Support Touchpad MCU as a special of CrOS EC devices. The current
Touchpad MCU is used on Eve Chromebook and used the same protocol as
other CrOS EC devices.
When a MCU has touchpad support (aka EC_FEATURE_TOUCHPAD), it is
instantiated as a special CrOS EC device with device name 'cros_tp'. So
regardless of the probing order between the actual cros_ec and cros_tp,
the userspace and other kernel drivers should not confuse them.
Signed-off-by: Wei-Ning Huang <wnhu...@google.com>
Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
---
Changes in v3: None
Changes in v2: None
drivers/mfd/cros_ec_dev.c | 10 ++++++++++
include/linux/mfd/cros_ec.h | 1 +
2 files changed, 11 insertions(+)
diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 79746e817cdb..be827910e9d0 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -659,6 +659,16 @@ static int ec_device_probe(struct platform_device *pdev)
ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
}
+ /* Check whether this is actually a Touchpad MCU rather than an EC */
+ if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) {
+ dev_info(dev, "CrOS Touchpad MCU detected.\n");
+ /*
+ * Help userspace differentiating ECs from TP MCU,
+ * regardless of the probing order.
+ */
+ ec_platform->ec_name = CROS_EC_DEV_TP_NAME;
+ }
+
/*
* Add the class device
* Link to the character device for creating the /dev entry
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index b393bd4e4b73..981381fbb3fd 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -26,6 +26,7 @@
#define CROS_EC_DEV_FP_NAME "cros_fp"
#define CROS_EC_DEV_ISH_NAME "cros_ish"
#define CROS_EC_DEV_PD_NAME "cros_pd"
+#define CROS_EC_DEV_TP_NAME "cros_tp"
/*
* The EC is unresponsive for a time after a reboot command. Add a
--
2.20.1
