drivers/usb/typec/ucsi/ucsi_acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * UCSI ACPI driver
   4  *
   5  * Copyright (C) 2017, Intel Corporation
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  */
   8
   9 #include <linux/platform_device.h>
  10 #include <linux/module.h>
  11 #include <linux/acpi.h>
  12
  13 #include "ucsi.h"
  14
  15 #define UCSI_DSM_UUID           "6f8398c2-7ca4-11e4-ad36-631042b5008f"
  16 #define UCSI_DSM_FUNC_WRITE     1
  17 #define UCSI_DSM_FUNC_READ      2
  18
  19 struct ucsi_acpi {
  20         struct device *dev;
  21         struct ucsi *ucsi;
  22         struct ucsi_ppm ppm;
  23         guid_t guid;
  24 };
  25
  26 static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
  27 {
  28         union acpi_object *obj;
  29
  30         obj = acpi_evaluate_dsm(ACPI_HANDLE(ua->dev), &ua->guid, 1, func,
  31                                 NULL);
  32         if (!obj) {
  33                 dev_err(ua->dev, "%s: failed to evaluate _DSM %d\n",
  34                         __func__, func);
  35                 return -EIO;
  36         }
  37
  38         ACPI_FREE(obj);
  39         return 0;
  40 }
  41
  42 static int ucsi_acpi_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
  43 {
  44         struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
  45
  46         ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
  47
  48         return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_WRITE);
  49 }
  50
  51 static int ucsi_acpi_sync(struct ucsi_ppm *ppm)
  52 {
  53         struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
  54
  55         return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
  56 }
  57
  58 static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
  59 {
  60         struct ucsi_acpi *ua = data;
  61
  62         ucsi_notify(ua->ucsi);
  63 }
  64
  65 static int ucsi_acpi_probe(struct platform_device *pdev)
  66 {
  67         struct ucsi_acpi *ua;
  68         struct resource *res;
  69         acpi_status status;
  70         int ret;
  71
  72         ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
  73         if (!ua)
  74                 return -ENOMEM;
  75
  76         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  77         if (!res) {
  78                 dev_err(&pdev->dev, "missing memory resource\n");
  79                 return -ENODEV;
  80         }
  81
  82         /*
  83          * NOTE: The memory region for the data structures is used also in an
  84          * operation region, which means ACPI has already reserved it. Therefore
  85          * it can not be requested here, and we can not use
  86          * devm_ioremap_resource().
  87          */
  88         ua->ppm.data = devm_ioremap(&pdev->dev, res->start, resource_size(res));
  89         if (!ua->ppm.data)
  90                 return -ENOMEM;
  91
  92         if (!ua->ppm.data->version)
  93                 return -ENODEV;
  94
  95         ret = guid_parse(UCSI_DSM_UUID, &ua->guid);
  96         if (ret)
  97                 return ret;
  98
  99         ua->ppm.cmd = ucsi_acpi_cmd;
 100         ua->ppm.sync = ucsi_acpi_sync;
 101         ua->dev = &pdev->dev;
 102
 103         status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
 104                                              ACPI_DEVICE_NOTIFY,
 105                                              ucsi_acpi_notify, ua);
 106         if (ACPI_FAILURE(status)) {
 107                 dev_err(&pdev->dev, "failed to install notify handler\n");
 108                 return -ENODEV;
 109         }
 110
 111         ua->ucsi = ucsi_register_ppm(&pdev->dev, &ua->ppm);
 112         if (IS_ERR(ua->ucsi)) {
 113                 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
 114                                            ACPI_DEVICE_NOTIFY,
 115                                            ucsi_acpi_notify);
 116                 return PTR_ERR(ua->ucsi);
 117         }
 118
 119         platform_set_drvdata(pdev, ua);
 120
 121         return 0;
 122 }
 123
 124 static int ucsi_acpi_remove(struct platform_device *pdev)
 125 {
 126         struct ucsi_acpi *ua = platform_get_drvdata(pdev);
 127
 128         ucsi_unregister_ppm(ua->ucsi);
 129
 130         acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY,
 131                                    ucsi_acpi_notify);
 132
 133         return 0;
 134 }
 135
 136 static const struct acpi_device_id ucsi_acpi_match[] = {
 137         { "PNP0CA0", 0 },
 138         { },
 139 };
 140 MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);
 141
 142 static struct platform_driver ucsi_acpi_platform_driver = {
 143         .driver = {
 144                 .name = "ucsi_acpi",
 145                 .acpi_match_table = ACPI_PTR(ucsi_acpi_match),
 146         },
 147         .probe = ucsi_acpi_probe,
 148         .remove = ucsi_acpi_remove,
 149 };
 150
 151 module_platform_driver(ucsi_acpi_platform_driver);
 152
 153 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 154 MODULE_LICENSE("GPL v2");
 155 MODULE_DESCRIPTION("UCSI ACPI driver");