clk: qcom: gdsc: add support for collapse-vote registers

Recent Qualcomm platforms have APCS collapse-vote registers that allow
for sharing GDSCs with other masters (e.g. LPASS).

Add support for using such vote registers instead of the control
register when updating the GDSC power state.
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220520100948.19622-3-johan+linaro@kernel.org

drivers/clk/qcom/gdsc.c

@@ -137,8 +137,13 @@ static int gdsc_update_collapse_bit(struct gdsc *sc, bool val)
 	u32 reg, mask;
 	int ret;
 
-	reg = sc->gdscr;
-	mask = SW_COLLAPSE_MASK;
+	if (sc->collapse_mask) {
+		reg = sc->collapse_ctrl;
+		mask = sc->collapse_mask;
+	} else {
+		reg = sc->gdscr;
+		mask = SW_COLLAPSE_MASK;
+	}
 
 	ret = regmap_update_bits(sc->regmap, reg, mask, val ? mask : 0);
 	if (ret)

drivers/clk/qcom/gdsc.h

@@ -18,6 +18,8 @@ struct reset_controller_dev;
  * @pd: generic power domain
  * @regmap: regmap for MMIO accesses
  * @gdscr: gsdc control register
+ * @collapse_ctrl: APCS collapse-vote register
+ * @collapse_mask: APCS collapse-vote mask
  * @gds_hw_ctrl: gds_hw_ctrl register
  * @cxcs: offsets of branch registers to toggle mem/periph bits in
  * @cxc_count: number of @cxcs
@@ -35,6 +37,8 @@ struct gdsc {
 	struct generic_pm_domain	*parent;
 	struct regmap			*regmap;
 	unsigned int			gdscr;
+	unsigned int			collapse_ctrl;
+	unsigned int			collapse_mask;
 	unsigned int			gds_hw_ctrl;
 	unsigned int			clamp_io_ctrl;
 	unsigned int			*cxcs;