i2c: designware: Add debug print for SDA hold time value

SDA hold time is an important timing parameter and often reason for
arbitration lost errors if not set to a correct value. Add a debug print
for it in order to see what value gets programmed to a HW.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 6f1c773..bcc1bcb 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -210,6 +210,10 @@ int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
                 */
                if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
                        dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
+
+               dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n",
+                       dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK,
+                       dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT);
        } else if (dev->sda_hold_time) {
                dev_warn(dev->dev,
                        "Hardware too old to adjust SDA hold time.\n");