drivers/cdx/controller/cdx_rpmsg.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Platform driver for CDX bus.
   4  *
   5  * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
   6  */
   7
   8 #include <linux/rpmsg.h>
   9 #include <linux/remoteproc.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/cdx/cdx_bus.h>
  13 #include <linux/module.h>
  14
  15 #include "../cdx.h"
  16 #include "cdx_controller.h"
  17 #include "mcdi_functions.h"
  18 #include "mcdi.h"
  19
  20 static struct rpmsg_device_id cdx_rpmsg_id_table[] = {
  21         { .name = "mcdi_ipc" },
  22         { },
  23 };
  24 MODULE_DEVICE_TABLE(rpmsg, cdx_rpmsg_id_table);
  25
  26 int cdx_rpmsg_send(struct cdx_mcdi *cdx_mcdi,
  27                    const struct cdx_dword *hdr, size_t hdr_len,
  28                    const struct cdx_dword *sdu, size_t sdu_len)
  29 {
  30         unsigned char *send_buf;
  31         int ret;
  32
  33         send_buf = kzalloc(hdr_len + sdu_len, GFP_KERNEL);
  34         if (!send_buf)
  35                 return -ENOMEM;
  36
  37         memcpy(send_buf, hdr, hdr_len);
  38         memcpy(send_buf + hdr_len, sdu, sdu_len);
  39
  40         ret = rpmsg_send(cdx_mcdi->ept, send_buf, hdr_len + sdu_len);
  41         kfree(send_buf);
  42
  43         return ret;
  44 }
  45
  46 static int cdx_attach_to_rproc(struct platform_device *pdev)
  47 {
  48         struct device_node *r5_core_node;
  49         struct cdx_controller *cdx_c;
  50         struct cdx_mcdi *cdx_mcdi;
  51         struct device *dev;
  52         struct rproc *rp;
  53         int ret;
  54
  55         dev = &pdev->dev;
  56         cdx_c = platform_get_drvdata(pdev);
  57         cdx_mcdi = cdx_c->priv;
  58
  59         r5_core_node = of_parse_phandle(dev->of_node, "xlnx,rproc", 0);
  60         if (!r5_core_node) {
  61                 dev_err(&pdev->dev, "xlnx,rproc: invalid phandle\n");
  62                 return -EINVAL;
  63         }
  64
  65         rp = rproc_get_by_phandle(r5_core_node->phandle);
  66         if (!rp) {
  67                 ret = -EPROBE_DEFER;
  68                 goto pdev_err;
  69         }
  70
  71         /* Attach to remote processor */
  72         ret = rproc_boot(rp);
  73         if (ret) {
  74                 dev_err(&pdev->dev, "Failed to attach to remote processor\n");
  75                 rproc_put(rp);
  76                 goto pdev_err;
  77         }
  78
  79         cdx_mcdi->r5_rproc = rp;
  80 pdev_err:
  81         of_node_put(r5_core_node);
  82         return ret;
  83 }
  84
  85 static void cdx_detach_to_r5(struct platform_device *pdev)
  86 {
  87         struct cdx_controller *cdx_c;
  88         struct cdx_mcdi *cdx_mcdi;
  89
  90         cdx_c = platform_get_drvdata(pdev);
  91         cdx_mcdi = cdx_c->priv;
  92
  93         rproc_detach(cdx_mcdi->r5_rproc);
  94         rproc_put(cdx_mcdi->r5_rproc);
  95 }
  96
  97 static int cdx_rpmsg_cb(struct rpmsg_device *rpdev, void *data,
  98                         int len, void *priv, u32 src)
  99 {
 100         struct cdx_controller *cdx_c = dev_get_drvdata(&rpdev->dev);
 101         struct cdx_mcdi *cdx_mcdi = cdx_c->priv;
 102
 103         if (len > MCDI_BUF_LEN)
 104                 return -EINVAL;
 105
