clk: renesas: rzg2l: Trust value returned by hardware

The onitial value of the CPG_PL2SDHI_DSEL bits 0..1 or 4..6 is 01b.  The
hardware user's manual (r01uh0914ej0130-rzg2l-rzg2lc.pdf) specifies that
setting 0 is prohibited.  Hence rzg2l_cpg_sd_clk_mux_get_parent() should
just read CPG_PL2SDHI_DSEL, trust the value, and return the proper clock
parent index based on the value read.

Fixes: eaff336 ("clk: renesas: rzg2l: Add SDHI clk mux support")
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Geert Uytterhoeven <[email protected]>

Author: claudiubeznea

drivers/clk/renesas/rzg2l-cpg.c

@@ -238,14 +238,8 @@ static u8 rzg2l_cpg_sd_clk_mux_get_parent(struct clk_hw *hw)
 
 	val >>= GET_SHIFT(hwdata->conf);
 	val &= GENMASK(GET_WIDTH(hwdata->conf) - 1, 0);
-	if (val) {
-		val--;
-	} else {
-		/* Prohibited clk source, change it to 533 MHz(reset value) */
-		rzg2l_cpg_sd_clk_mux_set_parent(hw, 0);
-	}
 
-	return val;
+	return val ? val - 1 : 0;
 }
 
 static const struct clk_ops rzg2l_cpg_sd_clk_mux_ops = {