drivers/soc/xilinx/zynqmp_pm_domains.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ZynqMP Generic PM domain support
   4  *
   5  *  Copyright (C) 2015-2019 Xilinx, Inc.
   6  *
   7  *  Davorin Mista <davorin.mista@aggios.com>
   8  *  Jolly Shah <jollys@xilinx.com>
   9  *  Rajan Vaja <rajan.vaja@xilinx.com>
  10  */
  11
  12 #include <linux/err.h>
  13 #include <linux/list.h>
  14 #include <linux/module.h>
  15 #include <linux/of_platform.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/pm_domain.h>
  18 #include <linux/slab.h>
  19
  20 #include <linux/firmware/xlnx-zynqmp.h>
  21
  22 #define ZYNQMP_NUM_DOMAINS              (100)
  23 /* Flag stating if PM nodes mapped to the PM domain has been requested */
  24 #define ZYNQMP_PM_DOMAIN_REQUESTED      BIT(0)
  25
  26 static int min_capability;
  27
  28 /**
  29  * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
  30  * @gpd:                Generic power domain
  31  * @node_id:            PM node ID corresponding to device inside PM domain
  32  * @flags:              ZynqMP PM domain flags
  33  */
  34 struct zynqmp_pm_domain {
  35         struct generic_pm_domain gpd;
  36         u32 node_id;
  37         u8 flags;
  38 };
  39
  40 /**
  41  * zynqmp_gpd_is_active_wakeup_path() - Check if device is in wakeup source
  42  *                                      path
  43  * @dev:        Device to check for wakeup source path
  44  * @not_used:   Data member (not required)
  45  *
  46  * This function is checks device's child hierarchy and checks if any device is
  47  * set as wakeup source.
  48  *
  49  * Return: 1 if device is in wakeup source path else 0
  50  */
  51 static int zynqmp_gpd_is_active_wakeup_path(struct device *dev, void *not_used)
  52 {
  53         int may_wakeup;
  54
  55         may_wakeup = device_may_wakeup(dev);
  56         if (may_wakeup)
  57                 return may_wakeup;
  58
  59         return device_for_each_child(dev, NULL,
  60                         zynqmp_gpd_is_active_wakeup_path);
  61 }
  62
  63 /**
  64  * zynqmp_gpd_power_on() - Power on PM domain
  65  * @domain:     Generic PM domain
  66  *
  67  * This function is called before devices inside a PM domain are resumed, to
  68  * power on PM domain.
  69  *
  70  * Return: 0 on success, error code otherwise
  71  */
  72 static int zynqmp_gpd_power_on(struct generic_pm_domain *domain)
  73 {
  74         int ret;
  75         struct zynqmp_pm_domain *pd;
  76
  77         pd = container_of(domain, struct zynqmp_pm_domain, gpd);
  78         ret = zynqmp_pm_set_requirement(pd->node_id,
  79                                         ZYNQMP_PM_CAPABILITY_ACCESS,
  80                                         ZYNQMP_PM_MAX_QOS,
  81                                         ZYNQMP_PM_REQUEST_ACK_BLOCKING);
  82         if (ret) {
  83                 pr_err("%s() %s set requirement for node %d failed: %d\n",
  84                        __func__, domain->name, pd->node_id, ret);
  85                 return ret;
  86         }
  87
  88         pr_debug("%s() Powered on %s domain\n", __func__, domain->name);
  89         return 0;
  90 }
  91
  92 /**
  93  * zynqmp_gpd_power_off() - Power off PM domain
  94  * @domain:     Generic PM domain
  95  *
  96  * This function is called after devices inside a PM domain are suspended, to
  97  * power off PM domain.
