[PATCH] clk: qcom: Support bypass RCG configuration

[Stephen Boyd]

In the case of HDMI clocks, we want to bypass the RCG's ability
to divide the output clock and pass through the parent HDMI PLL
rate through. Add a simple set of clk_ops to configure the RCG to
do this. This removes the need to keep adding more frequency
entries to the tv_src clock whenever we want to support a new
rate.

Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
---

On 07/11, Rob Clark wrote:
> It would probably be better to get rid of the fixed table, which
> duplicates the set of fixed frequences in the hdmi pll clk (in
> drm/msm/hdmi).  But I'll leave that as an exercise for someone
> who knows the clk driver better than myself.  Until then, this
> trivial fix is useful.

Here's a quick attempt at that. Let me know if this works.

 drivers/clk/qcom/clk-rcg.c      | 51 +++++++++++++++++++++++++++++++++++------
 drivers/clk/qcom/clk-rcg.h      |  1 +
 drivers/clk/qcom/mmcc-msm8960.c |  9 ++------
 3 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/qcom/clk-rcg.c b/drivers/clk/qcom/clk-rcg.c
index abfc2b675aea..b638c5846dbf 100644
--- a/drivers/clk/qcom/clk-rcg.c
+++ b/drivers/clk/qcom/clk-rcg.c
@@ -417,20 +417,25 @@ static long clk_dyn_rcg_determine_rate(struct clk_hw *hw, unsigned long rate,
 	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
 }
 
-static int clk_rcg_set_rate(struct clk_hw *hw, unsigned long rate,
-			    unsigned long parent_rate)
+static long clk_rcg_bypass_determine_rate(struct clk_hw *hw, unsigned long rate,
+		unsigned long *p_rate, struct clk **p)
 {
 	struct clk_rcg *rcg = to_clk_rcg(hw);
-	const struct freq_tbl *f;
+	const struct freq_tbl *f = rcg->freq_tbl;
+
+	*p = clk_get_parent_by_index(hw->clk, f->src);
+	*p_rate = __clk_round_rate(*p, rate);
+
+	return *p_rate;
+}
+
+static int __clk_rcg_set_rate(struct clk_rcg *rcg, const struct freq_tbl *f)
+{
 	u32 ns, md, ctl;
 	struct mn *mn = &rcg->mn;
 	u32 mask = 0;
 	unsigned int reset_reg;
 
-	f = find_freq(rcg->freq_tbl, rate);
-	if (!f)
-		return -EINVAL;
-
 	if (rcg->mn.reset_in_cc)
 		reset_reg = rcg->clkr.enable_reg;
 	else
@@ -466,6 +471,27 @@ static int clk_rcg_set_rate(struct clk_hw *hw, unsigned long rate,
 	return 0;
 }
 
+static int clk_rcg_set_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 = find_freq(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)
+{
+	struct clk_rcg *rcg = to_clk_rcg(hw);
+
+	return __clk_rcg_set_rate(rcg, rcg->freq_tbl);
+}
+
 static int __clk_dyn_rcg_set_rate(struct clk_hw *hw, unsigned long rate)
 {
 	struct clk_dyn_rcg *rcg = to_clk_dyn_rcg(hw);
@@ -503,6 +529,17 @@ const struct clk_ops clk_rcg_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_rcg_ops);
 
+const struct clk_ops clk_rcg_bypass_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_bypass_determine_rate,
+	.set_rate = clk_rcg_bypass_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_rcg_bypass_ops);
+
 const struct clk_ops clk_dyn_rcg_ops = {
 	.enable = clk_enable_regmap,
 	.is_enabled = clk_is_enabled_regmap,
diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index b9ec11dfd1b4..ba0523cefd2e 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/drivers/clk/qcom/clk-rcg.h
@@ -95,6 +95,7 @@ struct clk_rcg {
 };
 
 extern const struct clk_ops clk_rcg_ops;
+extern const struct clk_ops clk_rcg_bypass_ops;
 
 #define to_clk_rcg(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg, clkr)
 
diff --git a/drivers/clk/qcom/mmcc-msm8960.c b/drivers/clk/qcom/mmcc-msm8960.c
index 12f3c0b64fcd..14eeeba005f3 100644
--- a/drivers/clk/qcom/mmcc-msm8960.c
+++ b/drivers/clk/qcom/mmcc-msm8960.c
@@ -1218,12 +1218,7 @@ static const char *mmcc_pxo_hdmi[] = {
 };
 
 static struct freq_tbl clk_tbl_tv[] = {
-	{  25200000, P_HDMI_PLL, 1, 0, 0 },
-	{  27000000, P_HDMI_PLL, 1, 0, 0 },
-	{  27030000, P_HDMI_PLL, 1, 0, 0 },
-	{  74250000, P_HDMI_PLL, 1, 0, 0 },
-	{ 108000000, P_HDMI_PLL, 1, 0, 0 },
-	{ 148500000, P_HDMI_PLL, 1, 0, 0 },
+	{  .src = P_HDMI_PLL, .pre_div = 1 },
 	{ }
 };
 
@@ -1254,7 +1249,7 @@ static struct clk_rcg tv_src = {
 			.name = "tv_src",
 			.parent_names = mmcc_pxo_hdmi,
 			.num_parents = 2,
-			.ops = &clk_rcg_ops,
+			.ops = &clk_rcg_bypass_ops,
 			.flags = CLK_SET_RATE_PARENT,
 		},
 	},
-- 
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