linux/drivers/i2c/i2c-slave-testunit.c
Uwe Kleine-König 834a9dc46d i2c: Convert drivers to new .probe() callback
Now that .probe() was changed not to get the id parameter, drivers can
be converted back to that with the eventual goal to drop .probe_new().

Implement that for the i2c drivers that are part of the i2c core.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-03-09 21:59:30 +01:00

183 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* I2C slave mode testunit
*
* Copyright (C) 2020 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
* Copyright (C) 2020 by Renesas Electronics Corporation
*/
#include <linux/bitops.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_CUR_VERSION 0x01
enum testunit_cmds {
TU_CMD_READ_BYTES = 1, /* save 0 for ABORT, RESET or similar */
TU_CMD_HOST_NOTIFY,
TU_CMD_SMBUS_BLOCK_PROC_CALL,
TU_NUM_CMDS
};
enum testunit_regs {
TU_REG_CMD,
TU_REG_DATAL,
TU_REG_DATAH,
TU_REG_DELAY,
TU_NUM_REGS
};
enum testunit_flags {
TU_FLAG_IN_PROCESS,
};
struct testunit_data {
unsigned long flags;
u8 regs[TU_NUM_REGS];
u8 reg_idx;
struct i2c_client *client;
struct delayed_work worker;
};
static void i2c_slave_testunit_work(struct work_struct *work)
{
struct testunit_data *tu = container_of(work, struct testunit_data, worker.work);
struct i2c_msg msg;
u8 msgbuf[256];
int ret = 0;
msg.addr = I2C_CLIENT_END;
msg.buf = msgbuf;
switch (tu->regs[TU_REG_CMD]) {
case TU_CMD_READ_BYTES:
msg.addr = tu->regs[TU_REG_DATAL];
msg.flags = I2C_M_RD;
msg.len = tu->regs[TU_REG_DATAH];
break;
case TU_CMD_HOST_NOTIFY:
msg.addr = 0x08;
msg.flags = 0;
msg.len = 3;
msgbuf[0] = tu->client->addr;
msgbuf[1] = tu->regs[TU_REG_DATAL];
msgbuf[2] = tu->regs[TU_REG_DATAH];
break;
default:
break;
}
if (msg.addr != I2C_CLIENT_END) {
ret = i2c_transfer(tu->client->adapter, &msg, 1);
/* convert '0 msgs transferred' to errno */
ret = (ret == 0) ? -EIO : ret;
}
if (ret < 0)
dev_err(&tu->client->dev, "CMD%02X failed (%d)\n", tu->regs[TU_REG_CMD], ret);
clear_bit(TU_FLAG_IN_PROCESS, &tu->flags);
}
static int i2c_slave_testunit_slave_cb(struct i2c_client *client,
enum i2c_slave_event event, u8 *val)
{
struct testunit_data *tu = i2c_get_clientdata(client);
bool is_proc_call = tu->reg_idx == 3 && tu->regs[TU_REG_DATAL] == 1 &&
tu->regs[TU_REG_CMD] == TU_CMD_SMBUS_BLOCK_PROC_CALL;
int ret = 0;
switch (event) {
case I2C_SLAVE_WRITE_RECEIVED:
if (test_bit(TU_FLAG_IN_PROCESS, &tu->flags))
return -EBUSY;
if (tu->reg_idx < TU_NUM_REGS)
tu->regs[tu->reg_idx] = *val;
else
ret = -EMSGSIZE;
if (tu->reg_idx <= TU_NUM_REGS)
tu->reg_idx++;
/* TU_REG_CMD always written at this point */
if (tu->regs[TU_REG_CMD] >= TU_NUM_CMDS)
ret = -EINVAL;
break;
case I2C_SLAVE_STOP:
if (tu->reg_idx == TU_NUM_REGS) {
set_bit(TU_FLAG_IN_PROCESS, &tu->flags);
queue_delayed_work(system_long_wq, &tu->worker,
msecs_to_jiffies(10 * tu->regs[TU_REG_DELAY]));
}
fallthrough;
case I2C_SLAVE_WRITE_REQUESTED:
memset(tu->regs, 0, TU_NUM_REGS);
tu->reg_idx = 0;
break;
case I2C_SLAVE_READ_PROCESSED:
if (is_proc_call && tu->regs[TU_REG_DATAH])
tu->regs[TU_REG_DATAH]--;
fallthrough;
case I2C_SLAVE_READ_REQUESTED:
*val = is_proc_call ? tu->regs[TU_REG_DATAH] : TU_CUR_VERSION;
break;
}
return ret;
}
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_DELAYED_WORK(&tu->worker, i2c_slave_testunit_work);
return i2c_slave_register(client, i2c_slave_testunit_slave_cb);
};
static void i2c_slave_testunit_remove(struct i2c_client *client)
{
struct testunit_data *tu = i2c_get_clientdata(client);
cancel_delayed_work_sync(&tu->worker);
i2c_slave_unregister(client);
}
static const struct i2c_device_id i2c_slave_testunit_id[] = {
{ "slave-testunit", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, i2c_slave_testunit_id);
static struct i2c_driver i2c_slave_testunit_driver = {
.driver = {
.name = "i2c-slave-testunit",
},
.probe = i2c_slave_testunit_probe,
.remove = i2c_slave_testunit_remove,
.id_table = i2c_slave_testunit_id,
};
module_i2c_driver(i2c_slave_testunit_driver);
MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
MODULE_DESCRIPTION("I2C slave mode test unit");
MODULE_LICENSE("GPL v2");