[PATCH] clk: sunxi-ng: v3s: add support for variable rate audio pll output

* [PATCH] clk: sunxi-ng: v3s: add support for variable rate audio pll output
@ 2021-02-12 13:57 ` Tobias Schramm
  0 siblings, 0 replies; 18+ messages in thread
From: Tobias Schramm @ 2021-02-12 13:57 UTC (permalink / raw)
  To: Michael Turquette, Stephen Boyd, Icenowy Zheng
  Cc: Maxime Ripard, Chen-Yu Tsai, Jernej Skrabec, linux-clk,
	linux-arm-kernel, linux-kernel, Tobias Schramm

Previously the variable rate audio pll output was fixed to a divider of
four. This is unfortunately incompatible with generating commonly used
I2S core clock rates like 24.576MHz from the 24MHz parent clock.
This commit adds support for arbitrary audio pll output dividers to fix
that.

Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
---
 drivers/clk/sunxi-ng/ccu-sun8i-v3s.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-v3s.c b/drivers/clk/sunxi-ng/ccu-sun8i-v3s.c
index 0e36ca3bf3d5..c6cf590b235a 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-v3s.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-v3s.c
@@ -36,12 +36,9 @@ static SUNXI_CCU_NKMP_WITH_GATE_LOCK(pll_cpu_clk, "pll-cpu",
 				     0);
 
 /*
- * The Audio PLL is supposed to have 4 outputs: 3 fixed factors from
- * the base (2x, 4x and 8x), and one variable divider (the one true
- * pll audio).
- *
- * We don't have any need for the variable divider for now, so we just
- * hardcode it to match with the clock names
+ * The Audio PLL has 4 outputs: 3 fixed factors from the base (2x, 4x and 8x),
+ * and one variable divider (the one true pll audio).
+ * The variable rate output is supported via a a separate divider below.
  */
 #define SUN8I_V3S_PLL_AUDIO_REG	0x008
 
@@ -53,6 +50,11 @@ static SUNXI_CCU_NM_WITH_GATE_LOCK(pll_audio_base_clk, "pll-audio-base",
 				   BIT(28),	/* lock */
 				   0);
 
+static SUNXI_CCU_M(pll_audio_clk, "pll-audio",
+		   "pll-audio-base", 0x008,
+		   16, 4, /* P from audio pll */
+		   CLK_SET_RATE_PARENT);
+
 static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_video_clk, "pll-video",
 					"osc24M", 0x0010,
 					8, 7,		/* N */
@@ -377,6 +379,7 @@ static SUNXI_CCU_M_WITH_MUX_GATE(mipi_csi_clk, "mipi-csi", mipi_csi_parents,
 static struct ccu_common *sun8i_v3s_ccu_clks[] = {
 	&pll_cpu_clk.common,
 	&pll_audio_base_clk.common,
+	&pll_audio_clk.common,
 	&pll_video_clk.common,
 	&pll_ve_clk.common,
 	&pll_ddr0_clk.common,
@@ -453,6 +456,7 @@ static const struct clk_hw *clk_parent_pll_audio[] = {
 static struct ccu_common *sun8i_v3_ccu_clks[] = {
 	&pll_cpu_clk.common,
 	&pll_audio_base_clk.common,
+	&pll_audio_clk.common,
 	&pll_video_clk.common,
 	&pll_ve_clk.common,
 	&pll_ddr0_clk.common,
@@ -524,10 +528,6 @@ static struct ccu_common *sun8i_v3_ccu_clks[] = {
 	&mipi_csi_clk.common,
 };
 
-/* We hardcode the divider to 4 for now */
-static CLK_FIXED_FACTOR_HWS(pll_audio_clk, "pll-audio",
-			    clk_parent_pll_audio,
-			    4, 1, CLK_SET_RATE_PARENT);
 static CLK_FIXED_FACTOR_HWS(pll_audio_2x_clk, "pll-audio-2x",
 			    clk_parent_pll_audio,
 			    2, 1, CLK_SET_RATE_PARENT);
@@ -545,7 +545,7 @@ static struct clk_hw_onecell_data sun8i_v3s_hw_clks = {
 	.hws	= {
 		[CLK_PLL_CPU]		= &pll_cpu_clk.common.hw,
 		[CLK_PLL_AUDIO_BASE]	= &pll_audio_base_clk.common.hw,
-		[CLK_PLL_AUDIO]		= &pll_audio_clk.hw,
+		[CLK_PLL_AUDIO]		= &pll_audio_clk.common.hw,
 		[CLK_PLL_AUDIO_2X]	= &pll_audio_2x_clk.hw,
 		[CLK_PLL_AUDIO_4X]	= &pll_audio_4x_clk.hw,
 		[CLK_PLL_AUDIO_8X]	= &pll_audio_8x_clk.hw,
@@ -625,7 +625,7 @@ static struct clk_hw_onecell_data sun8i_v3_hw_clks = {
 	.hws	= {
 		[CLK_PLL_CPU]		= &pll_cpu_clk.common.hw,
 		[CLK_PLL_AUDIO_BASE]	= &pll_audio_base_clk.common.hw,
-		[CLK_PLL_AUDIO]		= &pll_audio_clk.hw,
+		[CLK_PLL_AUDIO]		= &pll_audio_clk.common.hw,
 		[CLK_PLL_AUDIO_2X]	= &pll_audio_2x_clk.hw,
 		[CLK_PLL_AUDIO_4X]	= &pll_audio_4x_clk.hw,
 		[CLK_PLL_AUDIO_8X]	= &pll_audio_8x_clk.hw,
-- 
2.30.0


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