text: // SPDX-License-Identifier: GPL-2.0
  /*
   * ZynqMP Generic PM domain support
   *
   *  Copyright (C) 2015-2018 Xilinx, Inc.
   *
   *  Davorin Mista <davorin.mista@aggios.com>
   *  Jolly Shah <jollys@xilinx.com>
   *  Rajan Vaja <rajan.vaja@xilinx.com>
   */
  
  #include <linux/err.h>
  #include <linux/list.h>
  #include <linux/module.h>
  #include <linux/of_platform.h>
  #include <linux/platform_device.h>
  #include <linux/pm_domain.h>
  #include <linux/slab.h>
  
  #include <linux/firmware/xlnx-zynqmp.h>
  
  #define ZYNQMP_NUM_DOMAINS		(100)
  /* Flag stating if PM nodes mapped to the PM domain has been requested */
  #define ZYNQMP_PM_DOMAIN_REQUESTED	BIT(0)
  
  /**
   * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
   * @gpd:		Generic power domain
   * @node_id:		PM node ID corresponding to device inside PM domain
   * @flags:		ZynqMP PM domain flags
   */
  struct zynqmp_pm_domain {
  	struct generic_pm_domain gpd;
  	u32 node_id;
  	u8 flags;
  };
  
  /**
   * zynqmp_gpd_is_active_wakeup_path() - Check if device is in wakeup source
   *					path
   * @dev:	Device to check for wakeup source path
   * @not_used:	Data member (not required)
   *
   * This function is checks device's child hierarchy and checks if any device is
   * set as wakeup source.
   *
   * Return: 1 if device is in wakeup source path else 0
   */
  static int zynqmp_gpd_is_active_wakeup_path(struct device *dev, void *not_used)
  {
  	int may_wakeup;
  
  	may_wakeup = device_may_wakeup(dev);
  	if (may_wakeup)
  		return may_wakeup;
  
  	return device_for_each_child(dev, NULL,
  			zynqmp_gpd_is_active_wakeup_path);
  }
  
  /**
   * zynqmp_gpd_power_on() - Power on PM domain
   * @domain:	Generic PM domain
   *
   * This function is called before devices inside a PM domain are resumed, to
   * power on PM domain.
   *
   * Return: 0 on success, error code otherwise
   */
  static int zynqmp_gpd_power_on(struct generic_pm_domain *domain)
  {
  	int ret;
  	struct zynqmp_pm_domain *pd;
  	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  
  	if (!eemi_ops || !eemi_ops->set_requirement)
  		return -ENXIO;
  
  	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
  	ret = eemi_ops->set_requirement(pd->node_id,
  					ZYNQMP_PM_CAPABILITY_ACCESS,
  					ZYNQMP_PM_MAX_QOS,
  					ZYNQMP_PM_REQUEST_ACK_BLOCKING);
  	if (ret) {
  		pr_err("%s() %s set requirement for node %d failed: %d\n",
  		       __func__, domain->name, pd->node_id, ret);
  		return ret;
  	}
  
  	pr_debug("%s() Powered on %s domain\n", __func__, domain->name);
  	return 0;
  }
  
  /**
   * zynqmp_gpd_power_off() - Power off PM domain
   * @domain:	Generic PM domain
   *
   * This function is called after devices inside a PM domain are suspended, to
   * power off PM domain.
   *
   * Return: 0 on success, error code otherwise
   */
  static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
  {
  	int ret;
  	struct pm_domain_data *pdd, *tmp;
  	struct zynqmp_pm_domain *pd;
  	u32 capabilities = 0;
  	bool may_wakeup;
  	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  
  	if (!eemi_ops || !eemi_ops->set_requirement)
  		return -ENXIO;
  
  	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
  
  	/* If domain is already released there is nothing to be done */
  	if (!(pd->flags & ZYNQMP_PM_DOMAIN_REQUESTED)) {
  		pr_debug("%s() %s domain is already released\n",
  			 __func__, domain->name);
  		return 0;
  	}
  
  	list_for_each_entry_safe(pdd, tmp, &domain->dev_list, list_node) {
  		/* If device is in wakeup path, set capability to WAKEUP */
  		may_wakeup = zynqmp_gpd_is_active_wakeup_path(pdd->dev, NULL);
  		if (may_wakeup) {
  			dev_dbg(pdd->dev, "device is in wakeup path in %s\n",
  				domain->name);
  			capabilities = ZYNQMP_PM_CAPABILITY_WAKEUP;
  			break;
  		}
  	}
  
  	ret = eemi_ops->set_requirement(pd->node_id, capabilities, 0,
  					ZYNQMP_PM_REQUEST_ACK_NO);
  	/**
  	 * If powering down of any node inside this domain fails,
  	 * report and return the error
  	 */
  	if (ret) {
  		pr_err("%s() %s set requirement for node %d failed: %d\n",
  		       __func__, domain->name, pd->node_id, ret);
  		return ret;
  	}
  
  	pr_debug("%s() Powered off %s domain\n", __func__, domain->name);
  	return 0;
  }
  
  /**
   * zynqmp_gpd_attach_dev() - Attach device to the PM domain
   * @domain:	Generic PM domain
   * @dev:	Device to attach
   *
   * Return: 0 on success, error code otherwise
   */
  static int zynqmp_gpd_attach_dev(struct generic_pm_domain *domain,
  				 struct device *dev)
  {
  	int ret;
  	struct zynqmp_pm_domain *pd;
  	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  
  	if (!eemi_ops || !eemi_ops->request_node)
  		return -ENXIO;
  
  	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
  
  	/* If this is not the first device to attach there is nothing to do */
  	if (domain->device_count)
  		return 0;
  
  	ret = eemi_ops->request_node(pd->node_id, 0, 0,
  				     ZYNQMP_PM_REQUEST_ACK_BLOCKING);
  	/* If requesting a node fails print and return the error */
  	if (ret) {
  		pr_err("%s() %s request failed for node %d: %d\n",
  		       __func__, domain->name, pd->node_id, ret);
  		return ret;
  	}
  
  	pd->flags |= ZYNQMP_PM_DOMAIN_REQUESTED;
  
  	pr_debug("%s() %s attached to %s domain\n", __func__,
  		 dev_name(dev), domain->name);
  	return 0;
  }
  
  /**
   * zynqmp_gpd_detach_dev() - Detach device from the PM domain
   * @domain:	Generic PM domain
   * @dev:	Device to detach
   */
  static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
  				  struct device *dev)
  {
  	int ret;
  	struct zynqmp_pm_domain *pd;
  	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  
  	if (!eemi_ops || !eemi_ops->release_node)
  		return;
  
  	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
  
  	/* If this is not the last device to detach there is nothing to do */
  	if (domain->device_count)
  		return;
  
  	ret = eemi_ops->release_node(pd->node_id);
  	/* If releasing a node fails print the error and return */
  	if (ret) {
  		pr_err("%s() %s release failed for node %d: %d\n",
  		       __func__, domain->name, pd->node_id, ret);
  		return;
  	}
  
  	pd->flags &= ~ZYNQMP_PM_DOMAIN_REQUESTED;
  
  	pr_debug("%s() %s detached from %s domain\n", __func__,
  		 dev_name(dev), domain->name);
  }
  
  static struct generic_pm_domain *zynqmp_gpd_xlate
  				(struct of_phandle_args *genpdspec, void *data)
  {
  	struct genpd_onecell_data *genpd_data = data;
  	unsigned int i, idx = genpdspec->args[0];
  	struct zynqmp_pm_domain *pd;
  
  	pd = container_of(genpd_data->domains[0], struct zynqmp_pm_domain, gpd);
  
  	if (genpdspec->args_count != 1)
  		return ERR_PTR(-EINVAL);
  
  	/* Check for existing pm domains */
  	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
  		if (pd[i].node_id == idx)
  			goto done;
  	}
  
  	/**
  	 * Add index in empty node_id of power domain list as no existing
  	 * power domain found for current index.
  	 */
  	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
  		if (pd[i].node_id == 0) {
  			pd[i].node_id = idx;
  			break;
  		}
  	}
  
  done:
  	if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
  		return ERR_PTR(-ENOENT);
  
  	return genpd_data->domains[i];
  }
  
  static int zynqmp_gpd_probe(struct platform_device *pdev)
  {
  	int i;
  	struct genpd_onecell_data *zynqmp_pd_data;
  	struct generic_pm_domain **domains;
  	struct zynqmp_pm_domain *pd;
  	struct device *dev = &pdev->dev;
  
  	pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
  	if (!pd)
  		return -ENOMEM;
  
  	zynqmp_pd_data = devm_kzalloc(dev, sizeof(*zynqmp_pd_data), GFP_KERNEL);
  	if (!zynqmp_pd_data)
  		return -ENOMEM;
  
  	zynqmp_pd_data->xlate = zynqmp_gpd_xlate;
  
  	domains = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*domains),
  			       GFP_KERNEL);
  	if (!domains)
  		return -ENOMEM;
  
  	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
  		pd->node_id = 0;
  		pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
  		pd->gpd.power_off = zynqmp_gpd_power_off;
  		pd->gpd.power_on = zynqmp_gpd_power_on;
  		pd->gpd.attach_dev = zynqmp_gpd_attach_dev;
  		pd->gpd.detach_dev = zynqmp_gpd_detach_dev;
  
  		domains[i] = &pd->gpd;
  
  		/* Mark all PM domains as initially powered off */
  		pm_genpd_init(&pd->gpd, NULL, true);
  	}
  
  	zynqmp_pd_data->domains = domains;
  	zynqmp_pd_data->num_domains = ZYNQMP_NUM_DOMAINS;
  	of_genpd_add_provider_onecell(dev->parent->of_node, zynqmp_pd_data);
  
  	return 0;
  }
  
  static int zynqmp_gpd_remove(struct platform_device *pdev)
  {
  	of_genpd_del_provider(pdev->dev.parent->of_node);
  
  	return 0;
  }
  
  static struct platform_driver zynqmp_power_domain_driver = {
  	.driver	= {
  		.name = "zynqmp_power_controller",
  	},
  	.probe = zynqmp_gpd_probe,
  	.remove = zynqmp_gpd_remove,
  };
  module_platform_driver(zynqmp_power_domain_driver);
  
  MODULE_ALIAS("platform:zynqmp_power_controller");
  