pci: brcmstb: Cleanup controller state before handover

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>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>

diff --git a/drivers/pci/pcie_brcmstb.c b/drivers/pci/pcie_brcmstb.c
index dd2a4ef629b2e4898b196f1bd19dd5bf8fcfde74..54aa02c80990ed206d248da747d8737194a88f32 100644 (file)
--- a/drivers/pci/pcie_brcmstb.c
+++ b/drivers/pci/pcie_brcmstb.c
@@ -579,6 +579,24 @@ 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);
@@ -618,6 +636,8 @@ 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,
 };