i2c: designware: Move SDA hold time configuration to common code

SDA hold time configuration is common to both master and slave code. It
is also something that can be done once during probe and do only
register write when HW needs to be reinitialized.

Remove duplication and move SDA hold time configuration to common code.
It will be called from slave probe and for master code from a new
i2c_dw_set_timings_master() to where we will populate more probe time
timing parameter setting.

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>

1 files changed, 6 insertions, 21 deletions

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index a1f802001e1f..8af4c978938e 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -51,7 +51,6 @@ static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
  */
 static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 {
-	u32 reg;
 	int ret;
 
 	ret = i2c_dw_acquire_lock(dev);
@@ -61,27 +60,9 @@ static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 	/* Disable the adapter. */
 	__i2c_dw_disable(dev);
 
-	/* Configure SDA Hold Time if required. */
-	reg = dw_readl(dev, DW_IC_COMP_VERSION);
-	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
-		if (!dev->sda_hold_time) {
-			/* Keep previous hold time setting if no one set it. */
-			dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
-		}
-		/*
-		 * Workaround for avoiding TX arbitration lost in case I2C
-		 * slave pulls SDA down "too quickly" after falling egde of
-		 * SCL by enabling non-zero SDA RX hold. Specification says it
-		 * extends incoming SDA low to high transition while SCL is
-		 * high but it apprears to help also above issue.
-		 */
-		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
-			dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
+	/* Write SDA hold time if supported */
+	if (dev->sda_hold_time)
 		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
-	} else {
-		dev_warn(dev->dev,
-			 "Hardware too old to adjust SDA hold time.\n");
-	}
 
 	i2c_dw_configure_fifo_slave(dev);
 	i2c_dw_release_lock(dev);
@@ -287,6 +268,10 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
+	ret = i2c_dw_set_sda_hold(dev);
+	if (ret)
+		return ret;
+
 	ret = dev->init(dev);
 	if (ret)
 		return ret;