clk: renesas: rzg2l: Wait for status bit of SD mux before continuing

The hardware user manual for RZ/G2L (r01uh0914ej0130-rzg2l-rzg2lc.pdf,
chapter 7.4.7 Procedure for Switching Clocks by the Dynamic Switching
Frequency Selectors) specifies that we need to check CPG_PL2SDHI_DSEL
for SD clock switching status.

Fixes: eaff336 ("clk: renesas: rzg2l: Add SDHI clk mux support")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230929053915.1530607-3-claudiu.beznea@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: claudiubeznea

drivers/clk/renesas/rzg2l-cpg.c

@@ -188,7 +188,8 @@ static int rzg2l_cpg_sd_clk_mux_set_parent(struct clk_hw *hw, u8 index)
 	u32 off = GET_REG_OFFSET(hwdata->conf);
 	u32 shift = GET_SHIFT(hwdata->conf);
 	const u32 clk_src_266 = 2;
-	u32 bitmask;
+	u32 msk, val, bitmask;
+	int ret;
 
 	/*
 	 * As per the HW manual, we should not directly switch from 533 MHz to
@@ -202,14 +203,10 @@ static int rzg2l_cpg_sd_clk_mux_set_parent(struct clk_hw *hw, u8 index)
 	 * the index to value mapping is done by adding 1 to the index.
 	 */
 	bitmask = (GENMASK(GET_WIDTH(hwdata->conf) - 1, 0) << shift) << 16;
+	msk = off ? CPG_CLKSTATUS_SELSDHI1_STS : CPG_CLKSTATUS_SELSDHI0_STS;
 	if (index != clk_src_266) {
-		u32 msk, val;
-		int ret;
-
 		writel(bitmask | ((clk_src_266 + 1) << shift), priv->base + off);
 
-		msk = off ? CPG_CLKSTATUS_SELSDHI1_STS : CPG_CLKSTATUS_SELSDHI0_STS;
-
 		ret = readl_poll_timeout(priv->base + CPG_CLKSTATUS, val,
 					 !(val & msk), 100,
 					 CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US);
@@ -221,7 +218,13 @@ static int rzg2l_cpg_sd_clk_mux_set_parent(struct clk_hw *hw, u8 index)
 
 	writel(bitmask | ((index + 1) << shift), priv->base + off);
 
-	return 0;
+	ret = readl_poll_timeout(priv->base + CPG_CLKSTATUS, val,
+				 !(val & msk), 100,
+				 CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US);
+	if (ret)
+		dev_err(priv->dev, "failed to switch clk source\n");
+
+	return ret;
 }
 
 static u8 rzg2l_cpg_sd_clk_mux_get_parent(struct clk_hw *hw)