121 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Driver for Qualcomm Secure Execution Environment (SEE) interface (QSEECOM).4 * Responsible for setting up and managing QSEECOM client devices.5 *6 * Copyright (C) 2023 Maximilian Luz <luzmaximilian@gmail.com>7 */8#include <linux/auxiliary_bus.h>9#include <linux/module.h>10#include <linux/platform_device.h>11#include <linux/slab.h>12#include <linux/types.h>13 14#include <linux/firmware/qcom/qcom_qseecom.h>15#include <linux/firmware/qcom/qcom_scm.h>16 17struct qseecom_app_desc {18 const char *app_name;19 const char *dev_name;20};21 22static void qseecom_client_release(struct device *dev)23{24 struct qseecom_client *client;25 26 client = container_of(dev, struct qseecom_client, aux_dev.dev);27 kfree(client);28}29 30static void qseecom_client_remove(void *data)31{32 struct qseecom_client *client = data;33 34 auxiliary_device_delete(&client->aux_dev);35 auxiliary_device_uninit(&client->aux_dev);36}37 38static int qseecom_client_register(struct platform_device *qseecom_dev,39 const struct qseecom_app_desc *desc)40{41 struct qseecom_client *client;42 u32 app_id;43 int ret;44 45 /* Try to find the app ID, skip device if not found */46 ret = qcom_scm_qseecom_app_get_id(desc->app_name, &app_id);47 if (ret)48 return ret == -ENOENT ? 0 : ret;49 50 dev_info(&qseecom_dev->dev, "setting up client for %s\n", desc->app_name);51 52 /* Allocate and set-up the client device */53 client = kzalloc(sizeof(*client), GFP_KERNEL);54 if (!client)55 return -ENOMEM;56 57 client->aux_dev.name = desc->dev_name;58 client->aux_dev.dev.parent = &qseecom_dev->dev;59 client->aux_dev.dev.release = qseecom_client_release;60 client->app_id = app_id;61 62 ret = auxiliary_device_init(&client->aux_dev);63 if (ret) {64 kfree(client);65 return ret;66 }67 68 ret = auxiliary_device_add(&client->aux_dev);69 if (ret) {70 auxiliary_device_uninit(&client->aux_dev);71 return ret;72 }73 74 ret = devm_add_action_or_reset(&qseecom_dev->dev, qseecom_client_remove, client);75 if (ret)76 return ret;77 78 return 0;79}80 81/*82 * List of supported applications. One client device will be created per entry,83 * assuming the app has already been loaded (usually by firmware bootloaders)84 * and its ID can be queried successfully.85 */86static const struct qseecom_app_desc qcom_qseecom_apps[] = {87 { "qcom.tz.uefisecapp", "uefisecapp" },88};89 90static int qcom_qseecom_probe(struct platform_device *qseecom_dev)91{92 int ret;93 int i;94 95 /* Set up client devices for each base application */96 for (i = 0; i < ARRAY_SIZE(qcom_qseecom_apps); i++) {97 ret = qseecom_client_register(qseecom_dev, &qcom_qseecom_apps[i]);98 if (ret)99 return ret;100 }101 102 return 0;103}104 105static struct platform_driver qcom_qseecom_driver = {106 .driver = {107 .name = "qcom_qseecom",108 },109 .probe = qcom_qseecom_probe,110};111 112static int __init qcom_qseecom_init(void)113{114 return platform_driver_register(&qcom_qseecom_driver);115}116subsys_initcall(qcom_qseecom_init);117 118MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");119MODULE_DESCRIPTION("Driver for the Qualcomm SEE (QSEECOM) interface");120MODULE_LICENSE("GPL");121