i2c: designware: refactor low-level enable/disable

Low-level controller enable function __i2c_dw_enable is overloaded to
also handle disabling. What's worse, even though the documentation
requires polling the IC_ENABLE_STATUS register when disabling, this
is not done: polling needs to be requested specifically by calling
__i2c_dw_enable_and_wait, which can also poll on enabling, but that
doesn't work if the IC_ENABLE_STATUS register is not implemented.
This is quite confusing if not in fact backwards.

Especially since the documentation says that disabling should be
followed by polling, the driver should be using a separate function
where it does one-shot disables to make the optimization stand out.

This refactors the two functions so that requested status is given
in the name rather than in a boolean argument. Specifically:

 - __i2c_dw_enable: enable without polling (in accordance with docs)
 - __i2c_dw_disable: disable and do poll (also as suggested by docs)
 - __i2c_dw_disable_nowait: disable without polling (Linux-specific)

No functional change.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: fixed blank lines in header file]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 0cdba29ae0a9..27436a937492 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -81,7 +81,7 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
 
 	/* Disable the adapter */
-	__i2c_dw_enable_and_wait(dev, false);
+	__i2c_dw_disable(dev);
 
 	/* Set standard and fast speed deviders for high/low periods */
 
@@ -180,7 +180,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 	u32 ic_con, ic_tar = 0;
 
 	/* Disable the adapter */
-	__i2c_dw_enable_and_wait(dev, false);
+	__i2c_dw_disable(dev);
 
 	/* If the slave address is ten bit address, enable 10BITADDR */
 	ic_con = dw_readl(dev, DW_IC_CON);
@@ -209,7 +209,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 	i2c_dw_disable_int(dev);
 
 	/* Enable the adapter */
-	__i2c_dw_enable(dev, true);
+	__i2c_dw_enable(dev);
 
 	/* Dummy read to avoid the register getting stuck on Bay Trail */
 	dw_readl(dev, DW_IC_ENABLE_STATUS);
@@ -462,7 +462,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	 * additional interrupts are a hardware bug or this driver doesn't
 	 * handle them correctly yet.
 	 */
-	__i2c_dw_enable(dev, false);
+	__i2c_dw_disable_nowait(dev);
 
 	if (dev->msg_err) {
 		ret = dev->msg_err;