[PATCH v4 1/1] iio: common: cros_ec_sensors: determine protocol version

[Fabien Lahoudere]

This patch adds a function to determine which version of the
protocol is used to communicate with EC.

Signed-off-by: Fabien Lahoudere <fabien.lahoud...@collabora.com>
Signed-off-by: Nick Vaccaro <nvacc...@chromium.org>
Reviewed-by: Gwendal Grignou <gwen...@chromium.org>
Tested-by: Gwendal Grignou <gwen...@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
---
 .../cros_ec_sensors/cros_ec_sensors_core.c    | 36 ++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c 
b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 130362ca421b..81111af8a167 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -25,6 +25,31 @@ static char *cros_ec_loc[] = {
        [MOTIONSENSE_LOC_MAX] = "unknown",
 };
 
+static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
+                                            u16 cmd_offset, u16 cmd, u32 *mask)
+{
+       int ret;
+       struct {
+               struct cros_ec_command msg;
+               union {
+                       struct ec_params_get_cmd_versions params;
+                       struct ec_response_get_cmd_versions resp;
+               };
+       } __packed buf = {
+               .msg = {
+                       .command = EC_CMD_GET_CMD_VERSIONS + cmd_offset,
+                       .insize = sizeof(struct ec_response_get_cmd_versions),
+                       .outsize = sizeof(struct ec_params_get_cmd_versions)
+                       },
+               .params = {.cmd = cmd}
+       };
+
+       ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
+       if (ret >= 0)
+               *mask = buf.resp.version_mask;
+       return ret;
+}
+
 int cros_ec_sensors_core_init(struct platform_device *pdev,
                              struct iio_dev *indio_dev,
                              bool physical_device)
@@ -33,6 +58,8 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
        struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
        struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
        struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
+       u32 ver_mask;
+       int ret;
 
        platform_set_drvdata(pdev, indio_dev);
 
@@ -47,8 +74,15 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 
        mutex_init(&state->cmd_lock);
 
+       ret = cros_ec_get_host_cmd_version_mask(state->ec,
+                                               ec->cmd_offset,
+                                               EC_CMD_MOTION_SENSE_CMD,
+                                               &ver_mask);
+       if (ret < 0)
+               return ret;
+
        /* Set up the host command structure. */
-       state->msg->version = 2;
+       state->msg->version = fls(ver_mask) - 1;
        state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
        state->msg->outsize = sizeof(struct ec_params_motion_sense);
 
-- 
2.19.2