[PATCH 0/4] clk: meson: g12a: add support for DVFS

[PATCH 0/4] clk: meson: g12a: add support for DVFS

[Neil Armstrong]

The G12A/G12B Socs embeds a specific clock tree for each CPU cluster :
cpu_clk / cpub_clk
|   \- cpu_clk_dyn
|      |  \- cpu_clk_premux0
|      |        |- cpu_clk_postmux0
|      |        |    |- cpu_clk_dyn0_div
|      |        |    \- xtal/fclk_div2/fclk_div3
|      |        \- xtal/fclk_div2/fclk_div3
|      \- cpu_clk_premux1
|            |- cpu_clk_postmux1
|            |    |- cpu_clk_dyn1_div
|            |    \- xtal/fclk_div2/fclk_div3
|            \- xtal/fclk_div2/fclk_div3
\ sys_pll / sys1_pll

This patchset adds notifiers on cpu_clk / cpub_clk, cpu_clk_dyn,
cpu_clk_premux0 and sys_pll / sys1_pll to permit change frequency of
the CPU clock in a safe way as recommended by the vendor Documentation
and reference code.

This patchset :
- introduces needed core and meson clk changes
- adds the clock notifiers

Dependencies:
- None

This patchset is split from the v3 RFC/RFC patchset at [3]

Changes from RFT/RFC v3 at [3]:
- Rebased on clk-meson v5.4/drivers tree with Alexandre's patches
- Removed the eeclk setup() callback, moved to a toplevel g12a-data struct

Changes since RFT/RFC v2 at [2]:
- Rebased on clk-meson v5.3/drivers trees
- added Kevin's review tags

Changes since RFT/RFC v1 at [1]:
- Added EXPORT_SYMBOL_GPL() to clk_hw_set_parent
- Added missing static to g12b_cpub_clk_mux0_div_ops and g12a_cpu_clk_mux_nb
- Simplified g12a_cpu_clk_mux_notifier_cb() without switch/case
- Fixed typo in "this the current path" in g12a.c
- Fixed various checkpatch errors

[1] https://patchwork.kernel.org/cover/11006929/
[2] https://patchwork.kernel.org/cover/11017273/
[3] https://patchwork.kernel.org/cover/11025309/

Neil Armstrong (4):
  clk: core: introduce clk_hw_set_parent()
  clk: meson: regmap: export regmap_div ops functions
  clk: meson: g12a: add notifiers to handle cpu clock change
  clk: meson: g12a: expose CPUB clock ID for G12B

 drivers/clk/clk.c                     |   6 +
 drivers/clk/meson/clk-regmap.c        |  10 +-
 drivers/clk/meson/clk-regmap.h        |   5 +
 drivers/clk/meson/g12a.c              | 567 +++++++++++++++++++++++---
 include/dt-bindings/clock/g12a-clkc.h |   1 +
 include/linux/clk-provider.h          |   1 +
 6 files changed, 540 insertions(+), 50 deletions(-)

-- 
2.22.0

[PATCH 1/4] clk: core: introduce clk_hw_set_parent()

[Neil Armstrong]

Introduce the clk_hw_set_parent() provider call to change parent of
a clock by using the clk_hw pointers.

This eases the clock reparenting from clock rate notifiers and
implementing DVFS with simpler code avoiding the boilerplates
functions as __clk_lookup(clk_hw_get_name()) then clk_set_parent().

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/clk/clk.c            | 6 ++++++
 include/linux/clk-provider.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c0990703ce54..c11b1781d24a 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2487,6 +2487,12 @@ static int clk_core_set_parent_nolock(struct clk_core *core,
 	return ret;
 }
 
+int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
+{
+	return clk_core_set_parent_nolock(hw->core, parent->core);
+}
+EXPORT_SYMBOL_GPL(clk_hw_set_parent);
+
 /**
  * clk_set_parent - switch the parent of a mux clk
  * @clk: the mux clk whose input we are switching
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 2ae7604783dd..dce5521a9bf6 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -817,6 +817,7 @@ unsigned int clk_hw_get_num_parents(const struct clk_hw *hw);
 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw);
 struct clk_hw *clk_hw_get_parent_by_index(const struct clk_hw *hw,
 					  unsigned int index);
+int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *new_parent);
 unsigned int __clk_get_enable_count(struct clk *clk);
 unsigned long clk_hw_get_rate(const struct clk_hw *hw);
 unsigned long __clk_get_flags(struct clk *clk);
-- 
2.22.0

[PATCH 2/4] clk: meson: regmap: export regmap_div ops functions

[Neil Armstrong]

The G12A CPU Clock Postmux divider needs a custom div_set_rate() call.

Export the clk_regmap_div_round_rate() and clk_regmap_div_recalc_rate()
to be able to override the default clk_regmap_div_set_rate() callback.
---
 drivers/clk/meson/clk-regmap.c | 10 ++++++----
 drivers/clk/meson/clk-regmap.h |  5 +++++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/meson/clk-regmap.c b/drivers/clk/meson/clk-regmap.c
index dcd1757cc5df..26c8c74a8cf0 100644
--- a/drivers/clk/meson/clk-regmap.c
+++ b/drivers/clk/meson/clk-regmap.c
@@ -56,8 +56,8 @@ const struct clk_ops clk_regmap_gate_ro_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_regmap_gate_ro_ops);
 
-static unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
-						unsigned long prate)
+unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
+					 unsigned long prate)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
@@ -74,9 +74,10 @@ static unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
 	return divider_recalc_rate(hw, prate, val, div->table, div->flags,
 				   div->width);
 }
+EXPORT_SYMBOL_GPL(clk_regmap_div_recalc_rate);
 
-static long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
-				      unsigned long *prate)
+long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *prate)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
@@ -100,6 +101,7 @@ static long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
 	return divider_round_rate(hw, rate, prate, div->table, div->width,
 				  div->flags);
 }
+EXPORT_SYMBOL_GPL(clk_regmap_div_round_rate);
 
 static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
 				   unsigned long parent_rate)
diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
index c4a39604cffd..ebf776a32ce3 100644
--- a/drivers/clk/meson/clk-regmap.h
+++ b/drivers/clk/meson/clk-regmap.h
@@ -78,6 +78,11 @@ clk_get_regmap_div_data(struct clk_regmap *clk)
 	return (struct clk_regmap_div_data *)clk->data;
 }
 
+unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
+					 unsigned long prate);
+long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *prate);
+
 extern const struct clk_ops clk_regmap_divider_ops;
 extern const struct clk_ops clk_regmap_divider_ro_ops;
 
-- 
2.22.0

[PATCH 3/4] clk: meson: g12a: add notifiers to handle cpu clock change

[Neil Armstrong]

In order to implement clock switching for the CLKID_CPU_CLK and
CLKID_CPUB_CLK, notifiers are added on specific points of the
clock tree :

cpu_clk / cpub_clk
|   \- cpu_clk_dyn
|      |  \- cpu_clk_premux0
|      |        |- cpu_clk_postmux0
|      |        |    |- cpu_clk_dyn0_div
|      |        |    \- xtal/fclk_div2/fclk_div3
|      |        \- xtal/fclk_div2/fclk_div3
|      \- cpu_clk_premux1
|            |- cpu_clk_postmux1
|            |    |- cpu_clk_dyn1_div
|            |    \- xtal/fclk_div2/fclk_div3
|            \- xtal/fclk_div2/fclk_div3
\ sys_pll / sys1_pll

This for each cluster, a single one for G12A, two for G12B.

Each cpu_clk_premux1 tree is marked as read-only and CLK_SET_RATE_NO_REPARENT,
to be used as "parking" clock in a safe clock frequency.

A notifier is added on each cpu_clk_premux0 to detech when CCF want to
change the frequency of the cpu_clk_dyn tree.
In this notifier, the cpu_clk_premux1 tree is configured to use the xtal
clock and then the cpu_clk_dyn is switch to cpu_clk_premux1 while CCF
updates the cpu_clk_premux0 tree.

