[PATCH 0/6] clk: samsung: exynos850: Clock driver improvements

[PATCH 0/6] clk: samsung: exynos850: Clock driver improvements

[Sam Protsenko]

This cumulative series supersedes next patches/series:
  1. CMU_APM domain implementation series [1]
  2. CMU_CMGP domain implementation series [2]
  3. "Register clocks early" patch [3]

with changes as follows:
  - add "Keep some crucial clocks running" patch [6/6]
  - enable CMU_PERI parent clock early
  - move bindings headers changes into bindings doc patches

Tested:
  - CMU_TOP is registered before CMU_PERI
  - CMU_PERI parent clock is enabled early and successfully, and running
    before any access to CMU_PERI registers
  - kernel boots successfully without "clk_ignore_unused" param
  - MCT timer works fine and doesn't panic during bootup

[1] https://lkml.org/lkml/2021/10/22/978
[2] https://lkml.org/lkml/2021/11/9/660
[3] https://lkml.org/lkml/2021/10/25/818

Sam Protsenko (6):
  dt-bindings: clock: Add bindings for Exynos850 CMU_APM
  clk: samsung: exynos850: Implement CMU_APM domain
  dt-bindings: clock: Add bindings for Exynos850 CMU_CMGP
  clk: samsung: exynos850: Implement CMU_CMGP domain
  clk: samsung: exynos850: Register clocks early
  clk: samsung: exynos850: Keep some crucial clocks running

 .../clock/samsung,exynos850-clock.yaml        |  38 ++
 drivers/clk/samsung/clk-exynos850.c           | 327 ++++++++++++++++--
 include/dt-bindings/clock/exynos850.h         |  46 ++-
 3 files changed, 387 insertions(+), 24 deletions(-)

-- 
2.30.2

[PATCH 1/6] dt-bindings: clock: Add bindings for Exynos850 CMU_APM

[Sam Protsenko]

CMU_APM generates clocks for APM IP-core (Active Power Management). In
particular it generates RTC clocks, which are needed to enable rtc-s3c
driver on Exynos850 SoC.

Add clock indices and binding documentation for CMU_APM.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 .../clock/samsung,exynos850-clock.yaml        | 19 ++++++++++++
 include/dt-bindings/clock/exynos850.h         | 29 ++++++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
index 7f8c91a29b91..5618cfa62f80 100644
--- a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
+++ b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
@@ -32,6 +32,7 @@ properties:
   compatible:
     enum:
       - samsung,exynos850-cmu-top
+      - samsung,exynos850-cmu-apm
       - samsung,exynos850-cmu-core
       - samsung,exynos850-cmu-dpu
       - samsung,exynos850-cmu-hsi
@@ -68,6 +69,24 @@ allOf:
           items:
             - const: oscclk
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos850-cmu-apm
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: External reference clock (26 MHz)
+            - description: CMU_APM bus clock (from CMU_TOP)
+
+        clock-names:
+          items:
+            - const: oscclk
+            - const: dout_clkcmu_apm_bus
+
   - if:
       properties:
         compatible:
diff --git a/include/dt-bindings/clock/exynos850.h b/include/dt-bindings/clock/exynos850.h
index 8999184f94a2..df3978b58304 100644
--- a/include/dt-bindings/clock/exynos850.h
+++ b/include/dt-bindings/clock/exynos850.h
@@ -55,7 +55,34 @@
 #define CLK_GOUT_PERI_BUS		43
 #define CLK_GOUT_PERI_UART		44
 #define CLK_GOUT_PERI_IP		45
-#define TOP_NR_CLK			46
+#define CLK_MOUT_CLKCMU_APM_BUS		46
+#define CLK_DOUT_CLKCMU_APM_BUS		47
+#define CLK_GOUT_CLKCMU_APM_BUS		48
+#define TOP_NR_CLK			49
+
+/* CMU_APM */
+#define CLK_RCO_I3C_PMIC		1
+#define OSCCLK_RCO_APM			2
+#define CLK_RCO_APM__ALV		3
+#define CLK_DLL_DCO			4
+#define CLK_MOUT_APM_BUS_USER		5
+#define CLK_MOUT_RCO_APM_I3C_USER	6
+#define CLK_MOUT_RCO_APM_USER		7
+#define CLK_MOUT_DLL_USER		8
+#define CLK_MOUT_CLKCMU_CHUB_BUS	9
+#define CLK_MOUT_APM_BUS		10
+#define CLK_MOUT_APM_I3C		11
+#define CLK_DOUT_CLKCMU_CHUB_BUS	12
+#define CLK_DOUT_APM_BUS		13
+#define CLK_DOUT_APM_I3C		14
+#define CLK_GOUT_CLKCMU_CMGP_BUS	15
+#define CLK_GOUT_CLKCMU_CHUB_BUS	16
+#define CLK_GOUT_RTC_PCLK		17
+#define CLK_GOUT_TOP_RTC_PCLK		18
+#define CLK_GOUT_I3C_PCLK		19
+#define CLK_GOUT_I3C_SCLK		20
+#define CLK_GOUT_SPEEDY_PCLK		21
+#define APM_NR_CLK			22
 
 /* CMU_HSI */
 #define CLK_MOUT_HSI_BUS_USER		1
-- 
2.30.2

Re: [PATCH 1/6] dt-bindings: clock: Add bindings for Exynos850 CMU_APM

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> CMU_APM generates clocks for APM IP-core (Active Power Management). In
> particular it generates RTC clocks, which are needed to enable rtc-s3c
> driver on Exynos850 SoC.
> 
> Add clock indices and binding documentation for CMU_APM.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Applied, thanks.

[PATCH 2/6] clk: samsung: exynos850: Implement CMU_APM domain

[Sam Protsenko]

CMU_APM clock domain provides clocks for APM IP-core (Active Power
Management). According to Exynos850 TRM, CMU_APM generates I3C, Mailbox,
Speedy, Timer, WDT, RTC and PMU clocks for BLK_ALIVE.

