diff options
Diffstat (limited to 'drivers/firmware/raspberrypi.c')
| -rw-r--r-- | drivers/firmware/raspberrypi.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c index a3e85186f8e6..ef8098856a47 100644 --- a/drivers/firmware/raspberrypi.c +++ b/drivers/firmware/raspberrypi.c @@ -12,6 +12,8 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/slab.h> +#include <linux/pci.h> +#include <linux/delay.h> #include <soc/bcm2835/raspberrypi-firmware.h> #define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf)) @@ -19,6 +21,8 @@ #define MBOX_DATA28(msg) ((msg) & ~0xf) #define MBOX_CHAN_PROPERTY 8 +#define VL805_PCI_CONFIG_VERSION_OFFSET 0x50 + static struct platform_device *rpi_hwmon; static struct platform_device *rpi_clk; @@ -280,6 +284,63 @@ struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) } EXPORT_SYMBOL_GPL(rpi_firmware_get); +/* + * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that + * implements xHCI. After a PCI reset, VL805's firmware may either be loaded + * directly from an EEPROM or, if not present, by the SoC's co-processor, + * VideoCore. RPi4's VideoCore OS contains both the non public firmware load + * logic and the VL805 firmware blob. This function triggers the aforementioned + * process. + */ +int rpi_firmware_init_vl805(struct pci_dev *pdev) +{ + struct device_node *fw_np; + struct rpi_firmware *fw; + u32 dev_addr, version; + 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 -ENODEV; + + /* + * Make sure we don't trigger a firmware load unnecessarily. + * + * If something went wrong with PCI, this whole exercise would be + * futile as VideoCore expects from us a configured PCI bus. Just take + * the faulty version (likely ~0) and let xHCI's registration fail + * further down the line. + */ + pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, &version); + if (version) + goto exit; + + 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; + + /* Wait for vl805 to startup */ + usleep_range(200, 1000); + + pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, + &version); +exit: + pci_info(pdev, "VL805 firmware version %08x\n", version); + + return 0; +} +EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805); + static const struct of_device_id rpi_firmware_of_match[] = { { .compatible = "raspberrypi,bcm2835-firmware", }, {}, |