soc/xilinx/zynqmp_power.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Xilinx Zynq MPSoC Power Management
0004  *
0005  *  Copyright (C) 2014-2019 Xilinx, Inc.
0006  *
0007  *  Davorin Mista <davorin.mista@aggios.com>
0008  *  Jolly Shah <jollys@xilinx.com>
0009  *  Rajan Vaja <rajan.vaja@xilinx.com>
0010  */
0011
0012 #include <linux/mailbox_client.h>
0013 #include <linux/module.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/reboot.h>
0016 #include <linux/suspend.h>
0017
0018 #include <linux/firmware/xlnx-zynqmp.h>
0019 #include <linux/firmware/xlnx-event-manager.h>
0020 #include <linux/mailbox/zynqmp-ipi-message.h>
0021
0022 /**
0023  * struct zynqmp_pm_work_struct - Wrapper for struct work_struct
0024  * @callback_work:  Work structure
0025  * @args:       Callback arguments
0026  */
0027 struct zynqmp_pm_work_struct {
0028     struct work_struct callback_work;
0029     u32 args[CB_ARG_CNT];
0030 };
0031
0032 static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
0033 static struct mbox_chan *rx_chan;
0034 static bool event_registered;
0035
0036 enum pm_suspend_mode {
0037     PM_SUSPEND_MODE_FIRST = 0,
0038     PM_SUSPEND_MODE_STD = PM_SUSPEND_MODE_FIRST,
0039     PM_SUSPEND_MODE_POWER_OFF,
0040 };
0041
0042 #define PM_SUSPEND_MODE_FIRST   PM_SUSPEND_MODE_STD
0043
0044 static const char *const suspend_modes[] = {
0045     [PM_SUSPEND_MODE_STD] = "standard",
0046     [PM_SUSPEND_MODE_POWER_OFF] = "power-off",
0047 };
0048
0049 static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
0050
0051 static void zynqmp_pm_get_callback_data(u32 *buf)
0052 {
0053     zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
0054 }
0055
0056 static void suspend_event_callback(const u32 *payload, void *data)
0057 {
0058     /* First element is callback API ID, others are callback arguments */
0059     if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
0060         return;
0061
0062     /* Copy callback arguments into work's structure */
0063     memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
0064            sizeof(zynqmp_pm_init_suspend_work->args));
0065
0066     queue_work(system_unbound_wq, &zynqmp_pm_init_suspend_work->callback_work);
0067 }
0068
0069 static irqreturn_t zynqmp_pm_isr(int irq, void *data)
0070 {
0071     u32 payload[CB_PAYLOAD_SIZE];
0072
0073     zynqmp_pm_get_callback_data(payload);
0074
0075     /* First element is callback API ID, others are callback arguments */
0076     if (payload[0] == PM_INIT_SUSPEND_CB) {
0077         switch (payload[1]) {
0078         case SUSPEND_SYSTEM_SHUTDOWN:
0079             orderly_poweroff(true);
0080             break;
0081         case SUSPEND_POWER_REQUEST:
0082             pm_suspend(PM_SUSPEND_MEM);
0083             break;
0084         default:
0085             pr_err("%s Unsupported InitSuspendCb reason "
0086                 "code %d\n", __func__, payload[1]);
0087         }
0088     }
0089
0090     return IRQ_HANDLED;
0091 }
0092
0093 static void ipi_receive_callback(struct mbox_client *cl, void *data)
0094 {
0095     struct zynqmp_ipi_message *msg = (struct zynqmp_ipi_message *)data;
0096     u32 payload[CB_PAYLOAD_SIZE];
0097     int ret;
0098
0099     memcpy(payload, msg->data, sizeof(msg->len));
0100     /* First element is callback API ID, others are callback arguments */
0101     if (payload[0] == PM_INIT_SUSPEND_CB) {
0102         if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
0103             return;
0104
0105         /* Copy callback arguments into work's structure */
0106         memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
0107                sizeof(zynqmp_pm_init_suspend_work->args));
0108
0109         queue_work(system_unbound_wq,
0110                &zynqmp_pm_init_suspend_work->callback_work);
0111
0112         /* Send NULL message to mbox controller to ack the message */
0113         ret = mbox_send_message(rx_chan, NULL);
0114         if (ret)
0115             pr_err("IPI ack failed. Error %d\n", ret);
0116     }
0117 }
0118
0119 /**
0120  * zynqmp_pm_init_suspend_work_fn - Initialize suspend
0121  * @work:   Pointer to work_struct
0122  *
0123  * Bottom-half of PM callback IRQ handler.
