWR_ACK = 0 */
  	ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, !tmp, MTK_POLL_DELAY_US,
  				 MTK_POLL_TIMEOUT);
  	if (ret < 0)
  		return ret;
  
  	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
  
  	scpsys_regulator_disable(pd->supply);
  
  	return 0;
  }
  
  static struct
  generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node)
  {
  	const struct scpsys_domain_data *domain_data;
  	struct scpsys_domain *pd;
  	struct device_node *root_node = scpsys->dev->of_node;
  	struct device_node *smi_node;
  	struct property *prop;
  	const char *clk_name;
  	int i, ret, num_clks;
  	struct clk *clk;
  	int clk_ind = 0;
  	u32 id;
  
  	ret = of_property_read_u32(node, "reg", &id);
  	if (ret) {
  		dev_err(scpsys->dev, "%pOF: failed to retrieve domain id from reg: %d\n",
  			node, ret);
  		return ERR_PTR(-EINVAL);
  	}
  
  	if (id >= scpsys->soc_data->num_domains) {
  		dev_err(scpsys->dev, "%pOF: invalid domain id %d\n", node, id);
  		return ERR_PTR(-EINVAL);
  	}
  
  	domain_data = &scpsys->soc_data->domains_data[id];
  	if (domain_data->sta_mask == 0) {
  		dev_err(scpsys->dev, "%pOF: undefined domain id %d\n", node, id);
  		return ERR_PTR(-EINVAL);
  	}
  
  	pd = devm_kzalloc(scpsys->dev, sizeof(*pd), GFP_KERNEL);
  	if (!pd)
  		return ERR_PTR(-ENOMEM);
  
  	pd->data = domain_data;
  	pd->scpsys = scpsys;
  
  	if (MTK_SCPD_CAPS(pd, MTK_SCPD_DOMAIN_SUPPLY)) {
  		/*
  		 * Find regulator in current power domain node.
  		 * devm_regulator_get() finds regulator in a node and its child
  		 * node, so set of_node to current power domain node then change
  		 * back to original node after regulator is found for current
  		 * power domain node.
  		 */
  		scpsys->dev->of_node = node;
  		pd->supply = devm_regulator_get(scpsys->dev, "domain");
  		scpsys->dev->of_node = root_node;
  		if (IS_ERR(pd->supply)) {
  			dev_err_probe(scpsys->dev, PTR_ERR(pd->supply),
  				      "%pOF: failed to get power supply.\n",
  				      node);
  			return ERR_CAST(pd->supply);
  		}
  	}
  
  	pd->infracfg = syscon_regmap_lookup_by_phandle_optional(node, "mediatek,infracfg");
  	if (IS_ERR(pd->infracfg))
  		return ERR_CAST(pd->infracfg);
  
  	smi_node = of_parse_phandle(node, "mediatek,smi", 0);
  	if (smi_node) {
  		pd->smi = device_node_to_regmap(smi_node);
  		of_node_put(smi_node);
  		if (IS_ERR(pd->smi))
  			return ERR_CAST(pd->smi);
  	}
  
  	num_clks = of_clk_get_parent_count(node);
  	if (num_clks > 0) {
  		/* Calculate number of subsys_clks */
  		of_property_for_each_string(node, "clock-names", prop, clk_name) {
  			char *subsys;
  
  			subsys = strchr(clk_name, '-');
  			if (subsys)
  				pd->num_subsys_clks++;
  			else
  				pd->num_clks++;
  		}
  
  		pd->clks = devm_kcalloc(scpsys->dev, pd->num_clks, sizeof(*pd->clks), GFP_KERNEL);
  		if (!pd->clks)
  			return ERR_PTR(-ENOMEM);
  
  		pd->subsys_clks = devm_kcalloc(scpsys->dev, pd->num_subsys_clks,
  					       sizeof(*pd->subsys_clks), GFP_KERNEL);
  		if (!pd->subsys_clks)
  			return ERR_PTR(-ENOMEM);
  
