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
18static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
19
20struct 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 */
36int cros_usbpd_register_notify(struct notifier_block *nb)
37{
38 return blocking_notifier_chain_register(nh: &cros_usbpd_notifier_list,
39 nb);
40}
41EXPORT_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 */
50void cros_usbpd_unregister_notify(struct notifier_block *nb)
51{
52 blocking_notifier_chain_unregister(nh: &cros_usbpd_notifier_list, nb);
53}
54EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
55
56static 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, version: 0, EC_CMD_PD_HOST_EVENT_STATUS,
75 NULL, outsize: 0, indata: &host_event_status, insize: 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
83send_notify:
84 blocking_notifier_call_chain(nh: &cros_usbpd_notifier_list, val: event, NULL);
85}
86
87#ifdef CONFIG_ACPI
88
89static 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(dev: pdnotify->dev, ec_dev: pdnotify->ec);
94}
95
96static 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, size: 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: 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(device: adev->handle,
125 ACPI_ALL_NOTIFY,
126 handler: cros_usbpd_notify_acpi,
127 context: 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
137static void 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(device: adev->handle, ACPI_ALL_NOTIFY,
143 handler: cros_usbpd_notify_acpi);
144}
145
146static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
147 { ACPI_DRV_NAME, 0 },
148 { }
149};
150MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);
151
152static struct platform_driver cros_usbpd_notify_acpi_driver = {
153 .driver = {
154 .name = DRV_NAME_PLAT_ACPI,
155 .acpi_match_table = cros_usbpd_notify_acpi_device_ids,
156 },
157 .probe = cros_usbpd_notify_probe_acpi,
158 .remove_new = cros_usbpd_notify_remove_acpi,
159};
160
161#endif /* CONFIG_ACPI */
162
163static int cros_usbpd_notify_plat(struct notifier_block *nb,
164 unsigned long queued_during_suspend,
165 void *data)
166{
167 struct cros_usbpd_notify_data *pdnotify = container_of(nb,
168 struct cros_usbpd_notify_data, nb);
169 struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
170 u32 host_event = cros_ec_get_host_event(ec_dev);
171
172 if (!host_event)
173 return NOTIFY_DONE;
174
175 if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
176 EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
177 cros_usbpd_get_event_and_notify(dev: pdnotify->dev, ec_dev);
178 return NOTIFY_OK;
179 }
180 return NOTIFY_DONE;
181}
182
183static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
184{
185 struct device *dev = &pdev->dev;
186 struct cros_ec_dev *ecdev = dev_get_drvdata(dev: dev->parent);
187 struct cros_usbpd_notify_data *pdnotify;
188 int ret;
189
190 pdnotify = devm_kzalloc(dev, size: sizeof(*pdnotify), GFP_KERNEL);
191 if (!pdnotify)
192 return -ENOMEM;
193
194 pdnotify->dev = dev;
195 pdnotify->ec = ecdev->ec_dev;
196 pdnotify->nb.notifier_call = cros_usbpd_notify_plat;
197
198 dev_set_drvdata(dev, data: pdnotify);
199
200 ret = blocking_notifier_chain_register(nh: &ecdev->ec_dev->event_notifier,
201 nb: &pdnotify->nb);
202 if (ret < 0) {
203 dev_err(dev, "Failed to register notifier\n");
204 return ret;
205 }
206
207 return 0;
208}
209
210static void cros_usbpd_notify_remove_plat(struct platform_device *pdev)
211{
212 struct device *dev = &pdev->dev;
213 struct cros_ec_dev *ecdev = dev_get_drvdata(dev: dev->parent);
214 struct cros_usbpd_notify_data *pdnotify =
215 (struct cros_usbpd_notify_data *)dev_get_drvdata(dev);
216
217 blocking_notifier_chain_unregister(nh: &ecdev->ec_dev->event_notifier,
218 nb: &pdnotify->nb);
219}
220
221static struct platform_driver cros_usbpd_notify_plat_driver = {
222 .driver = {
223 .name = DRV_NAME,
224 },
225 .probe = cros_usbpd_notify_probe_plat,
226 .remove_new = cros_usbpd_notify_remove_plat,
227};
228
229static int __init cros_usbpd_notify_init(void)
230{
231 int ret;
232
233 ret = platform_driver_register(&cros_usbpd_notify_plat_driver);
234 if (ret < 0)
235 return ret;
236
237#ifdef CONFIG_ACPI
238 ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);
239 if (ret) {
240 platform_driver_unregister(&cros_usbpd_notify_plat_driver);
241 return ret;
242 }
243#endif
244 return 0;
245}
246
247static void __exit cros_usbpd_notify_exit(void)
248{
249#ifdef CONFIG_ACPI
250 platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
251#endif
252 platform_driver_unregister(&cros_usbpd_notify_plat_driver);
253}
254
255module_init(cros_usbpd_notify_init);
256module_exit(cros_usbpd_notify_exit);
257
258MODULE_LICENSE("GPL");
259MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
260MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>");
261MODULE_ALIAS("platform:" DRV_NAME);
262

source code of linux/drivers/platform/chrome/cros_usbpd_notify.c