// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2022-2024, Linaro Ltd
* Authors:
* Bjorn Andersson
* Dmitry Baryshkov
*/
#include <linux/auxiliary_bus.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/irqreturn.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/slab.h>
#include <linux/platform_data/lenovo-yoga-c630.h>
#define LENOVO_EC_RESPONSE_REG 0x01
#define LENOVO_EC_REQUEST_REG 0x02
#define LENOVO_EC_UCSI_WRITE 0x20
#define LENOVO_EC_UCSI_READ 0x21
#define LENOVO_EC_READ_REG 0xb0
#define LENOVO_EC_REQUEST_NEXT_EVENT 0x84
#define LENOVO_EC_UCSI_VERSION 0x20
struct yoga_c630_ec {
struct i2c_client *client;
struct mutex lock;
struct blocking_notifier_head notifier_list;
};
static int yoga_c630_ec_request(struct yoga_c630_ec *ec, u8 *req, size_t req_len,
u8 *resp, size_t resp_len)
{
int ret;
lockdep_assert_held(&ec->lock);
ret = i2c_smbus_write_i2c_block_data(ec->client, LENOVO_EC_REQUEST_REG,
req_len, req);
if (ret < 0)
return ret;
return i2c_smbus_read_i2c_block_data(ec->client, LENOVO_EC_RESPONSE_REG,
resp_len, resp);
}
int yoga_c630_ec_read8(struct yoga_c630_ec *ec, u8 addr)
{
u8 req[2] = { LENOVO_EC_READ_REG, };
int ret;
u8 val;
guard(mutex)(&ec->lock);
req[1] = addr;
ret = yoga_c630_ec_request(ec, req, sizeof(req), &val, 1);
if (ret < 0)
return ret;
return val;
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_read8);
int yoga_c630_ec_read16(struct yoga_c630_ec *ec, u8 addr)
{
u8 req[2] = { LENOVO_EC_READ_REG, };
int ret;
u8 msb;
u8 lsb;
/* don't overflow the address */
if (addr == 0xff)
return -EINVAL;
guard(mutex)(&ec->lock);
req[1] = addr;
ret = yoga_c630_ec_request(ec, req, sizeof(req), &lsb, 1);
if (ret < 0)
return ret;
req[1] = addr + 1;
ret = yoga_c630_ec_request(ec, req, sizeof(req), &msb, 1);
if (ret < 0)
return ret;
return msb << 8 | lsb;
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_read16);
u16 yoga_c630_ec_ucsi_get_version(struct yoga_c630_ec *ec)
{
u8 req[3] = { 0xb3, 0xf2, };
int ret;
u8 msb;
u8 lsb;
guard(mutex)(&ec->lock);
req[2] = LENOVO_EC_UCSI_VERSION;
ret = yoga_c630_ec_request(ec, req, sizeof(req), &lsb, 1);
if (ret < 0)
return ret;
req[2] = LENOVO_EC_UCSI_VERSION + 1;
ret = yoga_c630_ec_request(ec, req, sizeof(req), &msb, 1);
if (ret < 0)
return ret;
return msb << 8 | lsb;
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_get_version);
int yoga_c630_ec_ucsi_write(struct yoga_c630_ec *ec,
const u8 req[YOGA_C630_UCSI_WRITE_SIZE])
{
int ret;
mutex_lock(&ec->lock);
ret = i2c_smbus_write_i2c_block_data(ec->client, LENOVO_EC_UCSI_WRITE,
YOGA_C630_UCSI_WRITE_SIZE, req);
mutex_unlock(&ec->lock);
return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_write);
int yoga_c630_ec_ucsi_read(struct yoga_c630_ec *ec,
u8 resp[YOGA_C630_UCSI_READ_SIZE])
{
int ret;
mutex_lock(&ec->lock);
ret = i2c_smbus_read_i2c_block_data(ec->client, LENOVO_EC_UCSI_READ,
YOGA_C630_UCSI_READ_SIZE, resp);
mutex_unlock(&ec->lock);
return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_read);
static irqreturn_t yoga_c630_ec_thread_intr(int irq, void *data)
{
u8 req[] = { LENOVO_EC_REQUEST_NEXT_EVENT };
struct yoga_c630_ec *ec = data;
u8 event;
int ret;
mutex_lock(&ec->lock);
ret = yoga_c630_ec_request(ec, req, sizeof(req), &event, 1);
mutex_unlock(&ec->lock);
if (ret < 0)
return IRQ_HANDLED;
blocking_notifier_call_chain(&ec->notifier_list, event, ec);
return IRQ_HANDLED;
}
/**
* yoga_c630_ec_register_notify - Register a notifier callback for EC events.
