From: Stephen Barber <smbarber@xxxxxxxxxxxx> Add support in cros_ec.c to handle EC host command protocol v3. For v3+, probe for maximum shared protocol version and max request, response, and passthrough sizes. For now, this will always fall back to v2, since there is no bus-specific code for handling proto v3 packets. Signed-off-by: Stephen Barber <smbarber@xxxxxxxxxxxx> Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> Reviewed-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> Tested-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx> --- Changes since v5: None Changes since v4: None Changes since v3: - Added tested-by from Heiko Stuebner. - Added acked-by tag from Lee Jones. Changes since v2: - Add the helpers to the drivers/platform/chrome/cros_ec_proto.c driver instead of drivers/mfd/cros_ec.c. Suggested by Lee Jones. - Rename the proto probe functions for proto_query since probe has a special meaning in Linux so is confusing. Changes since v1: - Squash change https://chromium-review.googlesource.com/#/c/262870/ in the patch. Suggested by Gwendal Grignou - Add Reviewed-by and Tested-by tags from Gwendal Grignou --- drivers/mfd/cros_ec.c | 23 ++- drivers/mfd/cros_ec_i2c.c | 4 + drivers/mfd/cros_ec_spi.c | 7 +- drivers/platform/chrome/cros_ec_lpc.c | 4 + drivers/platform/chrome/cros_ec_proto.c | 339 ++++++++++++++++++++++++++++---- include/linux/mfd/cros_ec.h | 28 ++- 6 files changed, 355 insertions(+), 50 deletions(-) diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c index d857f6a2b57b..08d82bfc5268 100644 --- a/drivers/mfd/cros_ec.c +++ b/drivers/mfd/cros_ec.c @@ -36,19 +36,22 @@ int cros_ec_register(struct cros_ec_device *ec_dev) struct device *dev = ec_dev->dev; int err = 0; - if (ec_dev->din_size) { - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); - if (!ec_dev->din) - return -ENOMEM; - } - if (ec_dev->dout_size) { - ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); - if (!ec_dev->dout) - return -ENOMEM; - } + ec_dev->max_request = sizeof(struct ec_params_hello); + ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); + ec_dev->max_passthru = 0; + + ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); + if (!ec_dev->din) + return -ENOMEM; + + ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); + if (!ec_dev->dout) + return -ENOMEM; mutex_init(&ec_dev->lock); + cros_ec_query_all(ec_dev); + err = mfd_add_devices(dev, 0, cros_devs, ARRAY_SIZE(cros_devs), NULL, ec_dev->irq, NULL); diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c index fbf7819f5de5..b400bfa2772a 100644 --- a/drivers/mfd/cros_ec_i2c.c +++ b/drivers/mfd/cros_ec_i2c.c @@ -143,8 +143,12 @@ static int cros_ec_i2c_probe(struct i2c_client *client, ec_dev->priv = client; ec_dev->irq = client->irq; ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c; + ec_dev->pkt_xfer = NULL; ec_dev->ec_name = client->name; ec_dev->phys_name = client->adapter->name; + ec_dev->din_size = sizeof(struct ec_host_response) + + sizeof(struct ec_response_get_protocol_info); + ec_dev->dout_size = sizeof(struct ec_host_request); err = cros_ec_register(ec_dev); if (err) { diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index 573730fec947..04da2f288ef8 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -361,10 +361,13 @@ static int cros_ec_spi_probe(struct spi_device *spi) ec_dev->priv = ec_spi; ec_dev->irq = spi->irq; ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi; + ec_dev->pkt_xfer = NULL; ec_dev->ec_name = ec_spi->spi->modalias; ec_dev->phys_name = dev_name(&ec_spi->spi->dev); - ec_dev->din_size = EC_MSG_BYTES + EC_MSG_PREAMBLE_COUNT; - ec_dev->dout_size = EC_MSG_BYTES; + ec_dev->din_size = EC_MSG_PREAMBLE_COUNT + + sizeof(struct ec_host_response) + + sizeof(struct ec_response_get_protocol_info); + ec_dev->dout_size = sizeof(struct ec_host_request); err = cros_ec_register(ec_dev); if (err) { diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index 214ae7fef984..06c5790b2c28 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -205,7 +205,11 @@ static int