Add support for version 3 of the ec protocol. It basically works by stitching some additional header in front (special command code), and having a result and packet_length stitched on for the reply.
Signed-off-by: Moritz Fischer moritz.fischer@ettus.com Cc: Simon Glass sjg@chromium.org Cc: u-boot@lists.denx.de --- Hi Simon,
I tested this on a v3 EC, but again as for the previous patch, I do not have a v2 EC to test with. I'm not perfectly happy with the memmove back and forth, so if you have a better solution for that I'm all ears.
Thanks, Moritz
--- drivers/misc/cros_ec_i2c.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+)
diff --git a/drivers/misc/cros_ec_i2c.c b/drivers/misc/cros_ec_i2c.c index f2f6961..c46215b 100644 --- a/drivers/misc/cros_ec_i2c.c +++ b/drivers/misc/cros_ec_i2c.c @@ -24,6 +24,89 @@ #define debug_trace(fmt, b...) #endif
+/** + * Request format for protocol v3 + * byte 0 0xda (EC_COMMAND_PROTOCOL_3) + * byte 1-8 struct ec_host_request + * byte 10- response data + */ +struct ec_host_request_i2c { + /* Always 0xda to backward compatible with v2 struct */ + uint8_t command_protocol; + struct ec_host_request ec_request; +} __packed; + +/* + * Response format for protocol v3 + * byte 0 result code + * byte 1 packet_length + * byte 2-9 struct ec_host_response + * byte 10- response data + */ +struct ec_host_response_i2c { + uint8_t result; + uint8_t packet_length; + struct ec_host_response ec_response; +} __packed; + +static int cros_ec_i2c_packet(struct udevice *udev, int out_bytes, int in_bytes) +{ + struct cros_ec_dev *dev = dev_get_uclass_priv(udev); + struct dm_i2c_chip *chip = dev_get_parent_platdata(udev); + struct ec_host_request_i2c *ec_request_i2c = + (struct ec_host_request_i2c *)dev->dout; + struct ec_host_response_i2c *ec_response_i2c = + (struct ec_host_response_i2c *)dev->din; + struct i2c_msg i2c_msg[2]; + int ret; + + i2c_msg[0].addr = chip->chip_addr; + i2c_msg[0].flags = 0; + i2c_msg[1].addr = chip->chip_addr; + i2c_msg[1].flags = I2C_M_RD; + + /* one extra byte, to indicate v3 */ + i2c_msg[0].len = out_bytes + 1; + i2c_msg[0].buf = dev->dout; + + /* stitch on EC_COMMAND_PROTOCOL_3 */ + memmove(&ec_request_i2c->ec_request, dev->dout, out_bytes); + ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3; + + /* two extra bytes for v3 */ + i2c_msg[1].len = in_bytes + 2; + i2c_msg[1].buf = dev->din; + + ret = dm_i2c_xfer(udev, &i2c_msg[0], 2); + if (ret) { + printf("%s: Could not execute transfer: %d\n", __func__, ret); + ret = -1; + } + + /* When we send a v3 request to v2 ec, ec won't recognize the 0xda + * (EC_COMMAND_PROTOCOL_3) and will return with status + * EC_RES_INVALID_COMMAND with zero data length + * + * In case of invalid command for v3 protocol the data length + * will be at least sizeof(struct ec_host_response) + */ + if (ec_response_i2c->result == EC_RES_INVALID_COMMAND && + ec_response_i2c->packet_length == 0) + return -EPROTONOSUPPORT; + + if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) { + printf("%s: response of %u bytes too short; not a full hdr\n", + __func__, ec_response_i2c->packet_length); + return -EBADMSG; + } + + + /* drop result and packet_len */ + memmove(dev->din, &ec_response_i2c->ec_response, in_bytes); + + return in_bytes; +} + static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd, int cmd_version, const uint8_t *dout, int dout_len, uint8_t **dinp, int din_len) @@ -140,6 +223,7 @@ static int cros_ec_probe(struct udevice *dev)
static struct dm_cros_ec_ops cros_ec_ops = { .command = cros_ec_i2c_command, + .packet = cros_ec_i2c_packet, };
static const struct udevice_id cros_ec_ids[] = {