0124  */
0125 static void zynqmp_pm_init_suspend_work_fn(struct work_struct *work)
0126 {
0127     struct zynqmp_pm_work_struct *pm_work =
0128         container_of(work, struct zynqmp_pm_work_struct, callback_work);
0129
0130     if (pm_work->args[0] == SUSPEND_SYSTEM_SHUTDOWN) {
0131         orderly_poweroff(true);
0132     } else if (pm_work->args[0] == SUSPEND_POWER_REQUEST) {
0133         pm_suspend(PM_SUSPEND_MEM);
0134     } else {
0135         pr_err("%s Unsupported InitSuspendCb reason code %d.\n",
0136                __func__, pm_work->args[0]);
0137     }
0138 }
0139
0140 static ssize_t suspend_mode_show(struct device *dev,
0141                  struct device_attribute *attr, char *buf)
0142 {
0143     char *s = buf;
0144     int md;
0145
0146     for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
0147         if (suspend_modes[md]) {
0148             if (md == suspend_mode)
0149                 s += sprintf(s, "[%s] ", suspend_modes[md]);
0150             else
0151                 s += sprintf(s, "%s ", suspend_modes[md]);
0152         }
0153
0154     /* Convert last space to newline */
0155     if (s != buf)
0156         *(s - 1) = '\n';
0157     return (s - buf);
0158 }
0159
0160 static ssize_t suspend_mode_store(struct device *dev,
0161                   struct device_attribute *attr,
0162                   const char *buf, size_t count)
0163 {
0164     int md, ret = -EINVAL;
0165
0166     for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
0167         if (suspend_modes[md] &&
0168             sysfs_streq(suspend_modes[md], buf)) {
0169             ret = 0;
0170             break;
0171         }
0172
0173     if (!ret && md != suspend_mode) {
0174         ret = zynqmp_pm_set_suspend_mode(md);
0175         if (likely(!ret))
0176             suspend_mode = md;
0177     }
0178
0179     return ret ? ret : count;
0180 }
0181
0182 static DEVICE_ATTR_RW(suspend_mode);
0183
0184 static int zynqmp_pm_probe(struct platform_device *pdev)
0185 {
0186     int ret, irq;
0187     u32 pm_api_version;
0188     struct mbox_client *client;
0189
0190     zynqmp_pm_get_api_version(&pm_api_version);
0191
0192     /* Check PM API version number */
0193     if (pm_api_version < ZYNQMP_PM_VERSION)
0194         return -ENODEV;
0195
0196     /*
0197      * First try to use Xilinx Event Manager by registering suspend_event_callback
0198      * for suspend/shutdown event.
0199      * If xlnx_register_event() returns -EACCES (Xilinx Event Manager
0200      * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
0201      * then use ipi-mailbox or interrupt method.
0202      */
0203     ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
0204                   suspend_event_callback, NULL);
0205     if (!ret) {
0206         zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
0207                                sizeof(struct zynqmp_pm_work_struct),
0208                                GFP_KERNEL);
0209         if (!zynqmp_pm_init_suspend_work) {
0210             xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
0211                           suspend_event_callback, NULL);
0212             return -ENOMEM;
0213         }
0214         event_registered = true;
0215
0216         INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
0217               zynqmp_pm_init_suspend_work_fn);
0218     } else if (ret != -EACCES && ret != -ENODEV) {
0219         dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
0220         return ret;
0221     } else if (of_find_property(pdev->dev.of_node, "mboxes", NULL)) {
0222         zynqmp_pm_init_suspend_work =
0223             devm_kzalloc(&pdev->dev,
0224                      sizeof(struct zynqmp_pm_work_struct),
0225                      GFP_KERNEL);
0226         if (!zynqmp_pm_init_suspend_work)
0227             return -ENOMEM;
0228
0229         INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
0230               zynqmp_pm_init_suspend_work_fn);
0231         client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
0232         if (!client)
0233             return -ENOMEM;
0234
0235         client->dev = &pdev->dev;
0236         client->rx_callback = ipi_receive_callback;
0237
0238         rx_chan = mbox_request_channel_byname(client, "rx");
0239         if (IS_ERR(rx_chan)) {
0240             dev_err(&pdev->dev, "Failed to request rx channel\n");
0241             return PTR_ERR(rx_chan);
0242         }
0243     } else if (of_find_property(pdev->dev.of_node, "interrupts", NULL)) {
0244         irq = platform_get_irq(pdev, 0);
0245         if (irq <= 0)
0246             return -ENXIO;
0247
0248         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
0249                         zynqmp_pm_isr,
0250                         IRQF_NO_SUSPEND | IRQF_ONESHOT,
0251                         dev_name(&pdev->dev),
0252                         &pdev->dev);
0253         if (ret) {
0254             dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
0255                         "failed with %d\n", irq, ret);
0256             return ret;
0257         }
0258     } else {
0259         dev_err(&pdev->dev, "Required property not found in DT node\n");
0260         return -ENOENT;
0261     }
0262
0263     ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
0264     if (ret) {
0265         if (event_registered) {
0266             xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback,
0267                           NULL);
0268             event_registered = false;
0269         }
0270         dev_err(&pdev->dev, "unable to create sysfs interface\n");
0271         return ret;
0272     }
0273
0274     return 0;
0275 }
0276
0277 static int zynqmp_pm_remove(struct platform_device *pdev)
0278 {
0279     sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
0280     if (event_registered)
0281         xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);
0282
0283     if (!rx_chan)
0284         mbox_free_channel(rx_chan);
0285
0286     return 0;
0287 }
0288
0289 static const struct of_device_id pm_of_match[] = {
0290     { .compatible = "xlnx,zynqmp-power", },
0291     { /* end of table */ },
0292 };
0293 MODULE_DEVICE_TABLE(of, pm_of_match);
0294
0295 static struct platform_driver zynqmp_pm_platform_driver = {
0296     .probe = zynqmp_pm_probe,
0297     .remove = zynqmp_pm_remove,
0298     .driver = {
0299         .name = "zynqmp_power",
0300         .of_match_table = pm_of_match,
0301     },
0302 };
0303 module_platform_driver(zynqmp_pm_platform_driver);