cros_ec_lpc_probe(struct platform_device *pdev) ec_dev->ec_name = pdev->name; ec_dev->phys_name = dev_name(dev); ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc; + ec_dev->pkt_xfer = NULL; ec_dev->cmd_readmem = cros_ec_lpc_readmem; + ec_dev->din_size = sizeof(struct ec_host_response) + + sizeof(struct ec_response_get_protocol_info); + ec_dev->dout_size = sizeof(struct ec_host_request); ret = cros_ec_register(ec_dev); if (ret) { diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index 58e98a24fd08..990308ca384f 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -22,11 +22,100 @@ #define EC_COMMAND_RETRIES 50 +static int prepare_packet(struct cros_ec_device *ec_dev, + struct cros_ec_command *msg) +{ + struct ec_host_request *request; + u8 *out; + int i; + u8 csum = 0; + + BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION); + BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size); + + out = ec_dev->dout; + request = (struct ec_host_request *)out; + request->struct_version = EC_HOST_REQUEST_VERSION; + request->checksum = 0; + request->command = msg->command; + request->command_version = msg->version; + request->reserved = 0; + request->data_len = msg->outsize; + + for (i = 0; i < sizeof(*request); i++) + csum += out[i]; + + /* Copy data and update checksum */ + memcpy(out + sizeof(*request), msg->data, msg->outsize); + for (i = 0; i < msg->outsize; i++) + csum += msg->data[i]; + + request->checksum = -csum; + + return sizeof(*request) + msg->outsize; +} + +static int send_command(struct cros_ec_device *ec_dev, + struct cros_ec_command *msg) +{ + int ret; + + if (ec_dev->proto_version > 2) + ret = ec_dev->pkt_xfer(ec_dev, msg); + else + ret = ec_dev->cmd_xfer(ec_dev, msg); + + if (msg->result == EC_RES_IN_PROGRESS) { + int i; + struct cros_ec_command *status_msg; + struct ec_response_get_comms_status *status; + + status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status), + GFP_KERNEL); + if (!status_msg) + return -ENOMEM; + + status_msg->version = 0; + status_msg->command = EC_CMD_GET_COMMS_STATUS; + status_msg->insize = sizeof(*status); + status_msg->outsize = 0; + + /* + * Query the EC's status until it's no longer busy or + * we encounter an error. + */ + for (i = 0; i < EC_COMMAND_RETRIES; i++) { + usleep_range(10000, 11000); + + ret = ec_dev->cmd_xfer(ec_dev, status_msg); + if (ret < 0) + break; + + msg->result = status_msg->result; + if (status_msg->result != EC_RES_SUCCESS) + break; + + status = (struct ec_response_get_comms_status *) + status_msg->data; + if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) + break; + } + + kfree(status_msg); + } + + return ret; +} + int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) { - uint8_t *out; - int csum, i; + u8 *out; + u8 csum; + int i; + + if (ec_dev->proto_version > 2) + return prepare_packet(ec_dev, msg); BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE); out = ec_dev->dout; @@ -36,7 +125,7 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, csum = out[0] + out[1] + out[2]; for (i = 0; i < msg->outsize; i++) csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i]; - out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff); + out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum; return EC_MSG_TX_PROTO_BYTES + msg->outsize; } @@ -60,54 +149,232 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev, } EXPORT_SYMBOL(cros_ec_check_result); -int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, - struct cros_ec_command *msg) +static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev, + int devidx, + struct cros_ec_command *msg) { + /* + * Try using v3+ to query for supported protocols. If this + * command fails, fall back to v2. Returns the highest protocol + * supported by the EC. + * Also sets the max request/response/passthru size. + */ int ret; - mutex_lock(&ec_dev->lock); - ret = ec_dev->cmd_xfer(ec_dev, msg); - if (msg->result == EC_RES_IN_PROGRESS) { - int i; - struct cros_ec_command *status_msg; - struct ec_response_get_comms_status *status; + if (!ec_dev->pkt_xfer) + return -EPROTONOSUPPORT; - status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status), - GFP_KERNEL); - if (!status_msg) { - ret = -ENOMEM; - goto exit; - } + memset(msg, 0, sizeof(*msg)); + msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO; + msg->insize = sizeof(struct ec_response_get_protocol_info); - status_msg->version = 0; - status_msg->command = EC_CMD_GET_COMMS_STATUS; - status_msg->insize = sizeof(*status); - status_msg->outsize = 0; + ret = send_command(ec_dev, msg); + + if (ret < 0) { + dev_dbg(ec_dev->dev, + "failed to check for EC[%d] protocol version: %d\n", + devidx, ret); + return ret; + } + + if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND) + return -ENODEV; + else if (msg->result != EC_RES_SUCCESS) + return msg->result; + + return 0; +} + +static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev) +{ + struct cros_ec_command *msg; + struct ec_params_hello *hello_params; + struct ec_response_hello *hello_response; + int ret; + int len = max(sizeof(*hello_params), sizeof(*hello_response)); + + msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + msg->version = 0; + msg->command = EC_CMD_HELLO; + hello_params = (struct ec_params_hello *)msg->data; + msg->outsize = sizeof(*hello_params); + hello_response = (struct ec_response_hello *)msg->data; + msg->insize = sizeof(*hello_response); + + hello_params->in_data = 0xa0b0c0d0; + + ret = send_command(ec_dev, msg); + + if (ret < 0) { + dev_dbg(ec_dev->dev, + "EC failed to respond to v2 hello: %d\n", + ret); + goto exit; + } else if (msg->result != EC_RES_SUCCESS) { + dev_err(ec_dev->dev, + "EC responded to v2 hello with error: %d\n", + msg->result); + ret = msg->result; + goto exit; + } else if (hello_response->out_data != 0xa1b2c3d4) { + dev_err(ec_dev->dev, + "EC responded to v2 hello with bad result: %u\n", + hello_response->out_data); + ret = -EBADMSG; + goto exit; + } + + ret = 0; + + exit: + kfree(msg); + return ret; +} + +int cros_ec_query_all(struct cros_ec_device *ec_dev) +{ + struct device *dev = ec_dev->dev; + struct cros_ec_command *proto_msg; + struct ec_response_get_protocol_info *proto_info; + int ret; + + proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info), + GFP_KERNEL); + if (!proto_msg) + return -ENOMEM; + + /* First try sending with proto v3. */ + ec_dev->proto_version = 3; + ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg); + + if (ret == 0) { + proto_info = (struct ec_response_get_protocol_info *) + proto_msg->data; + ec_dev->max_request = proto_info->max_request_packet_size - + sizeof(struct ec_host_request); + ec_dev->max_response = proto_info->max_response_packet_size - + sizeof(struct ec_host_response); + ec_dev->proto_version = + min(EC_HOST_REQUEST_VERSION, + fls(proto_info->protocol_versions) - 1); + dev_dbg(ec_dev->dev, + "using proto v%u\n", + ec_dev->proto_version); + + ec_dev->din_size = ec_dev->max_response + + sizeof(struct ec_host_response) + + EC_MAX_RESPONSE_OVERHEAD; + ec_dev->dout_size = ec_dev->max_request + + sizeof(struct ec_host_request) + + EC_MAX_REQUEST_OVERHEAD; /* - * Query the EC's status until it's no longer busy or - * we encounter an error. + * Check for PD */ - for (i = 0; i < EC_COMMAND_RETRIES; i++) { - usleep_range(10000, 11000); + ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg); - ret = ec_dev->cmd_xfer(ec_dev, status_msg); - if (ret < 0) - break; + if (ret) { + dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret); + ec_dev->max_passthru = 0; + } else { + dev_dbg(ec_dev->dev, "found PD chip\n"); + ec_dev->max_passthru = + proto_info->max_request_packet_size - + sizeof(struct ec_host_request); + } + } else { + /* Try querying with a v2 hello message. */ + ec_dev->proto_version = 2; + ret = cros_ec_host_command_proto_query_v2(ec_dev); - msg->result = status_msg->result; - if (status_msg->result != EC_RES_SUCCESS) - break; + if (ret == 0) { + /* V2 hello succeeded. */ + dev_dbg(ec_dev->dev, "falling back to proto v2\n"); - status = (struct ec_response_get_comms_status *) - status_msg->data; - if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) - break; + ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE; + ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE; + ec_dev->max_passthru = 0; + ec_dev->pkt_xfer = NULL; + ec_dev->din_size = EC_MSG_BYTES; + ec_dev->dout_size = EC_MSG_BYTES; + } else { + /* + * It's possible for a test to occur too early when + * the EC isn't listening. If this happens, we'll + * test later when the first command is run. + */ + ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN; + dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret); + goto exit; } + } - kfree(status_msg); + devm_kfree(dev, ec_dev->din); + devm_kfree(dev, ec_dev->dout); + + ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); + if (!ec_dev->din) { + ret = -ENOMEM; + goto exit; } + + ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); + if (!ec_dev->dout) { + devm_kfree(dev, ec_dev->din); + ret = -ENOMEM; + goto exit; + } + exit: + kfree(proto_msg); + return ret; +} +EXPORT_SYMBOL(cros_ec_query_all); + +int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, + struct cros_ec_command *msg) +{ + int ret; + + mutex_lock(&ec_dev->lock); + if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) { + ret = cros_ec_query_all(ec_dev); + if (ret) { + dev_err(ec_dev->dev, + "EC version unknown and query failed; aborting command\n"); + mutex_unlock(&ec_dev->lock); + return ret; + } + } + + if (msg->insize > ec_dev->max_response) { + dev_dbg(ec_dev->dev, "clamping message receive buffer\n"); + msg->insize = ec_dev->max_response; + } + + if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) { + if (msg->outsize > ec_dev->max_request) { + dev_err(ec_dev->dev, + "request of size %u is too big (max: %u)\n", + msg->outsize, + ec_dev->max_request); + mutex_unlock(&ec_dev->lock); + return -EMSGSIZE; + } + } else { + if (msg->outsize > ec_dev->max_passthru) { + dev_err(ec_dev->dev, + "passthru rq of size %u is too big (max: %u)\n", + msg->outsize, + ec_dev->max_passthru); + mutex_unlock(&ec_dev->lock); + return -EMSGSIZE; + } + } + ret = send_command(ec_dev, msg); mutex_unlock(&ec_dev->lock); return ret; diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h index 7eee38abd02a..59d909434efd 100644 --- a/include/linux/mfd/cros_ec.h +++ b/include/linux/mfd/cros_ec.h @@ -22,6 +22,15 @@ #include <linux/mutex.h> /* + * Max bus-specific overhead incurred by request/responses. + * I2C requires 1 additional byte for requests. + * I2C requires 2 additional bytes for responses. + * */ +#define EC_PROTO_VERSION_UNKNOWN 0 +#define EC_MAX_REQUEST_OVERHEAD 1 +#define EC_MAX_RESPONSE_OVERHEAD 2 + +/* * Command interface between EC and AP, for LPC, I2C and SPI interfaces. */ enum { @@ -88,6 +97,7 @@ struct cros_ec_command { * Returns the number of bytes received if the communication succeeded, but * that doesn't mean the EC was happy with the command. The caller * should check msg.result for the EC's result code. + * @pkt_xfer: send packet to EC and get response * @lock: one transaction at a time */ struct cros_ec_device { @@ -104,15 +114,21 @@ struct cros_ec_device { unsigned int bytes, void *dest); /* These are used to implement the platform-specific interface */ + u16 max_request; + u16 max_response; + u16 max_passthru; + u16 proto_version; void *priv; int irq; - uint8_t *din; - uint8_t *dout; + u8 *din; + u8 *dout; int din_size; int dout_size; bool wake_enabled; int (*cmd_xfer)(struct cros_ec_device *ec, struct cros_ec_command *msg); + int (*pkt_xfer)(struct cros_ec_device *ec, + struct cros_ec_command *msg); struct mutex lock; }; @@ -194,4 +210,12 @@ int cros_ec_remove(struct cros_ec_device *ec_dev); */ int cros_ec_register(struct cros_ec_device *ec_dev); +/** + * cros_ec_register - Query the protocol version supported by the ChromeOS EC + * + * @ec_dev: Device to register + * @return 0 if ok, -ve on error + */ +int cros_ec_query_all(struct cros_ec_device *ec_dev); + #endif /* __LINUX_MFD_CROS_EC_H */ -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