* @ec: Yoga C630 EC
* @nb: Notifier block pointer to register
*
* Return: 0 on success or negative error code.
*/
int yoga_c630_ec_register_notify(struct yoga_c630_ec *ec, struct notifier_block *nb)
{
return blocking_notifier_chain_register(&ec->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_register_notify);
/**
* yoga_c630_ec_unregister_notify - Unregister notifier callback for EC events.
* @ec: Yoga C630 EC
* @nb: Notifier block pointer to unregister
*
* Unregister a notifier callback that was previously registered with
* yoga_c630_ec_register_notify().
*/
void yoga_c630_ec_unregister_notify(struct yoga_c630_ec *ec, struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&ec->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(yoga_c630_ec_unregister_notify);
static void yoga_c630_aux_release(struct device *dev)
{
struct auxiliary_device *adev = to_auxiliary_dev(dev);
kfree(adev);
}
static void yoga_c630_aux_remove(void *data)
{
struct auxiliary_device *adev = data;
auxiliary_device_delete(adev);
auxiliary_device_uninit(adev);
}
static int yoga_c630_aux_init(struct device *parent, const char *name,
struct yoga_c630_ec *ec)
{
struct auxiliary_device *adev;
int ret;
adev = kzalloc(sizeof(*adev), GFP_KERNEL);
if (!adev)
return -ENOMEM;
adev->name = name;
adev->id = 0;
adev->dev.parent = parent;
adev->dev.release = yoga_c630_aux_release;
adev->dev.platform_data = ec;
ret = auxiliary_device_init(adev);
if (ret) {
kfree(adev);
return ret;
}
ret = auxiliary_device_add(adev);
if (ret) {
auxiliary_device_uninit(adev);
return ret;
}
return devm_add_action_or_reset(parent, yoga_c630_aux_remove, adev);
}
static int yoga_c630_ec_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct yoga_c630_ec *ec;
int ret;
ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
if (!ec)
return -ENOMEM;
mutex_init(&ec->lock);
ec->client = client;
BLOCKING_INIT_NOTIFIER_HEAD(&ec->notifier_list);
ret = devm_request_threaded_irq(dev, client->irq,
NULL, yoga_c630_ec_thread_intr,
IRQF_ONESHOT, "yoga_c630_ec", ec);
if (ret < 0)
return dev_err_probe(dev, ret, "unable to request irq\n");
ret = yoga_c630_aux_init(dev, YOGA_C630_DEV_PSY, ec);
if (ret)
return ret;
return yoga_c630_aux_init(dev, YOGA_C630_DEV_UCSI, ec);
}
static const struct of_device_id yoga_c630_ec_of_match[] = {
{ .compatible = "lenovo,yoga-c630-ec" },
{}
};
MODULE_DEVICE_TABLE(of, yoga_c630_ec_of_match);
static const struct i2c_device_id yoga_c630_ec_i2c_id_table[] = {
{ "yoga-c630-ec", },
{}
};
MODULE_DEVICE_TABLE(i2c, yoga_c630_ec_i2c_id_table);
static struct i2c_driver yoga_c630_ec_i2c_driver = {
.driver = {
.name = "yoga-c630-ec",
.of_match_table = yoga_c630_ec_of_match
},
.probe = yoga_c630_ec_probe,
.id_table = yoga_c630_ec_i2c_id_table,
};
module_i2c_driver(yoga_c630_ec_i2c_driver);
MODULE_DESCRIPTION("Lenovo Yoga C630 Embedded Controller");
MODULE_LICENSE("GPL");
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