i2c: mediatek: Dump i2c/dma register when a timeout occurs

When a timeout error occurs in i2c transter, it is usually related
to the i2c/dma IP hardware configuration. Therefore, the purpose of
this patch is to dump the key register values of i2c/dma when a
timeout occurs in i2c for debugging.

Signed-off-by: Kewei Xu <[email protected]>
Reviewed-by: Qii Wang <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

Author: Kewei Xu

drivers/i2c/busses/i2c-mt65xx.c

@@ -130,6 +130,7 @@ enum I2C_REGS_OFFSET {
 	OFFSET_HS,
 	OFFSET_SOFTRESET,
 	OFFSET_DCM_EN,
+	OFFSET_MULTI_DMA,
 	OFFSET_PATH_DIR,
 	OFFSET_DEBUGSTAT,
 	OFFSET_DEBUGCTRL,
@@ -197,6 +198,7 @@ static const u16 mt_i2c_regs_v2[] = {
 	[OFFSET_TRANSFER_LEN_AUX] = 0x44,
 	[OFFSET_CLOCK_DIV] = 0x48,
 	[OFFSET_SOFTRESET] = 0x50,
+	[OFFSET_MULTI_DMA] = 0x8c,
 	[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
 	[OFFSET_DEBUGSTAT] = 0xe4,
 	[OFFSET_DEBUGCTRL] = 0xe8,
@@ -845,6 +847,57 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 	return 0;
 }
 
+static void i2c_dump_register(struct mtk_i2c *i2c)
+{
+	dev_dbg(i2c->dev, "SLAVE_ADDR: 0x%x, INTR_MASK: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_SLAVE_ADDR),
+		mtk_i2c_readw(i2c, OFFSET_INTR_MASK));
+	dev_dbg(i2c->dev, "INTR_STAT: 0x%x, CONTROL: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_INTR_STAT),
+		mtk_i2c_readw(i2c, OFFSET_CONTROL));
+	dev_dbg(i2c->dev, "TRANSFER_LEN: 0x%x, TRANSAC_LEN: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN),
+		mtk_i2c_readw(i2c, OFFSET_TRANSAC_LEN));
+	dev_dbg(i2c->dev, "DELAY_LEN: 0x%x, HTIMING: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DELAY_LEN),
+		mtk_i2c_readw(i2c, OFFSET_TIMING));
+	dev_dbg(i2c->dev, "START: 0x%x, EXT_CONF: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_START),
+		mtk_i2c_readw(i2c, OFFSET_EXT_CONF));
+	dev_dbg(i2c->dev, "HS: 0x%x, IO_CONFIG: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_HS),
+		mtk_i2c_readw(i2c, OFFSET_IO_CONFIG));
+	dev_dbg(i2c->dev, "DCM_EN: 0x%x, TRANSFER_LEN_AUX: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DCM_EN),
+		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN_AUX));
+	dev_dbg(i2c->dev, "CLOCK_DIV: 0x%x, FIFO_STAT: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_CLOCK_DIV),
+		mtk_i2c_readw(i2c, OFFSET_FIFO_STAT));
+	dev_dbg(i2c->dev, "DEBUGCTRL : 0x%x, DEBUGSTAT: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DEBUGCTRL),
+		mtk_i2c_readw(i2c, OFFSET_DEBUGSTAT));
+	if (i2c->dev_comp->regs == mt_i2c_regs_v2) {
+		dev_dbg(i2c->dev, "LTIMING: 0x%x, MULTI_DMA: 0x%x\n",
+			mtk_i2c_readw(i2c, OFFSET_LTIMING),
+			mtk_i2c_readw(i2c, OFFSET_MULTI_DMA));
+	}
+	dev_dbg(i2c->dev, "\nDMA_INT_FLAG: 0x%x, DMA_INT_EN: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_INT_FLAG),
+		readl(i2c->pdmabase + OFFSET_INT_EN));
+	dev_dbg(i2c->dev, "DMA_EN: 0x%x, DMA_CON: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_EN),
+		readl(i2c->pdmabase + OFFSET_CON));
+	dev_dbg(i2c->dev, "DMA_TX_MEM_ADDR: 0x%x, DMA_RX_MEM_ADDR: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_TX_MEM_ADDR),
+		readl(i2c->pdmabase + OFFSET_RX_MEM_ADDR));
+	dev_dbg(i2c->dev, "DMA_TX_LEN: 0x%x, DMA_RX_LEN: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_TX_LEN),
+		readl(i2c->pdmabase + OFFSET_RX_LEN));
+	dev_dbg(i2c->dev, "DMA_TX_4G_MODE: 0x%x, DMA_RX_4G_MODE: 0x%x",
+		readl(i2c->pdmabase + OFFSET_TX_4G_MODE),
+		readl(i2c->pdmabase + OFFSET_RX_4G_MODE));
+}
+
 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 			       int num, int left_num)
 {
@@ -1075,6 +1128,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 
 	if (ret == 0) {
 		dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+		i2c_dump_register(i2c);
 		mtk_i2c_init_hw(i2c);
 		return -ETIMEDOUT;
 	}