A notifier is added on each sys_pll/sys1_pll to detect when CCF wants to
change the PLL clock source of the cpu_clk.
In this notifier, the cpu_clk is switched to cpu_clk_dyn while CCF
updates the sys_pll/sys1_pll frequency.

A third small notifier is added on each cpu_clk / cpub_clk and cpu_clk_dyn,
add a small delay at PRE_RATE_CHANGE/POST_RATE_CHANGE to let the other
notofiers change propagate before changing the cpu_clk_premux0 and sys_pll
clock trees.

This notifier set permits switching the cpu_clk / cpub_clk without any
glitches and using a safe parking clock while switching between sub-GHz
clocks using the cpu_clk_dyn tree.

This setup has been tested and validated on the Amlogic G12A and G12B
SoCs running the arm64 cpuburn at [1] and cycling between all the possible
cpufreq translations of each cluster and checking the final frequency using
the clock-measurer, script at [2].

[1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
[2] https://gist.github.com/superna9999/d4de964dbc0f84b7d527e1df2ddea25f
---
 drivers/clk/meson/g12a.c | 567 +++++++++++++++++++++++++++++++++++----
 1 file changed, 521 insertions(+), 46 deletions(-)

diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
index e4957fd9f91f..23162310c7ee 100644
--- a/drivers/clk/meson/g12a.c
+++ b/drivers/clk/meson/g12a.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/clk.h>
 
 #include "clk-mpll.h"
 #include "clk-pll.h"
@@ -88,16 +89,9 @@ static struct clk_regmap g12a_fixed_pll = {
 	},
 };
 
-/*
- * Internal sys pll emulation configuration parameters
- */
-static const struct reg_sequence g12a_sys_init_regs[] = {
-	{ .reg = HHI_SYS_PLL_CNTL1,	.def = 0x00000000 },
-	{ .reg = HHI_SYS_PLL_CNTL2,	.def = 0x00000000 },
-	{ .reg = HHI_SYS_PLL_CNTL3,	.def = 0x48681c00 },
-	{ .reg = HHI_SYS_PLL_CNTL4,	.def = 0x88770290 },
-	{ .reg = HHI_SYS_PLL_CNTL5,	.def = 0x39272000 },
-	{ .reg = HHI_SYS_PLL_CNTL6,	.def = 0x56540000 },
+static const struct pll_mult_range g12a_sys_pll_mult_range = {
+	.min = 128,
+	.max = 250,
 };
 
 static struct clk_regmap g12a_sys_pll_dco = {
@@ -127,16 +121,17 @@ static struct clk_regmap g12a_sys_pll_dco = {
 			.shift   = 29,
 			.width   = 1,
 		},
-		.init_regs = g12a_sys_init_regs,
-		.init_count = ARRAY_SIZE(g12a_sys_init_regs),
+		.range = &g12a_sys_pll_mult_range,
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "sys_pll_dco",
-		.ops = &meson_clk_pll_ro_ops,
+		.ops = &meson_clk_pll_ops,
 		.parent_data = &(const struct clk_parent_data) {
 			.fw_name = "xtal",
 		},
 		.num_parents = 1,
+		/* This clock feeds the CPU, avoid disabling it */
+		.flags = CLK_IS_CRITICAL,
 	},
 };
 
@@ -149,11 +144,12 @@ static struct clk_regmap g12a_sys_pll = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "sys_pll",
-		.ops = &clk_regmap_divider_ro_ops,
+		.ops = &clk_regmap_divider_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_sys_pll_dco.hw
 		},
 		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -184,14 +180,17 @@ static struct clk_regmap g12b_sys1_pll_dco = {
 			.shift   = 29,
 			.width   = 1,
 		},
+		.range = &g12a_sys_pll_mult_range,
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "sys1_pll_dco",
-		.ops = &meson_clk_pll_ro_ops,
+		.ops = &meson_clk_pll_ops,
 		.parent_data = &(const struct clk_parent_data) {
 			.fw_name = "xtal",
 		},
 		.num_parents = 1,
+		/* This clock feeds the CPU, avoid disabling it */
+		.flags = CLK_IS_CRITICAL,
 	},
 };
 
@@ -204,11 +203,12 @@ static struct clk_regmap g12b_sys1_pll = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "sys1_pll",
-		.ops = &clk_regmap_divider_ro_ops,
+		.ops = &clk_regmap_divider_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_sys1_pll_dco.hw
 		},
 		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -345,13 +345,15 @@ static struct clk_regmap g12a_cpu_clk_premux0 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn0_sel",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_data = (const struct clk_parent_data []) {
 			{ .fw_name = "xtal", },
 			{ .hw = &g12a_fclk_div2.hw },
 			{ .hw = &g12a_fclk_div3.hw },
 		},
 		.num_parents = 3,
+		/* This sub-tree is used a parking clock */
+		.flags = CLK_SET_RATE_NO_REPARENT,
 	},
 };
 
@@ -364,16 +366,50 @@ static struct clk_regmap g12a_cpu_clk_premux1 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn1_sel",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_data = (const struct clk_parent_data []) {
 			{ .fw_name = "xtal", },
 			{ .hw = &g12a_fclk_div2.hw },
 			{ .hw = &g12a_fclk_div3.hw },
 		},
 		.num_parents = 3,
+		/* This sub-tree is used a parking clock */
+		.flags = CLK_SET_RATE_NO_REPARENT
 	},
 };
 
+#define SYS_CPU_DYN_ENABLE	BIT(26)
+
+/* This divider uses bit 26 to take change in account */
+static int g12a_cpu_clk_mux0_div_set_rate(struct clk_hw *hw, unsigned long rate,
+					  unsigned long parent_rate)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = divider_get_val(rate, parent_rate, div->table, div->width,
+			      div->flags);
+	if (ret < 0)
+		return ret;
+
+	val = (unsigned int)ret << div->shift;
+
+	regmap_update_bits(clk->map, HHI_SYS_CPU_CLK_CNTL0,
+			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
+
+	return regmap_update_bits(clk->map, div->offset,
+				  clk_div_mask(div->width) << div->shift |
+				  SYS_CPU_DYN_ENABLE, val);
+};
+
+const struct clk_ops g12a_cpu_clk_mux0_div_ops = {
+	.recalc_rate = clk_regmap_div_recalc_rate,
+	.round_rate = clk_regmap_div_round_rate,
+	.set_rate = g12a_cpu_clk_mux0_div_set_rate,
+};
+
 /* Datasheet names this field as "mux0_divn_tcnt" */
 static struct clk_regmap g12a_cpu_clk_mux0_div = {
 	.data = &(struct clk_regmap_div_data){
@@ -383,11 +419,12 @@ static struct clk_regmap g12a_cpu_clk_mux0_div = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn0_div",
-		.ops = &clk_regmap_divider_ro_ops,
+		.ops = &g12a_cpu_clk_mux0_div_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_premux0.hw
 		},
 		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -400,12 +437,13 @@ static struct clk_regmap g12a_cpu_clk_postmux0 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn0",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_premux0.hw,
 			&g12a_cpu_clk_mux0_div.hw,
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -435,12 +473,14 @@ static struct clk_regmap g12a_cpu_clk_postmux1 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn1",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_premux1.hw,
 			&g12a_cpu_clk_mux1_div.hw,
 		},
 		.num_parents = 2,
+		/* This sub-tree is used a parking clock */
+		.flags = CLK_SET_RATE_NO_REPARENT,
 	},
 };
 
@@ -453,12 +493,13 @@ static struct clk_regmap g12a_cpu_clk_dyn = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk_dyn",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_postmux0.hw,
 			&g12a_cpu_clk_postmux1.hw,
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -471,12 +512,13 @@ static struct clk_regmap g12a_cpu_clk = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_dyn.hw,
 			&g12a_sys_pll.hw,
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -489,12 +531,13 @@ static struct clk_regmap g12b_cpu_clk = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpu_clk",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12a_cpu_clk_dyn.hw,
 			&g12b_sys1_pll.hw
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -507,7 +550,7 @@ static struct clk_regmap g12b_cpub_clk_premux0 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn0_sel",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_data = (const struct clk_parent_data []) {
 			{ .fw_name = "xtal", },
 			{ .hw = &g12a_fclk_div2.hw },
@@ -517,6 +560,37 @@ static struct clk_regmap g12b_cpub_clk_premux0 = {
 	},
 };
 
+/* This divider uses bit 26 to take change in account */
+static int g12b_cpub_clk_mux0_div_set_rate(struct clk_hw *hw,
+					   unsigned long rate,
+					   unsigned long parent_rate)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = divider_get_val(rate, parent_rate, div->table, div->width,
+			      div->flags);
+	if (ret < 0)
+		return ret;
+
+	val = (unsigned int)ret << div->shift;
+
+	regmap_update_bits(clk->map, HHI_SYS_CPUB_CLK_CNTL,
+			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
+
+	return regmap_update_bits(clk->map, div->offset,
+				  clk_div_mask(div->width) << div->shift |
+				  SYS_CPU_DYN_ENABLE, val);
+};
+
+static const struct clk_ops g12b_cpub_clk_mux0_div_ops = {
+	.recalc_rate = clk_regmap_div_recalc_rate,
+	.round_rate = clk_regmap_div_round_rate,
+	.set_rate = g12b_cpub_clk_mux0_div_set_rate,
+};
+
 /* Datasheet names this field as "mux0_divn_tcnt" */
 static struct clk_regmap g12b_cpub_clk_mux0_div = {
 	.data = &(struct clk_regmap_div_data){
@@ -526,11 +600,12 @@ static struct clk_regmap g12b_cpub_clk_mux0_div = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn0_div",
-		.ops = &clk_regmap_divider_ro_ops,
+		.ops = &g12b_cpub_clk_mux0_div_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_cpub_clk_premux0.hw
 		},
 		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -543,12 +618,13 @@ static struct clk_regmap g12b_cpub_clk_postmux0 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn0",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_cpub_clk_premux0.hw,
 			&g12b_cpub_clk_mux0_div.hw
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -561,13 +637,15 @@ static struct clk_regmap g12b_cpub_clk_premux1 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn1_sel",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_data = (const struct clk_parent_data []) {
 			{ .fw_name = "xtal", },
 			{ .hw = &g12a_fclk_div2.hw },
 			{ .hw = &g12a_fclk_div3.hw },
 		},
 		.num_parents = 3,
+		/* This sub-tree is used a parking clock */
+		.flags = CLK_SET_RATE_NO_REPARENT,
 	},
 };
 
@@ -597,12 +675,14 @@ static struct clk_regmap g12b_cpub_clk_postmux1 = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn1",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_cpub_clk_premux1.hw,
 			&g12b_cpub_clk_mux1_div.hw
 		},
 		.num_parents = 2,
+		/* This sub-tree is used a parking clock */
+		.flags = CLK_SET_RATE_NO_REPARENT,
 	},
 };
 
@@ -615,12 +695,13 @@ static struct clk_regmap g12b_cpub_clk_dyn = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk_dyn",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_cpub_clk_postmux0.hw,
 			&g12b_cpub_clk_postmux1.hw
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
@@ -633,15 +714,227 @@ static struct clk_regmap g12b_cpub_clk = {
 	},
 	.hw.init = &(struct clk_init_data){
 		.name = "cpub_clk",
-		.ops = &clk_regmap_mux_ro_ops,
+		.ops = &clk_regmap_mux_ops,
 		.parent_hws = (const struct clk_hw *[]) {
 			&g12b_cpub_clk_dyn.hw,
 			&g12a_sys_pll.hw
 		},
 		.num_parents = 2,
+		.flags = CLK_SET_RATE_PARENT,
 	},
 };
 