  	}
  
  	for (i = 0; i < pd->num_clks; i++) {
  		clk = of_clk_get(node, i);
  		if (IS_ERR(clk)) {
  			ret = PTR_ERR(clk);
  			dev_err_probe(scpsys->dev, ret,
  				      "%pOF: failed to get clk at index %d: %d\n", node, i, ret);
  			goto err_put_clocks;
  		}
  
  		pd->clks[clk_ind++].clk = clk;
  	}
  
  	for (i = 0; i < pd->num_subsys_clks; i++) {
  		clk = of_clk_get(node, i + clk_ind);
  		if (IS_ERR(clk)) {
  			ret = PTR_ERR(clk);
  			dev_err_probe(scpsys->dev, ret,
  				      "%pOF: failed to get clk at index %d: %d\n", node,
  				      i + clk_ind, ret);
  			goto err_put_subsys_clocks;
  		}
  
  		pd->subsys_clks[i].clk = clk;
  	}
  
  	/*
  	 * Initially turn on all domains to make the domains usable
  	 * with !CONFIG_PM and to get the hardware in sync with the
  	 * software.  The unused domains will be switched off during
  	 * late_init time.
  	 */
  	if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF)) {
  		if (scpsys_domain_is_on(pd))
  			dev_warn(scpsys->dev,
  				 "%pOF: A default off power domain has been ON\n", node);
  	} else {
  		ret = scpsys_power_on(&pd->genpd);
  		if (ret < 0) {
  			dev_err(scpsys->dev, "%pOF: failed to power on domain: %d\n", node, ret);
  			goto err_put_subsys_clocks;
  		}
  	}
  
  	if (scpsys->domains[id]) {
  		ret = -EINVAL;
  		dev_err(scpsys->dev,
  			"power domain with id %d already exists, check your device-tree\n", id);
  		goto err_put_subsys_clocks;
  	}
  
  	if (!pd->data->name)
  		pd->genpd.name = node->name;
  	else
  		pd->genpd.name = pd->data->name;
  
  	pd->genpd.power_off = scpsys_power_off;
  	pd->genpd.power_on = scpsys_power_on;
  
  	if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
  		pm_genpd_init(&pd->genpd, NULL, true);
  	else
  		pm_genpd_init(&pd->genpd, NULL, false);
  
  	scpsys->domains[id] = &pd->genpd;
  
  	return scpsys->pd_data.domains[id];
  
  err_put_subsys_clocks:
  	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
  err_put_clocks:
  	clk_bulk_put(pd->num_clks, pd->clks);
  	return ERR_PTR(ret);
  }
  
  static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *parent)
  {
  	struct generic_pm_domain *child_pd, *parent_pd;
  	struct device_node *child;
  	int ret;
  
  	for_each_child_of_node(parent, child) {
  		u32 id;
  
  		ret = of_property_read_u32(parent, "reg", &id);
  		if (ret) {
  			dev_err(scpsys->dev, "%pOF: failed to get parent domain id\n", child);
  			goto err_put_node;
  		}
  
  		if (!scpsys->pd_data.domains[id]) {
  			ret = -EINVAL;
  			dev_err(scpsys->dev, "power domain with id %d does not exist\n", id);
  			goto err_put_node;
  		}
  
  		parent_pd = scpsys->pd_data.domains[id];
  
  		child_pd = scpsys_add_one_domain(scpsys, child);
  		if (IS_ERR(child_pd)) {
  			ret = PTR_ERR(child_pd);
  			dev_err_probe(scpsys->dev, ret, "%pOF: failed to get child domain id\n",
  				      child);
  			goto err_put_node;
  		}
  
  		ret = pm_genpd_add_subdomain(parent_pd, child_pd);
  		if (ret) {
  			dev_err(scpsys->dev, "failed to add %s subdomain to parent %s\n",
  				child_pd->name, parent_pd->name);
  			goto err_put_node;
  		} else {
  			dev_dbg(scpsys->dev, "%s add subdomain: %s\n", parent_pd->name,
  				child_pd->name);
  		}
  
  		/* recursive call to add all subdomains */
  		ret = scpsys_add_subdomain(scpsys, child);
  		if (ret)
  			goto err_put_node;
  	}
  
  	return 0;
  
  err_put_node:
  	of_node_put(child);
  	return ret;
  }
  
  static void scpsys_remove_one_domain(struct scpsys_domain *pd)
  {
  	int ret;
  
  	if (scpsys_domain_is_on(pd))
  		scpsys_power_off(&pd->genpd);
  