This patch adds next clocks:
  - bus clocks in CMU_TOP needed for CMU_APM
  - all internal CMU_APM clocks
  - leaf clocks for I3C, Speedy and RTC IP-cores
  - bus clocks for CMU_CMGP and CMU_CHUB

CMU_APM doesn't belong to Power Domains, but platform driver is used for
its registration to keep its bus clock always running. Otherwise rtc-s3c
driver disables that clock and system freezes.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/clk/samsung/clk-exynos850.c | 142 +++++++++++++++++++++++++++-
 1 file changed, 141 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-exynos850.c b/drivers/clk/samsung/clk-exynos850.c
index 2294989e244c..95e373d17b42 100644
--- a/drivers/clk/samsung/clk-exynos850.c
+++ b/drivers/clk/samsung/clk-exynos850.c
@@ -72,6 +72,7 @@ static void __init exynos850_init_clocks(struct device_node *np,
 #define PLL_CON3_PLL_SHARED0			0x014c
 #define PLL_CON0_PLL_SHARED1			0x0180
 #define PLL_CON3_PLL_SHARED1			0x018c
+#define CLK_CON_MUX_MUX_CLKCMU_APM_BUS		0x1000
 #define CLK_CON_MUX_MUX_CLKCMU_CORE_BUS		0x1014
 #define CLK_CON_MUX_MUX_CLKCMU_CORE_CCI		0x1018
 #define CLK_CON_MUX_MUX_CLKCMU_CORE_MMC_EMBD	0x101c
@@ -83,6 +84,7 @@ static void __init exynos850_init_clocks(struct device_node *np,
 #define CLK_CON_MUX_MUX_CLKCMU_PERI_BUS		0x1070
 #define CLK_CON_MUX_MUX_CLKCMU_PERI_IP		0x1074
 #define CLK_CON_MUX_MUX_CLKCMU_PERI_UART	0x1078
+#define CLK_CON_DIV_CLKCMU_APM_BUS		0x180c
 #define CLK_CON_DIV_CLKCMU_CORE_BUS		0x1820
 #define CLK_CON_DIV_CLKCMU_CORE_CCI		0x1824
 #define CLK_CON_DIV_CLKCMU_CORE_MMC_EMBD	0x1828
@@ -100,6 +102,7 @@ static void __init exynos850_init_clocks(struct device_node *np,
 #define CLK_CON_DIV_PLL_SHARED1_DIV2		0x1898
 #define CLK_CON_DIV_PLL_SHARED1_DIV3		0x189c
 #define CLK_CON_DIV_PLL_SHARED1_DIV4		0x18a0
+#define CLK_CON_GAT_GATE_CLKCMU_APM_BUS		0x2008
 #define CLK_CON_GAT_GATE_CLKCMU_CORE_BUS	0x201c
 #define CLK_CON_GAT_GATE_CLKCMU_CORE_CCI	0x2020
 #define CLK_CON_GAT_GATE_CLKCMU_CORE_MMC_EMBD	0x2024
@@ -122,6 +125,7 @@ static const unsigned long top_clk_regs[] __initconst = {
 	PLL_CON3_PLL_SHARED0,
 	PLL_CON0_PLL_SHARED1,
 	PLL_CON3_PLL_SHARED1,
+	CLK_CON_MUX_MUX_CLKCMU_APM_BUS,
 	CLK_CON_MUX_MUX_CLKCMU_CORE_BUS,
 	CLK_CON_MUX_MUX_CLKCMU_CORE_CCI,
 	CLK_CON_MUX_MUX_CLKCMU_CORE_MMC_EMBD,
@@ -133,6 +137,7 @@ static const unsigned long top_clk_regs[] __initconst = {
 	CLK_CON_MUX_MUX_CLKCMU_PERI_BUS,
 	CLK_CON_MUX_MUX_CLKCMU_PERI_IP,
 	CLK_CON_MUX_MUX_CLKCMU_PERI_UART,
+	CLK_CON_DIV_CLKCMU_APM_BUS,
 	CLK_CON_DIV_CLKCMU_CORE_BUS,
 	CLK_CON_DIV_CLKCMU_CORE_CCI,
 	CLK_CON_DIV_CLKCMU_CORE_MMC_EMBD,
@@ -150,6 +155,7 @@ static const unsigned long top_clk_regs[] __initconst = {
 	CLK_CON_DIV_PLL_SHARED1_DIV2,
 	CLK_CON_DIV_PLL_SHARED1_DIV3,
 	CLK_CON_DIV_PLL_SHARED1_DIV4,
+	CLK_CON_GAT_GATE_CLKCMU_APM_BUS,
 	CLK_CON_GAT_GATE_CLKCMU_CORE_BUS,
 	CLK_CON_GAT_GATE_CLKCMU_CORE_CCI,
 	CLK_CON_GAT_GATE_CLKCMU_CORE_MMC_EMBD,
@@ -183,6 +189,8 @@ static const struct samsung_pll_clock top_pll_clks[] __initconst = {
 PNAME(mout_shared0_pll_p)	= { "oscclk", "fout_shared0_pll" };
 PNAME(mout_shared1_pll_p)	= { "oscclk", "fout_shared1_pll" };
 PNAME(mout_mmc_pll_p)		= { "oscclk", "fout_mmc_pll" };
+/* List of parent clocks for Muxes in CMU_TOP: for CMU_APM */
+PNAME(mout_clkcmu_apm_bus_p)	= { "dout_shared0_div4", "pll_shared1_div4" };
 /* List of parent clocks for Muxes in CMU_TOP: for CMU_CORE */
 PNAME(mout_core_bus_p)		= { "dout_shared1_div2", "dout_shared0_div3",
 				    "dout_shared1_div3", "dout_shared0_div4" };
@@ -222,6 +230,10 @@ static const struct samsung_mux_clock top_mux_clks[] __initconst = {
 	MUX(CLK_MOUT_MMC_PLL, "mout_mmc_pll", mout_mmc_pll_p,
 	    PLL_CON0_PLL_MMC, 4, 1),
 
+	/* APM */
+	MUX(CLK_MOUT_CLKCMU_APM_BUS, "mout_clkcmu_apm_bus",
+	    mout_clkcmu_apm_bus_p, CLK_CON_MUX_MUX_CLKCMU_APM_BUS, 0, 1),
+
 	/* CORE */
 	MUX(CLK_MOUT_CORE_BUS, "mout_core_bus", mout_core_bus_p,
 	    CLK_CON_MUX_MUX_CLKCMU_CORE_BUS, 0, 2),
@@ -268,6 +280,10 @@ static const struct samsung_div_clock top_div_clks[] __initconst = {
 	DIV(CLK_DOUT_SHARED1_DIV4, "dout_shared1_div4", "dout_shared1_div2",
 	    CLK_CON_DIV_PLL_SHARED1_DIV4, 0, 1),
 
+	/* APM */
+	DIV(CLK_DOUT_CLKCMU_APM_BUS, "dout_clkcmu_apm_bus",
+	    "gout_clkcmu_apm_bus", CLK_CON_DIV_CLKCMU_APM_BUS, 0, 3),
+
 	/* CORE */
 	DIV(CLK_DOUT_CORE_BUS, "dout_core_bus", "gout_core_bus",
 	    CLK_CON_DIV_CLKCMU_CORE_BUS, 0, 4),
@@ -310,6 +326,10 @@ static const struct samsung_gate_clock top_gate_clks[] __initconst = {
 	GATE(CLK_GOUT_CORE_SSS, "gout_core_sss", "mout_core_sss",
 	     CLK_CON_GAT_GATE_CLKCMU_CORE_SSS, 21, 0, 0),
 
