[PATCH v2] usb: typec: ucsi: Add support for READ_POWER_LEVEL command

[PATCH v2] usb: typec: ucsi: Add support for READ_POWER_LEVEL command

[Venkat Jayaraman]

Add support for UCSI READ_POWER_LEVEL command as per
UCSI specification v2.1 and above to debugfs.

Following power related fields will be exposed as files in debugfs:-
peak_current (Peak current),
avg_current (Average current) and
vbus_voltage (VBUS voltage)

These files will be updated either when a READ_POWER_LEVEL
command is sent from OS or when a device is connected.

Signed-off-by: Venkat Jayaraman <venkat.jayaraman@intel.com>
---
Changelog v2:
- Removed extra space in declaration
- Made the call to debugfs_create_file single line for clarity

 drivers/usb/typec/ucsi/debugfs.c | 31 +++++++++++++++++++++++++++++++
 drivers/usb/typec/ucsi/ucsi.c    | 16 ++++++++++++++++
 drivers/usb/typec/ucsi/ucsi.h    | 13 +++++++++++++
 3 files changed, 60 insertions(+)

diff --git a/drivers/usb/typec/ucsi/debugfs.c b/drivers/usb/typec/ucsi/debugfs.c
index 92ebf1a2defd..f73f2b54554e 100644
--- a/drivers/usb/typec/ucsi/debugfs.c
+++ b/drivers/usb/typec/ucsi/debugfs.c
@@ -35,6 +35,7 @@ static int ucsi_cmd(void *data, u64 val)
 	case UCSI_SET_SINK_PATH:
 	case UCSI_SET_NEW_CAM:
 	case UCSI_SET_USB:
+	case UCSI_READ_POWER_LEVEL:
 		ret = ucsi_send_command(ucsi, val, NULL, 0);
 		break;
 	case UCSI_GET_CAPABILITY:
@@ -80,6 +81,33 @@ static int ucsi_resp_show(struct seq_file *s, void *not_used)
 }
 DEFINE_SHOW_ATTRIBUTE(ucsi_resp);
 
+static int ucsi_peak_curr_show(struct seq_file *m, void *v)
+{
+	struct ucsi *ucsi = m->private;
+
+	seq_printf(m, "%u mA\n", ucsi->connector->peak_current);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ucsi_peak_curr);
+
+static int ucsi_avg_curr_show(struct seq_file *m, void *v)
+{
+	struct ucsi *ucsi = m->private;
+
+	seq_printf(m, "%u mA\n", ucsi->connector->avg_current);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ucsi_avg_curr);
+
+static int ucsi_vbus_volt_show(struct seq_file *m, void *v)
+{
+	struct ucsi *ucsi = m->private;
+
+	seq_printf(m, "%u mV\n", ucsi->connector->vbus_voltage);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ucsi_vbus_volt);
+
 void ucsi_debugfs_register(struct ucsi *ucsi)
 {
 	ucsi->debugfs = kzalloc(sizeof(*ucsi->debugfs), GFP_KERNEL);
@@ -89,6 +117,9 @@ void ucsi_debugfs_register(struct ucsi *ucsi)
 	ucsi->debugfs->dentry = debugfs_create_dir(dev_name(ucsi->dev), ucsi_debugfs_root);
 	debugfs_create_file("command", 0200, ucsi->debugfs->dentry, ucsi, &ucsi_cmd_fops);
 	debugfs_create_file("response", 0400, ucsi->debugfs->dentry, ucsi, &ucsi_resp_fops);
+	debugfs_create_file("peak_current", 0400, ucsi->debugfs->dentry, ucsi, &ucsi_peak_curr_fops);
+	debugfs_create_file("avg_current", 0400, ucsi->debugfs->dentry, ucsi, &ucsi_avg_curr_fops);
+	debugfs_create_file("vbus_voltage", 0400, ucsi->debugfs->dentry, ucsi, &ucsi_vbus_volt_fops);
 }
 
 void ucsi_debugfs_unregister(struct ucsi *ucsi)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 01ce858a1a2b..89b3ddc3d9ea 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1218,9 +1218,11 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 	struct ucsi_connector *con = container_of(work, struct ucsi_connector,
 						  work);
 	struct ucsi *ucsi = con->ucsi;
+	u8 curr_scale, volt_scale;
 	enum typec_role role;
 	u16 change;
 	int ret;
+	u32 val;
 
 	mutex_lock(&con->lock);
 
@@ -1291,6 +1293,20 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 	if (change & UCSI_CONSTAT_BC_CHANGE)
 		ucsi_port_psy_changed(con);
 
