Enable support for printing the LTSSM link state for debugging PCI
when link is down.

Signed-off-by: Faiz Abbas <faiz_ab...@ti.com>
---
v2:
 1. Changed dev_err() to dev_dbg()
 2. Changed static char array to static const char * const
 3. format changes

 drivers/pci/dwc/pci-dra7xx.c | 48 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 34427a6..0e70e77 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -98,6 +98,45 @@ struct dra7xx_pcie_of_data {
 
 #define to_dra7xx_pcie(x)      dev_get_drvdata((x)->dev)
 
+static const char * const state[] = {
+       "DETECT_QUIET",
+       "DETECT_ACT",
+       "POLL_ACTIVE",
+       "POLL_COMPLIANCE",
+       "POLL_CONFIG",
+       "PRE_DETECT_QUIET",
+       "DETECT_WAIT",
+       "CFG_LINKWD_START",
+       "CFG_LINKWD_ACEPT",
+       "CFG_LANENUM_WAIT",
+       "CFG_LANENUM_ACEPT",
+       "CFG_COMPLETE",
+       "CFG_IDLE",
+       "RCVRY_LOCK",
+       "RCVRY_SPEED",
+       "RCVRY_RCVRCFG",
+       "RCVRY_IDLE",
+       "L0",
+       "L0S",
+       "L123_SEND_EIDLE",
+       "L1_IDLE",
+       "L2_IDLE",
+       "L2_WAKE",
+       "DISABLED_ENTRY",
+       "DISABLED_IDLE",
+       "DISABLED",
+       "LPBK_ENTRY",
+       "LPBK_ACTIVE",
+       "LPBK_EXIT",
+       "LPBK_EXIT_TIMEOUT",
+       "HOT_RESET_ENTRY",
+       "HOT_RESET",
+       "RCVRY_EQ0",
+       "RCVRY_EQ1",
+       "RCVRY_EQ2",
+       "RCVRY_EQ3"
+};
+
 static inline u32 dra7xx_pcie_readl(struct dra7xx_pcie *pcie, u32 offset)
 {
        return readl(pcie->base + offset);
@@ -118,6 +157,15 @@ static int dra7xx_pcie_link_up(struct dw_pcie *pci)
 {
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        u32 reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_PHY_CS);
+       u32 cmd_reg;
+       u32 ltssm_state;
+
+       if (!(reg & LINK_UP)) {
+               cmd_reg = dra7xx_pcie_readl(dra7xx,
+                                           PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
+               ltssm_state = (cmd_reg & GENMASK(7, 2)) >> 2;
+               dev_dbg(pci->dev, "Link state:%s\n", state[ltssm_state]);
+       }
 
        return !!(reg & LINK_UP);
 }
-- 
2.7.4

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