  	/*
  	 * We're in the error cleanup already, so we only complain,
  	 * but won't emit another error on top of the original one.
  	 */
  	ret = pm_genpd_remove(&pd->genpd);
  	if (ret < 0)
  		dev_err(pd->scpsys->dev,
  			"failed to remove domain '%s' : %d - state may be inconsistent\n",
  			pd->genpd.name, ret);
  
  	clk_bulk_put(pd->num_clks, pd->clks);
  	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
  }
  
  static void scpsys_domain_cleanup(struct scpsys *scpsys)
  {
  	struct generic_pm_domain *genpd;
  	struct scpsys_domain *pd;
  	int i;
  
  	for (i = scpsys->pd_data.num_domains - 1; i >= 0; i--) {
  		genpd = scpsys->pd_data.domains[i];
  		if (genpd) {
  			pd = to_scpsys_domain(genpd);
  			scpsys_remove_one_domain(pd);
  		}
  	}
  }
  
  static const struct of_device_id scpsys_of_match[] = {
  	{
  		.compatible = "mediatek,mt8167-power-controller",
  		.data = &mt8167_scpsys_data,
  	},
  	{
  		.compatible = "mediatek,mt8173-power-controller",
  		.data = &mt8173_scpsys_data,
  	},
  	{
  		.compatible = "mediatek,mt8183-power-controller",
  		.data = &mt8183_scpsys_data,
  	},
  	{
  		.compatible = "mediatek,mt8192-power-controller",
  		.data = &mt8192_scpsys_data,
  	},
  	{ }
  };
  
  static int scpsys_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct device_node *np = dev->of_node;
  	const struct scpsys_soc_data *soc;
  	struct device_node *node;
  	struct device *parent;
  	struct scpsys *scpsys;
  	int ret;
  
  	soc = of_device_get_match_data(&pdev->dev);
  	if (!soc) {
  		dev_err(&pdev->dev, "no power controller data\n");
  		return -EINVAL;
  	}
  
  	scpsys = devm_kzalloc(dev, struct_size(scpsys, domains, soc->num_domains), GFP_KERNEL);
  	if (!scpsys)
  		return -ENOMEM;
  
  	scpsys->dev = dev;
  	scpsys->soc_data = soc;
  
  	scpsys->pd_data.domains = scpsys->domains;
  	scpsys->pd_data.num_domains = soc->num_domains;
  
  	parent = dev->parent;
  	if (!parent) {
  		dev_err(dev, "no parent for syscon devices\n");
  		return -ENODEV;
  	}
  
  	scpsys->base = syscon_node_to_regmap(parent->of_node);
  	if (IS_ERR(scpsys->base)) {
  		dev_err(dev, "no regmap available\n");
  		return PTR_ERR(scpsys->base);
  	}
  
  	ret = -ENODEV;
  	for_each_available_child_of_node(np, node) {
  		struct generic_pm_domain *domain;
  
  		domain = scpsys_add_one_domain(scpsys, node);
  		if (IS_ERR(domain)) {
  			ret = PTR_ERR(domain);
  			of_node_put(node);
  			goto err_cleanup_domains;
  		}
  
  		ret = scpsys_add_subdomain(scpsys, node);
  		if (ret) {
  			of_node_put(node);
  			goto err_cleanup_domains;
  		}
  	}
  
  	if (ret) {
  		dev_dbg(dev, "no power domains present\n");
  		return ret;
  	}
  
  	ret = of_genpd_add_provider_onecell(np, &scpsys->pd_data);
  	if (ret) {
  		dev_err(dev, "failed to add provider: %d\n", ret);
  		goto err_cleanup_domains;
  	}
  
  	return 0;
  
  err_cleanup_domains:
  	scpsys_domain_cleanup(scpsys);
  	return ret;
  }
  
  static struct platform_driver scpsys_pm_domain_driver = {
  	.probe = scpsys_probe,
  	.driver = {
  		.name = "mtk-power-controller",
  		.suppress_bind_attrs = true,
  		.of_match_table = scpsys_of_match,
  	},
  };
  builtin_platform_driver(scpsys_pm_domain_driver);
  