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 /** 57 * cros_ec_pd_command - Send a command to the EC. 58 * 59 * @ec_dev: EC device 60 * @command: EC command 61 * @outdata: EC command output data 62 * @outsize: Size of outdata 63 * @indata: EC command input data 64 * @insize: Size of indata 65 * 66 * Return: >= 0 on success, negative error number on failure. 67 */ 68 static int cros_ec_pd_command(struct cros_ec_device *ec_dev, 69 int command, 70 uint8_t *outdata, 71 int outsize, 72 uint8_t *indata, 73 int insize) 74 { 75 struct cros_ec_command *msg; 76 int ret; 77 78 msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL); 79 if (!msg) 80 return -ENOMEM; 81 82 msg->command = command; 83 msg->outsize = outsize; 84 msg->insize = insize; 85 86 if (outsize) 87 memcpy(msg->data, outdata, outsize); 88 89 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 90 if (ret < 0) 91 goto error; 92 93 if (insize) 94 memcpy(indata, msg->data, insize); 95 error: 96 kfree(msg); 97 return ret; 98 } 99 100 static void cros_usbpd_get_event_and_notify(struct device *dev, 101 struct cros_ec_device *ec_dev) 102 { 103 struct ec_response_host_event_status host_event_status; 104 u32 event = 0; 105 int ret; 106 107 /* 108 * We still send a 0 event out to older devices which don't 109 * have the updated device heirarchy. 110 */ 111 if (!ec_dev) { 112 dev_dbg(dev, 113 "EC device inaccessible; sending 0 event status.\n"); 114 goto send_notify; 115 } 116 117 /* Check for PD host events on EC. */ 118 ret = cros_ec_pd_command(ec_dev, EC_CMD_PD_HOST_EVENT_STATUS, 119 NULL, 0, 120 (uint8_t *)&host_event_status, 121 sizeof(host_event_status)); 122 if (ret < 0) { 123 dev_warn(dev, "Can't get host event status (err: %d)\n", ret); 124 goto send_notify; 125 } 126 127 event = host_event_status.status; 128 129 send_notify: 130 blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL); 131 } 132 133 #ifdef CONFIG_ACPI 134 135 static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data) 136 { 137 struct cros_usbpd_notify_data *pdnotify = data; 138 139 cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec); 140 } 141 142 static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev) 143 { 144 struct cros_usbpd_notify_data *pdnotify; 145 struct device *dev = &pdev->dev; 146 struct acpi_device *adev; 147 struct cros_ec_device *ec_dev; 148 acpi_status status; 149 150 adev = ACPI_COMPANION(dev); 151 152 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); 153 if (!pdnotify) 154 return -ENOMEM; 155 156 /* Get the EC device pointer needed to talk to the EC. */ 157 ec_dev = dev_get_drvdata(dev->parent); 158 if (!ec_dev) { 159 /* 160 * We continue even for older devices which don't have the 161 * correct device heirarchy, namely, GOOG0003 is a child 162 * of GOOG0004. 163 */ 164 dev_warn(dev, "Couldn't get Chrome EC device pointer.\n"); 165 } 166 167 pdnotify->dev = dev; 168 pdnotify->ec = ec_dev; 169 170 status = acpi_install_notify_handler(adev->handle, 171 ACPI_ALL_NOTIFY, 172 cros_usbpd_notify_acpi, 173 pdnotify); 174 if (ACPI_FAILURE(status)) { 175 dev_warn(dev, "Failed to register notify handler %08x\n", 176 status); 177 return -EINVAL; 178 } 179 180 return 0; 181 } 182 183 static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev) 184 { 185 struct device *dev = &pdev->dev; 186 struct acpi_device *adev = ACPI_COMPANION(dev); 187 188 acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY, 189 cros_usbpd_notify_acpi); 190 191 return 0; 192 } 193 194 static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = { 195 { ACPI_DRV_NAME, 0 }, 196 { } 197 }; 198 MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids); 199 200 static struct platform_driver cros_usbpd_notify_acpi_driver = { 201 .driver = { 202 .name = DRV_NAME_PLAT_ACPI, 203 .acpi_match_table = cros_usbpd_notify_acpi_device_ids, 204 }, 205 .probe = cros_usbpd_notify_probe_acpi, 206 .remove = cros_usbpd_notify_remove_acpi, 207 }; 208 209 #endif /* CONFIG_ACPI */ 210 211 static int cros_usbpd_notify_plat(struct notifier_block *nb, 212 unsigned long queued_during_suspend, 213 void *data) 214 { 215 struct cros_usbpd_notify_data *pdnotify = container_of(nb, 216 struct cros_usbpd_notify_data, nb); 217 struct cros_ec_device *ec_dev = (struct cros_ec_device *)data; 218 u32 host_event = cros_ec_get_host_event(ec_dev); 219 220 if (!host_event) 221 return NOTIFY_DONE; 222 223 if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) | 224 EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) { 225 cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev); 226 return NOTIFY_OK; 227 } 228 return NOTIFY_DONE; 229 } 230 231 static int cros_usbpd_notify_probe_plat(struct platform_device *pdev) 232 { 233 struct device *dev = &pdev->dev; 234 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); 235 struct cros_usbpd_notify_data *pdnotify; 236 int ret; 237 238 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); 239 if (!pdnotify) 240 return -ENOMEM; 241 242 pdnotify->dev = dev; 243 pdnotify->ec = ecdev->ec_dev; 244 pdnotify->nb.notifier_call = cros_usbpd_notify_plat; 245 246 dev_set_drvdata(dev, pdnotify); 247 248 ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier, 249 &pdnotify->nb); 250 if (ret < 0) { 251 dev_err(dev, "Failed to register notifier\n"); 252 return ret; 253 } 254 255 return 0; 256 } 257 258 static int cros_usbpd_notify_remove_plat(struct platform_device *pdev) 259 { 260 struct device *dev = &pdev->dev; 261 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); 262 struct cros_usbpd_notify_data *pdnotify = 263 (struct cros_usbpd_notify_data *)dev_get_drvdata(dev); 264 265 blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier, 266 &pdnotify->nb); 267 268 return 0; 269 } 270 271 static struct platform_driver cros_usbpd_notify_plat_driver = { 272 .driver = { 273 .name = DRV_NAME, 274 }, 275 .probe = cros_usbpd_notify_probe_plat, 276 .remove = cros_usbpd_notify_remove_plat, 277 }; 278 279 static int __init cros_usbpd_notify_init(void) 280 { 281 int ret; 282 283 ret = platform_driver_register(&cros_usbpd_notify_plat_driver); 284 if (ret < 0) 285 return ret; 286 287 #ifdef CONFIG_ACPI 288 platform_driver_register(&cros_usbpd_notify_acpi_driver); 289 #endif 290 return 0; 291 } 292 293 static void __exit cros_usbpd_notify_exit(void) 294 { 295 #ifdef CONFIG_ACPI 296 platform_driver_unregister(&cros_usbpd_notify_acpi_driver); 297 #endif 298 platform_driver_unregister(&cros_usbpd_notify_plat_driver); 299 } 300 301 module_init(cros_usbpd_notify_init); 302 module_exit(cros_usbpd_notify_exit); 303 304 MODULE_LICENSE("GPL"); 305 MODULE_DESCRIPTION("ChromeOS power delivery notifier device"); 306 MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>"); 307 MODULE_ALIAS("platform:" DRV_NAME); 308