[PATCH v7 7/7] cros_ec: differentiate SCP from EC by feature bit.

Peter Shih
2019-03-27T05:15:41Z

From: Pi-Hsun Shih <pihsun@chromium.org>

Since a SCP and EC would both exist on a system, and use the cros_ec_dev
driver, we need to differentiate between them for the userspace, or they
would both be registered at /dev/cros_ec, causing a conflict.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
Changes from v6:
- No change.

Changes from v5:
- No change.

Changes from v4:
- No change.

Changes from v3:
- No change.

Changes from v2:
- No change.

Changes from v1:
- New patch extracted from Patch 5.
---
drivers/mfd/cros_ec_dev.c | 10 ++++++++++
include/linux/mfd/cros_ec.h | 1 +
include/linux/mfd/cros_ec_commands.h | 2 ++
3 files changed, 13 insertions(+)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index d275deaecb12..da2f2145d31d 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -418,6 +418,16 @@ static int ec_device_probe(struct platform_device *pdev)
device_initialize(&ec->class_dev);
cdev_init(&ec->cdev, &fops);

+ /* check whether this is actually a SCP rather than an EC */
+ if (cros_ec_check_features(ec, EC_FEATURE_SCP)) {
+ dev_info(dev, "SCP detected.\n");
+ /*
+ * Help userspace differentiating ECs from SCP,
+ * regardless of the probing order.
+ */
+ ec_platform->ec_name = CROS_EC_DEV_SCP_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 8f2a8918bfa3..a971399bad82 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -24,6 +24,7 @@

#define CROS_EC_DEV_NAME "cros_ec"
#define CROS_EC_DEV_PD_NAME "cros_pd"
+#define CROS_EC_DEV_SCP_NAME "cros_scp"

/*
* The EC is unresponsive for a time after a reboot command. Add a
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index fc91082d4c35..3e5da6e93b2f 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -856,6 +856,8 @@ enum ec_feature_code {
EC_FEATURE_RTC = 27,
/* EC supports CEC commands */
EC_FEATURE_CEC = 35,
+ /* The MCU exposes a SCP */
+ EC_FEATURE_SCP = 39,
};

#define EC_FEATURE_MASK_0(event_code) (1UL << (event_code % 32))
--
2.21.0.392.gf8f6787159e-goog