1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2020 Google LLC 4 * 5 * This driver serves as the receiver of cros_ec PD host events. 6 */ 7 8 #include <linux/acpi.h> 9 #include <linux/module.h> 10 #include <linux/platform_data/cros_ec_proto.h> 11 #include <linux/platform_data/cros_usbpd_notify.h> 12 #include <linux/platform_device.h> 13 14 #define DRV_NAME "cros-usbpd-notify" 15 #define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi" 16 #define ACPI_DRV_NAME "GOOG0003" 17 18 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list); 19 20 struct cros_usbpd_notify_data { 21 struct device *dev; 22 struct cros_ec_device *ec; 23 struct notifier_block nb; 24 }; 25 26 /** 27 * cros_usbpd_register_notify - Register a notifier callback for PD events. 28 * @nb: Notifier block pointer to register 29 * 30 * On ACPI platforms this corresponds to host events on the ECPD 31 * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events 32 * for USB PD events. 33 * 34 * Return: 0 on success or negative error code. 35 */ 36 int cros_usbpd_register_notify(struct notifier_block *nb) 37 { 38 return blocking_notifier_chain_register(&cros_usbpd_notifier_list, 39 nb); 40 } 41 EXPORT_SYMBOL_GPL(cros_usbpd_register_notify); 42 43 /** 44 * cros_usbpd_unregister_notify - Unregister notifier callback for PD events. 45 * @nb: Notifier block pointer to unregister 46 * 47 * Unregister a notifier callback that was previously registered with 48 * cros_usbpd_register_notify(). 49 */ 50 void cros_usbpd_unregister_notify(struct notifier_block *nb) 51 { 52 blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb); 53 } 54 EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify); 55 56 static void cros_usbpd_get_event_and_notify(struct device *dev, 57 struct cros_ec_device *ec_dev) 58 { 59 struct ec_response_host_event_status host_event_status; 60 u32 event = 0; 61 int ret; 62 63 /* 64 * We still send a 0 event out to older devices which don't 65 * have the updated device heirarchy. 66 */ 67 if (!ec_dev) { 68 dev_dbg(dev, 69 "EC device inaccessible; sending 0 event status.\n"); 70 goto send_notify; 71 } 72 73 /* Check for PD host events on EC. */ 74 ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS, 75 NULL, 0, &host_event_status, sizeof(host_event_status)); 76 if (ret < 0) { 77 dev_warn(dev, "Can't get host event status (err: %d)\n", ret); 78 goto send_notify; 79 } 80 81 event = host_event_status.status; 82 83 send_notify: 84 blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL); 85 } 86 87 #ifdef CONFIG_ACPI 88 89 static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data) 90 { 91 struct cros_usbpd_notify_data *pdnotify = data; 92 93 cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec); 94 } 95 96 static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev) 97 { 98 struct cros_usbpd_notify_data *pdnotify; 99 struct device *dev = &pdev->dev; 100 struct acpi_device *adev; 101 struct cros_ec_device *ec_dev; 102 acpi_status status; 103 104 adev = ACPI_COMPANION(dev); 105 106 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); 107 if (!pdnotify) 108 return -ENOMEM; 109 110 /* Get the EC device pointer needed to talk to the EC. */ 111 ec_dev = dev_get_drvdata(dev->parent); 112 if (!ec_dev) { 113 /* 114 * We continue even for older devices which don't have the 115 * correct device heirarchy, namely, GOOG0003 is a child 116 * of GOOG0004. 117 */ 118 dev_warn(dev, "Couldn't get Chrome EC device pointer.