+static int g12a_cpu_clk_mux_notifier_cb(struct notifier_block *nb,
+					unsigned long event, void *data)
+{
+	if (event == POST_RATE_CHANGE || event == PRE_RATE_CHANGE) {
+		/* Wait for clock propagation before/after changing the mux */
+		udelay(100);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block g12a_cpu_clk_mux_nb = {
+	.notifier_call = g12a_cpu_clk_mux_notifier_cb,
+};
+
+struct g12a_cpu_clk_postmux_nb_data {
+	struct notifier_block nb;
+	struct clk_hw *xtal;
+	struct clk_hw *cpu_clk_dyn;
+	struct clk_hw *cpu_clk_postmux0;
+	struct clk_hw *cpu_clk_postmux1;
+	struct clk_hw *cpu_clk_premux1;
+};
+
+static int g12a_cpu_clk_postmux_notifier_cb(struct notifier_block *nb,
+					    unsigned long event, void *data)
+{
+	struct g12a_cpu_clk_postmux_nb_data *nb_data =
+		container_of(nb, struct g12a_cpu_clk_postmux_nb_data, nb);
+
+	switch (event) {
+	case PRE_RATE_CHANGE:
+		/*
+		 * This notifier means cpu_clk_postmux0 clock will be changed
+		 * to feed cpu_clk, this is the current path :
+		 * cpu_clk
+		 *    \- cpu_clk_dyn
+		 *          \- cpu_clk_postmux0
+		 *                \- cpu_clk_muxX_div
+		 *                      \- cpu_clk_premux0
+		 *				\- fclk_div3 or fclk_div2
+		 *		OR
+		 *                \- cpu_clk_premux0
+		 *			\- fclk_div3 or fclk_div2
+		 */
+
+		/* Setup cpu_clk_premux1 to xtal */
+		clk_hw_set_parent(nb_data->cpu_clk_premux1,
+				  nb_data->xtal);
+
+		/* Setup cpu_clk_postmux1 to bypass divider */
+		clk_hw_set_parent(nb_data->cpu_clk_postmux1,
+				  nb_data->cpu_clk_premux1);
+
+		/* Switch to parking clk on cpu_clk_postmux1 */
+		clk_hw_set_parent(nb_data->cpu_clk_dyn,
+				  nb_data->cpu_clk_postmux1);
+
+		/*
+		 * Now, cpu_clk is 24MHz in the current path :
+		 * cpu_clk
+		 *    \- cpu_clk_dyn
+		 *          \- cpu_clk_postmux1
+		 *                \- cpu_clk_premux1
+		 *                      \- xtal
+		 */
+
+		udelay(100);
+
+		return NOTIFY_OK;
+
+	case POST_RATE_CHANGE:
+		/*
+		 * The cpu_clk_postmux0 has ben updated, now switch back
+		 * cpu_clk_dyn to cpu_clk_postmux0 and take the changes
+		 * in account.
+		 */
+
+		/* Configure cpu_clk_dyn back to cpu_clk_postmux0 */
+		clk_hw_set_parent(nb_data->cpu_clk_dyn,
+				  nb_data->cpu_clk_postmux0);
+
+		/*
+		 * new path :
+		 * cpu_clk
+		 *    \- cpu_clk_dyn
+		 *          \- cpu_clk_postmux0
+		 *                \- cpu_clk_muxX_div
+		 *                      \- cpu_clk_premux0
+		 *				\- fclk_div3 or fclk_div2
+		 *		OR
+		 *                \- cpu_clk_premux0
+		 *			\- fclk_div3 or fclk_div2
+		 */
+
+		udelay(100);
+
+		return NOTIFY_OK;
+
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static struct g12a_cpu_clk_postmux_nb_data g12a_cpu_clk_postmux0_nb_data = {
+	.cpu_clk_dyn = &g12a_cpu_clk_dyn.hw,
+	.cpu_clk_postmux0 = &g12a_cpu_clk_postmux0.hw,
+	.cpu_clk_postmux1 = &g12a_cpu_clk_postmux1.hw,
+	.cpu_clk_premux1 = &g12a_cpu_clk_premux1.hw,
+	.nb.notifier_call = g12a_cpu_clk_postmux_notifier_cb,
+};
+
+static struct g12a_cpu_clk_postmux_nb_data g12b_cpub_clk_postmux0_nb_data = {
+	.cpu_clk_dyn = &g12b_cpub_clk_dyn.hw,
+	.cpu_clk_postmux0 = &g12b_cpub_clk_postmux0.hw,
+	.cpu_clk_postmux1 = &g12b_cpub_clk_postmux1.hw,
+	.cpu_clk_premux1 = &g12b_cpub_clk_premux1.hw,
+	.nb.notifier_call = g12a_cpu_clk_postmux_notifier_cb,
+};
+
+struct g12a_sys_pll_nb_data {
+	struct notifier_block nb;
+	struct clk_hw *sys_pll;
+	struct clk_hw *cpu_clk;
+	struct clk_hw *cpu_clk_dyn;
+};
+
+static int g12a_sys_pll_notifier_cb(struct notifier_block *nb,
+				    unsigned long event, void *data)
+{
+	struct g12a_sys_pll_nb_data *nb_data =
+		container_of(nb, struct g12a_sys_pll_nb_data, nb);
+
+	switch (event) {
+	case PRE_RATE_CHANGE:
+		/*
+		 * This notifier means sys_pll clock will be changed
+		 * to feed cpu_clk, this the current path :
+		 * cpu_clk
+		 *    \- sys_pll
+		 *          \- sys_pll_dco
+		 */
+
+		/* Configure cpu_clk to use cpu_clk_dyn */
+		clk_hw_set_parent(nb_data->cpu_clk,
+				  nb_data->cpu_clk_dyn);
+
+		/*
+		 * Now, cpu_clk uses the dyn path
+		 * cpu_clk
+		 *    \- cpu_clk_dyn
+		 *          \- cpu_clk_dynX
+		 *                \- cpu_clk_dynX_sel
+		 *		     \- cpu_clk_dynX_div
+		 *                      \- xtal/fclk_div2/fclk_div3
+		 *                   \- xtal/fclk_div2/fclk_div3
+		 */
+
+		udelay(100);
+
+		return NOTIFY_OK;
+
+	case POST_RATE_CHANGE:
+		/*
+		 * The sys_pll has ben updated, now switch back cpu_clk to
+		 * sys_pll
+		 */
+
+		/* Configure cpu_clk to use sys_pll */
+		clk_hw_set_parent(nb_data->cpu_clk,
+				  nb_data->sys_pll);
+
+		udelay(100);
+
+		/* new path :
+		 * cpu_clk
+		 *    \- sys_pll
+		 *          \- sys_pll_dco
+		 */
+
+		return NOTIFY_OK;
+
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static struct g12a_sys_pll_nb_data g12a_sys_pll_nb_data = {
+	.sys_pll = &g12a_sys_pll.hw,
+	.cpu_clk = &g12a_cpu_clk.hw,
+	.cpu_clk_dyn = &g12a_cpu_clk_dyn.hw,
+	.nb.notifier_call = g12a_sys_pll_notifier_cb,
+};
+
+/* G12B first CPU cluster uses sys1_pll */
+static struct g12a_sys_pll_nb_data g12b_cpu_clk_sys1_pll_nb_data = {
+	.sys_pll = &g12b_sys1_pll.hw,
+	.cpu_clk = &g12b_cpu_clk.hw,
+	.cpu_clk_dyn = &g12a_cpu_clk_dyn.hw,
+	.nb.notifier_call = g12a_sys_pll_notifier_cb,
+};
+
+/* G12B second CPU cluster uses sys_pll */
+static struct g12a_sys_pll_nb_data g12b_cpub_clk_sys_pll_nb_data = {
+	.sys_pll = &g12a_sys_pll.hw,
+	.cpu_clk = &g12b_cpub_clk.hw,
+	.cpu_clk_dyn = &g12b_cpub_clk_dyn.hw,
+	.nb.notifier_call = g12a_sys_pll_notifier_cb,
+};
+
 static struct clk_regmap g12a_cpu_clk_div16_en = {
 	.data = &(struct clk_regmap_gate_data){
 		.offset = HHI_SYS_CPU_CLK_CNTL1,
@@ -4097,28 +4390,210 @@ static const struct reg_sequence g12a_init_regs[] = {
 	{ .reg = HHI_MPLL_CNTL0,	.def = 0x00000543 },
 };
 
-static const struct meson_eeclkc_data g12a_clkc_data = {
-	.regmap_clks = g12a_clk_regmaps,
-	.regmap_clk_num = ARRAY_SIZE(g12a_clk_regmaps),
-	.hw_onecell_data = &g12a_hw_onecell_data,
-	.init_regs = g12a_init_regs,
-	.init_count = ARRAY_SIZE(g12a_init_regs),
-};
-
-static const struct meson_eeclkc_data g12b_clkc_data = {
-	.regmap_clks = g12a_clk_regmaps,
-	.regmap_clk_num = ARRAY_SIZE(g12a_clk_regmaps),
-	.hw_onecell_data = &g12b_hw_onecell_data
+static int meson_g12a_dvfs_setup_common(struct platform_device *pdev,
+					struct clk_hw **hws)
+{
+	const char *notifier_clk_name;
+	struct clk *notifier_clk;
+	struct clk_hw *xtal;
+	int ret;
+
+	xtal = clk_hw_get_parent_by_index(hws[CLKID_CPU_CLK_DYN1_SEL], 0);
+
+	/* Setup clock notifier for cpu_clk_postmux0 */
+	g12a_cpu_clk_postmux0_nb_data.xtal = xtal;
+	notifier_clk_name = clk_hw_get_name(&g12a_cpu_clk_postmux0.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk,
+				    &g12a_cpu_clk_postmux0_nb_data.nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpu_clk_postmux0 notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for cpu_clk_dyn mux */
+	notifier_clk_name = clk_hw_get_name(&g12a_cpu_clk_dyn.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_cpu_clk_mux_nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpu_clk_dyn notifier\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int meson_g12b_dvfs_setup(struct platform_device *pdev)
+{
+	struct clk_hw **hws = g12b_hw_onecell_data.hws;
+	const char *notifier_clk_name;
+	struct clk *notifier_clk;
+	struct clk_hw *xtal;
+	int ret;
+
+	ret = meson_g12a_dvfs_setup_common(pdev, hws);
+	if (ret)
+		return ret;
+
+	xtal = clk_hw_get_parent_by_index(hws[CLKID_CPU_CLK_DYN1_SEL], 0);
+
+	/* Setup clock notifier for cpu_clk mux */
+	notifier_clk_name = clk_hw_get_name(&g12b_cpu_clk.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_cpu_clk_mux_nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpu_clk notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for sys1_pll */
+	notifier_clk_name = clk_hw_get_name(&g12b_sys1_pll.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk,
+				    &g12b_cpu_clk_sys1_pll_nb_data.nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the sys1_pll notifier\n");
+		return ret;
+	}
+
+	/* Add notifiers for the second CPU cluster */
+
+	/* Setup clock notifier for cpub_clk_postmux0 */
+	g12b_cpub_clk_postmux0_nb_data.xtal = xtal;
+	notifier_clk_name = clk_hw_get_name(&g12b_cpub_clk_postmux0.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk,
+				    &g12b_cpub_clk_postmux0_nb_data.nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpub_clk_postmux0 notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for cpub_clk_dyn mux */
+	notifier_clk_name = clk_hw_get_name(&g12b_cpub_clk_dyn.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_cpu_clk_mux_nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpub_clk_dyn notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for cpub_clk mux */
+	notifier_clk_name = clk_hw_get_name(&g12b_cpub_clk.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_cpu_clk_mux_nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpub_clk notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for sys_pll */
+	notifier_clk_name = clk_hw_get_name(&g12a_sys_pll.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk,
+				    &g12b_cpub_clk_sys_pll_nb_data.nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the sys_pll notifier\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int meson_g12a_dvfs_setup(struct platform_device *pdev)
+{
+	struct clk_hw **hws = g12a_hw_onecell_data.hws;
+	const char *notifier_clk_name;
+	struct clk *notifier_clk;
+	int ret;
+
+	ret = meson_g12a_dvfs_setup_common(pdev, hws);
+	if (ret)
+		return ret;
+
+	/* Setup clock notifier for cpu_clk mux */
+	notifier_clk_name = clk_hw_get_name(&g12a_cpu_clk.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_cpu_clk_mux_nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the cpu_clk notifier\n");
+		return ret;
+	}
+
+	/* Setup clock notifier for sys_pll */
+	notifier_clk_name = clk_hw_get_name(&g12a_sys_pll.hw);
+	notifier_clk = __clk_lookup(notifier_clk_name);
+	ret = clk_notifier_register(notifier_clk, &g12a_sys_pll_nb_data.nb);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register the sys_pll notifier\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+struct meson_g12a_data {
+	const struct meson_eeclkc_data eeclkc_data;
+	int (*dvfs_setup)(struct platform_device *pdev);
+};
+
+static int meson_g12a_probe(struct platform_device *pdev)
+{
+	const struct meson_eeclkc_data *eeclkc_data;
+	const struct meson_g12a_data *g12a_data;
+	int ret;
+
+	eeclkc_data = of_device_get_match_data(&pdev->dev);
+	if (!eeclkc_data)
+		return -EINVAL;
+
+	ret = meson_eeclkc_probe(pdev);
+	if (ret)
+		return ret;
+
+	g12a_data = container_of(eeclkc_data, struct meson_g12a_data,
+				 eeclkc_data);
+
+	if (g12a_data->dvfs_setup)
+		return g12a_data->dvfs_setup(pdev);
+
+	return 0;
+}
+
+static const struct meson_g12a_data g12a_clkc_data = {
+	.eeclkc_data = {
+		.regmap_clks = g12a_clk_regmaps,
+		.regmap_clk_num = ARRAY_SIZE(g12a_clk_regmaps),
+		.hw_onecell_data = &g12a_hw_onecell_data,
+		.init_regs = g12a_init_regs,
+		.init_count = ARRAY_SIZE(g12a_init_regs),
+	},
+	.dvfs_setup = meson_g12a_dvfs_setup,
+};
+
+static const struct meson_g12a_data g12b_clkc_data = {
+	.eeclkc_data = {
+		.regmap_clks = g12a_clk_regmaps,
+		.regmap_clk_num = ARRAY_SIZE(g12a_clk_regmaps),
+		.hw_onecell_data = &g12b_hw_onecell_data,
+	},
+	.dvfs_setup = meson_g12b_dvfs_setup,
 };
 
