clk: mediatek: make dpi0_sel propagate rate changes

This mux is supposed to select a fitting divider after the PLL
is already set to the correct rate.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: James Liao <jamesjj.liao@mediatek.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/mediatek/clk-mt8173.c

@@ -558,7 +558,11 @@ static const struct mtk_composite top_muxes[] __initconst = {
 	MUX_GATE(CLK_TOP_ATB_SEL, "atb_sel", atb_parents, 0x0090, 16, 2, 23),
 	MUX_GATE(CLK_TOP_VENC_LT_SEL, "venclt_sel", venc_lt_parents, 0x0090, 24, 4, 31),
 	/* CLK_CFG_6 */
-	MUX_GATE(CLK_TOP_DPI0_SEL, "dpi0_sel", dpi0_parents, 0x00a0, 0, 3, 7),
+	/*
+	 * The dpi0_sel clock should not propagate rate changes to its parent
+	 * clock so the dpi driver can have full control over PLL and divider.
+	 */
+	MUX_GATE_FLAGS(CLK_TOP_DPI0_SEL, "dpi0_sel", dpi0_parents, 0x00a0, 0, 3, 7, 0),
 	MUX_GATE(CLK_TOP_IRDA_SEL, "irda_sel", irda_parents, 0x00a0, 8, 2, 15),
 	MUX_GATE(CLK_TOP_CCI400_SEL, "cci400_sel", cci400_parents, 0x00a0, 16, 3, 23),
 	MUX_GATE(CLK_TOP_AUD_1_SEL, "aud_1_sel", aud_1_parents, 0x00a0, 24, 2, 31),

drivers/clk/mediatek/clk-mtk.h

@@ -83,7 +83,11 @@ struct mtk_composite {
 	signed char num_parents;
 };
 
-#define MUX_GATE(_id, _name, _parents, _reg, _shift, _width, _gate) {	\
+/*
+ * In case the rate change propagation to parent clocks is undesirable,
+ * this macro allows to specify the clock flags manually.
+ */
+#define MUX_GATE_FLAGS(_id, _name, _parents, _reg, _shift, _width, _gate, _flags) {	\
 		.id = _id,						\
 		.name = _name,						\
 		.mux_reg = _reg,					\
@@ -94,9 +98,16 @@ struct mtk_composite {
 		.divider_shift = -1,					\
 		.parent_names = _parents,				\
 		.num_parents = ARRAY_SIZE(_parents),			\
-		.flags = CLK_SET_RATE_PARENT,				\
+		.flags = _flags,					\
 	}
 
+/*
+ * Unless necessary, all MUX_GATE clocks propagate rate changes to their
+ * parent clock by default.
+ */
+#define MUX_GATE(_id, _name, _parents, _reg, _shift, _width, _gate)	\
+	MUX_GATE_FLAGS(_id, _name, _parents, _reg, _shift, _width, _gate, CLK_SET_RATE_PARENT)
+
 #define MUX(_id, _name, _parents, _reg, _shift, _width) {		\
 		.id = _id,						\
 		.name = _name,						\