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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2020 Google LLC
*
* This driver serves as the receiver of cros_ec PD host events.
*/
#include <linux/acpi.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_data/cros_usbpd_notify.h>
#include <linux/platform_device.h>
#define DRV_NAME "cros-usbpd-notify"
#define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
#define ACPI_DRV_NAME "GOOG0003"
static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
struct cros_usbpd_notify_data {
struct device *dev;
struct cros_ec_device *ec;
struct notifier_block nb;
};
/**
* cros_usbpd_register_notify - Register a notifier callback for PD events.
* @nb: Notifier block pointer to register
*
* On ACPI platforms this corresponds to host events on the ECPD
* "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events
* for USB PD events.
*
* Return: 0 on success or negative error code.
*/
int cros_usbpd_register_notify(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&cros_usbpd_notifier_list,
nb);
}
EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);
/**
* cros_usbpd_unregister_notify - Unregister notifier callback for PD events.
* @nb: Notifier block pointer to unregister
*
* Unregister a notifier callback that was previously registered with
* cros_usbpd_register_notify().
*/
void cros_usbpd_unregister_notify(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
static void cros_usbpd_get_event_and_notify(struct device *dev,
struct cros_ec_device *ec_dev)
{
struct ec_response_host_event_status host_event_status;
u32 event = 0;
int ret;
/*
* We still send a 0 event out to older devices which don't
* have the updated device heirarchy.
*/
if (!ec_dev) {
dev_dbg(dev,
"EC device inaccessible; sending 0 event status.\n");
goto send_notify;
}
/* Check for PD host events on EC. */
ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS,
NULL, 0, &host_event_status, sizeof(host_event_status));
if (ret < 0) {
dev_warn(dev, "Can't get host event status (err: %d)\n", ret);
goto send_notify;
}
event = host_event_status.status;
send_notify:
blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
}
#ifdef CONFIG_ACPI
static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
{
struct cros_usbpd_notify_data *pdnotify = data;
cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec);
}
static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
{
struct cros_usbpd_notify_data *pdnotify;
struct device *dev = &pdev->dev;
struct acpi_device *adev;
struct cros_ec_device *ec_dev;
acpi_status status;
adev = ACPI_COMPANION(dev);
pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
if (!pdnotify)
return -ENOMEM;
/* Get the EC device pointer needed to talk to the EC. */
ec_dev = dev_get_drvdata(dev->parent);
if (!ec_dev) {
/*
* We continue even for older devices which don't have the
* correct device heirarchy, namely, GOOG0003 is a child
* of GOOG0004.
*/
dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
}
pdnotify->dev = dev;
pdnotify->ec = ec_dev;
status = acpi_install_notify_handler(adev->handle,
ACPI_ALL_NOTIFY,
cros_usbpd_notify_acpi,
pdnotify);
if (ACPI_FAILURE(status)) {
dev_warn(dev, "Failed to register notify handler %08x\n",
status);
return -EINVAL;
}
return 0;
}
static void cros_usbpd_notify_remove_acpi(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct acpi_device *adev = ACPI_COMPANION(dev);
acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
cros_usbpd_notify_acpi);
}
static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
{ ACPI_DRV_NAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);
static struct platform_driver cros_usbpd_notify_acpi_driver = {
.driver = {
.name = DRV_NAME_PLAT_ACPI,
.acpi_match_table = cros_usbpd_notify_acpi_device_ids,
},
.probe = cros_usbpd_notify_probe_acpi,
.remove_new = cros_usbpd_notify_remove_acpi,
};
#endif /* CONFIG_ACPI */
static int cros_usbpd_notify_plat(struct notifier_block *nb,
unsigned long queued_during_suspend,
void *data)
{
struct cros_usbpd_notify_data *pdnotify = container_of(nb,
struct cros_usbpd_notify_data, nb);
struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
u32 host_event = cros_ec_get_host_event(ec_dev);
if (!host_event)
return NOTIFY_DONE;
if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
struct cros_usbpd_notify_data *pdnotify;
int ret;
pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
if (!pdnotify)
return -ENOMEM;
pdnotify->dev = dev;
pdnotify->ec = ecdev->ec_dev;
pdnotify->nb.notifier_call = cros_usbpd_notify_plat;
dev_set_drvdata(dev, pdnotify);
ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
&pdnotify->nb);
if (ret < 0) {
dev_err(dev, "Failed to register notifier\n");
return ret;
}
return 0;
}
static void cros_usbpd_notify_remove_plat(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
struct cros_usbpd_notify_data *pdnotify =
(struct cros_usbpd_notify_data *)dev_get_drvdata(dev);
blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
&pdnotify->nb);
}
static const struct platform_device_id cros_usbpd_notify_id[] = {
{ DRV_NAME, 0 },
{}
};
MODULE_DEVICE_TABLE(platform, cros_usbpd_notify_id);
static struct platform_driver cros_usbpd_notify_plat_driver = {
.driver = {
.name = DRV_NAME,
},
.probe = cros_usbpd_notify_probe_plat,
.remove_new = cros_usbpd_notify_remove_plat,
.id_table = cros_usbpd_notify_id,
};
static int __init cros_usbpd_notify_init(void)
{
int ret;
ret = platform_driver_register(&cros_usbpd_notify_plat_driver);
if (ret < 0)
return ret;
#ifdef CONFIG_ACPI
ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);
if (ret) {
platform_driver_unregister(&cros_usbpd_notify_plat_driver);
return ret;
}
#endif
return 0;
}
static void __exit cros_usbpd_notify_exit(void)
{
#ifdef CONFIG_ACPI
platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
#endif
platform_driver_unregister(&cros_usbpd_notify_plat_driver);
}
module_init(cros_usbpd_notify_init);
module_exit(cros_usbpd_notify_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>");
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