[PATCH v4 4/4] iio: cros_ec_accel_legacy: Add support for veyron-minnie

[Gwendal Grignou]

Veyron minnie embedded controller presents 2 accelerometers using an
older interface. Add function to query the data in cros_ec_accel.

Verify accelerometers on veyron-minnie are presented and working.

Signed-off-by: Gwendal Grignou <gwen...@chromium.org>
---
 drivers/iio/accel/cros_ec_accel_legacy.c | 40 ++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c 
b/drivers/iio/accel/cros_ec_accel_legacy.c
index 2399f0cbdf2b..2c6196446d90 100644
--- a/drivers/iio/accel/cros_ec_accel_legacy.c
+++ b/drivers/iio/accel/cros_ec_accel_legacy.c
@@ -5,7 +5,7 @@
  * Copyright 2017 Google, Inc
  *
  * This driver uses the memory mapper cros-ec interface to communicate
- * with the Chrome OS EC about accelerometer data.
+ * with the Chrome OS EC about accelerometer data or older commands.
  * Accelerometer access is presented through iio sysfs.
  */
 
@@ -33,6 +33,39 @@
  */
 #define ACCEL_LEGACY_NSCALE 9586168
 
+static int cros_ec_accel_legacy_read_cmd(struct iio_dev *indio_dev,
+                                 unsigned long scan_mask, s16 *data)
+{
+       struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+       int ret;
+       unsigned int i;
+       u8 sensor_num;
+
+       /*
+        * Read all sensor data through a command.
+        * Save sensor_num, it is assumed to stay.
+        */
+       sensor_num = st->param.info.sensor_num;
+       st->param.cmd = MOTIONSENSE_CMD_DUMP;
+       st->param.dump.max_sensor_count = CROS_EC_SENSOR_LEGACY_NUM;
+       ret = cros_ec_motion_send_host_cmd(st,
+                       sizeof(st->resp->dump) + CROS_EC_SENSOR_LEGACY_NUM *
+                       sizeof(struct ec_response_motion_sensor_data));
+       st->param.info.sensor_num = sensor_num;
+       if (ret != 0) {
+               dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
+               return ret;
+       }
+
+       for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
+               *data = st->resp->dump.sensor[sensor_num].data[i] *
+                       st->sign[i];
+               data++;
+       }
+
+       return 0;
+}
+
 static int cros_ec_accel_legacy_read(struct iio_dev *indio_dev,
                                     struct iio_chan_spec const *chan,
                                     int *val, int *val2, long mask)
@@ -149,7 +182,10 @@ static int cros_ec_accel_legacy_probe(struct 
platform_device *pdev)
        indio_dev->info = &cros_ec_accel_legacy_info;
        state = iio_priv(indio_dev);
 
-       state->read_ec_sensors_data = cros_ec_sensors_read_lpc;
+       if (state->ec->cmd_readmem != NULL)
+               state->read_ec_sensors_data = cros_ec_sensors_read_lpc;
+       else
+               state->read_ec_sensors_data = cros_ec_accel_legacy_read_cmd;
 
        indio_dev->channels = cros_ec_accel_legacy_channels;
        indio_dev->num_channels = ARRAY_SIZE(cros_ec_accel_legacy_channels);
-- 
2.22.0.410.gd8fdbe21b5-goog