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: eaff33646f4cb ("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/20230929053915.1530607-5-claudiu.beznea@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index 0679f2c7649e609573732297101d8477dbb6fb64..6f50f0329ecf234c5a4d4a5e81a1701dcf9f8b80 100644 (file)
--- a/drivers/clk/renesas/rzg2l-cpg.c
+++ b/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 = {