[PATCH 0/2] Add sysfs attributes to cros-ec-typec

[PATCH 0/2] Add sysfs attributes to cros-ec-typec

[Andrei Kuchynski]

This patch series adds sysfs attributes to expose the state of EC.
These attributes provide user-space applications with a read-only view of
the EC state, eliminating the need for ioct calls and facilitating
diagnostics.

Tested on a ChromeOS Brya device with kernel 6.6. Verified that user-space
applications can correctly read the new sysfs attributes.

Andrei Kuchynski (2):
  platform/chrome: cros_ec_typec: Expose PD mux status via sysfs
  platform/chrome: cros_ec_typec: Expose AP_MODE_ENTRY feature state via
    sysfs

 .../ABI/testing/sysfs-class-chromeos          | 20 ++++++
 drivers/platform/chrome/cros_ec_sysfs.c       | 71 +++++++++++++++++++
 2 files changed, 91 insertions(+)

-- 
2.48.1.362.g079036d154-goog

[PATCH 1/2] platform/chrome: cros_ec_typec: Expose PD mux status via sysfs

[Andrei Kuchynski]

This adds sysfs attribute /sys/class/chromeos/cros_ec/usbpdmuxinfo
to expose the PD mux status for each Type-C port.
This allows user-space applications to easily determine
the current mux state without using ioctls.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
---
 .../ABI/testing/sysfs-class-chromeos          | 13 +++++
 drivers/platform/chrome/cros_ec_sysfs.c       | 58 +++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-chromeos b/Documentation/ABI/testing/sysfs-class-chromeos
index 74ece942722e..e067dbdab170 100644
--- a/Documentation/ABI/testing/sysfs-class-chromeos
+++ b/Documentation/ABI/testing/sysfs-class-chromeos
@@ -31,3 +31,16 @@ Date:		August 2015
 KernelVersion:	4.2
 Description:
 		Show the information about the EC software and hardware.
+
+What:		/sys/class/chromeos/cros_ec/usbpdmuxinfo
+Date:		February 2025
+Description:
+		Show PD mux status for each typec port with following flags:
+		- "USB": USB connected
+		- "DP": DP connected
+		- "POLARITY": CC line Polarity inverted
+		- "HPD_IRQ": Hot Plug Detect interrupt is asserted
+		- "HPD_LVL": Hot Plug Detect level is asserted
+		- "SAFE": DP is in safe mode
+		- "TBT": TBT enabled
+		- "USB4": USB4 enabled
diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index bc1a5ba09528..93e9ed87249c 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -296,18 +296,69 @@ static ssize_t kb_wake_angle_store(struct device *dev,
 	return count;
 }
 
+static ssize_t usbpdmuxinfo_show(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
+	ssize_t count = 0;
+	struct ec_response_usb_pd_ports resp_pd_ports;
+	int ret;
+	int i;
+
+	ret = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
+			  &resp_pd_ports, sizeof(resp_pd_ports));
+	if (ret < 0)
+		return -EIO;
+
+	for (i = 0; i < resp_pd_ports.num_ports; i++) {
+		struct ec_response_usb_pd_mux_info resp_mux;
+		struct ec_params_usb_pd_mux_info req = {
+			.port = i,
+		};
+
+		ret = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_USB_PD_MUX_INFO,
+			  &req, sizeof(req), &resp_mux, sizeof(resp_mux));
+
+		if (ret >= 0) {
+			count += sysfs_emit_at(buf, count, "Port %d:", i);
+			count += sysfs_emit_at(buf, count, " USB=%d",
+					!!(resp_mux.flags & USB_PD_MUX_USB_ENABLED));
+			count += sysfs_emit_at(buf, count, " DP=%d",
+					!!(resp_mux.flags & USB_PD_MUX_DP_ENABLED));
+			count += sysfs_emit_at(buf, count, " POLARITY=%s",
+					(resp_mux.flags & USB_PD_MUX_POLARITY_INVERTED) ?
+					"INVERTED" : "NORMAL");
+			count += sysfs_emit_at(buf, count, " HPD_IRQ=%d",
+					!!(resp_mux.flags & USB_PD_MUX_HPD_IRQ));
+			count += sysfs_emit_at(buf, count, " HPD_LVL=%d",
+					!!(resp_mux.flags & USB_PD_MUX_HPD_LVL));
+			count += sysfs_emit_at(buf, count, " SAFE=%d",
+					!!(resp_mux.flags & USB_PD_MUX_SAFE_MODE));
+			count += sysfs_emit_at(buf, count, " TBT=%d",
+					!!(resp_mux.flags & USB_PD_MUX_TBT_COMPAT_ENABLED));
+			count += sysfs_emit_at(buf, count, " USB4=%d\n",
+					!!(resp_mux.flags & USB_PD_MUX_USB4_ENABLED));
+		}
+	}
+
+	return count ? : -EIO;
+}
+
 /* Module initialization */
 
 static DEVICE_ATTR_RW(reboot);
 static DEVICE_ATTR_RO(version);
 static DEVICE_ATTR_RO(flashinfo);
 static DEVICE_ATTR_RW(kb_wake_angle);
+static DEVICE_ATTR_RO(usbpdmuxinfo);
 
 static struct attribute *__ec_attrs[] = {
 	&dev_attr_kb_wake_angle.attr,
 	&dev_attr_reboot.attr,
 	&dev_attr_version.attr,
 	&dev_attr_flashinfo.attr,
+	&dev_attr_usbpdmuxinfo.attr,
 	NULL,
 };
 
