clk: qcom: clk-rcg: add clk_rcg_floor_ops ops

Add clk_rcg_floor_ops for clock that can't provide a stable freq and
require to use a floor freq to provide the requested frequency.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220226135235.10051-10-ansuelsmth@gmail.com

Author: Ansuel

drivers/clk/qcom/clk-rcg.c

@@ -526,6 +526,19 @@ static int clk_rcg_set_rate(struct clk_hw *hw, unsigned long rate,
 	return __clk_rcg_set_rate(rcg, f);
 }
 
+static int clk_rcg_set_floor_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	struct clk_rcg *rcg = to_clk_rcg(hw);
+	const struct freq_tbl *f;
+
+	f = qcom_find_freq_floor(rcg->freq_tbl, rate);
+	if (!f)
+		return -EINVAL;
+
+	return __clk_rcg_set_rate(rcg, f);
+}
+
 static int clk_rcg_bypass_set_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long parent_rate)
 {
@@ -816,6 +829,17 @@ const struct clk_ops clk_rcg_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_rcg_ops);
 
+const struct clk_ops clk_rcg_floor_ops = {
+	.enable = clk_enable_regmap,
+	.disable = clk_disable_regmap,
+	.get_parent = clk_rcg_get_parent,
+	.set_parent = clk_rcg_set_parent,
+	.recalc_rate = clk_rcg_recalc_rate,
+	.determine_rate = clk_rcg_determine_rate,
+	.set_rate = clk_rcg_set_floor_rate,
+};
+EXPORT_SYMBOL_GPL(clk_rcg_floor_ops);
+
 const struct clk_ops clk_rcg_bypass_ops = {
 	.enable = clk_enable_regmap,
 	.disable = clk_disable_regmap,

drivers/clk/qcom/clk-rcg.h

@@ -86,6 +86,7 @@ struct clk_rcg {
 };
 
 extern const struct clk_ops clk_rcg_ops;
+extern const struct clk_ops clk_rcg_floor_ops;
 extern const struct clk_ops clk_rcg_bypass_ops;
 extern const struct clk_ops clk_rcg_bypass2_ops;
 extern const struct clk_ops clk_rcg_pixel_ops;