clk: si5341: fix reported clk_rate when output divider is 2

SI5341_OUT_CFG_RDIV_FORCE2 shall be checked first to distinguish whether
a divider for a given output is set to 2 (SI5341_OUT_CFG_RDIV_FORCE2
is set) or the output is disabled (SI5341_OUT_CFG_RDIV_FORCE2 not set,
SI5341_OUT_R_REG is set 0).
Before the change, divider set to 2 (SI5341_OUT_R_REG set to 0) was
interpreted as output is disabled.

Signed-off-by: Adam Wujek <dev_public@wujek.eu>
Link: https://lore.kernel.org/r/20211203141125.2447520-1-dev_public@wujek.eu
Reviewed-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: awujek

drivers/clk/clk-si5341.c

@@ -798,6 +798,15 @@ static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
 	u32 r_divider;
 	u8 r[3];
 
+	err = regmap_read(output->data->regmap,
+			SI5341_OUT_CONFIG(output), &val);
+	if (err < 0)
+		return err;
+
+	/* If SI5341_OUT_CFG_RDIV_FORCE2 is set, r_divider is 2 */
+	if (val & SI5341_OUT_CFG_RDIV_FORCE2)
+		return parent_rate / 2;
+
 	err = regmap_bulk_read(output->data->regmap,
 			SI5341_OUT_R_REG(output), r, 3);
 	if (err < 0)
@@ -814,13 +823,6 @@ static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
 	r_divider += 1;
 	r_divider <<= 1;
 
-	err = regmap_read(output->data->regmap,
-			SI5341_OUT_CONFIG(output), &val);
-	if (err < 0)
-		return err;
-
-	if (val & SI5341_OUT_CFG_RDIV_FORCE2)
-		r_divider = 2;
 
 	return parent_rate / r_divider;
 }