+	/* APM */
+	GATE(CLK_GOUT_CLKCMU_APM_BUS, "gout_clkcmu_apm_bus",
+	     "mout_clkcmu_apm_bus", CLK_CON_GAT_GATE_CLKCMU_APM_BUS, 21, 0, 0),
+
 	/* DPU */
 	GATE(CLK_GOUT_DPU, "gout_dpu", "mout_dpu",
 	     CLK_CON_GAT_GATE_CLKCMU_DPU, 21, 0, 0),
@@ -354,6 +374,124 @@ static void __init exynos850_cmu_top_init(struct device_node *np)
 CLK_OF_DECLARE(exynos850_cmu_top, "samsung,exynos850-cmu-top",
 	       exynos850_cmu_top_init);
 
+/* ---- CMU_APM ------------------------------------------------------------- */
+
+/* Register Offset definitions for CMU_APM (0x11800000) */
+#define PLL_CON0_MUX_CLKCMU_APM_BUS_USER		0x0600
+#define PLL_CON0_MUX_CLK_RCO_APM_I3C_USER		0x0610
+#define PLL_CON0_MUX_CLK_RCO_APM_USER			0x0620
+#define PLL_CON0_MUX_DLL_USER				0x0630
+#define CLK_CON_MUX_MUX_CLKCMU_CHUB_BUS			0x1000
+#define CLK_CON_MUX_MUX_CLK_APM_BUS			0x1004
+#define CLK_CON_MUX_MUX_CLK_APM_I3C			0x1008
+#define CLK_CON_DIV_CLKCMU_CHUB_BUS			0x1800
+#define CLK_CON_DIV_DIV_CLK_APM_BUS			0x1804
+#define CLK_CON_DIV_DIV_CLK_APM_I3C			0x1808
+#define CLK_CON_GAT_CLKCMU_CMGP_BUS			0x2000
+#define CLK_CON_GAT_GATE_CLKCMU_CHUB_BUS		0x2014
+#define CLK_CON_GAT_GOUT_APM_APBIF_RTC_PCLK		0x2024
+#define CLK_CON_GAT_GOUT_APM_APBIF_TOP_RTC_PCLK		0x2028
+#define CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_PCLK	0x2034
+#define CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_SCLK	0x2038
+#define CLK_CON_GAT_GOUT_APM_SPEEDY_APM_PCLK		0x20bc
+
+static const unsigned long apm_clk_regs[] __initconst = {
+	PLL_CON0_MUX_CLKCMU_APM_BUS_USER,
+	PLL_CON0_MUX_CLK_RCO_APM_I3C_USER,
+	PLL_CON0_MUX_CLK_RCO_APM_USER,
+	PLL_CON0_MUX_DLL_USER,
+	CLK_CON_MUX_MUX_CLKCMU_CHUB_BUS,
+	CLK_CON_MUX_MUX_CLK_APM_BUS,
+	CLK_CON_MUX_MUX_CLK_APM_I3C,
+	CLK_CON_DIV_CLKCMU_CHUB_BUS,
+	CLK_CON_DIV_DIV_CLK_APM_BUS,
+	CLK_CON_DIV_DIV_CLK_APM_I3C,
+	CLK_CON_GAT_CLKCMU_CMGP_BUS,
+	CLK_CON_GAT_GATE_CLKCMU_CHUB_BUS,
+	CLK_CON_GAT_GOUT_APM_APBIF_RTC_PCLK,
+	CLK_CON_GAT_GOUT_APM_APBIF_TOP_RTC_PCLK,
+	CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_PCLK,
+	CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_SCLK,
+	CLK_CON_GAT_GOUT_APM_SPEEDY_APM_PCLK,
+};
+
+/* List of parent clocks for Muxes in CMU_APM */
+PNAME(mout_apm_bus_user_p)	= { "oscclk_rco_apm", "dout_clkcmu_apm_bus" };
+PNAME(mout_rco_apm_i3c_user_p)	= { "oscclk_rco_apm", "clk_rco_i3c_pmic" };
+PNAME(mout_rco_apm_user_p)	= { "oscclk_rco_apm", "clk_rco_apm__alv" };
+PNAME(mout_dll_user_p)		= { "oscclk_rco_apm", "clk_dll_dco" };
+PNAME(mout_clkcmu_chub_bus_p)	= { "mout_apm_bus_user", "mout_dll_user" };
+PNAME(mout_apm_bus_p)		= { "mout_rco_apm_user", "mout_apm_bus_user",
+				    "mout_dll_user", "oscclk_rco_apm" };
+PNAME(mout_apm_i3c_p)		= { "dout_apm_i3c", "mout_rco_apm_i3c_user" };
+
+static const struct samsung_fixed_rate_clock apm_fixed_clks[] __initconst = {
+	FRATE(CLK_RCO_I3C_PMIC, "clk_rco_i3c_pmic", NULL, 0, 491520000),
+	FRATE(OSCCLK_RCO_APM, "oscclk_rco_apm", NULL, 0, 24576000),
+	FRATE(CLK_RCO_APM__ALV, "clk_rco_apm__alv", NULL, 0, 49152000),
+	FRATE(CLK_DLL_DCO, "clk_dll_dco", NULL, 0, 360000000),
+};
+
+static const struct samsung_mux_clock apm_mux_clks[] __initconst = {
+	MUX(CLK_MOUT_APM_BUS_USER, "mout_apm_bus_user", mout_apm_bus_user_p,
+	    PLL_CON0_MUX_CLKCMU_APM_BUS_USER, 4, 1),
+	MUX(CLK_MOUT_RCO_APM_I3C_USER, "mout_rco_apm_i3c_user",
+	    mout_rco_apm_i3c_user_p, PLL_CON0_MUX_CLK_RCO_APM_I3C_USER, 4, 1),
+	MUX(CLK_MOUT_RCO_APM_USER, "mout_rco_apm_user", mout_rco_apm_user_p,
+	    PLL_CON0_MUX_CLK_RCO_APM_USER, 4, 1),
+	MUX(CLK_MOUT_DLL_USER, "mout_dll_user", mout_dll_user_p,
+	    PLL_CON0_MUX_DLL_USER, 4, 1),
+	MUX(CLK_MOUT_CLKCMU_CHUB_BUS, "mout_clkcmu_chub_bus",
+	    mout_clkcmu_chub_bus_p, CLK_CON_MUX_MUX_CLKCMU_CHUB_BUS, 0, 1),
+	MUX(CLK_MOUT_APM_BUS, "mout_apm_bus", mout_apm_bus_p,
+	    CLK_CON_MUX_MUX_CLK_APM_BUS, 0, 2),
+	MUX(CLK_MOUT_APM_I3C, "mout_apm_i3c", mout_apm_i3c_p,
+	    CLK_CON_MUX_MUX_CLK_APM_I3C, 0, 1),
+};
+
+static const struct samsung_div_clock apm_div_clks[] __initconst = {
+	DIV(CLK_DOUT_CLKCMU_CHUB_BUS, "dout_clkcmu_chub_bus",
+	    "gout_clkcmu_chub_bus",
+	    CLK_CON_DIV_CLKCMU_CHUB_BUS, 0, 3),
+	DIV(CLK_DOUT_APM_BUS, "dout_apm_bus", "mout_apm_bus",
+	    CLK_CON_DIV_DIV_CLK_APM_BUS, 0, 3),
+	DIV(CLK_DOUT_APM_I3C, "dout_apm_i3c", "mout_apm_bus",
+	    CLK_CON_DIV_DIV_CLK_APM_I3C, 0, 3),
+};
+
+static const struct samsung_gate_clock apm_gate_clks[] __initconst = {
+	GATE(CLK_GOUT_CLKCMU_CMGP_BUS, "gout_clkcmu_cmgp_bus", "dout_apm_bus",
+	     CLK_CON_GAT_CLKCMU_CMGP_BUS, 21, 0, 0),
+	GATE(CLK_GOUT_CLKCMU_CHUB_BUS, "gout_clkcmu_chub_bus",
+	     "mout_clkcmu_chub_bus",
+	     CLK_CON_GAT_GATE_CLKCMU_CHUB_BUS, 21, 0, 0),
+	GATE(CLK_GOUT_RTC_PCLK, "gout_rtc_pclk", "dout_apm_bus",
+	     CLK_CON_GAT_GOUT_APM_APBIF_RTC_PCLK, 21, 0, 0),
+	GATE(CLK_GOUT_TOP_RTC_PCLK, "gout_top_rtc_pclk", "dout_apm_bus",
+	     CLK_CON_GAT_GOUT_APM_APBIF_TOP_RTC_PCLK, 21, 0, 0),
+	GATE(CLK_GOUT_I3C_PCLK, "gout_i3c_pclk", "dout_apm_bus",
+	     CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_PCLK, 21, 0, 0),
+	GATE(CLK_GOUT_I3C_SCLK, "gout_i3c_sclk", "mout_apm_i3c",
+	     CLK_CON_GAT_GOUT_APM_I3C_APM_PMIC_I_SCLK, 21, 0, 0),
+	GATE(CLK_GOUT_SPEEDY_PCLK, "gout_speedy_pclk", "dout_apm_bus",
+	     CLK_CON_GAT_GOUT_APM_SPEEDY_APM_PCLK, 21, 0, 0),
+};
+
+static const struct samsung_cmu_info apm_cmu_info __initconst = {
+	.mux_clks		= apm_mux_clks,
+	.nr_mux_clks		= ARRAY_SIZE(apm_mux_clks),
+	.div_clks		= apm_div_clks,
+	.nr_div_clks		= ARRAY_SIZE(apm_div_clks),
+	.gate_clks		= apm_gate_clks,
+	.nr_gate_clks		= ARRAY_SIZE(apm_gate_clks),
+	.fixed_clks		= apm_fixed_clks,
+	.nr_fixed_clks		= ARRAY_SIZE(apm_fixed_clks),
+	.nr_clk_ids		= APM_NR_CLK,
+	.clk_regs		= apm_clk_regs,
+	.nr_clk_regs		= ARRAY_SIZE(apm_clk_regs),
+	.clk_name		= "dout_clkcmu_apm_bus",
+};
+
 /* ---- CMU_HSI ------------------------------------------------------------- */
 
