Add a property to allow specifying that the external I2C IO pins are using
3.3V voltage thresholds rather than 1.8V.

Signed-off-by: Robert Hancock <redacted>
---
  drivers/clk/clk-si5341.c | 10 +++++++++-
  1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index 11740855bcde..4cd80ef389d2 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c

@@ -81,6 +81,7 @@ struct clk_si5341 {
  	u8 num_synth;
  	u16 chip_id;
  	bool xaxb_ext_clk;
+	bool iovdd_33;
  };
  #define to_clk_si5341(_hw)	container_of(_hw, struct clk_si5341, hw)
  

@@ -103,6 +104,7 @@ struct clk_si5341_output_config {
  #define SI5341_IN_SEL		0x0021
  #define SI5341_DEVICE_READY	0x00FE
  #define SI5341_XAXB_CFG		0x090E
+#define SI5341_IO_VDD_SEL	0x0943
  #define SI5341_IN_EN		0x0949
  #define SI5341_INX_TO_PFD_EN	0x094A
  

@@ -351,7 +353,6 @@ static const struct si5341_reg_default si5341_reg_defaults[] = {
  	{ 0x0804, 0x00 }, /* Not in datasheet */
  	{ 0x090E, 0x02 }, /* XAXB_EXTCLK_EN=0 XAXB_PDNB=1 (use XTAL) */
  	{ 0x091C, 0x04 }, /* ZDM_EN=4 (Normal mode) */
-	{ 0x0943, 0x00 }, /* IO_VDD_SEL=0 (0=1v8, use 1=3v3) */
  	{ 0x0949, 0x00 }, /* IN_EN (disable input clocks) */
  	{ 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */
  	{ 0x0A02, 0x00 }, /* Not in datasheet */

@@ -1160,6 +1161,11 @@ static int si5341_finalize_defaults(struct clk_si5341 *data)
  	int res;
  	u32 revision;
  
+	res = regmap_write(data->regmap, SI5341_IO_VDD_SEL,
+			   data->iovdd_33 ? 1 : 0);
+	if (res < 0)
+		return res;
+
  	res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
  	if (res < 0)
  		return res;

@@ -1565,6 +1571,8 @@ static int si5341_probe(struct i2c_client *client,
  	}
  	data->xaxb_ext_clk = of_property_read_bool(client->dev.of_node,
  						   "silabs,xaxb-ext-clk");
+	data->iovdd_33 = of_property_read_bool(client->dev.of_node,
+					       "silabs,iovdd-33");