On Tue, Mar 24, 2020 at 07:28:10PM +0100, Nicolas Saenz Julienne wrote:
> 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. The function informs VideCore that VL805 was just reset, or
> requests for a probe defer.
Cover letter mentions both "VideCore" and "VideoCore". I dunno which
is correct, but between the commit log and the comment, this patch
mentions "VideCore" four times.
> Based on Tim Gover's downstream implementation.
Maybe a URL?
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
>
> ---
> Changes since v4:
> - Inline function definition when RASPBERRYPI_FIRMWARE is not defined
>
> Changes since v1:
> - Move include into .c file and add forward declaration to .h
>
> drivers/firmware/raspberrypi.c | 38 ++++++++++++++++++++++
> include/soc/bcm2835/raspberrypi-firmware.h | 7 ++++
> 2 files changed, 45 insertions(+)
>
> diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
> index da26a584dca0..cbb495aff6a0 100644
> --- a/drivers/firmware/raspberrypi.c
> +++ b/drivers/firmware/raspberrypi.c
> @@ -12,6 +12,7 @@
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> +#include <linux/pci.h>
> #include <soc/bcm2835/raspberrypi-firmware.h>
>
> #define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
> @@ -286,6 +287,43 @@ struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
> }
> EXPORT_SYMBOL_GPL(rpi_firmware_get);
>
> +/*
> + * 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.
s/trough/through/
I don't see anything in this patch that looks like a mailbox
interface, but maybe that's just because I don't know anything about
Raspberry Pi.
> + */
> +int rpi_firmware_init_vl805(struct pci_dev *pdev)
> +{
> + 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;
> +
> + dev_dbg(&pdev->dev, "loaded Raspberry Pi's VL805 firmware\n");
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805);
> +
> static const struct of_device_id rpi_firmware_of_match[] = {
> { .compatible = "raspberrypi,bcm2835-firmware", },
> {},
> diff --git a/include/soc/bcm2835/raspberrypi-firmware.h b/include/soc/bcm2835/raspberrypi-firmware.h
> index cc9cdbc66403..3025aca3c358 100644
> --- a/include/soc/bcm2835/raspberrypi-firmware.h
> +++ b/include/soc/bcm2835/raspberrypi-firmware.h
> @@ -10,6 +10,7 @@
> #include <linux/of_device.h>
>
> struct rpi_firmware;
> +struct pci_dev;
>
> enum rpi_firmware_property_status {
> RPI_FIRMWARE_STATUS_REQUEST = 0,
> @@ -141,6 +142,7 @@ int rpi_firmware_property(struct rpi_firmware *fw,
> int rpi_firmware_property_list(struct rpi_firmware *fw,
> void *data, size_t tag_size);
> struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node);
> +int rpi_firmware_init_vl805(struct pci_dev *pdev);
> #else
> static inline int rpi_firmware_property(struct rpi_firmware *fw, u32 tag,
> void *data, size_t len)
> @@ -158,6 +160,11 @@ static inline struct rpi_firmware *rpi_firmware_get(struct device_node *firmware
> {
> return NULL;
> }
> +
> +static inline int rpi_firmware_init_vl805(struct pci_dev *pdev)
> +{
> + return 0;
> +}
> #endif
>
> #endif /* __SOC_RASPBERRY_FIRMWARE_H__ */
> --
> 2.25.1
>