 /* Register Offset definitions for CMU_HSI (0x13400000) */
@@ -801,9 +939,11 @@ static int __init exynos850_cmu_probe(struct platform_device *pdev)
 	return 0;
 }
 
-/* CMUs which belong to Power Domains and need runtime PM to be implemented */
 static const struct of_device_id exynos850_cmu_of_match[] = {
 	{
+		.compatible = "samsung,exynos850-cmu-apm",
+		.data = &apm_cmu_info,
+	}, {
 		.compatible = "samsung,exynos850-cmu-hsi",
 		.data = &hsi_cmu_info,
 	}, {
-- 
2.30.2

Re: [PATCH 2/6] clk: samsung: exynos850: Implement CMU_APM domain

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> CMU_APM clock domain provides clocks for APM IP-core (Active Power
> Management). According to Exynos850 TRM, CMU_APM generates I3C, Mailbox,
> Speedy, Timer, WDT, RTC and PMU clocks for BLK_ALIVE.
> 
> This patch adds next clocks:
>   - bus clocks in CMU_TOP needed for CMU_APM
>   - all internal CMU_APM clocks
>   - leaf clocks for I3C, Speedy and RTC IP-cores
>   - bus clocks for CMU_CMGP and CMU_CHUB

Applied, thanks.

[PATCH 3/6] dt-bindings: clock: Add bindings for Exynos850 CMU_CMGP

[Sam Protsenko]

CMU_CMGP generates USI and ADC clocks for BLK_ALIVE. In particular USI
clocks are needed for HSI2C_3 and HSI2C_4 instances.

Add clock indices and bindings documentation for CMU_CMGP domain.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 .../clock/samsung,exynos850-clock.yaml        | 19 +++++++++++++++++++
 include/dt-bindings/clock/exynos850.h         | 17 +++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
index 5618cfa62f80..80ba60838f2b 100644
--- a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
+++ b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
@@ -33,6 +33,7 @@ properties:
     enum:
       - samsung,exynos850-cmu-top
       - samsung,exynos850-cmu-apm
+      - samsung,exynos850-cmu-cmgp
       - samsung,exynos850-cmu-core
       - samsung,exynos850-cmu-dpu
       - samsung,exynos850-cmu-hsi
@@ -87,6 +88,24 @@ allOf:
             - const: oscclk
             - const: dout_clkcmu_apm_bus
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos850-cmu-cmgp
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: External reference clock (26 MHz)
+            - description: CMU_CMGP bus clock (from CMU_APM)
+
+        clock-names:
+          items:
+            - const: oscclk
+            - const: gout_clkcmu_cmgp_bus
+
   - if:
       properties:
         compatible:
diff --git a/include/dt-bindings/clock/exynos850.h b/include/dt-bindings/clock/exynos850.h
index df3978b58304..8aa5e82af0d3 100644
--- a/include/dt-bindings/clock/exynos850.h
+++ b/include/dt-bindings/clock/exynos850.h
@@ -84,6 +84,23 @@
 #define CLK_GOUT_SPEEDY_PCLK		21
 #define APM_NR_CLK			22
 
+/* CMU_CMGP */
+#define CLK_RCO_CMGP			1
+#define CLK_MOUT_CMGP_ADC		2
+#define CLK_MOUT_CMGP_USI0		3
+#define CLK_MOUT_CMGP_USI1		4
+#define CLK_DOUT_CMGP_ADC		5
+#define CLK_DOUT_CMGP_USI0		6
+#define CLK_DOUT_CMGP_USI1		7
+#define CLK_GOUT_CMGP_ADC_S0_PCLK	8
+#define CLK_GOUT_CMGP_ADC_S1_PCLK	9
+#define CLK_GOUT_CMGP_GPIO_PCLK		10
+#define CLK_GOUT_CMGP_USI0_IPCLK	11
+#define CLK_GOUT_CMGP_USI0_PCLK		12
+#define CLK_GOUT_CMGP_USI1_IPCLK	13
+#define CLK_GOUT_CMGP_USI1_PCLK		14
+#define CMGP_NR_CLK			15
+
 /* CMU_HSI */
 #define CLK_MOUT_HSI_BUS_USER		1
 #define CLK_MOUT_HSI_MMC_CARD_USER	2
-- 
2.30.2

Re: [PATCH 3/6] dt-bindings: clock: Add bindings for Exynos850 CMU_CMGP

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> CMU_CMGP generates USI and ADC clocks for BLK_ALIVE. In particular USI
> clocks are needed for HSI2C_3 and HSI2C_4 instances.
> 
> Add clock indices and bindings documentation for CMU_CMGP domain.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

Applied, thanks.

