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 /* This will make sure we can use ioremap_nocache() */ 83 status = acpi_release_memory(ACPI_HANDLE(&pdev->dev), res, 1); 84 if (ACPI_FAILURE(status)) 85 return -ENOMEM; 86 87 /* 88 * NOTE: The memory region for the data structures is used also in an 89 * operation region, which means ACPI has already reserved it. Therefore 90 * it can not be requested here, and we can not use 91 * devm_ioremap_resource(). 92 */ 93 ua->ppm.data = devm_ioremap(&pdev->dev, res->start, resource_size(res)); 94 if (!ua->ppm.data) 95 return -ENOMEM; 96 97 if (!ua->ppm.data->version) 98 return -ENODEV; 99 100 ret = guid_parse(UCSI_DSM_UUID, &ua->guid); 101 if (ret) 102 return ret; 103 104 ua->ppm.cmd = ucsi_acpi_cmd; 105 ua->ppm.sync = ucsi_acpi_sync; 106 ua->dev = &pdev->dev; 107 108 status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev), 109 ACPI_DEVICE_NOTIFY, 110 ucsi_acpi_notify, ua); 111 if (ACPI_FAILURE(status)) { 112 dev_err(&pdev->dev, "failed to install notify handler\n"); 113 return -ENODEV; 114 } 115 116 ua->ucsi = ucsi_register_ppm(&pdev->dev, &ua->ppm); 117 if (IS_ERR(ua->ucsi)) { 118 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), 119 ACPI_DEVICE_NOTIFY, 120 ucsi_acpi_notify); 121 return PTR_ERR(ua->ucsi); 122 } 123 124 platform_set_drvdata(pdev, ua); 125 126 return 0; 127 } 128 129 static int ucsi_acpi_remove(struct platform_device *pdev) 130 { 131 struct ucsi_acpi *ua = platform_get_drvdata(pdev); 132 133 ucsi_unregister_ppm(ua->ucsi); 134 135 acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY, 136 ucsi_acpi_notify); 137 138 return 0; 139 } 140 141 static const struct acpi_device_id ucsi_acpi_match[] = { 142 { "PNP0CA0", 0 }, 143 { }, 144 }; 145 MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match); 146 147 static struct platform_driver ucsi_acpi_platform_driver = { 148 .driver = { 149 .name = "ucsi_acpi", 150 .acpi_match_table = ACPI_PTR(ucsi_acpi_match), 151 }, 152 .probe = ucsi_acpi_probe, 153 .remove = ucsi_acpi_remove, 154 }; 155 156 module_platform_driver(ucsi_acpi_platform_driver); 157 158 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>"); 159 MODULE_LICENSE("GPL v2"); 160 MODULE_DESCRIPTION("UCSI ACPI driver"); 161