linux-kernel - [PATCH 6/6] ASoC: arizona: Add gating for source clocks of the FLLs

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Date:   Fri, 2 Sep 2016 16:52:48 +0100
From:   Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
To:     <lee.jones@...aro.org>, <broonie@...nel.org>
CC:     <lgirdwood@...il.com>, <s.nawrocki@...sung.com>,
        <alsa-devel@...a-project.org>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.wolfsonmicro.com>
Subject: [PATCH 6/6] ASoC: arizona: Add gating for source clocks of the FLLs

Whilst ultimately we would like to move all the clocking over to the
clock framework, as an intermediate step to get people going for now
enable the source clocks for FLLs as they are powered up.

Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
---
 sound/soc/codecs/arizona.c | 60 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 2a019e9..780cf4f 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -2244,6 +2244,42 @@ static int arizona_is_enabled_fll(struct arizona_fll *fll, int base)
 	return reg & ARIZONA_FLL1_ENA;
 }
 
+static int arizona_set_fll_clks(struct arizona_fll *fll, int base, bool ena)
+{
+	struct arizona *arizona = fll->arizona;
+	unsigned int val;
+	struct clk *clk;
+	int ret;
+
+	ret = regmap_read(arizona->regmap, base + 6, &val);
+	if (ret != 0) {
+		arizona_fll_err(fll, "Failed to read current source: %d\n",
+				ret);
+		return ret;
+	}
+
+	val &= ARIZONA_FLL1_CLK_REF_SRC_MASK;
+	val >>= ARIZONA_FLL1_CLK_REF_SRC_SHIFT;
+
+	switch (val) {
+	case ARIZONA_FLL_SRC_MCLK1:
+		clk = arizona->mclk[ARIZONA_MCLK1];
+		break;
+	case ARIZONA_FLL_SRC_MCLK2:
+		clk = arizona->mclk[ARIZONA_MCLK2];
+		break;
+	default:
+		return 0;
+	}
+
+	if (ena) {
+		return clk_prepare_enable(clk);
+	} else {
+		clk_disable_unprepare(clk);
+		return 0;
+	}
+}
+
 static int arizona_enable_fll(struct arizona_fll *fll)
 {
 	struct arizona *arizona = fll->arizona;
@@ -2266,6 +2302,10 @@ static int arizona_enable_fll(struct arizona_fll *fll)
 		udelay(32);
 		regmap_update_bits_async(fll->arizona->regmap, fll->base + 0x9,
 					 ARIZONA_FLL1_GAIN_MASK, 0);
+
+		if (arizona_is_enabled_fll(fll, fll->base + 0x10) > 0)
+			arizona_set_fll_clks(fll, fll->base + 0x10, false);
+		arizona_set_fll_clks(fll, fll->base, false);
 	}
 
 	/*
@@ -2320,10 +2360,13 @@ static int arizona_enable_fll(struct arizona_fll *fll)
 	if (!already_enabled)
 		pm_runtime_get_sync(arizona->dev);
 
-	if (use_sync)
+	if (use_sync) {
+		arizona_set_fll_clks(fll, fll->base + 0x10, true);
 		regmap_update_bits_async(arizona->regmap, fll->base + 0x11,
 					 ARIZONA_FLL1_SYNC_ENA,
 					 ARIZONA_FLL1_SYNC_ENA);
+	}
+	arizona_set_fll_clks(fll, fll->base, true);
 	regmap_update_bits_async(arizona->regmap, fll->base + 1,
 				 ARIZONA_FLL1_ENA, ARIZONA_FLL1_ENA);
 
@@ -2356,19 +2399,24 @@ static int arizona_enable_fll(struct arizona_fll *fll)
 static void arizona_disable_fll(struct arizona_fll *fll)
 {
 	struct arizona *arizona = fll->arizona;
-	bool change;
+	bool ref_change, sync_change;
 
 	regmap_update_bits_async(arizona->regmap, fll->base + 1,
 				 ARIZONA_FLL1_FREERUN, ARIZONA_FLL1_FREERUN);
 	regmap_update_bits_check(arizona->regmap, fll->base + 1,
-				 ARIZONA_FLL1_ENA, 0, &change);
-	regmap_update_bits(arizona->regmap, fll->base + 0x11,
-			   ARIZONA_FLL1_SYNC_ENA, 0);
+				 ARIZONA_FLL1_ENA, 0, &ref_change);
+	regmap_update_bits_check(arizona->regmap, fll->base + 0x11,
+				 ARIZONA_FLL1_SYNC_ENA, 0, &sync_change);
 	regmap_update_bits_async(arizona->regmap, fll->base + 1,
 				 ARIZONA_FLL1_FREERUN, 0);
 
-	if (change)
+	if (sync_change)
+		arizona_set_fll_clks(fll, fll->base + 0x10, false);
+
+	if (ref_change) {
+		arizona_set_fll_clks(fll, fll->base, false);
 		pm_runtime_put_autosuspend(arizona->dev);
+	}
 }
 
 int arizona_set_fll_refclk(struct arizona_fll *fll, int source,
-- 
2.1.4