1 // SPDX-License-Identifier: GPL-2.0+
3  * Chromium OS cros_ec driver - I2C interface
17 #include <i2c.h>
29  * byte 1-8	struct ec_host_request
30  * byte 10-	response data
42  * byte 2-9	struct ec_host_response
43  * byte 10-	response data
56 		(struct ec_host_request_i2c *)dev->dout;  in cros_ec_i2c_packet()
58 		(struct ec_host_response_i2c *)dev->din;  in cros_ec_i2c_packet()
62 	i2c_msg[0].addr = chip->chip_addr;  in cros_ec_i2c_packet()
64 	i2c_msg[1].addr = chip->chip_addr;  in cros_ec_i2c_packet()
69 	i2c_msg[0].buf = dev->dout;  in cros_ec_i2c_packet()
72 	memmove(&ec_request_i2c->ec_request, dev->dout, out_bytes);  in cros_ec_i2c_packet()
73 	ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;  in cros_ec_i2c_packet()
77 	i2c_msg[1].buf = dev->din;  in cros_ec_i2c_packet()
85 	/* When we send a v3 request to v2 ec, ec won't recognize the 0xda  in cros_ec_i2c_packet()
92 	if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&  in cros_ec_i2c_packet()
93 	    ec_response_i2c->packet_length == 0)  in cros_ec_i2c_packet()
94 		return -EPROTONOSUPPORT;  in cros_ec_i2c_packet()
96 	if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {  in cros_ec_i2c_packet()
98 		       __func__, ec_response_i2c->packet_length);  in cros_ec_i2c_packet()
99 		return -EBADMSG;  in cros_ec_i2c_packet()
104 	memmove(dev->din, &ec_response_i2c->ec_response, in_bytes);  in cros_ec_i2c_packet()
126 	 * Sanity-check I/O sizes given transaction overhead in internal  in cros_ec_i2c_command()
129 	if (out_bytes > sizeof(dev->dout)) {  in cros_ec_i2c_command()
131 		return -1;  in cros_ec_i2c_command()
133 	if (in_bytes > sizeof(dev->din)) {  in cros_ec_i2c_command()
135 		return -1;  in cros_ec_i2c_command()
140 	i2c_msg[0].addr = chip->chip_addr;  in cros_ec_i2c_command()
142 	i2c_msg[0].buf = dev->dout;  in cros_ec_i2c_command()
146 	 * Copy command and data into output buffer so we can do a single I2C  in cros_ec_i2c_command()
149 	ptr = dev->dout;  in cros_ec_i2c_command()
152 	 * in_ptr starts of pointing to a dword-aligned input data buffer.  in cros_ec_i2c_command()
157 	in_ptr = dev->din + sizeof(int64_t);  in cros_ec_i2c_command()
159 	if (dev->protocol_version != 2) {  in cros_ec_i2c_command()
162 		      __func__, dev->protocol_version);  in cros_ec_i2c_command()
163 		return -1;  in cros_ec_i2c_command()
169 	in_ptr -= 2;	/* Expect status, length bytes */  in cros_ec_i2c_command()
175 		cros_ec_calc_checksum(dev->dout, dout_len + 3);  in cros_ec_i2c_command()
177 	i2c_msg[1].addr = chip->chip_addr;  in cros_ec_i2c_command()
183 	cros_ec_dump_data("out", -1, dev->dout, out_bytes);  in cros_ec_i2c_command()
188 		      udev->name);  in cros_ec_i2c_command()
189 		ret = -1;  in cros_ec_i2c_command()
194 		return -(int)*in_ptr;  in cros_ec_i2c_command()
198 	if (len + 3 > sizeof(dev->din)) {  in cros_ec_i2c_command()
201 		return -1;  in cros_ec_i2c_command()
207 		return -1;  in cros_ec_i2c_command()
210 	cros_ec_dump_data("in", -1, in_ptr, din_len + 3);  in cros_ec_i2c_command()
212 	/* Return pointer to dword-aligned input data, if any */  in cros_ec_i2c_command()
213 	*dinp = dev->din + sizeof(int64_t);  in cros_ec_i2c_command()
229 	{ .compatible = "google,cros-ec-i2c" },