i2c: designware: move i2c_dw_plat_prepare_clk to common

Move the i2c_dw_plat_prepare_clk funciton to common file in preparation
for its use also by the master driver.
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-designware-common.c

@@ -21,6 +21,7 @@
  * ----------------------------------------------------------------------------
  *
  */
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/errno.h>
@@ -185,6 +186,18 @@ unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
 	return dev->get_clk_rate_khz(dev);
 }
 
+int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
+{
+	if (IS_ERR(i_dev->clk))
+		return PTR_ERR(i_dev->clk);
+
+	if (prepare)
+		return clk_prepare_enable(i_dev->clk);
+
+	clk_disable_unprepare(i_dev->clk);
+	return 0;
+}
+
 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
 {
 	int ret;

drivers/i2c/busses/i2c-designware-core.h

@@ -301,6 +301,7 @@ u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
 void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable);
 void __i2c_dw_enable_and_wait(struct dw_i2c_dev *dev, bool enable);
 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
+int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare);
 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
 void i2c_dw_release_lock(struct dw_i2c_dev *dev);
 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);

drivers/i2c/busses/i2c-designware-platdrv.c

@@ -203,18 +203,6 @@ static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
 	dev->mode = DW_IC_SLAVE;
 }
 
-static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
-{
-	if (IS_ERR(i_dev->clk))
-		return PTR_ERR(i_dev->clk);
-
-	if (prepare)
-		return clk_prepare_enable(i_dev->clk);
-
-	clk_disable_unprepare(i_dev->clk);
-	return 0;
-}
-
 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 {
 	u32 param, tx_fifo_depth, rx_fifo_depth;