From: Rajesh Gumasta <rguma...@nvidia.com>

Dump I2C regsiters for debug when transfer timeout occurs.

Signed-off-by: Rajesh Gumasta <rguma...@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlaga...@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 77198fc..cdc8664 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -126,6 +126,8 @@
 #define  I2C_HS_INTERFACE_TIMING_THD_STA       GENMASK(13, 8)
 #define  I2C_HS_INTERFACE_TIMING_TSU_STA       GENMASK(5, 0)
 
+#define I2C_MST_PACKET_TRANSFER_CNT_STATUS     0x0b0
+
 #define I2C_MST_FIFO_CONTROL                   0x0b4
 #define I2C_MST_FIFO_CONTROL_RX_FLUSH          BIT(0)
 #define I2C_MST_FIFO_CONTROL_TX_FLUSH          BIT(1)
@@ -1178,6 +1180,33 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter 
*adap)
        return -EAGAIN;
 }
 
+static void tegra_i2c_reg_dump(struct tegra_i2c_dev *i2c_dev)
+{
+       dev_dbg(i2c_dev->dev, "--- register dump for debugging ----\n");
+       dev_dbg(i2c_dev->dev, "I2C_CNFG - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_CNFG));
+       dev_dbg(i2c_dev->dev, "I2C_PACKET_TRANSFER_STATUS - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS));
+       dev_dbg(i2c_dev->dev, "I2C_FIFO_CONTROL - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_FIFO_CONTROL));
+       dev_dbg(i2c_dev->dev, "I2C_FIFO_STATUS - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_FIFO_STATUS));
+
+       if (i2c_dev->hw->has_mst_fifo) {
+               dev_dbg(i2c_dev->dev, "I2C_MST_FIFO_CONTROL - 0x%x\n",
+                       i2c_readl(i2c_dev, I2C_MST_FIFO_CONTROL));
+               dev_dbg(i2c_dev->dev, "I2C_MST_FIFO_STATUS - 0x%x\n",
+                       i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS));
+               dev_dbg(i2c_dev->dev, "I2C_MST_PACKET_TRANSFER_CNT - 0x%x\n",
+                       i2c_readl(i2c_dev,
+                                 I2C_MST_PACKET_TRANSFER_CNT_STATUS));
+       }
+       dev_dbg(i2c_dev->dev, "I2C_INT_MASK - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_INT_MASK));
+       dev_dbg(i2c_dev->dev, "I2C_INT_STATUS - 0x%x\n",
+               i2c_readl(i2c_dev, I2C_INT_STATUS));
+}
+
 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
                              struct i2c_msg *msg,
                              enum msg_end_type end_state)
@@ -1331,6 +1360,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev 
*i2c_dev,
 
                if (!time_left && !completion_done(&i2c_dev->dma_complete)) {
                        dev_err(i2c_dev->dev, "DMA transfer timeout\n");
+                       tegra_i2c_reg_dump(i2c_dev);
                        tegra_i2c_init(i2c_dev, true);
                        return -ETIMEDOUT;
                }
@@ -1352,6 +1382,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev 
*i2c_dev,
 
        if (time_left == 0) {
                dev_err(i2c_dev->dev, "i2c transfer timed out\n");
+               tegra_i2c_reg_dump(i2c_dev);
                tegra_i2c_init(i2c_dev, true);
                return -ETIMEDOUT;
        }
-- 
2.7.4

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