[PATCH 4/6] clk: samsung: exynos850: Implement CMU_CMGP domain

[Sam Protsenko]

CMU_CMGP clock domain provides clocks for CMGP IP-core (Common GPIO).
CMGP module encapsulates next blocks:
  - 8 GPIO lines
  - 1 GPADC
  - 2 USI blocks, each can be configured to provide one of
    UART/SPI/HSI2C serial interfaces

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
 drivers/clk/samsung/clk-exynos850.c | 100 ++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/drivers/clk/samsung/clk-exynos850.c b/drivers/clk/samsung/clk-exynos850.c
index 95e373d17b42..0eab7a115b44 100644
--- a/drivers/clk/samsung/clk-exynos850.c
+++ b/drivers/clk/samsung/clk-exynos850.c
@@ -492,6 +492,103 @@ static const struct samsung_cmu_info apm_cmu_info __initconst = {
 	.clk_name		= "dout_clkcmu_apm_bus",
 };
 
+/* ---- CMU_CMGP ------------------------------------------------------------ */
+
+/* Register Offset definitions for CMU_CMGP (0x11c00000) */
+#define CLK_CON_MUX_CLK_CMGP_ADC		0x1000
+#define CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP0	0x1004
+#define CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP1	0x1008
+#define CLK_CON_DIV_DIV_CLK_CMGP_ADC		0x1800
+#define CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP0	0x1804
+#define CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP1	0x1808
+#define CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S0	0x200c
+#define CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S1	0x2010
+#define CLK_CON_GAT_GOUT_CMGP_GPIO_PCLK		0x2018
+#define CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_IPCLK	0x2044
+#define CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_PCLK	0x2048
+#define CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_IPCLK	0x204c
+#define CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_PCLK	0x2050
+
+static const unsigned long cmgp_clk_regs[] __initconst = {
+	CLK_CON_MUX_CLK_CMGP_ADC,
+	CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP0,
+	CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP1,
+	CLK_CON_DIV_DIV_CLK_CMGP_ADC,
+	CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP0,
+	CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP1,
+	CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S0,
+	CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S1,
+	CLK_CON_GAT_GOUT_CMGP_GPIO_PCLK,
+	CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_IPCLK,
+	CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_PCLK,
+	CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_IPCLK,
+	CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_PCLK,
+};
+
+/* List of parent clocks for Muxes in CMU_CMGP */
+PNAME(mout_cmgp_usi0_p)	= { "clk_rco_cmgp", "gout_clkcmu_cmgp_bus" };
+PNAME(mout_cmgp_usi1_p)	= { "clk_rco_cmgp", "gout_clkcmu_cmgp_bus" };
+PNAME(mout_cmgp_adc_p)	= { "oscclk", "dout_cmgp_adc" };
+
+static const struct samsung_fixed_rate_clock cmgp_fixed_clks[] __initconst = {
+	FRATE(CLK_RCO_CMGP, "clk_rco_cmgp", NULL, 0, 49152000),
+};
+
+static const struct samsung_mux_clock cmgp_mux_clks[] __initconst = {
+	MUX(CLK_MOUT_CMGP_ADC, "mout_cmgp_adc", mout_cmgp_adc_p,
+	    CLK_CON_MUX_CLK_CMGP_ADC, 0, 1),
+	MUX(CLK_MOUT_CMGP_USI0, "mout_cmgp_usi0", mout_cmgp_usi0_p,
+	    CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP0, 0, 1),
+	MUX(CLK_MOUT_CMGP_USI1, "mout_cmgp_usi1", mout_cmgp_usi1_p,
+	    CLK_CON_MUX_MUX_CLK_CMGP_USI_CMGP1, 0, 1),
+};
+
+static const struct samsung_div_clock cmgp_div_clks[] __initconst = {
+	DIV(CLK_DOUT_CMGP_ADC, "dout_cmgp_adc", "gout_clkcmu_cmgp_bus",
+	    CLK_CON_DIV_DIV_CLK_CMGP_ADC, 0, 4),
+	DIV(CLK_DOUT_CMGP_USI0, "dout_cmgp_usi0", "mout_cmgp_usi0",
+	    CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP0, 0, 5),
+	DIV(CLK_DOUT_CMGP_USI1, "dout_cmgp_usi1", "mout_cmgp_usi1",
+	    CLK_CON_DIV_DIV_CLK_CMGP_USI_CMGP1, 0, 5),
+};
+
+static const struct samsung_gate_clock cmgp_gate_clks[] __initconst = {
+	GATE(CLK_GOUT_CMGP_ADC_S0_PCLK, "gout_adc_s0_pclk",
+	     "gout_clkcmu_cmgp_bus",
+	     CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S0, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_ADC_S1_PCLK, "gout_adc_s1_pclk",
+	     "gout_clkcmu_cmgp_bus",
+	     CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S1, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_GPIO_PCLK, "gout_gpio_cmgp_pclk",
+	     "gout_clkcmu_cmgp_bus",
+	     CLK_CON_GAT_GOUT_CMGP_GPIO_PCLK, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_USI0_IPCLK, "gout_cmgp_usi0_ipclk", "dout_cmgp_usi0",
+	     CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_IPCLK, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_USI0_PCLK, "gout_cmgp_usi0_pclk",
+	     "gout_clkcmu_cmgp_bus",
+	     CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_PCLK, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_USI1_IPCLK, "gout_cmgp_usi1_ipclk", "dout_cmgp_usi1",
+	     CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_IPCLK, 21, 0, 0),
+	GATE(CLK_GOUT_CMGP_USI1_PCLK, "gout_cmgp_usi1_pclk",
+	     "gout_clkcmu_cmgp_bus",
+	     CLK_CON_GAT_GOUT_CMGP_USI_CMGP1_PCLK, 21, 0, 0),
+};
+
+static const struct samsung_cmu_info cmgp_cmu_info __initconst = {
+	.mux_clks		= cmgp_mux_clks,
+	.nr_mux_clks		= ARRAY_SIZE(cmgp_mux_clks),
+	.div_clks		= cmgp_div_clks,
+	.nr_div_clks		= ARRAY_SIZE(cmgp_div_clks),
+	.gate_clks		= cmgp_gate_clks,
+	.nr_gate_clks		= ARRAY_SIZE(cmgp_gate_clks),
+	.fixed_clks		= cmgp_fixed_clks,
+	.nr_fixed_clks		= ARRAY_SIZE(cmgp_fixed_clks),
+	.nr_clk_ids		= CMGP_NR_CLK,
+	.clk_regs		= cmgp_clk_regs,
+	.nr_clk_regs		= ARRAY_SIZE(cmgp_clk_regs),
+	.clk_name		= "gout_clkcmu_cmgp_bus",
+};
+
 /* ---- CMU_HSI ------------------------------------------------------------- */
 
