1 // SPDX-License-Identifier: GPL-2.0-only
3  * I2C slave mode testunit
5  * Copyright (C) 2020 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
13 #include <linux/i2c.h>
64 		gpiod_set_value(tu->gpio, 0);  in i2c_slave_testunit_smbalert_cb()
67 		*val = tu->regs[TU_REG_DATAL];  in i2c_slave_testunit_smbalert_cb()
71 		complete(&tu->alert_done);  in i2c_slave_testunit_smbalert_cb()
76 		return -EOPNOTSUPP;  in i2c_slave_testunit_smbalert_cb()
86 	bool is_proc_call = tu->reg_idx == 3 && tu->regs[TU_REG_DATAL] == 1 &&  in i2c_slave_testunit_slave_cb()
87 			    tu->regs[TU_REG_CMD] == TU_CMD_SMBUS_BLOCK_PROC_CALL;  in i2c_slave_testunit_slave_cb()
88 	bool is_get_version = tu->reg_idx == 3 &&  in i2c_slave_testunit_slave_cb()
89 			      tu->regs[TU_REG_CMD] == TU_CMD_GET_VERSION_WITH_REP_START;  in i2c_slave_testunit_slave_cb()
94 		if (test_bit(TU_FLAG_IN_PROCESS | TU_FLAG_NACK, &tu->flags)) {  in i2c_slave_testunit_slave_cb()
95 			ret = -EBUSY;  in i2c_slave_testunit_slave_cb()
99 		memset(tu->regs, 0, TU_NUM_REGS);  in i2c_slave_testunit_slave_cb()
100 		tu->reg_idx = 0;  in i2c_slave_testunit_slave_cb()
101 		tu->read_idx = 0;  in i2c_slave_testunit_slave_cb()
105 		if (test_bit(TU_FLAG_IN_PROCESS | TU_FLAG_NACK, &tu->flags)) {  in i2c_slave_testunit_slave_cb()
106 			ret = -EBUSY;  in i2c_slave_testunit_slave_cb()
110 		if (tu->reg_idx < TU_NUM_REGS)  in i2c_slave_testunit_slave_cb()
111 			tu->regs[tu->reg_idx] = *val;  in i2c_slave_testunit_slave_cb()
113 			ret = -EMSGSIZE;  in i2c_slave_testunit_slave_cb()
115 		if (tu->reg_idx <= TU_NUM_REGS)  in i2c_slave_testunit_slave_cb()
116 			tu->reg_idx++;  in i2c_slave_testunit_slave_cb()
119 		if (tu->regs[TU_REG_CMD] >= TU_NUM_CMDS)  in i2c_slave_testunit_slave_cb()
120 			ret = -EINVAL;  in i2c_slave_testunit_slave_cb()
125 		if (tu->reg_idx == TU_NUM_REGS) {  in i2c_slave_testunit_slave_cb()
126 			set_bit(TU_FLAG_IN_PROCESS, &tu->flags);  in i2c_slave_testunit_slave_cb()
127 			queue_delayed_work(system_long_wq, &tu->worker,  in i2c_slave_testunit_slave_cb()
128 					   msecs_to_jiffies(10 * tu->regs[TU_REG_DELAY]));  in i2c_slave_testunit_slave_cb()
136 		tu->reg_idx = 0;  in i2c_slave_testunit_slave_cb()
138 		clear_bit(TU_FLAG_NACK, &tu->flags);  in i2c_slave_testunit_slave_cb()
143 		if (is_get_version && tu_version_info[tu->read_idx] != 0)  in i2c_slave_testunit_slave_cb()
144 			tu->read_idx++;  in i2c_slave_testunit_slave_cb()
145 		else if (is_proc_call && tu->regs[TU_REG_DATAH])  in i2c_slave_testunit_slave_cb()
146 			tu->regs[TU_REG_DATAH]--;  in i2c_slave_testunit_slave_cb()
152 			*val = tu_version_info[tu->read_idx];  in i2c_slave_testunit_slave_cb()
154 			*val = tu->regs[TU_REG_DATAH];  in i2c_slave_testunit_slave_cb()
156 			*val = test_bit(TU_FLAG_IN_PROCESS, &tu->flags) ?  in i2c_slave_testunit_slave_cb()
157 					tu->regs[TU_REG_CMD] : 0;  in i2c_slave_testunit_slave_cb()
163 		set_bit(TU_FLAG_NACK, &tu->flags);  in i2c_slave_testunit_slave_cb()
177 	msg.addr = I2C_CLIENT_END;  in i2c_slave_testunit_work()
