i2c: omap: enable traces for debug NACK and AL transfers

[Alexander Kochetkov]

Just for testing. Not for Upstream.

Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx>
---
 drivers/i2c/busses/i2c-omap.c |   29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 9cfadf3..7b62cf1 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -28,6 +28,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define DEBUG 1
+
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
@@ -277,6 +279,22 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
 }
 
+#ifdef DEBUG
+static inline void
+omap_i2c_dump_state(const char *func, int line, struct omap_i2c_dev *dev, const char *msg)
+{
+       dev_dbg(dev->dev, "%s: STAT=0x%04x; IE=0x%04x; CON=0x%04x (%s:%d)\n",
+               msg,
+               omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG),
+               omap_i2c_read_reg(dev, OMAP_I2C_IE_REG),
+               omap_i2c_read_reg(dev, OMAP_I2C_CON_REG),
+               func, line);
+}
+#define OMAP_I2C_DUMP_STATE(dev, msg) omap_i2c_dump_state(__func__, __LINE__, (dev), (msg))
+#else
+#define OMAP_I2C_DUMP_STATE(dev, msg)
+#endif
+
 static void __omap_i2c_init(struct omap_i2c_dev *dev)
 {
 
@@ -563,7 +581,9 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	if (!dev->b_hw && stop)
 		w |= OMAP_I2C_CON_STP;
 
+	OMAP_I2C_DUMP_STATE(dev, "Pre submit");
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
+	OMAP_I2C_DUMP_STATE(dev, "Post submit");
 
 	/*
 	 * Don't write stt and stp together on some hardware.
@@ -592,8 +612,10 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	 * REVISIT: We should abort the transfer on signals, but the bus goes
 	 * into arbitration and we're currently unable to recover from it.
 	 */
+	OMAP_I2C_DUMP_STATE(dev, "Wait comlete");
 	timeout = wait_for_completion_timeout(&dev->cmd_complete,
 						OMAP_I2C_TIMEOUT);
+	OMAP_I2C_DUMP_STATE(dev, "Got comlete");
 	if (timeout == 0) {
 		dev_err(dev->dev, "controller timed out\n");
 		omap_i2c_reset(dev);
@@ -607,6 +629,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	/* We have an error */
 	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
 			    OMAP_I2C_STAT_XUDF)) {
+		OMAP_I2C_DUMP_STATE(dev, "Got AL - i2c reset");
 		omap_i2c_reset(dev);
 		__omap_i2c_init(dev);
 		return -EIO;
@@ -616,6 +639,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 		if (msg->flags & I2C_M_IGNORE_NAK)
 			return 0;
 
+		OMAP_I2C_DUMP_STATE(dev, "Got NACK - send STP");
 		w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
 		w |= OMAP_I2C_CON_STP;
 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
@@ -884,6 +908,8 @@ omap_i2c_isr(int irq, void *dev_id)
 	mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 	stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 
+	OMAP_I2C_DUMP_STATE(dev, "Hard ISR");
+
 	if (stat & mask)
 		ret = IRQ_WAKE_THREAD;
 
@@ -907,6 +933,8 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 		stat &= bits;
 
+		OMAP_I2C_DUMP_STATE(dev, "Thread ISR");
+
 		/* If we're in receiver mode, ignore XDR/XRDY */
 		if (dev->receiver)
 			stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
@@ -1024,6 +1052,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 		}
 	} while (stat);
 
+	OMAP_I2C_DUMP_STATE(dev, "Complete");
 	omap_i2c_complete_cmd(dev, err);
 
 out:
-- 
1.7.9.5--
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