drivers/soc/xilinx/zynqmp_power.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Xilinx Zynq MPSoC Power Management
   4  *
   5  *  Copyright (C) 2014-2019 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/mailbox_client.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/reboot.h>
  17 #include <linux/suspend.h>
  18
  19 #include <linux/firmware/xlnx-zynqmp.h>
  20 #include <linux/firmware/xlnx-event-manager.h>
  21 #include <linux/mailbox/zynqmp-ipi-message.h>
  22
  23 /**
  24  * struct zynqmp_pm_work_struct - Wrapper for struct work_struct
  25  * @callback_work:      Work structure
  26  * @args:               Callback arguments
  27  */
  28 struct zynqmp_pm_work_struct {
  29         struct work_struct callback_work;
  30         u32 args[CB_ARG_CNT];
  31 };
  32
  33 static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
  34 static struct mbox_chan *rx_chan;
  35 static bool event_registered;
  36
  37 enum pm_suspend_mode {
  38         PM_SUSPEND_MODE_FIRST = 0,
  39         PM_SUSPEND_MODE_STD = PM_SUSPEND_MODE_FIRST,
  40         PM_SUSPEND_MODE_POWER_OFF,
  41 };
  42
  43 #define PM_SUSPEND_MODE_FIRST   PM_SUSPEND_MODE_STD
  44
  45 static const char *const suspend_modes[] = {
  46         [PM_SUSPEND_MODE_STD] = "standard",
  47         [PM_SUSPEND_MODE_POWER_OFF] = "power-off",
  48 };
  49
  50 static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
  51
  52 static void zynqmp_pm_get_callback_data(u32 *buf)
  53 {
  54         zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
  55 }
  56
  57 static void suspend_event_callback(const u32 *payload, void *data)
  58 {
  59         /* First element is callback API ID, others are callback arguments */
  60         if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
  61                 return;
  62
  63         /* Copy callback arguments into work's structure */
  64         memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
  65                sizeof(zynqmp_pm_init_suspend_work->args));
  66
  67         queue_work(system_unbound_wq, &zynqmp_pm_init_suspend_work->callback_work);
  68 }
  69
  70 static irqreturn_t zynqmp_pm_isr(int irq, void *data)
  71 {
  72         u32 payload[CB_PAYLOAD_SIZE];
  73
  74         zynqmp_pm_get_callback_data(payload);
  75
  76         /* First element is callback API ID, others are callback arguments */
  77         if (payload[0] == PM_INIT_SUSPEND_CB) {
  78                 switch (payload[1]) {
  79                 case SUSPEND_SYSTEM_SHUTDOWN:
  80                         orderly_poweroff(true);
  81                         break;
  82                 case SUSPEND_POWER_REQUEST:
  83                         pm_suspend(PM_SUSPEND_MEM);
  84                         break;
  85                 default:
  86                         pr_err("%s Unsupported InitSuspendCb reason "
  87                                 "code %d\n", __func__, payload[1]);
  88                 }
  89         }
  90
  91         return IRQ_HANDLED;
  92 }
  93
  94 static void ipi_receive_callback(struct mbox_client *cl, void *data)
  95 {
  96         struct zynqmp_ipi_message *msg = (struct zynqmp_ipi_message *)data;
  97         u32 payload[CB_PAYLOAD_SIZE];
  98         int ret;
  99
 100         memcpy(payload, msg->data, sizeof(msg->len));
 101         /* First element is callback API ID, others are callback arguments */
 102         if (payload[0] == PM_INIT_SUSPEND_CB) {
 103                 if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
 104                         return;
 105
 106                 /* Copy callback arguments into work's structure */
 107                 memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
 108                        sizeof(zynqmp_pm_init_suspend_work->args));
 109
 110                 queue_work(system_unbound_wq,
 111                            &zynqmp_pm_init_suspend_work->callback_work);
 112
 113                 /* Send NULL message to mbox controller to ack the message */
 114                 ret = mbox_send_message(rx_chan, NULL);
 115                 if (ret)
 116                         pr_err("IPI ack failed. Error %d\n", ret);
 117         }
 118 }
 119
 120 /**
 121  * zynqmp_pm_init_suspend_work_fn - Initialize suspend
 122  * @work:       Pointer to work_struct
 123  *
 124  * Bottom-half of PM callback IRQ handler.
