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