 static const struct of_device_id clkc_match_table[] = {
-	{ .compatible = "amlogic,g12a-clkc", .data = &g12a_clkc_data },
-	{ .compatible = "amlogic,g12b-clkc", .data = &g12b_clkc_data },
+	{
+		.compatible = "amlogic,g12a-clkc",
+		.data = &g12a_clkc_data.eeclkc_data
+	},
+	{
+		.compatible = "amlogic,g12b-clkc",
+		.data = &g12b_clkc_data.eeclkc_data
+	},
 	{}
 };
 
 static struct platform_driver g12a_driver = {
-	.probe		= meson_eeclkc_probe,
+	.probe		= meson_g12a_probe,
 	.driver		= {
 		.name	= "g12a-clkc",
 		.of_match_table = clkc_match_table,
-- 
2.22.0

[PATCH 4/4] clk: meson: g12a: expose CPUB clock ID for G12B

[Neil Armstrong]

Expose the CPUB clock id to add DVFS to the second CPU cluster of
the Amlogic G12B SoC.

Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 include/dt-bindings/clock/g12a-clkc.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/dt-bindings/clock/g12a-clkc.h b/include/dt-bindings/clock/g12a-clkc.h
index b6b127e45634..8ccc29ac7a72 100644
--- a/include/dt-bindings/clock/g12a-clkc.h
+++ b/include/dt-bindings/clock/g12a-clkc.h
@@ -137,5 +137,6 @@
 #define CLKID_VDEC_HEVC				207
 #define CLKID_VDEC_HEVCF			210
 #define CLKID_TS				212
+#define CLKID_CPUB_CLK				224
 
 #endif /* __G12A_CLKC_H */
-- 
2.22.0

Re: [PATCH 3/4] clk: meson: g12a: add notifiers to handle cpu clock change

[Jerome Brunet]

On Mon 29 Jul 2019 at 15:16, Neil Armstrong <narmstrong@baylibre.com> wrote:

> In order to implement clock switching for the CLKID_CPU_CLK and
> CLKID_CPUB_CLK, notifiers are added on specific points of the
> clock tree :
>
> cpu_clk / cpub_clk
> |   \- cpu_clk_dyn
> |      |  \- cpu_clk_premux0
> |      |        |- cpu_clk_postmux0
> |      |        |    |- cpu_clk_dyn0_div
> |      |        |    \- xtal/fclk_div2/fclk_div3
> |      |        \- xtal/fclk_div2/fclk_div3
> |      \- cpu_clk_premux1
> |            |- cpu_clk_postmux1
> |            |    |- cpu_clk_dyn1_div
> |            |    \- xtal/fclk_div2/fclk_div3
> |            \- xtal/fclk_div2/fclk_div3
> \ sys_pll / sys1_pll
>
> This for each cluster, a single one for G12A, two for G12B.
>
> Each cpu_clk_premux1 tree is marked as read-only and CLK_SET_RATE_NO_REPARENT,
> to be used as "parking" clock in a safe clock frequency.
>
> A notifier is added on each cpu_clk_premux0 to detech when CCF want to
> change the frequency of the cpu_clk_dyn tree.
> In this notifier, the cpu_clk_premux1 tree is configured to use the xtal
> clock and then the cpu_clk_dyn is switch to cpu_clk_premux1 while CCF
> updates the cpu_clk_premux0 tree.
>
> A notifier is added on each sys_pll/sys1_pll to detect when CCF wants to
> change the PLL clock source of the cpu_clk.
> In this notifier, the cpu_clk is switched to cpu_clk_dyn while CCF
> updates the sys_pll/sys1_pll frequency.
>
> A third small notifier is added on each cpu_clk / cpub_clk and cpu_clk_dyn,
> add a small delay at PRE_RATE_CHANGE/POST_RATE_CHANGE to let the other
> notofiers change propagate before changing the cpu_clk_premux0 and sys_pll
> clock trees.
>
> This notifier set permits switching the cpu_clk / cpub_clk without any
> glitches and using a safe parking clock while switching between sub-GHz
> clocks using the cpu_clk_dyn tree.
>
> This setup has been tested and validated on the Amlogic G12A and G12B
> SoCs running the arm64 cpuburn at [1] and cycling between all the possible
> cpufreq translations of each cluster and checking the final frequency using
> the clock-measurer, script at [2].
>
> [1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
> [2] https://gist.github.com/superna9999/d4de964dbc0f84b7d527e1df2ddea25f
> ---
>  drivers/clk/meson/g12a.c | 567 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 521 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
> index e4957fd9f91f..23162310c7ee 100644
> --- a/drivers/clk/meson/g12a.c
> +++ b/drivers/clk/meson/g12a.c
> @@ -14,6 +14,7 @@
>  #include <linux/init.h>
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
> +#include <linux/clk.h>
>  
>  #include "clk-mpll.h"
>  #include "clk-pll.h"
> @@ -88,16 +89,9 @@ static struct clk_regmap g12a_fixed_pll = {
>  	},
>  };
>  
> -/*
> - * Internal sys pll emulation configuration parameters
> - */
> -static const struct reg_sequence g12a_sys_init_regs[] = {
> -	{ .reg = HHI_SYS_PLL_CNTL1,	.def = 0x00000000 },
> -	{ .reg = HHI_SYS_PLL_CNTL2,	.def = 0x00000000 },
> -	{ .reg = HHI_SYS_PLL_CNTL3,	.def = 0x48681c00 },
> -	{ .reg = HHI_SYS_PLL_CNTL4,	.def = 0x88770290 },
> -	{ .reg = HHI_SYS_PLL_CNTL5,	.def = 0x39272000 },
> -	{ .reg = HHI_SYS_PLL_CNTL6,	.def = 0x56540000 },
> +static const struct pll_mult_range g12a_sys_pll_mult_range = {
> +	.min = 128,
> +	.max = 250,
>  };

The init sequence is removed, I suppose you were concerned about
glitching the clock on startup ?

Without the init sequence, it will inherit whatever is left by the
bootloader. We have seen in the past that this is not desirable.

I'm mostly concerned about CNTL3 to CNTL6. Should we apply the sequence
on .set_rate() instead ? It should be safe then ?

>

[...]

>  
> @@ -364,16 +366,50 @@ static struct clk_regmap g12a_cpu_clk_premux1 = {
>  	},
>  	.hw.init = &(struct clk_init_data){
>  		.name = "cpu_clk_dyn1_sel",
> -		.ops = &clk_regmap_mux_ro_ops,
> +		.ops = &clk_regmap_mux_ops,
>  		.parent_data = (const struct clk_parent_data []) {
>  			{ .fw_name = "xtal", },
>  			{ .hw = &g12a_fclk_div2.hw },
>  			{ .hw = &g12a_fclk_div3.hw },
>  		},
>  		.num_parents = 3,
> +		/* This sub-tree is used a parking clock */
> +		.flags = CLK_SET_RATE_NO_REPARENT
>  	},
>  };
>  
> +#define SYS_CPU_DYN_ENABLE	BIT(26)
> +
> +/* This divider uses bit 26 to take change in account */
> +static int g12a_cpu_clk_mux0_div_set_rate(struct clk_hw *hw, unsigned long rate,
> +					  unsigned long parent_rate)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = divider_get_val(rate, parent_rate, div->table, div->width,
> +			      div->flags);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = (unsigned int)ret << div->shift;
> +
> +	regmap_update_bits(clk->map, HHI_SYS_CPU_CLK_CNTL0,
> +			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
> +
> +	return regmap_update_bits(clk->map, div->offset,
> +				  clk_div_mask(div->width) << div->shift |
> +				  SYS_CPU_DYN_ENABLE, val);
> +};
> +
> +const struct clk_ops g12a_cpu_clk_mux0_div_ops = {
> +	.recalc_rate = clk_regmap_div_recalc_rate,
> +	.round_rate = clk_regmap_div_round_rate,
> +	.set_rate = g12a_cpu_clk_mux0_div_set_rate,
> +};

I would prefer if we could keep the clock drivers and clock controllers
separated.

Could you move the above above in another file ?

> +

[...]

>  
> +/* This divider uses bit 26 to take change in account */
> +static int g12b_cpub_clk_mux0_div_set_rate(struct clk_hw *hw,
> +					   unsigned long rate,
> +					   unsigned long parent_rate)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = divider_get_val(rate, parent_rate, div->table, div->width,
> +			      div->flags);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = (unsigned int)ret << div->shift;
> +
> +	regmap_update_bits(clk->map, HHI_SYS_CPUB_CLK_CNTL,

Unless I missed something, this function is same as the g12a with the
exception of the register address.

It seems this clock could have its own clock type and its own data
structure to store the 'dyn enable' register parameter.

> +			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
> +
> +	return regmap_update_bits(clk->map, div->offset,
> +				  clk_div_mask(div->width) << div->shift |
> +				  SYS_CPU_DYN_ENABLE, val);
> +};
> +
> +static const struct clk_ops g12b_cpub_clk_mux0_div_ops = {
> +	.recalc_rate = clk_regmap_div_recalc_rate,
> +	.round_rate = clk_regmap_div_round_rate,
> +	.set_rate = g12b_cpub_clk_mux0_div_set_rate,
> +};
> +

[...]

> +
> +static int g12a_cpu_clk_postmux_notifier_cb(struct notifier_block *nb,
> +					    unsigned long event, void *data)
> +{
> +	struct g12a_cpu_clk_postmux_nb_data *nb_data =
> +		container_of(nb, struct g12a_cpu_clk_postmux_nb_data, nb);
> +
> +	switch (event) {
> +	case PRE_RATE_CHANGE:
> +		/*
> +		 * This notifier means cpu_clk_postmux0 clock will be changed
> +		 * to feed cpu_clk, this is the current path :
> +		 * cpu_clk
> +		 *    \- cpu_clk_dyn
> +		 *          \- cpu_clk_postmux0
> +		 *                \- cpu_clk_muxX_div
> +		 *                      \- cpu_clk_premux0
> +		 *				\- fclk_div3 or fclk_div2
> +		 *		OR
> +		 *                \- cpu_clk_premux0
> +		 *			\- fclk_div3 or fclk_div2
> +		 */
> +
> +		/* Setup cpu_clk_premux1 to xtal */
> +		clk_hw_set_parent(nb_data->cpu_clk_premux1,
> +				  nb_data->xtal);
> +
> +		/* Setup cpu_clk_postmux1 to bypass divider */
> +		clk_hw_set_parent(nb_data->cpu_clk_postmux1,
> +				  nb_data->cpu_clk_premux1);
> +
> +		/* Switch to parking clk on cpu_clk_postmux1 */
> +		clk_hw_set_parent(nb_data->cpu_clk_dyn,
> +				  nb_data->cpu_clk_postmux1);
> +
> +		/*
> +		 * Now, cpu_clk is 24MHz in the current path :
> +		 * cpu_clk
> +		 *    \- cpu_clk_dyn
> +		 *          \- cpu_clk_postmux1
> +		 *                \- cpu_clk_premux1
> +		 *                      \- xtal
> +		 */
> +
> +		udelay(100);

Just curious about the this 100us delay. It seems fairly long, even at
24MHz. In your stress tests, have you tried shorter delays ? 10us maybe ?

> +
> +		return NOTIFY_OK;
> +
> +	case POST_RATE_CHANGE:
> +		/*
> +		 * The cpu_clk_postmux0 has ben updated, now switch back
> +		 * cpu_clk_dyn to cpu_clk_postmux0 and take the changes
> +		 * in account.
> +		 */
> +
> +		/* Configure cpu_clk_dyn back to cpu_clk_postmux0 */
> +		clk_hw_set_parent(nb_data->cpu_clk_dyn,
> +				  nb_data->cpu_clk_postmux0);
> +
> +		/*
> +		 * new path :
> +		 * cpu_clk
> +		 *    \- cpu_clk_dyn
> +		 *          \- cpu_clk_postmux0
> +		 *                \- cpu_clk_muxX_div
> +		 *                      \- cpu_clk_premux0
> +		 *				\- fclk_div3 or fclk_div2
> +		 *		OR
> +		 *                \- cpu_clk_premux0
> +		 *			\- fclk_div3 or fclk_div2
> +		 */
> +
> +		udelay(100);
> +
> +		return NOTIFY_OK;
> +
> +	default:
> +		return NOTIFY_DONE;
> +	}
> +}
> +

Re: [PATCH 3/4] clk: meson: g12a: add notifiers to handle cpu clock change

[Neil Armstrong]