 125  */
 126 static void zynqmp_pm_init_suspend_work_fn(struct work_struct *work)
 127 {
 128         struct zynqmp_pm_work_struct *pm_work =
 129                 container_of(work, struct zynqmp_pm_work_struct, callback_work);
 130
 131         if (pm_work->args[0] == SUSPEND_SYSTEM_SHUTDOWN) {
 132                 orderly_poweroff(true);
 133         } else if (pm_work->args[0] == SUSPEND_POWER_REQUEST) {
 134                 pm_suspend(PM_SUSPEND_MEM);
 135         } else {
 136                 pr_err("%s Unsupported InitSuspendCb reason code %d.\n",
 137                        __func__, pm_work->args[0]);
 138         }
 139 }
 140
 141 static ssize_t suspend_mode_show(struct device *dev,
 142                                  struct device_attribute *attr, char *buf)
 143 {
 144         char *s = buf;
 145         int md;
 146
 147         for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
 148                 if (suspend_modes[md]) {
 149                         if (md == suspend_mode)
 150                                 s += sprintf(s, "[%s] ", suspend_modes[md]);
 151                         else
 152                                 s += sprintf(s, "%s ", suspend_modes[md]);
 153                 }
 154
 155         /* Convert last space to newline */
 156         if (s != buf)
 157                 *(s - 1) = '\n';
 158         return (s - buf);
 159 }
 160
 161 static ssize_t suspend_mode_store(struct device *dev,
 162                                   struct device_attribute *attr,
 163                                   const char *buf, size_t count)
 164 {
 165         int md, ret = -EINVAL;
 166
 167         for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
 168                 if (suspend_modes[md] &&
 169                     sysfs_streq(suspend_modes[md], buf)) {
 170                         ret = 0;
 171                         break;
 172                 }
 173
 174         if (!ret && md != suspend_mode) {
 175                 ret = zynqmp_pm_set_suspend_mode(md);
 176                 if (likely(!ret))
 177                         suspend_mode = md;
 178         }
 179
 180         return ret ? ret : count;
 181 }
 182
 183 static DEVICE_ATTR_RW(suspend_mode);
 184
 185 static int zynqmp_pm_probe(struct platform_device *pdev)
 186 {
 187         int ret, irq;
 188         u32 pm_api_version;
 189         struct mbox_client *client;
 190
 191         zynqmp_pm_get_api_version(&pm_api_version);
 192
 193         /* Check PM API version number */
 194         if (pm_api_version < ZYNQMP_PM_VERSION)
 195                 return -ENODEV;
 196
 197         /*
 198          * First try to use Xilinx Event Manager by registering suspend_event_callback
 199          * for suspend/shutdown event.
 200          * If xlnx_register_event() returns -EACCES (Xilinx Event Manager
 201          * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
 202          * then use ipi-mailbox or interrupt method.
 203          */
 204         ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
 205                                   suspend_event_callback, NULL);
 206         if (!ret) {
 207                 zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
 208                                                            sizeof(struct zynqmp_pm_work_struct),
 209                                                            GFP_KERNEL);
 210                 if (!zynqmp_pm_init_suspend_work) {
 211                         xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
 212                                               suspend_event_callback, NULL);
 213                         return -ENOMEM;
 214                 }
 215                 event_registered = true;
 216
 217                 INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
 218                           zynqmp_pm_init_suspend_work_fn);
 219         } else if (ret != -EACCES && ret != -ENODEV) {
 220                 dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
 221                 return ret;
 222         } else if (of_property_present(pdev->dev.of_node, "mboxes")) {
 223                 zynqmp_pm_init_suspend_work =
 224                         devm_kzalloc(&pdev->dev,
 225                                      sizeof(struct zynqmp_pm_work_struct),
 226                                      GFP_KERNEL);
 227                 if (!zynqmp_pm_init_suspend_work)
 228                         return -ENOMEM;
 229
 230                 INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
 231                           zynqmp_pm_init_suspend_work_fn);
 232                 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
 233                 if (!client)
 234                         return -ENOMEM;
 235
 236                 client->dev = &pdev->dev;
 237                 client->rx_callback = ipi_receive_callback;
 238
 239                 rx_chan = mbox_request_channel_byname(client, "rx");
 240                 if (IS_ERR(rx_chan)) {
 241                         dev_err(&pdev->dev, "Failed to request rx channel\n");
 242                         return PTR_ERR(rx_chan);
 243                 }
 244         } else if (of_property_present(pdev->dev.of_node, "interrupts")) {
 245                 irq = platform_get_irq(pdev, 0);
 246                 if (irq < 0)
 247                         return irq;
 248
 249                 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 250                                                 zynqmp_pm_isr,
 251                                                 IRQF_NO_SUSPEND | IRQF_ONESHOT,
 252                                                 dev_name(&pdev->dev),
 253                                                 &pdev->dev);
 254                 if (ret) {
 255                         dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
 256                                             "failed with %d\n", irq, ret);
 257                         return ret;
 258                 }
 259         } else {
 260                 dev_err(&pdev->dev, "Required property not found in DT node\n");
 261                 return -ENOENT;
 262         }
 263
 264         ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
 265         if (ret) {
 266                 if (event_registered) {
 267                         xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback,
 268                                               NULL);
 269                         event_registered = false;
 270                 }
 271                 dev_err(&pdev->dev, "unable to create sysfs interface\n");
 272                 return ret;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int zynqmp_pm_remove(struct platform_device *pdev)
 279 {
 280         sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
 281         if (event_registered)
 282                 xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);
 283
 284         if (!rx_chan)
 285                 mbox_free_channel(rx_chan);
 286
 287         return 0;
 288 }
 289
 290 static const struct of_device_id pm_of_match[] = {
 291         { .compatible = "xlnx,zynqmp-power", },
 292         { /* end of table */ },
 293 };
 294 MODULE_DEVICE_TABLE(of, pm_of_match);
 295
 296 static struct platform_driver zynqmp_pm_platform_driver = {
 297         .probe = zynqmp_pm_probe,
 298         .remove = zynqmp_pm_remove,
 299         .driver = {
 300                 .name = "zynqmp_power",
 301                 .of_match_table = pm_of_match,
 302         },
 303 };
 304 module_platform_driver(zynqmp_pm_platform_driver);