@@ -320,6 +371,13 @@ static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
 		return 0;
 
+	if (a == &dev_attr_usbpdmuxinfo.attr) {
+		struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
+
+		if (strcmp(ec_platform->ec_name, CROS_EC_DEV_NAME))
+			return 0;
+	}
+
 	return a->mode;
 }
 
-- 
2.48.1.362.g079036d154-goog

[PATCH 2/2] platform/chrome: cros_ec_typec: Expose AP_MODE_ENTRY feature state via sysfs

[Andrei Kuchynski]

This adds sysfs attribute /sys/class/chromeos/cros_ec/ap_mode_entry
to expose the status of the AP_MODE_ENTRY feature. This attribute
indicate whether the EC requires direction from the Application
Processor (AP) before entering Type-C alternate modes or USB4 mode.
This allows user-space applications to easily determine if the AP needs
to be involved in mode entry.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
---
 Documentation/ABI/testing/sysfs-class-chromeos |  7 +++++++
 drivers/platform/chrome/cros_ec_sysfs.c        | 15 ++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-class-chromeos b/Documentation/ABI/testing/sysfs-class-chromeos
index e067dbdab170..7fa5be6cc774 100644
--- a/Documentation/ABI/testing/sysfs-class-chromeos
+++ b/Documentation/ABI/testing/sysfs-class-chromeos
@@ -44,3 +44,10 @@ Description:
 		- "SAFE": DP is in safe mode
 		- "TBT": TBT enabled
 		- "USB4": USB4 enabled
+
+What:		/sys/class/chromeos/cros_ec/ap_mode_entry
+Date:		February 2025
+Description:
+		Show if the AP mode entry EC feature is supported.
+		It indicates whether the EC waits for direction from the AP
+		to enter Type-C altmodes or USB4 mode.
diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index 93e9ed87249c..f22e9523da3e 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -345,6 +345,16 @@ static ssize_t usbpdmuxinfo_show(struct device *dev,
 	return count ? : -EIO;
 }
 
+static ssize_t ap_mode_entry_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
+	const bool ap_driven_altmode = cros_ec_check_features(
+		ec, EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY);
+
+	return sysfs_emit(buf, "%s\n", ap_driven_altmode ? "yes" : "no");
+}
+
 /* Module initialization */
 
 static DEVICE_ATTR_RW(reboot);
@@ -352,6 +362,7 @@ static DEVICE_ATTR_RO(version);
 static DEVICE_ATTR_RO(flashinfo);
 static DEVICE_ATTR_RW(kb_wake_angle);
 static DEVICE_ATTR_RO(usbpdmuxinfo);
+static DEVICE_ATTR_RO(ap_mode_entry);
 
 static struct attribute *__ec_attrs[] = {
 	&dev_attr_kb_wake_angle.attr,
@@ -359,6 +370,7 @@ static struct attribute *__ec_attrs[] = {
 	&dev_attr_version.attr,
 	&dev_attr_flashinfo.attr,
 	&dev_attr_usbpdmuxinfo.attr,
+	&dev_attr_ap_mode_entry.attr,
 	NULL,
 };
 
@@ -371,7 +383,8 @@ static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
 		return 0;
 
-	if (a == &dev_attr_usbpdmuxinfo.attr) {
+	if (a == &dev_attr_usbpdmuxinfo.attr ||
+		a == &dev_attr_ap_mode_entry.attr) {
 		struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
 
 		if (strcmp(ec_platform->ec_name, CROS_EC_DEV_NAME))
-- 
2.48.1.362.g079036d154-goog

Re: [PATCH 0/2] Add sysfs attributes to cros-ec-typec

[Tzung-Bi Shih]

On Mon, Feb 03, 2025 at 12:59:45PM +0000, Andrei Kuchynski wrote:
> This patch series adds sysfs attributes to expose the state of EC.
> These attributes provide user-space applications with a read-only view of
> the EC state, eliminating the need for ioct calls and facilitating
> diagnostics.
> 
> Tested on a ChromeOS Brya device with kernel 6.6. Verified that user-space
> applications can correctly read the new sysfs attributes.
> 
> [...]

Applied to

    https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next

[1/2] platform/chrome: cros_ec_sysfs: Expose PD mux status
      commit: e6a3215f78716d25ad60b002fd0585c04ffd5d01
[2/2] platform/chrome: cros_ec_sysfs: Expose AP_MODE_ENTRY feature state
      commit: 435a3d78b87a93c52a4f84e36ba4a0857554c958

Thanks!