  98  *
  99  * Return: 0 on success, error code otherwise
 100  */
 101 static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
 102 {
 103         int ret;
 104         struct pm_domain_data *pdd, *tmp;
 105         struct zynqmp_pm_domain *pd;
 106         u32 capabilities = min_capability;
 107         bool may_wakeup;
 108
 109         pd = container_of(domain, struct zynqmp_pm_domain, gpd);
 110
 111         /* If domain is already released there is nothing to be done */
 112         if (!(pd->flags & ZYNQMP_PM_DOMAIN_REQUESTED)) {
 113                 pr_debug("%s() %s domain is already released\n",
 114                          __func__, domain->name);
 115                 return 0;
 116         }
 117
 118         list_for_each_entry_safe(pdd, tmp, &domain->dev_list, list_node) {
 119                 /* If device is in wakeup path, set capability to WAKEUP */
 120                 may_wakeup = zynqmp_gpd_is_active_wakeup_path(pdd->dev, NULL);
 121                 if (may_wakeup) {
 122                         dev_dbg(pdd->dev, "device is in wakeup path in %s\n",
 123                                 domain->name);
 124                         capabilities = ZYNQMP_PM_CAPABILITY_WAKEUP;
 125                         break;
 126                 }
 127         }
 128
 129         ret = zynqmp_pm_set_requirement(pd->node_id, capabilities, 0,
 130                                         ZYNQMP_PM_REQUEST_ACK_NO);
 131         /**
 132          * If powering down of any node inside this domain fails,
 133          * report and return the error
 134          */
 135         if (ret) {
 136                 pr_err("%s() %s set requirement for node %d failed: %d\n",
 137                        __func__, domain->name, pd->node_id, ret);
 138                 return ret;
 139         }
 140
 141         pr_debug("%s() Powered off %s domain\n", __func__, domain->name);
 142         return 0;
 143 }
 144
 145 /**
 146  * zynqmp_gpd_attach_dev() - Attach device to the PM domain
 147  * @domain:     Generic PM domain
 148  * @dev:        Device to attach
 149  *
 150  * Return: 0 on success, error code otherwise
 151  */
 152 static int zynqmp_gpd_attach_dev(struct generic_pm_domain *domain,
 153                                  struct device *dev)
 154 {
 155         int ret;
 156         struct zynqmp_pm_domain *pd;
 157
 158         pd = container_of(domain, struct zynqmp_pm_domain, gpd);
 159
 160         /* If this is not the first device to attach there is nothing to do */
 161         if (domain->device_count)
 162                 return 0;
 163
 164         ret = zynqmp_pm_request_node(pd->node_id, 0, 0,
 165                                      ZYNQMP_PM_REQUEST_ACK_BLOCKING);
 166         /* If requesting a node fails print and return the error */
 167         if (ret) {
 168                 pr_err("%s() %s request failed for node %d: %d\n",
 169                        __func__, domain->name, pd->node_id, ret);
 170                 return ret;
 171         }
 172
 173         pd->flags |= ZYNQMP_PM_DOMAIN_REQUESTED;
 174
 175         pr_debug("%s() %s attached to %s domain\n", __func__,
 176                  dev_name(dev), domain->name);
 177         return 0;
 178 }
 179
 180 /**
 181  * zynqmp_gpd_detach_dev() - Detach device from the PM domain
 182  * @domain:     Generic PM domain
 183  * @dev:        Device to detach
 184  */
 185 static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
 186                                   struct device *dev)
 187 {
 188         int ret;
 189         struct zynqmp_pm_domain *pd;
 190
 191         pd = container_of(domain, struct zynqmp_pm_domain, gpd);
 192
 193         /* If this is not the last device to detach there is nothing to do */
 194         if (domain->device_count)
 195                 return;
 196
 197         ret = zynqmp_pm_release_node(pd->node_id);
 198         /* If releasing a node fails print the error and return */
 199         if (ret) {
 200                 pr_err("%s() %s release failed for node %d: %d\n",
 201                        __func__, domain->name, pd->node_id, ret);
 202                 return;
 203         }
 204
 205         pd->flags &= ~ZYNQMP_PM_DOMAIN_REQUESTED;
 206
 207         pr_debug("%s() %s detached from %s domain\n", __func__,
 208                  dev_name(dev), domain->name);
 209 }
 210
 211 static struct generic_pm_domain *zynqmp_gpd_xlate
 212                                 (struct of_phandle_args *genpdspec, void *data)
 213 {
 214         struct genpd_onecell_data *genpd_data = data;
 215         unsigned int i, idx = genpdspec->args[0];
 216         struct zynqmp_pm_domain *pd;
 217
 218         pd = container_of(genpd_data->domains[0], struct zynqmp_pm_domain, gpd);
 219
 220         if (genpdspec->args_count != 1)
 221                 return ERR_PTR(-EINVAL);
 222
 223         /* Check for existing pm domains */
 224         for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
 225                 if (pd[i].node_id == idx)
 226                         goto done;
 227         }
 228
 229         /**
 230          * Add index in empty node_id of power domain list as no existing
 231          * power domain found for current index.
