9  * Expose an I2C passthrough to the ChromeOS EC.
13 #include <linux/i2c.h>
22  * struct ec_i2c_device - Driver data for I2C tunnel
25  * @adap: I2C adapter
26  * @ec: Pointer to EC device
27  * @remote_bus: The EC bus number we tunnel to on the other side.
35 	struct cros_ec_device *ec;  member
44  * ec_i2c_count_message - Count bytes needed for ec_i2c_construct_message
46  * @i2c_msgs: The i2c messages to read
47  * @num: The number of i2c messages.
66  * ec_i2c_construct_message - construct a message to go to the EC
69  * a format that the EC understands.
72  * @i2c_msgs: The i2c messages to read.
73  * @num: The number of i2c messages.
89 	params->port = bus_num;  in ec_i2c_construct_message()
90 	params->num_msgs = num;  in ec_i2c_construct_message()
93 		struct ec_params_i2c_passthru_msg *msg = &params->msg[i];  in ec_i2c_construct_message()
95 		msg->len = i2c_msg->len;  in ec_i2c_construct_message()
96 		msg->addr_flags = i2c_msg->addr;  in ec_i2c_construct_message()
98 		if (i2c_msg->flags & I2C_M_TEN)  in ec_i2c_construct_message()
99 			return -EINVAL;  in ec_i2c_construct_message()
101 		if (i2c_msg->flags & I2C_M_RD) {  in ec_i2c_construct_message()
102 			msg->addr_flags |= EC_I2C_FLAG_READ;  in ec_i2c_construct_message()
104 			memcpy(out_data, i2c_msg->buf, msg->len);  in ec_i2c_construct_message()
105 			out_data += msg->len;  in ec_i2c_construct_message()
113  * ec_i2c_count_response - Count bytes needed for ec_i2c_parse_response
115  * @i2c_msgs: The i2c messages to to fill up.
116  * @num: The number of i2c messages expected.
134  * ec_i2c_parse_response - Parse a response from the EC
136  * We'll take the EC's response and copy it back into msgs.
139  * @i2c_msgs: The i2c messages to to fill up.
140  * @num: The number of i2c messages; will be modified to include the actual
155 	if (resp->i2c_status & EC_I2C_STATUS_TIMEOUT)  in ec_i2c_parse_response()
156 		return -ETIMEDOUT;  in ec_i2c_parse_response()
157 	else if (resp->i2c_status & EC_I2C_STATUS_NAK)  in ec_i2c_parse_response()
158 		return -ENXIO;  in ec_i2c_parse_response()
159 	else if (resp->i2c_status & EC_I2C_STATUS_ERROR)  in ec_i2c_parse_response()
160 		return -EIO;  in ec_i2c_parse_response()
163 	if (resp->num_msgs > *num)  in ec_i2c_parse_response()
164 		return -EPROTO;  in ec_i2c_parse_response()
165 	*num = resp->num_msgs;  in ec_i2c_parse_response()
171 			memcpy(i2c_msg->buf, in_data, i2c_msg->len);  in ec_i2c_parse_response()
172 			in_data += i2c_msg->len;  in ec_i2c_parse_response()
182 	struct ec_i2c_device *bus = adap->algo_data;  in ec_i2c_xfer()
183 	struct device *dev = bus->dev;  in ec_i2c_xfer()
184 	const u16 bus_num = bus->remote_bus;  in ec_i2c_xfer()
207 		return -ENOMEM;  in ec_i2c_xfer()
209 	result = ec_i2c_construct_message(msg->data, i2c_msgs, num, bus_num);  in ec_i2c_xfer()
211 		dev_err(dev, "Error constructing EC i2c message %d\n", result);  in ec_i2c_xfer()
215 	msg->version = 0;  in ec_i2c_xfer()
216 	msg->command = EC_CMD_I2C_PASSTHRU;  in ec_i2c_xfer()
217 	msg->outsize = request_len;  in ec_i2c_xfer()
218 	msg->insize = response_len;  in ec_i2c_xfer()
220 	result = cros_ec_cmd_xfer_status(bus->ec, msg);  in ec_i2c_xfer()
222 		dev_err(dev, "Error transferring EC i2c message %d\n", result);  in ec_i2c_xfer()
226 	result = ec_i2c_parse_response(msg->data, i2c_msgs, &num);  in ec_i2c_xfer()
249 	struct device_node *np = pdev->dev.of_node;  in ec_i2c_probe()
250 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);  in ec_i2c_probe()  local
251 	struct device *dev = &pdev->dev;  in ec_i2c_probe()
256 	if (!ec->cmd_xfer) {  in ec_i2c_probe()
258 		return -EINVAL;  in ec_i2c_probe()
263 		return -ENOMEM;  in ec_i2c_probe()
265 	err = of_property_read_u32(np, "google,remote-bus", &remote_bus);  in ec_i2c_probe()
267 		dev_err(dev, "Couldn't read remote-bus property\n");  in ec_i2c_probe()
270 	bus->remote_bus = remote_bus;  in ec_i2c_probe()
272 	bus->ec = ec;  in ec_i2c_probe()
273 	bus->dev = dev;  in ec_i2c_probe()
275 	bus->adap.owner = THIS_MODULE;  in ec_i2c_probe()
276 	strlcpy(bus->adap.name, "cros-ec-i2c-tunnel", sizeof(bus->adap.name));  in ec_i2c_probe()
277 	bus->adap.algo = &ec_i2c_algorithm;  in ec_i2c_probe()
278 	bus->adap.algo_data = bus;  in ec_i2c_probe()
279 	bus->adap.dev.parent = &pdev->dev;  in ec_i2c_probe()
280 	bus->adap.dev.of_node = np;  in ec_i2c_probe()
281 	bus->adap.retries = I2C_MAX_RETRIES;  in ec_i2c_probe()
283 	err = i2c_add_adapter(&bus->adap);  in ec_i2c_probe()
295 	i2c_del_adapter(&bus->adap);  in ec_i2c_remove()
302 	{ .compatible = "google,cros-ec-i2c-tunnel" },
312 		.name = "cros-ec-i2c-tunnel",
320 MODULE_DESCRIPTION("EC I2C tunnel driver");
321 MODULE_ALIAS("platform:cros-ec-i2c-tunnel");