// SPDX-License-Identifier: GPL-2.0-or-later
/*
* cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
*
* Copyright (C) 2014 Google, Inc.
*/
#include <linux/kconfig.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/platform_data/cros_ec_chardev.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/slab.h>
#define DRV_NAME "cros-ec-dev"
static struct class cros_class = {
.owner = THIS_MODULE,
.name = "chromeos",
};
/**
* cros_feature_to_name - CrOS feature id to name/short description.
* @id: The feature identifier.
* @name: Device name associated with the feature id.
* @desc: Short name that will be displayed.
*/
struct cros_feature_to_name {
unsigned int id;
const char *name;
const char *desc;
};
/**
* cros_feature_to_cells - CrOS feature id to mfd cells association.
* @id: The feature identifier.
* @mfd_cells: Pointer to the array of mfd cells that needs to be added.
* @num_cells: Number of mfd cells into the array.
*/
struct cros_feature_to_cells {
unsigned int id;
const struct mfd_cell *mfd_cells;
unsigned int num_cells;
};
static const struct cros_feature_to_name cros_mcu_devices[] = {
{
.id = EC_FEATURE_FINGERPRINT,
.name = CROS_EC_DEV_FP_NAME,
.desc = "Fingerprint",
},
{
.id = EC_FEATURE_ISH,
.name = CROS_EC_DEV_ISH_NAME,
.desc = "Integrated Sensor Hub",
},
{
.id = EC_FEATURE_SCP,
.name = CROS_EC_DEV_SCP_NAME,
.desc = "System Control Processor",
},
{
.id = EC_FEATURE_TOUCHPAD,
.name = CROS_EC_DEV_TP_NAME,
.desc = "Touchpad",
},
};
static const struct mfd_cell cros_ec_cec_cells[] = {
{ .name = "cros-ec-cec", },
};
static const struct mfd_cell cros_ec_rtc_cells[] = {
{ .name = "cros-ec-rtc", },
};
static const struct mfd_cell cros_ec_sensorhub_cells[] = {
{ .name = "cros-ec-sensorhub", },
};
static const struct mfd_cell cros_usbpd_charger_cells[] = {
{ .name = "cros-usbpd-charger", },
{ .name = "cros-usbpd-logger", },
};
static const struct mfd_cell cros_usbpd_notify_cells[] = {
{ .name = "cros-usbpd-notify", },
};
static const struct cros_feature_to_cells cros_subdevices[] = {
{
.id = EC_FEATURE_CEC,
.mfd_cells = cros_ec_cec_cells,
.num_cells = ARRAY_SIZE(cros_ec_cec_cells),
},
{
.id = EC_FEATURE_RTC,
.mfd_cells = cros_ec_rtc_cells,
.num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
},
{
.id = EC_FEATURE_USB_PD,
.mfd_cells = cros_usbpd_charger_cells,
.num_cells = ARRAY_SIZE(cros_usbpd_charger_cells),
},
};
static const struct mfd_cell cros_ec_platform_cells[] = {
{ .name = "cros-ec-chardev", },
{ .name = "cros-ec-debugfs", },
{ .name = "cros-ec-lightbar", },
{ .name = "cros-ec-sysfs", },
};
static const struct mfd_cell cros_ec_vbc_cells[] = {
{ .name = "cros-ec-vbc", }
};
static void cros_ec_class_release(struct device *dev)
{
kfree(to_cros_ec_dev(dev));
}
static int ec_device_probe(struct platform_device *pdev)
{
int retval = -ENOMEM;
struct device_node *node;
struct device *dev = &pdev->dev;
struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
int i;
if (!ec)
return retval;
dev_set_drvdata(dev, ec);
ec->ec_dev = dev_get_drvdata(dev->parent);
ec->dev = dev;
ec->cmd_offset = ec_platform->cmd_offset;
ec->features[0] = -1U; /* Not cached yet */
ec->features[1] = -1U; /* Not cached yet */
device_initialize(&ec->class_dev);
for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
/*
* Check whether this is actually a dedicated MCU rather
* than an standard EC.