+	if (UCSI_CONSTAT(con, PWR_READING_READY_V2_1)) {
+		curr_scale = UCSI_CONSTAT(con, CURRENT_SCALE_V2_1);
+		volt_scale = UCSI_CONSTAT(con, VOLTAGE_SCALE_V2_1);
+
+		val = UCSI_CONSTAT(con, PEAK_CURRENT_V2_1);
+		con->peak_current = UCSI_CONSTAT_CURR_SCALE_MULT * curr_scale * val;
+
+		val = UCSI_CONSTAT(con, AVG_CURRENT_V2_1);
+		con->avg_current = UCSI_CONSTAT_CURR_SCALE_MULT * curr_scale * val;
+
+		val = UCSI_CONSTAT(con, VBUS_VOLTAGE_V2_1);
+		con->vbus_voltage = UCSI_CONSTAT_VOLT_SCALE_MULT * volt_scale * val;
+	}
+
 out_unlock:
 	mutex_unlock(&con->lock);
 }
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 5a8f947fcece..791f031ff276 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -129,6 +129,7 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num);
 #define UCSI_GET_PD_MESSAGE			0x15
 #define UCSI_GET_CAM_CS			0x18
 #define UCSI_SET_SINK_PATH			0x1c
+#define UCSI_READ_POWER_LEVEL			0x1e
 #define UCSI_SET_USB				0x21
 #define UCSI_GET_LPM_PPM_INFO			0x22
 
@@ -357,6 +358,14 @@ struct ucsi_cable_property {
 #define   UCSI_CONSTAT_BC_SLOW_CHARGING		2
 #define   UCSI_CONSTAT_BC_TRICKLE_CHARGING	3
 #define UCSI_CONSTAT_PD_VERSION_V1_2		UCSI_DECLARE_BITFIELD_V1_2(70, 16)
+#define UCSI_CONSTAT_PWR_READING_READY_V2_1	UCSI_DECLARE_BITFIELD_V2_1(89, 1)
+#define UCSI_CONSTAT_CURRENT_SCALE_V2_1		UCSI_DECLARE_BITFIELD_V2_1(90, 3)
+#define UCSI_CONSTAT_PEAK_CURRENT_V2_1		UCSI_DECLARE_BITFIELD_V2_1(93, 16)
+#define UCSI_CONSTAT_AVG_CURRENT_V2_1		UCSI_DECLARE_BITFIELD_V2_1(109, 16)
+#define UCSI_CONSTAT_VOLTAGE_SCALE_V2_1		UCSI_DECLARE_BITFIELD_V2_1(125, 4)
+#define UCSI_CONSTAT_VBUS_VOLTAGE_V2_1		UCSI_DECLARE_BITFIELD_V2_1(129, 16)
+#define UCSI_CONSTAT_CURR_SCALE_MULT		5
+#define UCSI_CONSTAT_VOLT_SCALE_MULT		5
 
 /* Connector Status Change Bits.  */
 #define UCSI_CONSTAT_EXT_SUPPLY_CHANGE		BIT(1)
@@ -516,6 +525,10 @@ struct ucsi_connector {
 	u32 src_pdos[PDO_MAX_OBJECTS];
 	int num_pdos;
 
+	u32 peak_current;
+	u32 avg_current;
+	u32 vbus_voltage;
+
 	/* USB PD objects */
 	struct usb_power_delivery *pd;
 	struct usb_power_delivery_capabilities *port_source_caps;
-- 
2.34.1

Re: [PATCH v2] usb: typec: ucsi: Add support for READ_POWER_LEVEL command

[Greg KH]

On Thu, Jul 03, 2025 at 12:32:59PM -0700, Venkat Jayaraman wrote:
> Add support for UCSI READ_POWER_LEVEL command as per
> UCSI specification v2.1 and above to debugfs.
> 
> Following power related fields will be exposed as files in debugfs:-
> peak_current (Peak current),
> avg_current (Average current) and
> vbus_voltage (VBUS voltage)
> 
> These files will be updated either when a READ_POWER_LEVEL
> command is sent from OS or when a device is connected.
> 
> Signed-off-by: Venkat Jayaraman <venkat.jayaraman@intel.com>
> ---
> Changelog v2:
> - Removed extra space in declaration
> - Made the call to debugfs_create_file single line for clarity
> 
>  drivers/usb/typec/ucsi/debugfs.c | 31 +++++++++++++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.c    | 16 ++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h    | 13 +++++++++++++
>  3 files changed, 60 insertions(+)

You somehow did not cc: the proper maintainers on this at all, have you
gone through the proper Intel kernel developer training that should
document all of this type of thing?  If not, please do so.

thanks,

greg k-h