linux/drivers/i2c/i2c-slave-testunit.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * I2C slave mode testunit
 *
 * Copyright (C) 2020 by Wolfram Sang, Sang Engineering <[email protected]>
 * Copyright (C) 2020 by Renesas Electronics Corporation
 */

#include <generated/utsrelease.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/workqueue.h> /* FIXME: is system_long_wq the best choice? */

#define TU_VERSION_MAX_LENGTH …

enum testunit_cmds { … };

enum testunit_regs { … };

enum testunit_flags { … };

struct testunit_data { … };

static char tu_version_info[] = …;

static int i2c_slave_testunit_smbalert_cb(struct i2c_client *client,
					  enum i2c_slave_event event, u8 *val)
{ … }

static int i2c_slave_testunit_slave_cb(struct i2c_client *client,
				     enum i2c_slave_event event, u8 *val)
{ … }

static void i2c_slave_testunit_work(struct work_struct *work)
{ … }

static int i2c_slave_testunit_probe(struct i2c_client *client)
{
	struct testunit_data *tu;

	tu = devm_kzalloc(&client->dev, sizeof(struct testunit_data), GFP_KERNEL);
	if (!tu)
		return -ENOMEM;

	tu->client = client;
	i2c_set_clientdata(client, tu);
	init_completion(&tu->alert_done);
	INIT_DELAYED_WORK(&tu->worker, i2c_slave_testunit_work);

	tu->gpio = devm_gpiod_get_index_optional(&client->dev, NULL, 0, GPIOD_OUT_LOW);
	if (gpiod_cansleep(tu->gpio)) {
		dev_err(&client->dev, "GPIO access which may sleep is not allowed\n");
		return -EDEADLK;
	}

	if (sizeof(tu_version_info) > TU_VERSION_MAX_LENGTH)
		tu_version_info[TU_VERSION_MAX_LENGTH - 1] = 0;

	return i2c_slave_register(client, i2c_slave_testunit_slave_cb);
};

static void i2c_slave_testunit_remove(struct i2c_client *client)
{ … }

static const struct i2c_device_id i2c_slave_testunit_id[] = …;
MODULE_DEVICE_TABLE(i2c, i2c_slave_testunit_id);

static struct i2c_driver i2c_slave_testunit_driver = …;
module_i2c_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;