Make sure we handover the PCIe controller in a clean state. Some of the devices hanging from the PCIe bus might need to be properly reset through #PERST in order for Linux to be able to initialize them.
This is specially important in order to properly initialize Raspberry Pi 4 B and 400's USB chip.
Signed-off-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de --- drivers/pci/pcie_brcmstb.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/pci/pcie_brcmstb.c b/drivers/pci/pcie_brcmstb.c index bd645d7896..90225f6779 100644 --- a/drivers/pci/pcie_brcmstb.c +++ b/drivers/pci/pcie_brcmstb.c @@ -577,6 +577,24 @@ static int brcm_pcie_probe(struct udevice *dev) return 0; }
+static int brcm_pcie_remove(struct udevice *dev) +{ + struct brcm_pcie *pcie = dev_get_priv(dev); + void __iomem *base = pcie->base; + + /* Assert fundamental reset */ + setbits_le32(base + PCIE_RGR1_SW_INIT_1, RGR1_SW_INIT_1_PERST_MASK); + + /* Turn off SerDes */ + setbits_le32(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG, + PCIE_HARD_DEBUG_SERDES_IDDQ_MASK); + + /* Shutdown bridge */ + setbits_le32(base + PCIE_RGR1_SW_INIT_1, RGR1_SW_INIT_1_INIT_MASK); + + return 0; +} + static int brcm_pcie_of_to_plat(struct udevice *dev) { struct brcm_pcie *pcie = dev_get_priv(dev); @@ -616,6 +634,8 @@ U_BOOT_DRIVER(pcie_brcm_base) = { .ops = &brcm_pcie_ops, .of_match = brcm_pcie_ids, .probe = brcm_pcie_probe, + .remove = brcm_pcie_remove, .of_to_plat = brcm_pcie_of_to_plat, .priv_auto = sizeof(struct brcm_pcie), + .flags = DM_FLAG_OS_PREPARE, };