USB: xhci: add support for PWRON active high

Some PCIe-to-USB controllers such as TI's TUSB73x0 3.0 xHCI host
controller supports controlling the PWRONx polarity via the USB control
register (E0h). Add support for device tree property
ti,pwron-active-high which indicates PWRONx to be active high and
configure the E0h register accordingly.  This enables the software
control for the TUSB73x0's PWRONx outputs with an inverted polarity from
the default configuration which could be used as USB EN signals for the
other hubs or devices.

Signed-off-by: Parth Pancholi <parth.pancholi@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20241029072444.8827-3-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 7e538194a0a4e2fcb8188d3fb84ff81a0f1ad7fb..caafec46cc94a1a6ab68147ed1a8d12423186c0d 100644 (file)
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -646,6 +646,9 @@ int xhci_pci_common_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
        dma_set_max_seg_size(&dev->dev, UINT_MAX);
 
+       if (device_property_read_bool(&dev->dev, "ti,pwron-active-high"))
+               pci_clear_and_set_config_dword(dev, 0xE0, 0, 1 << 22);
+
        return 0;
 
 put_usb3_hcd: