[PATCH 2/3] clk: spacemit: k3: fix i2s clock topology

[Troy Mitchell]

The K3 i2s clocks were modelled as a single path behind one MPMU
register:

    pll1_d96_25p6 / i2s_153p6_base
      `-- i2s_sysclk_src (mux+gate, MPMU_ISCCR)
            `-- i2s1_sysclk (DDN, MPMU_ISCCR)
                  |-- i2s_bclk (div+gate, MPMU_ISCCR)
                  `-- i2s2_sysclk (mux, parent 0)

The hardware actually has two i2s clock control registers, ISCCR0
(0x0040) and ISCCR1 (0x0044): ISCCR1 drives the common sysclk shared
by i2s0/2/3/4/5 and the common bclk, whose divider always implies a
fixed 1/2 factor in front, while ISCCR0 drives a dedicated path for
i2s1:

    pll1_d96_25p6 / i2s_153p6_base
      |-- i2s_sysclk_src (mux+gate, MPMU_ISCCR1)
      |     `-- i2s_sysclk (DDN, MPMU_ISCCR1)
      |           |-- i2s_bclk_factor (fixed factor, /2)
      |           |     `-- i2s_bclk (div+gate, MPMU_ISCCR1)
      |           `-- i2s2_sysclk (mux, parent 0)
      `-- i2s1_sysclk_src (mux+gate, MPMU_ISCCR0)
            `-- i2s1_sysclk (DDN, MPMU_ISCCR0)

Because of this mismatch, i2s_bclk reported twice the real rate, and
the dedicated i2s1 clock path could not be described in DT at all.

Model the tree as above: split the MPMU_ISCCR register macro into
MPMU_ISCCR0 and MPMU_ISCCR1 to match the hardware register names,
rename the common DDN to i2s_sysclk, insert the fixed 1/2 factor
i2s_bclk_factor in front of i2s_bclk, and add the i2s1_sysclk_src mux
and i2s1_sysclk DDN backed by MPMU_ISCCR0. CLK_MPMU_I2S1_SYSCLK now
refers to the dedicated i2s1 clock; no in-tree user references this
ID, so nothing is affected by the change of meaning.

Fixes: e371a77255b8 ("clk: spacemit: k3: add the clock tree")
Signed-off-by: Troy Mitchell <troy.mitchell@xxxxxxxxxxxxxxxxxx>
---
 drivers/clk/spacemit/ccu-k3.c    | 21 ++++++++++++++++-----
 include/soc/spacemit/k3-syscon.h |  3 ++-
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/spacemit/ccu-k3.c b/drivers/clk/spacemit/ccu-k3.c
index cb0c4277f72a..abcc5caa67bd 100644
--- a/drivers/clk/spacemit/ccu-k3.c
+++ b/drivers/clk/spacemit/ccu-k3.c
@@ -218,11 +218,19 @@ static const struct clk_parent_data i2s_sysclk_src_parents[] = {
 	CCU_PARENT_HW(pll1_d96_25p6),
 	CCU_PARENT_HW(i2s_153p6_base),
 };
-CCU_MUX_GATE_DEFINE(i2s_sysclk_src, i2s_sysclk_src_parents, MPMU_ISCCR, 30, 1, BIT(31), 0);
+CCU_MUX_GATE_DEFINE(i2s_sysclk_src, i2s_sysclk_src_parents, MPMU_ISCCR1, 30, 1, BIT(31), 0);
 
-CCU_DDN_DEFINE(i2s1_sysclk, i2s_sysclk_src, MPMU_ISCCR, 0, 15, 15, 12, 1, 0);
+CCU_DDN_DEFINE(i2s_sysclk, i2s_sysclk_src, MPMU_ISCCR1, 0, 15, 15, 12, 1, 0);
 
