[U-Boot] [PATCH 2/2] pci/layerscape: fix link and class issues to support ls2085a

[Minghuan Lian]

1. LS2085a provides PCIE_LUT_DBG register rather than PCIE_LDBG
   to show the link status, so the patch fixes it.
2. Increase the delay time to make sure that link training
   has finished.
3. Return invalid value when accessing multi-function device
4. For LS2085a DBI_RO_WR_EN bit is cleared as default, so we
   must set this bit before change DBI register value.

Signed-off-by: Roy Zang <tie-fei.zang at freescale.com>
Signed-off-by: Minghuan Lian <Minghuan.Lian at freescale.com>
---
 drivers/pci/pcie_layerscape.c | 47 ++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/pcie_layerscape.c b/drivers/pci/pcie_layerscape.c
index 15e3546..8330380 100644
--- a/drivers/pci/pcie_layerscape.c
+++ b/drivers/pci/pcie_layerscape.c
@@ -50,11 +50,20 @@
 #define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
 #define PCIE_ATU_UPPER_TARGET		0x91C
 
+/* LUT registers */
+#define PCIE_LUT_BASE		0x80000
+#define PCIE_LUT_DBG		0x7FC
+
+#define PCIE_DBI_RO_WR_EN	0x8bc
+
 #define PCIE_LINK_CAP		0x7c
 #define PCIE_LINK_SPEED_MASK	0xf
 #define PCIE_LINK_STA		0x82
 
-#define PCIE_DBI_SIZE		(4 * 1024) /* 4K */
+#define LTSSM_STATE_MASK	0x3f
+#define LTSSM_PCIE_L0		0x11 /* L0 state */
+
+#define PCIE_DBI_SIZE		0x100000 /* 1M */
 
 struct ls_pcie {
 	int idx;
@@ -104,8 +113,6 @@ struct ls_pcie_info {
 
 /* PEX1/2 Misc Ports Status Register */
 #define LTSSM_STATE_SHIFT	20
-#define LTSSM_STATE_MASK	0x3f
-#define LTSSM_PCIE_L0		0x11 /* L0 state */
 
 static int ls_pcie_link_state(struct ls_pcie *pcie)
 {
@@ -122,18 +129,18 @@ static int ls_pcie_link_state(struct ls_pcie *pcie)
 	return 1;
 }
 #else
-#define PCIE_LDBG 0x7FC
-
 static int ls_pcie_link_state(struct ls_pcie *pcie)
 {
 	u32 state;
 
-	state = readl(pcie->dbi + PCIE_LDBG);
-	if (state)
-		return 1;
+	state = readl(pcie->dbi + PCIE_LUT_BASE + PCIE_LUT_DBG) &
+		LTSSM_STATE_MASK;
+	if (state < LTSSM_PCIE_L0) {
+		debug("....PCIe link error. LTSSM=0x%02x.\n", state);
+		return 0;
+	}
 
-	debug("....PCIe link error.\n");
-	return 0;
+	return 1;
 }
 #endif
 
@@ -149,7 +156,11 @@ static int ls_pcie_link_up(struct ls_pcie *pcie)
 	/* Try to download speed to gen1 */
 	cap = readl(pcie->dbi + PCIE_LINK_CAP);
 	writel((cap & (~PCIE_LINK_SPEED_MASK)) | 1, pcie->dbi + PCIE_LINK_CAP);
-	udelay(2000);
+	/*
+	 * Notice: the following delay has critical impact on link training
+	 * if too short (<30ms) the link doesn't get up.
+	 */
+	mdelay(100);
 	state = ls_pcie_link_state(pcie);
 	if (state)
 		return state;
@@ -251,6 +262,10 @@ static int ls_pcie_addr_valid(struct pci_controller *hose, pci_dev_t d)
 	if (PCI_DEV(d) > 0)
 		return -EINVAL;
 
+	/* Controller does not support multi-function in RC mode */
+	if ((PCI_BUS(d) == hose->first_busno) && (PCI_FUNC(d) > 0))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -327,8 +342,12 @@ static void ls_pcie_setup_ctrl(struct ls_pcie *pcie,
 	pci_hose_write_config_dword(hose, dev, PCI_BASE_ADDRESS_0, 0);
 
 	/* program correct class for RC */
+	writel(1, pcie->dbi + PCIE_DBI_RO_WR_EN);
 	pci_hose_write_config_word(hose, dev, PCI_CLASS_DEVICE,
 				   PCI_CLASS_BRIDGE_PCI);
+#ifndef CONFIG_LS102XA
+	writel(0, pcie->dbi + PCIE_DBI_RO_WR_EN);
+#endif
 }
 
 int ls_pcie_init_ctrl(int busno, enum srds_prtcl dev, struct ls_pcie_info *info)
@@ -417,9 +436,9 @@ int ls_pcie_init_ctrl(int busno, enum srds_prtcl dev, struct ls_pcie_info *info)
 	}
 
 	/* Print the negotiated PCIe link width */
-	pci_hose_read_config_word(hose, dev, PCIE_LINK_STA, &temp16);
-		printf("x%d gen%d, regs @ 0x%lx\n", (temp16 & 0x3f0) >> 4,
-		       (temp16 & 0xf), info->regs);
+	pci_hose_read_config_word(hose, pdev, PCIE_LINK_STA, &temp16);
+	printf("x%d gen%d, regs @ 0x%lx\n", (temp16 & 0x3f0) >> 4,
+	       (temp16 & 0xf), info->regs);
 
 	if (ep_mode)
 		return busno;
-- 
1.9.1