On 30/07/2019 10:37, Jerome Brunet wrote:
> On Mon 29 Jul 2019 at 15:16, Neil Armstrong <narmstrong@baylibre.com> wrote:
> 
>> In order to implement clock switching for the CLKID_CPU_CLK and
>> CLKID_CPUB_CLK, notifiers are added on specific points of the
>> clock tree :
>>
>> cpu_clk / cpub_clk
>> |   \- cpu_clk_dyn
>> |      |  \- cpu_clk_premux0
>> |      |        |- cpu_clk_postmux0
>> |      |        |    |- cpu_clk_dyn0_div
>> |      |        |    \- xtal/fclk_div2/fclk_div3
>> |      |        \- xtal/fclk_div2/fclk_div3
>> |      \- cpu_clk_premux1
>> |            |- cpu_clk_postmux1
>> |            |    |- cpu_clk_dyn1_div
>> |            |    \- xtal/fclk_div2/fclk_div3
>> |            \- xtal/fclk_div2/fclk_div3
>> \ sys_pll / sys1_pll
>>
>> This for each cluster, a single one for G12A, two for G12B.
>>
>> Each cpu_clk_premux1 tree is marked as read-only and CLK_SET_RATE_NO_REPARENT,
>> to be used as "parking" clock in a safe clock frequency.
>>
>> A notifier is added on each cpu_clk_premux0 to detech when CCF want to
>> change the frequency of the cpu_clk_dyn tree.
>> In this notifier, the cpu_clk_premux1 tree is configured to use the xtal
>> clock and then the cpu_clk_dyn is switch to cpu_clk_premux1 while CCF
>> updates the cpu_clk_premux0 tree.
>>
>> A notifier is added on each sys_pll/sys1_pll to detect when CCF wants to
>> change the PLL clock source of the cpu_clk.
>> In this notifier, the cpu_clk is switched to cpu_clk_dyn while CCF
>> updates the sys_pll/sys1_pll frequency.
>>
>> A third small notifier is added on each cpu_clk / cpub_clk and cpu_clk_dyn,
>> add a small delay at PRE_RATE_CHANGE/POST_RATE_CHANGE to let the other
>> notofiers change propagate before changing the cpu_clk_premux0 and sys_pll
>> clock trees.
>>
>> This notifier set permits switching the cpu_clk / cpub_clk without any
>> glitches and using a safe parking clock while switching between sub-GHz
>> clocks using the cpu_clk_dyn tree.
>>
>> This setup has been tested and validated on the Amlogic G12A and G12B
>> SoCs running the arm64 cpuburn at [1] and cycling between all the possible
>> cpufreq translations of each cluster and checking the final frequency using
>> the clock-measurer, script at [2].
>>
>> [1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
>> [2] https://gist.github.com/superna9999/d4de964dbc0f84b7d527e1df2ddea25f

Signoff missing.... will fix in v2

>> ---
>>  drivers/clk/meson/g12a.c | 567 +++++++++++++++++++++++++++++++++++----
>>  1 file changed, 521 insertions(+), 46 deletions(-)
>>
>> diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
>> index e4957fd9f91f..23162310c7ee 100644
>> --- a/drivers/clk/meson/g12a.c
>> +++ b/drivers/clk/meson/g12a.c
>> @@ -14,6 +14,7 @@
>>  #include <linux/init.h>
>>  #include <linux/of_device.h>
>>  #include <linux/platform_device.h>
>> +#include <linux/clk.h>
>>  
>>  #include "clk-mpll.h"
>>  #include "clk-pll.h"
>> @@ -88,16 +89,9 @@ static struct clk_regmap g12a_fixed_pll = {
>>  	},
>>  };
>>  
>> -/*
>> - * Internal sys pll emulation configuration parameters
>> - */
>> -static const struct reg_sequence g12a_sys_init_regs[] = {
>> -	{ .reg = HHI_SYS_PLL_CNTL1,	.def = 0x00000000 },
>> -	{ .reg = HHI_SYS_PLL_CNTL2,	.def = 0x00000000 },
>> -	{ .reg = HHI_SYS_PLL_CNTL3,	.def = 0x48681c00 },
>> -	{ .reg = HHI_SYS_PLL_CNTL4,	.def = 0x88770290 },
>> -	{ .reg = HHI_SYS_PLL_CNTL5,	.def = 0x39272000 },
>> -	{ .reg = HHI_SYS_PLL_CNTL6,	.def = 0x56540000 },
>> +static const struct pll_mult_range g12a_sys_pll_mult_range = {
>> +	.min = 128,
>> +	.max = 250,
>>  };
> 
> The init sequence is removed, I suppose you were concerned about
> glitching the clock on startup ?
> 
> Without the init sequence, it will inherit whatever is left by the
> bootloader. We have seen in the past that this is not desirable.
> 
> I'm mostly concerned about CNTL3 to CNTL6. Should we apply the sequence
> on .set_rate() instead ? It should be safe then ?
> 

This PLL (and the SYS1_PLL) cannot be disabled (thus re-initialized) until
the cpu has been parked on a safe clock, and the default beahavior of the
current G12A & G12B BL2 is to setup this PLL and the SYS1_PLL to start with
the cores at 1,2GHz. So we can consider theses PLLs has been correctly
initialized, thus removing the init code and still be safe.

>>
> 
> [...]
> 
>>  
>> @@ -364,16 +366,50 @@ static struct clk_regmap g12a_cpu_clk_premux1 = {
>>  	},
>>  	.hw.init = &(struct clk_init_data){
>>  		.name = "cpu_clk_dyn1_sel",
>> -		.ops = &clk_regmap_mux_ro_ops,
>> +		.ops = &clk_regmap_mux_ops,
>>  		.parent_data = (const struct clk_parent_data []) {
>>  			{ .fw_name = "xtal", },
>>  			{ .hw = &g12a_fclk_div2.hw },
>>  			{ .hw = &g12a_fclk_div3.hw },
>>  		},
>>  		.num_parents = 3,
>> +		/* This sub-tree is used a parking clock */
>> +		.flags = CLK_SET_RATE_NO_REPARENT
>>  	},
>>  };
>>  
>> +#define SYS_CPU_DYN_ENABLE	BIT(26)
>> +
>> +/* This divider uses bit 26 to take change in account */
>> +static int g12a_cpu_clk_mux0_div_set_rate(struct clk_hw *hw, unsigned long rate,
>> +					  unsigned long parent_rate)
>> +{
>> +	struct clk_regmap *clk = to_clk_regmap(hw);
>> +	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
>> +	unsigned int val;
>> +	int ret;
>> +
>> +	ret = divider_get_val(rate, parent_rate, div->table, div->width,
>> +			      div->flags);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	val = (unsigned int)ret << div->shift;
>> +
>> +	regmap_update_bits(clk->map, HHI_SYS_CPU_CLK_CNTL0,
>> +			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
>> +
>> +	return regmap_update_bits(clk->map, div->offset,
>> +				  clk_div_mask(div->width) << div->shift |
>> +				  SYS_CPU_DYN_ENABLE, val);
>> +};
>> +
>> +const struct clk_ops g12a_cpu_clk_mux0_div_ops = {
>> +	.recalc_rate = clk_regmap_div_recalc_rate,
>> +	.round_rate = clk_regmap_div_round_rate,
>> +	.set_rate = g12a_cpu_clk_mux0_div_set_rate,
>> +};
> 
> I would prefer if we could keep the clock drivers and clock controllers
> separated.
> 
> Could you move the above above in another file ?

Yup, done

> 
>> +
> 
> [...]
> 
>>  
>> +/* This divider uses bit 26 to take change in account */
>> +static int g12b_cpub_clk_mux0_div_set_rate(struct clk_hw *hw,
>> +					   unsigned long rate,
>> +					   unsigned long parent_rate)
>> +{
>> +	struct clk_regmap *clk = to_clk_regmap(hw);
>> +	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
>> +	unsigned int val;
>> +	int ret;
>> +
>> +	ret = divider_get_val(rate, parent_rate, div->table, div->width,
>> +			      div->flags);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	val = (unsigned int)ret << div->shift;
>> +
>> +	regmap_update_bits(clk->map, HHI_SYS_CPUB_CLK_CNTL,
> 
> Unless I missed something, this function is same as the g12a with the
> exception of the register address.
> 
> It seems this clock could have its own clock type and its own data
> structure to store the 'dyn enable' register parameter.