 /* Register Offset definitions for CMU_HSI (0x13400000) */
@@ -943,6 +1040,9 @@ static const struct of_device_id exynos850_cmu_of_match[] = {
 	{
 		.compatible = "samsung,exynos850-cmu-apm",
 		.data = &apm_cmu_info,
+	}, {
+		.compatible = "samsung,exynos850-cmu-cmgp",
+		.data = &cmgp_cmu_info,
 	}, {
 		.compatible = "samsung,exynos850-cmu-hsi",
 		.data = &hsi_cmu_info,
-- 
2.30.2

Re: [PATCH 4/6] clk: samsung: exynos850: Implement CMU_CMGP domain

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> CMU_CMGP clock domain provides clocks for CMGP IP-core (Common GPIO).
> CMGP module encapsulates next blocks:
>   - 8 GPIO lines
>   - 1 GPADC
>   - 2 USI blocks, each can be configured to provide one of
>     UART/SPI/HSI2C serial interfaces
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Applied, thanks.

[PATCH 5/6] clk: samsung: exynos850: Register clocks early

[Sam Protsenko]

Some clocks must be registered before init calls. For example MCT clock
(from CMU_PERI) is needed for MCT timer driver, which is registered
with TIMER_OF_DECLARE(). By the time we get to core_initcall() used for
clk-exynos850 platform driver init, it's already too late. Inability to
get "mct" clock in MCT driver leads to kernel panic, as functions
registered with *_OF_DECLARE() can't do deferred calls. MCT timer driver
can't be fixed either, as it's acting as a clock source and it's
essential to register it in start_kernel() -> time_init().

Let's register CMU_PERI clocks early, using CLK_OF_DECLARE_DRIVER(), and
do all stuff relying on "struct dev" object (like runtime PM) later in
platform driver probe. Basically CLK_OF_DECLARE_DRIVER() matches CMU
compatible, but clears OF_POPULATED flag, which allows the same device
to be matched again later. CMU_TOP generates clocks needed for CMU_PERI,
but it's already registered early.

While at it, let's cleanup the code a bit, by extracting everything
related to CMU initialization and registration to the separate function.

Similar issue was discussed at [1] and addressed in commit 1f7db7bbf031
("clk: renesas: cpg-mssr: Add early clock support"), as well as in
drivers/clk/mediatek/clk-mt2712.c.

[1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20180829132954.64862-2-chris.brandt@renesas.com/

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
 drivers/clk/samsung/clk-exynos850.c | 68 +++++++++++++++++++++--------
 1 file changed, 51 insertions(+), 17 deletions(-)

diff --git a/drivers/clk/samsung/clk-exynos850.c b/drivers/clk/samsung/clk-exynos850.c
index 0eab7a115b44..1d257bca8b37 100644
--- a/drivers/clk/samsung/clk-exynos850.c
+++ b/drivers/clk/samsung/clk-exynos850.c
@@ -60,6 +60,43 @@ static void __init exynos850_init_clocks(struct device_node *np,
 	iounmap(reg_base);
 }
 
+/**
+ * exynos850_register_cmu - Register specified Exynos850 CMU domain
+ * @dev:	Device object; may be NULL if this function is not being
+ *		called from platform driver probe function
+ * @np:		CMU device tree node
+ * @cmu:	CMU data
+ *
+ * Register specified CMU domain, which includes next steps:
+ *
+ * 1. Enable parent clock of @cmu CMU
+ * 2. Set initial registers configuration for @cmu CMU clocks
+ * 3. Register @cmu CMU clocks using Samsung clock framework API
+ */
+static void __init exynos850_register_cmu(struct device *dev,
+		struct device_node *np, const struct samsung_cmu_info *cmu)
+{
+	/* Keep CMU parent clock running (needed for CMU registers access) */
+	if (cmu->clk_name) {
+		struct clk *parent_clk;
+
+		if (dev)
+			parent_clk = clk_get(dev, cmu->clk_name);
+		else
+			parent_clk = of_clk_get_by_name(np, cmu->clk_name);
+
+		if (IS_ERR(parent_clk)) {
+			pr_err("%s: could not find bus clock %s; err = %ld\n",
+			       __func__, cmu->clk_name, PTR_ERR(parent_clk));
+		} else {
+			clk_prepare_enable(parent_clk);
+		}
+	}
+
+	exynos850_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
+	samsung_cmu_register_one(np, cmu);
+}
+
 /* ---- CMU_TOP ------------------------------------------------------------- */
 
 /* Register Offset definitions for CMU_TOP (0x120e0000) */
@@ -367,10 +404,10 @@ static const struct samsung_cmu_info top_cmu_info __initconst = {
 
 static void __init exynos850_cmu_top_init(struct device_node *np)
 {
-	exynos850_init_clocks(np, top_clk_regs, ARRAY_SIZE(top_clk_regs));
-	samsung_cmu_register_one(np, &top_cmu_info);
+	exynos850_register_cmu(NULL, np, &top_cmu_info);
 }
 
+/* Register CMU_TOP early, as it's a dependency for other early domains */
 CLK_OF_DECLARE(exynos850_cmu_top, "samsung,exynos850-cmu-top",
 	       exynos850_cmu_top_init);
 
@@ -850,6 +887,15 @@ static const struct samsung_cmu_info peri_cmu_info __initconst = {
 	.clk_name		= "dout_peri_bus",
 };
 
+static void __init exynos850_cmu_peri_init(struct device_node *np)
+{
+	exynos850_register_cmu(NULL, np, &peri_cmu_info);
+}
+
+/* Register CMU_PERI early, as it's needed for MCT timer */
+CLK_OF_DECLARE_DRIVER(exynos850_cmu_peri, "samsung,exynos850-cmu-peri",
+		      exynos850_cmu_peri_init);
+
 /* ---- CMU_CORE ------------------------------------------------------------ */
 
 /* Register Offset definitions for CMU_CORE (0x12000000) */
@@ -1014,24 +1060,12 @@ static int __init exynos850_cmu_probe(struct platform_device *pdev)
 {
 	const struct samsung_cmu_info *info;
 	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
 
 	info = of_device_get_match_data(dev);
-	exynos850_init_clocks(np, info->clk_regs, info->nr_clk_regs);
-	samsung_cmu_register_one(np, info);
 