*/
if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
dev_info(dev, "CrOS %s MCU detected\n",
cros_mcu_devices[i].desc);
/*
* Help userspace differentiating ECs from other MCU,
* regardless of the probing order.
*/
ec_platform->ec_name = cros_mcu_devices[i].name;
break;
}
}
/*
* Add the class device
*/
ec->class_dev.class = &cros_class;
ec->class_dev.parent = dev;
ec->class_dev.release = cros_ec_class_release;
retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
if (retval) {
dev_err(dev, "dev_set_name failed => %d\n", retval);
goto failed;
}
retval = device_add(&ec->class_dev);
if (retval)
goto failed;
/* check whether this EC is a sensor hub. */
if (cros_ec_get_sensor_count(ec) > 0) {
retval = mfd_add_hotplug_devices(ec->dev,
cros_ec_sensorhub_cells,
ARRAY_SIZE(cros_ec_sensorhub_cells));
if (retval)
dev_err(ec->dev, "failed to add %s subdevice: %d\n",
cros_ec_sensorhub_cells->name, retval);
}
/*
* The following subdevices can be detected by sending the
* EC_FEATURE_GET_CMD Embedded Controller device.
*/
for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
retval = mfd_add_hotplug_devices(ec->dev,
cros_subdevices[i].mfd_cells,
cros_subdevices[i].num_cells);
if (retval)
dev_err(ec->dev,
"failed to add %s subdevice: %d\n",
cros_subdevices[i].mfd_cells->name,
retval);
}
}
/*
* The PD notifier driver cell is separate since it only needs to be
* explicitly added on platforms that don't have the PD notifier ACPI
* device entry defined.
*/
if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
retval = mfd_add_hotplug_devices(ec->dev,
cros_usbpd_notify_cells,
ARRAY_SIZE(cros_usbpd_notify_cells));
if (retval)
dev_err(ec->dev,
"failed to add PD notify devices: %d\n",
retval);
}
}
/*
* The following subdevices cannot be detected by sending the
* EC_FEATURE_GET_CMD to the Embedded Controller device.
*/
retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
ARRAY_SIZE(cros_ec_platform_cells));
if (retval)
dev_warn(ec->dev,
"failed to add cros-ec platform devices: %d\n",
retval);
/* Check whether this EC instance has a VBC NVRAM */
node = ec->ec_dev->dev->of_node;
if (of_property_read_bool(node, "google,has-vbc-nvram")) {
retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
ARRAY_SIZE(cros_ec_vbc_cells));
if (retval)
dev_warn(ec->dev, "failed to add VBC devices: %d\n",
retval);
}
return 0;
failed:
put_device(&ec->class_dev);
return retval;
}
static int ec_device_remove(struct platform_device *pdev)
{
struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
mfd_remove_devices(ec->dev);
device_unregister(&ec->class_dev);
return 0;
}
static const struct platform_device_id cros_ec_id[] = {
{ DRV_NAME, 0 },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, cros_ec_id);
static struct platform_driver cros_ec_dev_driver = {
.driver = {
.name = DRV_NAME,
},
.id_table = cros_ec_id,
.probe = ec_device_probe,
.remove = ec_device_remove,
};
static int __init cros_ec_dev_init(void)
{
int ret;
ret = class_register(&cros_class);
if (ret) {
pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
return ret;
}
/* Register the driver */
ret = platform_driver_register(&cros_ec_dev_driver);
if (ret < 0) {
pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
goto failed_devreg;
}
return 0;
failed_devreg:
class_unregister(&cros_class);
return ret;
}
static void __exit cros_ec_dev_exit(void)
{
platform_driver_unregister(&cros_ec_dev_driver);
class_unregister(&cros_class);
}
module_init(cros_ec_dev_init);
module_exit(cros_ec_dev_exit);
MODULE_ALIAS("platform:" DRV_NAME);
MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");
