Hi Nicolas,
Am 17.02.20 um 11:07 schrieb Nicolas Saenz Julienne:
> On the Raspberry Pi 4, after a PCI reset, VL805's firmware may either be
> loaded directly from an EEPROM or, if not present, by the SoC's
> VideCore. Inform VideCore that VL805 was just reset, or defer xhci's
> probe if not yet joinable trough the mailbox interface.
>
> Based on Tim Gover's downstream implementation.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> ---
> drivers/usb/host/xhci-pci.c | 50 ++++++++++++++++++++++
> include/soc/bcm2835/raspberrypi-firmware.h | 2 +-
> 2 files changed, 51 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index 4917c5b033fa..eadace4a9339 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -13,6 +13,8 @@
> #include <linux/module.h>
> #include <linux/acpi.h>
>
> +#include <soc/bcm2835/raspberrypi-firmware.h>
> +
> #include "xhci.h"
> #include "xhci-trace.h"
>
> @@ -308,6 +310,44 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
> return xhci_pci_reinit(xhci, pdev);
> }
>
> +/*
> + * On the Raspberry Pi 4, after a PCI reset, VL805's firmware may either be
> + * loaded directly from an EEPROM or, if not present, by the SoC's VideCore.
> + * Inform VideCore that VL805 was just reset, or defer xhci's probe if not yet
> + * joinable trough the mailbox interface.
> + */
> +static int raspberrypi_load_vl805_fw(struct pci_dev *pdev)
> +{
> +#ifdef CONFIG_RASPBERRYPI_FIRMWARE
> + struct device_node *fw_np;
> + struct rpi_firmware *fw;
> + u32 dev_addr;
> + int ret;
> +
> + fw_np = of_find_compatible_node(NULL, NULL,
> + "raspberrypi,bcm2835-firmware");
> + if (!fw_np)
> + return 0;
> +
> + fw = rpi_firmware_get(fw_np);
> + of_node_put(fw_np);
> + if (!fw)
> + return -EPROBE_DEFER;
> +
> + dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 |
> + PCI_FUNC(pdev->devfn) << 12;
> +
> + ret = rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET,
> + &dev_addr, sizeof(dev_addr));
> + if (ret)
> + return ret;
not sure, but there could be a corner case which should be handled
differently. In case the Raspberry Pi 4 has an EEPROM for the VL805
firmware but the firmware is too old to handle
RPI_FIRMWARE_NOTIFY_XHCI_RESET, we should return with 0. I don't know
there is a change to detect this reliable. I just want to mention this.
> +
> + dev_dbg(&pdev->dev, "loaded Raspberry Pi's VL805 firmware\n");
> +
> +#endif
> + return 0;
> +}
> +
> /*
> * We need to register our own PCI probe function (instead of the USB core's
> * function) in order to create a second roothub under xHCI.
> @@ -321,6 +361,16 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
>
> driver = (struct hc_driver *)id->driver_data;
>
> + if (dev->vendor == PCI_VENDOR_ID_VIA && dev->device == 0x3483) {
> + retval = raspberrypi_load_vl805_fw(dev);
> + if (retval) {
> + if (retval != -EPROBE_DEFER)
> + dev_err(&dev->dev,
> + "Failed to load VL805's firmware");
> + return retval;
> + }
> + }
> +
> /* Prevent runtime suspending between USB-2 and USB-3 initialization */
> pm_runtime_get_noresume(&dev->dev);
>
> diff --git a/include/soc/bcm2835/raspberrypi-firmware.h b/include/soc/bcm2835/raspberrypi-firmware.h
> index 7800e12ee042..cc9cdbc66403 100644
> --- a/include/soc/bcm2835/raspberrypi-firmware.h
> +++ b/include/soc/bcm2835/raspberrypi-firmware.h
> @@ -90,7 +90,7 @@ enum rpi_firmware_property_tag {
> RPI_FIRMWARE_SET_PERIPH_REG = 0x00038045,
> RPI_FIRMWARE_GET_POE_HAT_VAL = 0x00030049,
> RPI_FIRMWARE_SET_POE_HAT_VAL = 0x00030050,
> -
> + RPI_FIRMWARE_NOTIFY_XHCI_RESET = 0x00030058,
In past we updated the firmware mailbox property interface in a bunch as
a separate patch. So we can avoid those gaps.
Best regards
Stefan
>
> /* Dispmanx TAGS */
> RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE = 0x00040001,