-	/* Keep bus clock running, so it's possible to access CMU registers */
-	if (info->clk_name) {
-		struct clk *bus_clk;
-
-		bus_clk = clk_get(dev, info->clk_name);
-		if (IS_ERR(bus_clk)) {
-			pr_err("%s: could not find bus clock %s; err = %ld\n",
-			       __func__, info->clk_name, PTR_ERR(bus_clk));
-		} else {
-			clk_prepare_enable(bus_clk);
-		}
-	}
+	/* Early clocks are already registered using CLK_OF_DECLARE_DRIVER() */
+	if (info != &peri_cmu_info)
+		exynos850_register_cmu(dev, dev->of_node, info);
 
 	return 0;
 }
-- 
2.30.2

Re: [PATCH 5/6] clk: samsung: exynos850: Register clocks early

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> /* Register Offset definitions for CMU_CORE (0x12000000) */
> @@ -1014,24 +1060,12 @@ static int __init exynos850_cmu_probe(struct platform_device *pdev)
>  {
>  	const struct samsung_cmu_info *info;
>  	struct device *dev = &pdev->dev;
> -	struct device_node *np = dev->of_node;
>  
>  	info = of_device_get_match_data(dev);
> -	exynos850_init_clocks(np, info->clk_regs, info->nr_clk_regs);
> -	samsung_cmu_register_one(np, info);
>  
> -	/* Keep bus clock running, so it's possible to access CMU registers */
> -	if (info->clk_name) {
> -		struct clk *bus_clk;
> -
> -		bus_clk = clk_get(dev, info->clk_name);
> -		if (IS_ERR(bus_clk)) {
> -			pr_err("%s: could not find bus clock %s; err = %ld\n",
> -			       __func__, info->clk_name, PTR_ERR(bus_clk));
> -		} else {
> -			clk_prepare_enable(bus_clk);
> -		}
> -	}


> +	/* Early clocks are already registered using CLK_OF_DECLARE_DRIVER() */
> +	if (info != &peri_cmu_info)
> +		exynos850_register_cmu(dev, dev->of_node, info);
>  

Do you still need this test? How about just removing "samsung,exynos850-cmu-peri"
from exynos850_cmu_of_match[] ?

-- 
Regards,
Sylwester

Re: [PATCH 5/6] clk: samsung: exynos850: Register clocks early

[Sam Protsenko]

On Mon, 22 Nov 2021 at 12:00, Sylwester Nawrocki <s.nawrocki@samsung.com> wrote:
>
> On 22.11.2021 00:27, Sam Protsenko wrote:
> > /* Register Offset definitions for CMU_CORE (0x12000000) */
> > @@ -1014,24 +1060,12 @@ static int __init exynos850_cmu_probe(struct platform_device *pdev)
> >  {
> >       const struct samsung_cmu_info *info;
> >       struct device *dev = &pdev->dev;
> > -     struct device_node *np = dev->of_node;
> >
> >       info = of_device_get_match_data(dev);
> > -     exynos850_init_clocks(np, info->clk_regs, info->nr_clk_regs);
> > -     samsung_cmu_register_one(np, info);
> >
> > -     /* Keep bus clock running, so it's possible to access CMU registers */
> > -     if (info->clk_name) {
> > -             struct clk *bus_clk;
> > -
> > -             bus_clk = clk_get(dev, info->clk_name);
> > -             if (IS_ERR(bus_clk)) {
> > -                     pr_err("%s: could not find bus clock %s; err = %ld\n",
> > -                            __func__, info->clk_name, PTR_ERR(bus_clk));
> > -             } else {
> > -                     clk_prepare_enable(bus_clk);
> > -             }
> > -     }
>
>
> > +     /* Early clocks are already registered using CLK_OF_DECLARE_DRIVER() */
> > +     if (info != &peri_cmu_info)
> > +             exynos850_register_cmu(dev, dev->of_node, info);
> >
>
> Do you still need this test? How about just removing "samsung,exynos850-cmu-peri"
> from exynos850_cmu_of_match[] ?
>

It'll be needed later, when I get to adding PM ops to platform driver,
as CMU_PERI is part of Power Domains. But you are right, it's not
needed right now. Will re-send this patch separately soon.

> --
> Regards,
> Sylwester

[PATCH 6/6] clk: samsung: exynos850: Keep some crucial clocks running

[Sam Protsenko]

Some clocks shouldn't be automatically disabled in clk_disable_unused(),
otherwise kernel hangs. Mark those clocks with:
  - CLK_IS_CRITICAL flag, when there won't be any consumers for that
    clock, but system can't function when it's gated
  - CLK_IGNORE_UNUSED flag, when consumer driver will be probably added
    later

That makes it possible to run the kernel without passing the
"clk_ignore_unused" param.

Next clocks were modified:
  - "gout_dpu_cmu_dpu_pclk":	CLK_IGNORE_UNUSED

    Will be enabled later in DSIM driver (Display Serial Interface
    Master).

  - "gout_gpio_peri_pclk":	CLK_IGNORE_UNUSED
    "gout_gpio_cmgp_pclk":	CLK_IGNORE_UNUSED
    "gout_gpio_hsi_pclk":	CLK_IGNORE_UNUSED

    Should be probably enabled in corresponding GPIO driver later, or
    made CLK_IS_CRITICAL. "gout_gpio_peri_clk" is actually used by LEDs
    on Exynos850-based dev board, so kernel hangs if this clock is not
    running. Other clocks were marked as "ignore unused" to prevent
    similar issues for other use cases or boards that might be added
    later.

  - "gout_cci_aclk":		CLK_IS_CRITICAL

    CCI (Cache Coherent Interconnect): obviously is critical.