 232          */
 233         for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
 234                 if (pd[i].node_id == 0) {
 235                         pd[i].node_id = idx;
 236                         break;
 237                 }
 238         }
 239
 240 done:
 241         if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
 242                 return ERR_PTR(-ENOENT);
 243
 244         return genpd_data->domains[i];
 245 }
 246
 247 static int zynqmp_gpd_probe(struct platform_device *pdev)
 248 {
 249         int i;
 250         struct genpd_onecell_data *zynqmp_pd_data;
 251         struct generic_pm_domain **domains;
 252         struct zynqmp_pm_domain *pd;
 253         struct device *dev = &pdev->dev;
 254
 255         pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
 256         if (!pd)
 257                 return -ENOMEM;
 258
 259         zynqmp_pd_data = devm_kzalloc(dev, sizeof(*zynqmp_pd_data), GFP_KERNEL);
 260         if (!zynqmp_pd_data)
 261                 return -ENOMEM;
 262
 263         zynqmp_pd_data->xlate = zynqmp_gpd_xlate;
 264
 265         domains = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*domains),
 266                                GFP_KERNEL);
 267         if (!domains)
 268                 return -ENOMEM;
 269
 270         if (!of_device_is_compatible(dev->parent->of_node,
 271                                      "xlnx,zynqmp-firmware"))
 272                 min_capability = ZYNQMP_PM_CAPABILITY_UNUSABLE;
 273
 274         for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
 275                 pd->node_id = 0;
 276                 pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
 277                 pd->gpd.power_off = zynqmp_gpd_power_off;
 278                 pd->gpd.power_on = zynqmp_gpd_power_on;
 279                 pd->gpd.attach_dev = zynqmp_gpd_attach_dev;
 280                 pd->gpd.detach_dev = zynqmp_gpd_detach_dev;
 281
 282                 domains[i] = &pd->gpd;
 283
 284                 /* Mark all PM domains as initially powered off */
 285                 pm_genpd_init(&pd->gpd, NULL, true);
 286         }
 287
 288         zynqmp_pd_data->domains = domains;
 289         zynqmp_pd_data->num_domains = ZYNQMP_NUM_DOMAINS;
 290         of_genpd_add_provider_onecell(dev->parent->of_node, zynqmp_pd_data);
 291
 292         return 0;
 293 }
 294
 295 static int zynqmp_gpd_remove(struct platform_device *pdev)
 296 {
 297         of_genpd_del_provider(pdev->dev.parent->of_node);
 298
 299         return 0;
 300 }
 301
 302 static struct platform_driver zynqmp_power_domain_driver = {
 303         .driver = {
 304                 .name = "zynqmp_power_controller",
 305         },
 306         .probe = zynqmp_gpd_probe,
 307         .remove = zynqmp_gpd_remove,
 308 };
 309 module_platform_driver(zynqmp_power_domain_driver);
 310
 311 MODULE_ALIAS("platform:zynqmp_power_controller");