\n"); 119 } 120 121 pdnotify->dev = dev; 122 pdnotify->ec = ec_dev; 123 124 status = acpi_install_notify_handler(adev->handle, 125 ACPI_ALL_NOTIFY, 126 cros_usbpd_notify_acpi, 127 pdnotify); 128 if (ACPI_FAILURE(status)) { 129 dev_warn(dev, "Failed to register notify handler %08x\n", 130 status); 131 return -EINVAL; 132 } 133 134 return 0; 135 } 136 137 static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev) 138 { 139 struct device *dev = &pdev->dev; 140 struct acpi_device *adev = ACPI_COMPANION(dev); 141 142 acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY, 143 cros_usbpd_notify_acpi); 144 145 return 0; 146 } 147 148 static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = { 149 { ACPI_DRV_NAME, 0 }, 150 { } 151 }; 152 MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids); 153 154 static struct platform_driver cros_usbpd_notify_acpi_driver = { 155 .driver = { 156 .name = DRV_NAME_PLAT_ACPI, 157 .acpi_match_table = cros_usbpd_notify_acpi_device_ids, 158 }, 159 .probe = cros_usbpd_notify_probe_acpi, 160 .remove = cros_usbpd_notify_remove_acpi, 161 }; 162 163 #endif /* CONFIG_ACPI */ 164 165 static int cros_usbpd_notify_plat(struct notifier_block *nb, 166 unsigned long queued_during_suspend, 167 void *data) 168 { 169 struct cros_usbpd_notify_data *pdnotify = container_of(nb, 170 struct cros_usbpd_notify_data, nb); 171 struct cros_ec_device *ec_dev = (struct cros_ec_device *)data; 172 u32 host_event = cros_ec_get_host_event(ec_dev); 173 174 if (!host_event) 175 return NOTIFY_DONE; 176 177 if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) | 178 EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) { 179 cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev); 180 return NOTIFY_OK; 181 } 182 return NOTIFY_DONE; 183 } 184 185 static int cros_usbpd_notify_probe_plat(struct platform_device *pdev) 186 { 187 struct device *dev = &pdev->dev; 188 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); 189 struct cros_usbpd_notify_data *pdnotify; 190 int ret; 191 192 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); 193 if (!pdnotify) 194 return -ENOMEM; 195 196 pdnotify->dev = dev; 197 pdnotify->ec = ecdev->ec_dev; 198 pdnotify->nb.notifier_call = cros_usbpd_notify_plat; 199 200 dev_set_drvdata(dev, pdnotify); 201 202 ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier, 203 &pdnotify->nb); 204 if (ret < 0) { 205 dev_err(dev, "Failed to register notifier\n"); 206 return ret; 207 } 208 209 return 0; 210 } 211 212 static int cros_usbpd_notify_remove_plat(struct platform_device *pdev) 213 { 214 struct device *dev = &pdev->dev; 215 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); 216 struct cros_usbpd_notify_data *pdnotify = 217 (struct cros_usbpd_notify_data *)dev_get_drvdata(dev); 218 219 blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier, 220 &pdnotify->nb); 221 222 return 0; 223 } 224 225 static struct platform_driver cros_usbpd_notify_plat_driver = { 226 .driver = { 227 .name = DRV_NAME, 228 }, 229 .probe = cros_usbpd_notify_probe_plat, 230 .remove = cros_usbpd_notify_remove_plat, 231 }; 232 233 static int __init cros_usbpd_notify_init(void) 234 { 235 int ret; 236 237 ret = platform_driver_register(&cros_usbpd_notify_plat_driver); 238 if (ret < 0) 239 return ret; 240 241 #ifdef CONFIG_ACPI 242 ret = platform_driver_register(&cros_usbpd_notify_acpi_driver); 243 if (ret) { 244 platform_driver_unregister(&cros_usbpd_notify_plat_driver); 245 return ret; 246 } 247 #endif 248 return 0; 249 } 250 251 static void __exit cros_usbpd_notify_exit(void) 252 { 253 #ifdef CONFIG_ACPI 254 platform_driver_unregister(&cros_usbpd_notify_acpi_driver); 255 #endif 256 platform_driver_unregister(&cros_usbpd_notify_plat_driver); 257 } 258 259 module_init(cros_usbpd_notify_init); 260 module_exit(cros_usbpd_notify_exit); 261 262 MODULE_LICENSE("GPL"); 263 MODULE_DESCRIPTION("ChromeOS power delivery notifier device"); 264 MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>"); 265 MODULE_ALIAS("platform:" DRV_NAME); 266