usb: typec: ucsi: Mark dGPUs as DEVICE scope

power_supply_is_system_supplied() checks whether any power
supplies are present that aren't batteries to decide whether
the system is running on DC or AC.  Downstream drivers use
this to make performance decisions.

Navi dGPUs include an UCSI function that has been exported
since commit 17631e8ca2d3 ("i2c: designware: Add driver
support for AMD NAVI GPU").

This UCSI function registers a power supply since commit
992a60ed0d5e ("usb: typec: ucsi: register with power_supply class")
but this is not a system power supply.

As the power supply for a dGPU is only for powering devices connected
to dGPU, create a device property to indicate that the UCSI endpoint
is only for the scope of `POWER_SUPPLY_SCOPE_DEVICE`.

Link: https://lore.kernel.org/lkml/20230516182541.5836-2-mario.limonciello@amd.com/
Reviewed-by: Evan Quan <evan.quan@amd.com>
Tested-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 782fe1ef3ca1..61d7a27aa070 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 
@@ -234,6 +235,16 @@ static const struct dev_pm_ops i2c_dw_pm_ops = {
 	SET_RUNTIME_PM_OPS(i2c_dw_pci_runtime_suspend, i2c_dw_pci_runtime_resume, NULL)
 };
 
+static const struct property_entry dgpu_properties[] = {
+	/* USB-C doesn't power the system */
+	PROPERTY_ENTRY_U8("scope", POWER_SUPPLY_SCOPE_DEVICE),
+	{}
+};
+
+static const struct software_node dgpu_node = {
+	.properties = dgpu_properties,
+};
+
 static int i2c_dw_pci_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *id)
 {
@@ -325,7 +336,7 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
 	}
 
 	if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU) {
-		dev->slave = i2c_new_ccgx_ucsi(&dev->adapter, dev->irq, NULL);
+		dev->slave = i2c_new_ccgx_ucsi(&dev->adapter, dev->irq, &dgpu_node);
 		if (IS_ERR(dev->slave))
 			return dev_err_probe(dev->dev, PTR_ERR(dev->slave),
 					     "register UCSI failed\n");