[PATCH v3 5/8] mfd: cros_ec_dev: Register cros_ec_accel_legacy driver as a subdevice.

From: Enric Balletbo i Serra
Date: Mon Feb 26 2018 - 05:27:46 EST


With this patch, the cros_ec_ctl driver will register the legacy
accelerometer driver (named cros_ec_accel_legacy) if it fails to
register sensors through the usual path cros_ec_sensors_register().
This legacy device is present on Chromebook devices with older EC
firmware only supporting deprecated EC commands (Glimmer based devices).

Tested-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Reviewed-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---

Changes in v3:
- [5/8] Add the Reviewed-by Andy Shevchenko.

Changes in v2:
- [5/8] Add the Reviewed-by Gwendal.

drivers/mfd/cros_ec_dev.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 33fe1b439ee2..fd7f0068fb45 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -389,6 +389,63 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
kfree(msg);
}

+#define CROS_EC_SENSOR_LEGACY_NUM 2
+static struct mfd_cell cros_ec_accel_legacy_cells[CROS_EC_SENSOR_LEGACY_NUM];
+
+static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
+{
+ struct cros_ec_device *ec_dev = ec->ec_dev;
+ u8 status;
+ int i, ret;
+ struct cros_ec_sensor_platform
+ sensor_platforms[CROS_EC_SENSOR_LEGACY_NUM];
+
+ /*
+ * EC that need legacy support are the main EC, directly connected to
+ * the AP.
+ */
+ if (ec->cmd_offset != 0)
+ return;
+
+ /*
+ * Check if EC supports direct memory reads and if EC has
+ * accelerometers.
+ */
+ if (!ec_dev->cmd_readmem)
+ return;
+
+ ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1, &status);
+ if (ret < 0) {
+ dev_warn(ec->dev, "EC does not support direct reads.\n");
+ return;
+ }
+
+ /* Check if EC has accelerometers. */
+ if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
+ dev_info(ec->dev, "EC does not have accelerometers.\n");
+ return;
+ }
+
+ /*
+ * Register 2 accelerometers
+ */
+ for (i = 0; i < CROS_EC_SENSOR_LEGACY_NUM; i++) {
+ cros_ec_accel_legacy_cells[i].name = "cros-ec-accel-legacy";
+ sensor_platforms[i].sensor_num = i;
+ cros_ec_accel_legacy_cells[i].id = i;
+ cros_ec_accel_legacy_cells[i].platform_data =
+ &sensor_platforms[i];
+ cros_ec_accel_legacy_cells[i].pdata_size =
+ sizeof(struct cros_ec_sensor_platform);
+ }
+ ret = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
+ cros_ec_accel_legacy_cells,
+ CROS_EC_SENSOR_LEGACY_NUM,
+ NULL, 0, NULL);
+ if (ret)
+ dev_err(ec_dev->dev, "failed to add EC sensors\n");
+}
+
static const struct mfd_cell cros_ec_rtc_cell = {
.name = "cros-ec-rtc",
};
@@ -440,6 +497,9 @@ static int ec_device_probe(struct platform_device *pdev)
/* check whether this EC is a sensor hub. */
if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
cros_ec_sensors_register(ec);
+ else
+ /* Workaroud for older EC firmware */
+ cros_ec_accel_legacy_register(ec);

/* check whether this EC instance has RTC host command support */
if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
--
2.16.1