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, 3 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index d42558d1b002..8ce2cd368477 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -75,7 +75,7 @@ static int i2c_dw_init_slave(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);
 
 	/* Configure SDA Hold Time if required. */
 	reg = dw_readl(dev, DW_IC_COMP_VERSION);
@@ -119,11 +119,11 @@ static int i2c_dw_reg_slave(struct i2c_client *slave)
 	 * Set slave address in the IC_SAR register,
 	 * the address to which the DW_apb_i2c responds.
 	 */
-	__i2c_dw_enable(dev, false);
+	__i2c_dw_disable_nowait(dev);
 	dw_writel(dev, slave->addr, DW_IC_SAR);
 	dev->slave = slave;
 
-	__i2c_dw_enable(dev, true);
+	__i2c_dw_enable(dev);
 
 	dev->cmd_err = 0;
 	dev->msg_write_idx = 0;