-CCU_DIV_GATE_DEFINE(i2s_bclk, CCU_PARENT_HW(i2s1_sysclk), MPMU_ISCCR, 27, 2, BIT(29), 0);
+CCU_FACTOR_DEFINE(i2s_bclk_factor, CCU_PARENT_HW(i2s_sysclk), 2, 1);
+/*
+ * Divider of i2s_bclk always implies a 1/2 factor, which is
+ * described by i2s_bclk_factor.
+ */
+CCU_DIV_GATE_DEFINE(i2s_bclk, CCU_PARENT_HW(i2s_bclk_factor), MPMU_ISCCR1, 27, 2, BIT(29), 0);
+
+CCU_MUX_GATE_DEFINE(i2s1_sysclk_src, i2s_sysclk_src_parents, MPMU_ISCCR0, 30, 1, BIT(31), 0);
+CCU_DDN_DEFINE(i2s1_sysclk, i2s1_sysclk_src, MPMU_ISCCR0, 0, 15, 15, 12, 1, 0);
 
 static const struct clk_parent_data i2s_sysclk_parents[] = {
 	CCU_PARENT_HW(pll1_d4_614p4),
@@ -243,7 +251,7 @@ CCU_DDN_DEFINE(i2s4_sysclk_div, i2s4_sysclk_sel, MPMU_I2S4_SYSCLK, 0, 16, 16, 16
 CCU_DDN_DEFINE(i2s5_sysclk_div, i2s5_sysclk_sel, MPMU_I2S5_SYSCLK, 0, 16, 16, 16, 1, 0);
 
 static const struct clk_parent_data i2s2_sysclk_parents[] = {
-	CCU_PARENT_HW(i2s1_sysclk),
+	CCU_PARENT_HW(i2s_sysclk),
 	CCU_PARENT_HW(i2s2_sysclk_div),
 };
 CCU_GATE_DEFINE(i2s0_sysclk, CCU_PARENT_HW(i2s0_sysclk_div), MPMU_I2S_SYSCLK_CTRL, BIT(2), 0);
@@ -1161,8 +1169,11 @@ static struct clk_hw *k3_ccu_mpmu_hws[] = {
 	[CLK_MPMU_I2S_153P6]		= &i2s_153p6.common.hw,
 	[CLK_MPMU_I2S_153P6_BASE]	= &i2s_153p6_base.common.hw,
 	[CLK_MPMU_I2S_SYSCLK_SRC]	= &i2s_sysclk_src.common.hw,
-	[CLK_MPMU_I2S1_SYSCLK]		= &i2s1_sysclk.common.hw,
+	[CLK_MPMU_I2S_SYSCLK]		= &i2s_sysclk.common.hw,
+	[CLK_MPMU_I2S_BCLK_FACTOR]	= &i2s_bclk_factor.common.hw,
 	[CLK_MPMU_I2S_BCLK]		= &i2s_bclk.common.hw,
+	[CLK_MPMU_I2S1_SYSCLK_SRC]	= &i2s1_sysclk_src.common.hw,
+	[CLK_MPMU_I2S1_SYSCLK]		= &i2s1_sysclk.common.hw,
 	[CLK_MPMU_I2S0_SYSCLK_SEL]	= &i2s0_sysclk_sel.common.hw,
 	[CLK_MPMU_I2S2_SYSCLK_SEL]	= &i2s2_sysclk_sel.common.hw,
 	[CLK_MPMU_I2S3_SYSCLK_SEL]	= &i2s3_sysclk_sel.common.hw,
diff --git a/include/soc/spacemit/k3-syscon.h b/include/soc/spacemit/k3-syscon.h
index a68255dd641f..959d8d0786fe 100644
--- a/include/soc/spacemit/k3-syscon.h
+++ b/include/soc/spacemit/k3-syscon.h
@@ -45,7 +45,8 @@
 #define POSR_PLL7_LOCK			BIT(30)
 #define POSR_PLL8_LOCK			BIT(31)
 #define MPMU_SUCCR			0x0014
-#define MPMU_ISCCR			0x0044
+#define MPMU_ISCCR0			0x0040
+#define MPMU_ISCCR1			0x0044
 #define MPMU_WDTPCR			0x0200
 #define MPMU_RIPCCR			0x0210
 #define MPMU_ACGR			0x1024

-- 
2.55.0