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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 2020 Google LLC4 *5 * This driver serves as the receiver of cros_ec PD host events.6 */7 8#include <linux/acpi.h>9#include <linux/mod_devicetable.h>10#include <linux/module.h>11#include <linux/platform_data/cros_ec_proto.h>12#include <linux/platform_data/cros_usbpd_notify.h>13#include <linux/platform_device.h>14 15#define DRV_NAME "cros-usbpd-notify"16#define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"17#define ACPI_DRV_NAME "GOOG0003"18 19static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);20 21struct cros_usbpd_notify_data {22 struct device *dev;23 struct cros_ec_device *ec;24 struct notifier_block nb;25};26 27/**28 * cros_usbpd_register_notify - Register a notifier callback for PD events.29 * @nb: Notifier block pointer to register30 *31 * On ACPI platforms this corresponds to host events on the ECPD32 * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events33 * for USB PD events.34 *35 * Return: 0 on success or negative error code.36 */37int cros_usbpd_register_notify(struct notifier_block *nb)38{39 return blocking_notifier_chain_register(&cros_usbpd_notifier_list,40 nb);41}42EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);43 44/**45 * cros_usbpd_unregister_notify - Unregister notifier callback for PD events.46 * @nb: Notifier block pointer to unregister47 *48 * Unregister a notifier callback that was previously registered with49 * cros_usbpd_register_notify().50 */51void cros_usbpd_unregister_notify(struct notifier_block *nb)52{53 blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);54}55EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);56 57static void cros_usbpd_get_event_and_notify(struct device *dev,58 struct cros_ec_device *ec_dev)59{60 struct ec_response_host_event_status host_event_status;61 u32 event = 0;62 int ret;63 64 /*65 * We still send a 0 event out to older devices which don't66 * have the updated device heirarchy.67 */68 if (!ec_dev) {69 dev_dbg(dev,70 "EC device inaccessible; sending 0 event status.\n");71 goto send_notify;72 }73 74 /* Check for PD host events on EC. */75 ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS,76 NULL, 0, &host_event_status, sizeof(host_event_status));77 if (ret < 0) {78 dev_warn(dev, "Can't get host event status (err: %d)\n", ret);79 goto send_notify;80 }81 82 event = host_event_status.status;83 84send_notify:85 blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);86}87 88#ifdef CONFIG_ACPI89 90static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)91{92 struct cros_usbpd_notify_data *pdnotify = data;93 94 cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec);95}96 97static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)98{99 struct cros_usbpd_notify_data *pdnotify;100 struct device *dev = &pdev->dev;101 struct acpi_device *adev;102 struct cros_ec_device *ec_dev;103 acpi_status status;104 105 adev = ACPI_COMPANION(dev);106 107 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);108 if (!pdnotify)109 return -ENOMEM;110 111 /* Get the EC device pointer needed to talk to the EC. */112 ec_dev = dev_get_drvdata(dev->parent);113 if (!ec_dev) {114 /*115 * We continue even for older devices which don't have the116 * correct device heirarchy, namely, GOOG0003 is a child117 * of GOOG0004.118 */119 dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");120 }121 122 pdnotify->dev = dev;123 pdnotify->ec = ec_dev;124 125 status = acpi_install_notify_handler(adev->handle,126 ACPI_ALL_NOTIFY,127 cros_usbpd_notify_acpi,128 pdnotify);129 if (ACPI_FAILURE(status)) {130 dev_warn(dev, "Failed to register notify handler %08x\n",131 status);132 return -EINVAL;133 }134 135 return 0;136}137 138static void cros_usbpd_notify_remove_acpi(struct platform_device *pdev)139{140 struct device *dev = &pdev->dev;141 struct acpi_device *adev = ACPI_COMPANION(dev);142 143 acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,144 cros_usbpd_notify_acpi);145}146 147static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {148 { ACPI_DRV_NAME, 0 },149 { }150};151MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);152 153static struct platform_driver cros_usbpd_notify_acpi_driver = {154 .driver = {155 .name = DRV_NAME_PLAT_ACPI,156 .acpi_match_table = cros_usbpd_notify_acpi_device_ids,157 },158 .probe = cros_usbpd_notify_probe_acpi,159 .remove_new = cros_usbpd_notify_remove_acpi,160};161 162#endif /* CONFIG_ACPI */163 164static int cros_usbpd_notify_plat(struct notifier_block *nb,165 unsigned long queued_during_suspend,166 void *data)167{168 struct cros_usbpd_notify_data *pdnotify = container_of(nb,169 struct cros_usbpd_notify_data, nb);170 struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;171 u32 host_event = cros_ec_get_host_event(ec_dev);172 173 if (!host_event)174 return NOTIFY_DONE;175 176 if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |177 EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {178 cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev);179 return NOTIFY_OK;180 }181 return NOTIFY_DONE;182}183 184static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)185{186 struct device *dev = &pdev->dev;187 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);188 struct cros_usbpd_notify_data *pdnotify;189 int ret;190 191 pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);192 if (!pdnotify)193 return -ENOMEM;194 195 pdnotify->dev = dev;196 pdnotify->ec = ecdev->ec_dev;197 pdnotify->nb.notifier_call = cros_usbpd_notify_plat;198 199 dev_set_drvdata(dev, pdnotify);200 201 ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,202 &pdnotify->nb);203 if (ret < 0) {204 dev_err(dev, "Failed to register notifier\n");205 return ret;206 }207 208 return 0;209}210 211static void cros_usbpd_notify_remove_plat(struct platform_device *pdev)212{213 struct device *dev = &pdev->dev;214 struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);215 struct cros_usbpd_notify_data *pdnotify =216 (struct cros_usbpd_notify_data *)dev_get_drvdata(dev);217 218 blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,219 &pdnotify->nb);220}221 222static const struct platform_device_id cros_usbpd_notify_id[] = {223 { DRV_NAME, 0 },224 {}225};226MODULE_DEVICE_TABLE(platform, cros_usbpd_notify_id);227 228static struct platform_driver cros_usbpd_notify_plat_driver = {229 .driver = {230 .name = DRV_NAME,231 },232 .probe = cros_usbpd_notify_probe_plat,233 .remove_new = cros_usbpd_notify_remove_plat,234 .id_table = cros_usbpd_notify_id,235};236 237static int __init cros_usbpd_notify_init(void)238{239 int ret;240 241 ret = platform_driver_register(&cros_usbpd_notify_plat_driver);242 if (ret < 0)243 return ret;244 245#ifdef CONFIG_ACPI246 ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);247 if (ret) {248 platform_driver_unregister(&cros_usbpd_notify_plat_driver);249 return ret;250 }251#endif252 return 0;253}254 255static void __exit cros_usbpd_notify_exit(void)256{257#ifdef CONFIG_ACPI258 platform_driver_unregister(&cros_usbpd_notify_acpi_driver);259#endif260 platform_driver_unregister(&cros_usbpd_notify_plat_driver);261}262 263module_init(cros_usbpd_notify_init);264module_exit(cros_usbpd_notify_exit);265 266MODULE_LICENSE("GPL");267MODULE_DESCRIPTION("ChromeOS power delivery notifier device");268MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>");269