Yup done

> 
>> +			   SYS_CPU_DYN_ENABLE, SYS_CPU_DYN_ENABLE);
>> +
>> +	return regmap_update_bits(clk->map, div->offset,
>> +				  clk_div_mask(div->width) << div->shift |
>> +				  SYS_CPU_DYN_ENABLE, val);
>> +};
>> +
>> +static const struct clk_ops g12b_cpub_clk_mux0_div_ops = {
>> +	.recalc_rate = clk_regmap_div_recalc_rate,
>> +	.round_rate = clk_regmap_div_round_rate,
>> +	.set_rate = g12b_cpub_clk_mux0_div_set_rate,
>> +};
>> +
> 
> [...]
> 
>> +
>> +static int g12a_cpu_clk_postmux_notifier_cb(struct notifier_block *nb,
>> +					    unsigned long event, void *data)
>> +{
>> +	struct g12a_cpu_clk_postmux_nb_data *nb_data =
>> +		container_of(nb, struct g12a_cpu_clk_postmux_nb_data, nb);
>> +
>> +	switch (event) {
>> +	case PRE_RATE_CHANGE:
>> +		/*
>> +		 * This notifier means cpu_clk_postmux0 clock will be changed
>> +		 * to feed cpu_clk, this is the current path :
>> +		 * cpu_clk
>> +		 *    \- cpu_clk_dyn
>> +		 *          \- cpu_clk_postmux0
>> +		 *                \- cpu_clk_muxX_div
>> +		 *                      \- cpu_clk_premux0
>> +		 *				\- fclk_div3 or fclk_div2
>> +		 *		OR
>> +		 *                \- cpu_clk_premux0
>> +		 *			\- fclk_div3 or fclk_div2
>> +		 */
>> +
>> +		/* Setup cpu_clk_premux1 to xtal */
>> +		clk_hw_set_parent(nb_data->cpu_clk_premux1,
>> +				  nb_data->xtal);
>> +
>> +		/* Setup cpu_clk_postmux1 to bypass divider */
>> +		clk_hw_set_parent(nb_data->cpu_clk_postmux1,
>> +				  nb_data->cpu_clk_premux1);
>> +
>> +		/* Switch to parking clk on cpu_clk_postmux1 */
>> +		clk_hw_set_parent(nb_data->cpu_clk_dyn,
>> +				  nb_data->cpu_clk_postmux1);
>> +
>> +		/*
>> +		 * Now, cpu_clk is 24MHz in the current path :
>> +		 * cpu_clk
>> +		 *    \- cpu_clk_dyn
>> +		 *          \- cpu_clk_postmux1
>> +		 *                \- cpu_clk_premux1
>> +		 *                      \- xtal
>> +		 */
>> +
>> +		udelay(100);
> 
> Just curious about the this 100us delay. It seems fairly long, even at
> 24MHz. In your stress tests, have you tried shorter delays ? 10us maybe ?

Honestly no, I took the values from Amlogic implementation to be safe for
the first implementation, and I gave all my test scripts and utilities for
others to re-run them to eventually reduce these values to 10us in a second
time.

> 
>> +
>> +		return NOTIFY_OK;
>> +
>> +	case POST_RATE_CHANGE:
>> +		/*
>> +		 * The cpu_clk_postmux0 has ben updated, now switch back
>> +		 * cpu_clk_dyn to cpu_clk_postmux0 and take the changes
>> +		 * in account.
>> +		 */
>> +
>> +		/* Configure cpu_clk_dyn back to cpu_clk_postmux0 */
>> +		clk_hw_set_parent(nb_data->cpu_clk_dyn,
>> +				  nb_data->cpu_clk_postmux0);
>> +
>> +		/*
>> +		 * new path :
>> +		 * cpu_clk
>> +		 *    \- cpu_clk_dyn
>> +		 *          \- cpu_clk_postmux0
>> +		 *                \- cpu_clk_muxX_div
>> +		 *                      \- cpu_clk_premux0
>> +		 *				\- fclk_div3 or fclk_div2
>> +		 *		OR
>> +		 *                \- cpu_clk_premux0
>> +		 *			\- fclk_div3 or fclk_div2
>> +		 */
>> +
>> +		udelay(100);
>> +
>> +		return NOTIFY_OK;
>> +
>> +	default:
>> +		return NOTIFY_DONE;
>> +	}
>> +}
>> +

Thanks,
Neil

Re: [PATCH 2/4] clk: meson: regmap: export regmap_div ops functions

[Neil Armstrong]

On 29/07/2019 15:16, Neil Armstrong wrote:
> The G12A CPU Clock Postmux divider needs a custom div_set_rate() call.
> 
> Export the clk_regmap_div_round_rate() and clk_regmap_div_recalc_rate()
> to be able to override the default clk_regmap_div_set_rate() callback.

Signoff missing.... will fix in v2

> ---
>  drivers/clk/meson/clk-regmap.c | 10 ++++++----
>  drivers/clk/meson/clk-regmap.h |  5 +++++
>  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/meson/clk-regmap.c b/drivers/clk/meson/clk-regmap.c
> index dcd1757cc5df..26c8c74a8cf0 100644
> --- a/drivers/clk/meson/clk-regmap.c
> +++ b/drivers/clk/meson/clk-regmap.c
> @@ -56,8 +56,8 @@ const struct clk_ops clk_regmap_gate_ro_ops = {
>  };
>  EXPORT_SYMBOL_GPL(clk_regmap_gate_ro_ops);
>  
> -static unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
> -						unsigned long prate)
> +unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
> +					 unsigned long prate)
>  {
>  	struct clk_regmap *clk = to_clk_regmap(hw);
>  	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
> @@ -74,9 +74,10 @@ static unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
>  	return divider_recalc_rate(hw, prate, val, div->table, div->flags,
>  				   div->width);
>  }
> +EXPORT_SYMBOL_GPL(clk_regmap_div_recalc_rate);
>  
> -static long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
> -				      unsigned long *prate)
> +long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
> +			       unsigned long *prate)
>  {
>  	struct clk_regmap *clk = to_clk_regmap(hw);
>  	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
> @@ -100,6 +101,7 @@ static long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
>  	return divider_round_rate(hw, rate, prate, div->table, div->width,
>  				  div->flags);
>  }
> +EXPORT_SYMBOL_GPL(clk_regmap_div_round_rate);
>  
>  static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
>  				   unsigned long parent_rate)
> diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
> index c4a39604cffd..ebf776a32ce3 100644
> --- a/drivers/clk/meson/clk-regmap.h
> +++ b/drivers/clk/meson/clk-regmap.h
> @@ -78,6 +78,11 @@ clk_get_regmap_div_data(struct clk_regmap *clk)
>  	return (struct clk_regmap_div_data *)clk->data;
>  }
>  
> +unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
> +					 unsigned long prate);
> +long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
> +			       unsigned long *prate);
> +
>  extern const struct clk_ops clk_regmap_divider_ops;
>  extern const struct clk_ops clk_regmap_divider_ro_ops;
>  
> 

Re: [PATCH 4/4] clk: meson: g12a: expose CPUB clock ID for G12B

[Neil Armstrong]

On 29/07/2019 15:16, Neil Armstrong wrote:
> Expose the CPUB clock id to add DVFS to the second CPU cluster of
> the Amlogic G12B SoC.
> 
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  include/dt-bindings/clock/g12a-clkc.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/dt-bindings/clock/g12a-clkc.h b/include/dt-bindings/clock/g12a-clkc.h
> index b6b127e45634..8ccc29ac7a72 100644
> --- a/include/dt-bindings/clock/g12a-clkc.h
> +++ b/include/dt-bindings/clock/g12a-clkc.h
> @@ -137,5 +137,6 @@
>  #define CLKID_VDEC_HEVC				207
>  #define CLKID_VDEC_HEVCF			210
>  #define CLKID_TS				212
> +#define CLKID_CPUB_CLK				224

Missing removal from private g12.h :-/ will fix in v2

>  
>  #endif /* __G12A_CLKC_H */
>