i2c: mvtwsi: Add support for DM clocks and resets

The controller may need to have clocks/resets enabled for it to work.
Add support for this. Since the clocks/resets are optional on some
platforms (per the device tree binding), do not prevent probing the
controller if they are missing.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c
index d33e2c7..236bfb8 100644
--- a/drivers/i2c/mvtwsi.c
+++ b/drivers/i2c/mvtwsi.c
@@ -17,7 +17,9 @@
 #include <linux/bitops.h>
 #include <linux/compat.h>
 #if CONFIG_IS_ENABLED(DM_I2C)
+#include <clk.h>
 #include <dm.h>
+#include <reset.h>
 #endif
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -835,7 +837,18 @@
 static int mvtwsi_i2c_probe(struct udevice *bus)
 {
 	struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
+	struct reset_ctl reset;
+	struct clk clk;
 	uint actual_speed;
+	int ret;
+
+	ret = reset_get_by_index(bus, 0, &reset);
+	if (!ret)
+		reset_deassert(&reset);
+
+	ret = clk_get_by_index(bus, 0, &clk);
+	if (!ret)
+		clk_enable(&clk);
 
 	__twsi_i2c_init(dev->base, dev->speed, dev->slaveadd, &actual_speed);
 	dev->speed = actual_speed;