On Tue, 09 Jun 2015, Javier Martinez Canillas wrote: > 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> > Acked-by: Olof Johansson <olof@xxxxxxxxx> Applied, thanks. > --- > > Changes since v6: > - Add Olof Johansson Acked-by tag > > 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 */ -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- 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