180 	switch (tu->regs[TU_REG_CMD]) {  in i2c_slave_testunit_work()
182 		msg.addr = tu->regs[TU_REG_DATAL];  in i2c_slave_testunit_work()
184 		msg.len = tu->regs[TU_REG_DATAH];  in i2c_slave_testunit_work()
188 		msg.addr = 0x08;  in i2c_slave_testunit_work()
191 		msgbuf[0] = tu->client->addr;  in i2c_slave_testunit_work()
192 		msgbuf[1] = tu->regs[TU_REG_DATAL];  in i2c_slave_testunit_work()
193 		msgbuf[2] = tu->regs[TU_REG_DATAH];  in i2c_slave_testunit_work()
197 		if (!tu->gpio) {  in i2c_slave_testunit_work()
198 			ret = -ENOENT;  in i2c_slave_testunit_work()
201 		i2c_slave_unregister(tu->client);  in i2c_slave_testunit_work()
202 		orig_addr = tu->client->addr;  in i2c_slave_testunit_work()
203 		tu->client->addr = 0x0c;  in i2c_slave_testunit_work()
204 		ret = i2c_slave_register(tu->client, i2c_slave_testunit_smbalert_cb);  in i2c_slave_testunit_work()
208 		reinit_completion(&tu->alert_done);  in i2c_slave_testunit_work()
209 		gpiod_set_value(tu->gpio, 1);  in i2c_slave_testunit_work()
210 		time_left = wait_for_completion_timeout(&tu->alert_done, HZ);  in i2c_slave_testunit_work()
212 			ret = -ETIMEDOUT;  in i2c_slave_testunit_work()
214 		i2c_slave_unregister(tu->client);  in i2c_slave_testunit_work()
216 		tu->client->addr = orig_addr;  in i2c_slave_testunit_work()
217 		i2c_slave_register(tu->client, i2c_slave_testunit_slave_cb);  in i2c_slave_testunit_work()
224 	if (msg.addr != I2C_CLIENT_END) {  in i2c_slave_testunit_work()
225 		ret = i2c_transfer(tu->client->adapter, &msg, 1);  in i2c_slave_testunit_work()
227 		ret = (ret == 0) ? -EIO : ret;  in i2c_slave_testunit_work()
231 		dev_err(&tu->client->dev, "CMD%02X failed (%d)\n", tu->regs[TU_REG_CMD], ret);  in i2c_slave_testunit_work()
233 	clear_bit(TU_FLAG_IN_PROCESS, &tu->flags);  in i2c_slave_testunit_work()
240 	tu = devm_kzalloc(&client->dev, sizeof(struct testunit_data), GFP_KERNEL);  in i2c_slave_testunit_probe()
242 		return -ENOMEM;  in i2c_slave_testunit_probe()
244 	tu->client = client;  in i2c_slave_testunit_probe()
246 	init_completion(&tu->alert_done);  in i2c_slave_testunit_probe()
247 	INIT_DELAYED_WORK(&tu->worker, i2c_slave_testunit_work);  in i2c_slave_testunit_probe()
249 	tu->gpio = devm_gpiod_get_index_optional(&client->dev, NULL, 0, GPIOD_OUT_LOW);  in i2c_slave_testunit_probe()
250 	if (IS_ERR(tu->gpio))  in i2c_slave_testunit_probe()
251 		return PTR_ERR(tu->gpio);  in i2c_slave_testunit_probe()
253 	if (gpiod_cansleep(tu->gpio)) {  in i2c_slave_testunit_probe()
254 		dev_err(&client->dev, "GPIO access which may sleep is not allowed\n");  in i2c_slave_testunit_probe()
255 		return -EDEADLK;  in i2c_slave_testunit_probe()
259 		tu_version_info[TU_VERSION_MAX_LENGTH - 1] = 0;  in i2c_slave_testunit_probe()
268 	cancel_delayed_work_sync(&tu->worker);  in i2c_slave_testunit_remove()
273 	{ "slave-testunit" },
276 MODULE_DEVICE_TABLE(i2c, i2c_slave_testunit_id);
280 		.name = "i2c-slave-testunit",
288 MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
289 MODULE_DESCRIPTION("I2C slave mode test unit");