 106         cdx_mcdi_process_cmd(cdx_mcdi, (struct cdx_dword *)data, len);
 107
 108         return 0;
 109 }
 110
 111 static void cdx_rpmsg_post_probe_work(struct work_struct *work)
 112 {
 113         struct cdx_controller *cdx_c;
 114         struct cdx_mcdi *cdx_mcdi;
 115
 116         cdx_mcdi = container_of(work, struct cdx_mcdi, work);
 117         cdx_c = dev_get_drvdata(&cdx_mcdi->rpdev->dev);
 118         cdx_rpmsg_post_probe(cdx_c);
 119 }
 120
 121 static int cdx_rpmsg_probe(struct rpmsg_device *rpdev)
 122 {
 123         struct rpmsg_channel_info chinfo = {0};
 124         struct cdx_controller *cdx_c;
 125         struct cdx_mcdi *cdx_mcdi;
 126
 127         cdx_c = (struct cdx_controller *)cdx_rpmsg_id_table[0].driver_data;
 128         cdx_mcdi = cdx_c->priv;
 129
 130         chinfo.src = RPMSG_ADDR_ANY;
 131         chinfo.dst = rpdev->dst;
 132         strscpy(chinfo.name, cdx_rpmsg_id_table[0].name,
 133                 strlen(cdx_rpmsg_id_table[0].name));
 134
 135         cdx_mcdi->ept = rpmsg_create_ept(rpdev, cdx_rpmsg_cb, NULL, chinfo);
 136         if (!cdx_mcdi->ept) {
 137                 dev_err_probe(&rpdev->dev, -ENXIO,
 138                               "Failed to create ept for channel %s\n",
 139                               chinfo.name);
 140                 return -EINVAL;
 141         }
 142
 143         cdx_mcdi->rpdev = rpdev;
 144         dev_set_drvdata(&rpdev->dev, cdx_c);
 145
 146         schedule_work(&cdx_mcdi->work);
 147         return 0;
 148 }
 149
 150 static void cdx_rpmsg_remove(struct rpmsg_device *rpdev)
 151 {
 152         struct cdx_controller *cdx_c = dev_get_drvdata(&rpdev->dev);
 153         struct cdx_mcdi *cdx_mcdi = cdx_c->priv;
 154
 155         flush_work(&cdx_mcdi->work);
 156         cdx_rpmsg_pre_remove(cdx_c);
 157
 158         rpmsg_destroy_ept(cdx_mcdi->ept);
 159         dev_set_drvdata(&rpdev->dev, NULL);
 160 }
 161
 162 static struct rpmsg_driver cdx_rpmsg_driver = {
 163         .drv.name = KBUILD_MODNAME,
 164         .id_table = cdx_rpmsg_id_table,
 165         .probe = cdx_rpmsg_probe,
 166         .remove = cdx_rpmsg_remove,
 167         .callback = cdx_rpmsg_cb,
 168 };
 169
 170 int cdx_setup_rpmsg(struct platform_device *pdev)
 171 {
 172         struct cdx_controller *cdx_c;
 173         struct cdx_mcdi *cdx_mcdi;
 174         int ret;
 175
 176         /* Attach to remote processor */
 177         ret = cdx_attach_to_rproc(pdev);
 178         if (ret)
 179                 return ret;
 180
 181         cdx_c = platform_get_drvdata(pdev);
 182         cdx_mcdi = cdx_c->priv;
 183
 184         /* Register RPMsg driver */
 185         cdx_rpmsg_id_table[0].driver_data = (kernel_ulong_t)cdx_c;
 186
 187         INIT_WORK(&cdx_mcdi->work, cdx_rpmsg_post_probe_work);
 188         ret = register_rpmsg_driver(&cdx_rpmsg_driver);
 189         if (ret) {
 190                 dev_err(&pdev->dev,
 191                         "Failed to register cdx RPMsg driver: %d\n", ret);
 192                 cdx_detach_to_r5(pdev);
 193         }
 194
 195         return ret;
 196 }
 197
 198 void cdx_destroy_rpmsg(struct platform_device *pdev)
 199 {
 200         unregister_rpmsg_driver(&cdx_rpmsg_driver);
 201
 202         cdx_detach_to_r5(pdev);
 203 }