drivers/usb/typec/ucsi/ucsi_acpi.c

   1 /*
   2  * UCSI ACPI driver
   3  *
   4  * Copyright (C) 2017, Intel Corporation
   5  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/platform_device.h>
  13 #include <linux/module.h>
  14 #include <linux/acpi.h>
  15
  16 #include "ucsi.h"
  17
  18 #define UCSI_DSM_UUID           "6f8398c2-7ca4-11e4-ad36-631042b5008f"
  19 #define UCSI_DSM_FUNC_WRITE     1
  20 #define UCSI_DSM_FUNC_READ      2
  21
  22 struct ucsi_acpi {
  23         struct device *dev;
  24         struct ucsi *ucsi;
  25         struct ucsi_ppm ppm;
  26         guid_t guid;
  27 };
  28
  29 static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
  30 {
  31         union acpi_object *obj;
  32
  33         obj = acpi_evaluate_dsm(ACPI_HANDLE(ua->dev), &ua->guid, 1, func,
  34                                 NULL);
  35         if (!obj) {
  36                 dev_err(ua->dev, "%s: failed to evaluate _DSM %d\n",
  37                         __func__, func);
  38                 return -EIO;
  39         }
  40
  41         ACPI_FREE(obj);
  42         return 0;
  43 }
  44
  45 static int ucsi_acpi_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
  46 {
  47         struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
  48
  49         ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
  50
  51         return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_WRITE);
  52 }
  53
  54 static int ucsi_acpi_sync(struct ucsi_ppm *ppm)
  55 {
  56         struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
  57
  58         return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
  59 }
  60
  61 static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
  62 {
  63         struct ucsi_acpi *ua = data;
  64
  65         ucsi_notify(ua->ucsi);
  66 }
  67
  68 static int ucsi_acpi_probe(struct platform_device *pdev)
  69 {
  70         struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
  71         struct ucsi_acpi *ua;
  72         struct resource *res;
  73         acpi_status status;
  74         int ret;
  75
  76         if (adev->dep_unmet)
  77                 return -EPROBE_DEFER;
  78
  79         ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
  80         if (!ua)
  81                 return -ENOMEM;
  82
  83         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  84         if (!res) {
  85                 dev_err(&pdev->dev, "missing memory resource\n");
  86                 return -ENODEV;
  87         }
  88
  89         /* This will make sure we can use ioremap_nocache() */
  90         status = acpi_release_memory(ACPI_HANDLE(&pdev->dev), res, 1);
  91         if (ACPI_FAILURE(status))
  92                 return -ENOMEM;
  93
  94         /*
  95          * NOTE: The memory region for the data structures is used also in an
  96          * operation region, which means ACPI has already reserved it. Therefore
  97          * it can not be requested here, and we can not use
  98          * devm_ioremap_resource().
  99          */
 100         ua->ppm.data = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 101         if (!ua->ppm.data)
 102                 return -ENOMEM;
 103
 104         if (!ua->ppm.data->version)
 105                 return -ENODEV;
 106
 107         ret = guid_parse(UCSI_DSM_UUID, &ua->guid);
 108         if (ret)
 109                 return ret;
 110
 111         ua->ppm.cmd = ucsi_acpi_cmd;
 112         ua->ppm.sync = ucsi_acpi_sync;
 113         ua->dev = &pdev->dev;
 114
 115         status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
 116                                              ACPI_DEVICE_NOTIFY,
 117                                              ucsi_acpi_notify, ua);
 118         if (ACPI_FAILURE(status)) {
 119                 dev_err(&pdev->dev, "failed to install notify handler\n");
 120                 return -ENODEV;
 121         }
 122
 123         ua->ucsi = ucsi_register_ppm(&pdev->dev, &ua->ppm);
 124         if (IS_ERR(ua->ucsi)) {
 125                 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
 126                                            ACPI_DEVICE_NOTIFY,
 127                                            ucsi_acpi_notify);
 128                 return PTR_ERR(ua->ucsi);
 129         }
 130
 131         platform_set_drvdata(pdev, ua);
 132
 133         return 0;
 134 }
 135
 136 static int ucsi_acpi_remove(struct platform_device *pdev)
 137 {
 138         struct ucsi_acpi *ua = platform_get_drvdata(pdev);
 139
 140         ucsi_unregister_ppm(ua->ucsi);
 141
 142         acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY,
 143                                    ucsi_acpi_notify);
 144
 145         return 0;
 146 }
 147
 148 static const struct acpi_device_id ucsi_acpi_match[] = {
 149         { "PNP0CA0", 0 },
 150         { },
 151 };
 152 MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);
 153
 154 static struct platform_driver ucsi_acpi_platform_driver = {
 155         .driver = {
 156                 .name = "ucsi_acpi",
 157                 .acpi_match_table = ACPI_PTR(ucsi_acpi_match),
 158         },
 159         .probe = ucsi_acpi_probe,
 160         .remove = ucsi_acpi_remove,
 161 };
 162
 163 module_platform_driver(ucsi_acpi_platform_driver);
 164
 165 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 166 MODULE_LICENSE("GPL v2");
 167 MODULE_DESCRIPTION("UCSI ACPI driver");