T2080QDS/PCIe: Soft Reset PCIe on T2080QDS for down-training issue

T2080QDS PEX1/Slot#1 will down-train from x4 to x2,
with SRDS_PRTCL_S1 = 0x66 and SRDS_PRTCL_S2 = 0x15.
Soft reset PCIe can fix this issue.

Signed-off-by: Zhao Qiang <B45475@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

drivers/pci/fsl_pci_init.c

@@ -444,6 +444,21 @@ void fsl_pci_init(struct pci_controller *hose, struct fsl_pci_info *pci_info)
 			ltssm = (in_be32(&pci->pex_csr0)
 				& PEX_CSR0_LTSSM_MASK) >> PEX_CSR0_LTSSM_SHIFT;
 			enabled = (ltssm == 0x11) ? 1 : 0;
+#ifdef CONFIG_FSL_PCIE_RESET
+			int i;
+			/* assert PCIe reset */
+			setbits_be32(&pci->pdb_stat, 0x08000000);
+			(void) in_be32(&pci->pdb_stat);
+			udelay(1000);
+			/* clear PCIe reset */
+			clrbits_be32(&pci->pdb_stat, 0x08000000);
+			asm("sync;isync");
+			for (i = 0; i < 100 && ltssm < PCI_LTSSM_L0; i++) {
+				pci_hose_read_config_word(hose, dev, PCI_LTSSM,
+							  &ltssm);
+				udelay(1000);
+			}
+#endif
 		} else {
 		/* pci_hose_read_config_word(hose, dev, PCI_LTSSM, &ltssm); */
 		/* enabled = ltssm >= PCI_LTSSM_L0; */

include/configs/T208xQDS.h

@@ -575,6 +575,7 @@ unsigned long get_board_ddr_clk(void);
 #define CONFIG_PCIE2		/* PCIE controler 2 */
 #define CONFIG_PCIE3		/* PCIE controler 3 */
 #define CONFIG_PCIE4		/* PCIE controler 4 */
+#define CONFIG_FSL_PCIE_RESET
 #define CONFIG_FSL_PCI_INIT	/* Use common FSL init code */
 #define CONFIG_SYS_PCI_64BIT	/* enable 64-bit PCI resources */
 /* controller 1, direct to uli, tgtid 3, Base address 20000 */