  - "gout_gic_clk":		CLK_IS_CRITICAL

    GIC (Generic Interrupt Controller): obviously is critical.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/clk/samsung/clk-exynos850.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/samsung/clk-exynos850.c b/drivers/clk/samsung/clk-exynos850.c
index 1d257bca8b37..c885ffb1aa24 100644
--- a/drivers/clk/samsung/clk-exynos850.c
+++ b/drivers/clk/samsung/clk-exynos850.c
@@ -596,9 +596,10 @@ static const struct samsung_gate_clock cmgp_gate_clks[] __initconst = {
 	GATE(CLK_GOUT_CMGP_ADC_S1_PCLK, "gout_adc_s1_pclk",
 	     "gout_clkcmu_cmgp_bus",
 	     CLK_CON_GAT_GOUT_CMGP_ADC_PCLK_S1, 21, 0, 0),
+	/* TODO: Should be enabled in GPIO driver (or made CLK_IS_CRITICAL) */
 	GATE(CLK_GOUT_CMGP_GPIO_PCLK, "gout_gpio_cmgp_pclk",
 	     "gout_clkcmu_cmgp_bus",
-	     CLK_CON_GAT_GOUT_CMGP_GPIO_PCLK, 21, 0, 0),
+	     CLK_CON_GAT_GOUT_CMGP_GPIO_PCLK, 21, CLK_IGNORE_UNUSED, 0),
 	GATE(CLK_GOUT_CMGP_USI0_IPCLK, "gout_cmgp_usi0_ipclk", "dout_cmgp_usi0",
 	     CLK_CON_GAT_GOUT_CMGP_USI_CMGP0_IPCLK, 21, 0, 0),
 	GATE(CLK_GOUT_CMGP_USI0_PCLK, "gout_cmgp_usi0_pclk",
@@ -685,8 +686,9 @@ static const struct samsung_gate_clock hsi_gate_clks[] __initconst = {
 	     CLK_CON_GAT_HSI_USB20DRD_TOP_I_REF_CLK_50, 21, 0, 0),
 	GATE(CLK_GOUT_USB_PHY_REF_CLK, "gout_usb_phy_ref", "oscclk",
 	     CLK_CON_GAT_HSI_USB20DRD_TOP_I_PHY_REFCLK_26, 21, 0, 0),
+	/* TODO: Should be enabled in GPIO driver (or made CLK_IS_CRITICAL) */
 	GATE(CLK_GOUT_GPIO_HSI_PCLK, "gout_gpio_hsi_pclk", "mout_hsi_bus_user",
-	     CLK_CON_GAT_GOUT_HSI_GPIO_HSI_PCLK, 21, 0, 0),
+	     CLK_CON_GAT_GOUT_HSI_GPIO_HSI_PCLK, 21, CLK_IGNORE_UNUSED, 0),
 	GATE(CLK_GOUT_MMC_CARD_ACLK, "gout_mmc_card_aclk", "mout_hsi_bus_user",
 	     CLK_CON_GAT_GOUT_HSI_MMC_CARD_I_ACLK, 21, 0, 0),
 	GATE(CLK_GOUT_MMC_CARD_SDCLKIN, "gout_mmc_card_sdclkin",
@@ -869,9 +871,10 @@ static const struct samsung_gate_clock peri_gate_clks[] __initconst = {
 	     CLK_CON_GAT_GOUT_PERI_WDT_0_PCLK, 21, 0, 0),
 	GATE(CLK_GOUT_WDT1_PCLK, "gout_wdt1_pclk", "mout_peri_bus_user",
 	     CLK_CON_GAT_GOUT_PERI_WDT_1_PCLK, 21, 0, 0),
+	/* TODO: Should be enabled in GPIO driver (or made CLK_IS_CRITICAL) */
 	GATE(CLK_GOUT_GPIO_PERI_PCLK, "gout_gpio_peri_pclk",
 	     "mout_peri_bus_user",
-	     CLK_CON_GAT_GOUT_PERI_GPIO_PERI_PCLK, 21, 0, 0),
+	     CLK_CON_GAT_GOUT_PERI_GPIO_PERI_PCLK, 21, CLK_IGNORE_UNUSED, 0),
 };
 
 static const struct samsung_cmu_info peri_cmu_info __initconst = {
@@ -954,10 +957,12 @@ static const struct samsung_div_clock core_div_clks[] __initconst = {
 };
 
 static const struct samsung_gate_clock core_gate_clks[] __initconst = {
+	/* CCI (interconnect) clock must be always running */
 	GATE(CLK_GOUT_CCI_ACLK, "gout_cci_aclk", "mout_core_cci_user",
-	     CLK_CON_GAT_GOUT_CORE_CCI_550_ACLK, 21, 0, 0),
+	     CLK_CON_GAT_GOUT_CORE_CCI_550_ACLK, 21, CLK_IS_CRITICAL, 0),
+	/* GIC (interrupt controller) clock must be always running */
 	GATE(CLK_GOUT_GIC_CLK, "gout_gic_clk", "mout_core_gic",
-	     CLK_CON_GAT_GOUT_CORE_GIC_CLK, 21, 0, 0),
+	     CLK_CON_GAT_GOUT_CORE_GIC_CLK, 21, CLK_IS_CRITICAL, 0),
 	GATE(CLK_GOUT_MMC_EMBD_ACLK, "gout_mmc_embd_aclk", "dout_core_busp",
 	     CLK_CON_GAT_GOUT_CORE_MMC_EMBD_I_ACLK, 21, 0, 0),
 	GATE(CLK_GOUT_MMC_EMBD_SDCLKIN, "gout_mmc_embd_sdclkin",
@@ -1023,8 +1028,10 @@ static const struct samsung_div_clock dpu_div_clks[] __initconst = {
 };
 
 static const struct samsung_gate_clock dpu_gate_clks[] __initconst = {
+	/* TODO: Should be enabled in DSIM driver */
 	GATE(CLK_GOUT_DPU_CMU_DPU_PCLK, "gout_dpu_cmu_dpu_pclk",
-	     "dout_dpu_busp", CLK_CON_GAT_CLK_DPU_CMU_DPU_PCLK, 21, 0, 0),
+	     "dout_dpu_busp",
+	     CLK_CON_GAT_CLK_DPU_CMU_DPU_PCLK, 21, CLK_IGNORE_UNUSED, 0),
 	GATE(CLK_GOUT_DPU_DECON0_ACLK, "gout_dpu_decon0_aclk", "mout_dpu_user",
 	     CLK_CON_GAT_GOUT_DPU_ACLK_DECON0, 21, 0, 0),
 	GATE(CLK_GOUT_DPU_DMA_ACLK, "gout_dpu_dma_aclk", "mout_dpu_user",
-- 
2.30.2

Re: [PATCH 6/6] clk: samsung: exynos850: Keep some crucial clocks running

[Krzysztof Kozlowski]

On 22/11/2021 00:27, Sam Protsenko wrote:
> Some clocks shouldn't be automatically disabled in clk_disable_unused(),
> otherwise kernel hangs. Mark those clocks with:
>   - CLK_IS_CRITICAL flag, when there won't be any consumers for that
>     clock, but system can't function when it's gated
>   - CLK_IGNORE_UNUSED flag, when consumer driver will be probably added
>     later
> 
> That makes it possible to run the kernel without passing the
> "clk_ignore_unused" param.
> 
> Next clocks were modified:
>   - "gout_dpu_cmu_dpu_pclk":	CLK_IGNORE_UNUSED
> 
>     Will be enabled later in DSIM driver (Display Serial Interface
>     Master).
> 
>   - "gout_gpio_peri_pclk":	CLK_IGNORE_UNUSED
>     "gout_gpio_cmgp_pclk":	CLK_IGNORE_UNUSED
>     "gout_gpio_hsi_pclk":	CLK_IGNORE_UNUSED
> 
>     Should be probably enabled in corresponding GPIO driver later, or
>     made CLK_IS_CRITICAL. "gout_gpio_peri_clk" is actually used by LEDs
>     on Exynos850-based dev board, so kernel hangs if this clock is not
>     running. Other clocks were marked as "ignore unused" to prevent
>     similar issues for other use cases or boards that might be added
>     later.
> 
>   - "gout_cci_aclk":		CLK_IS_CRITICAL
> 
>     CCI (Cache Coherent Interconnect): obviously is critical.
> 
>   - "gout_gic_clk":		CLK_IS_CRITICAL
> 
>     GIC (Generic Interrupt Controller): obviously is critical.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
>  drivers/clk/samsung/clk-exynos850.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Re: [PATCH 6/6] clk: samsung: exynos850: Keep some crucial clocks running

[Sylwester Nawrocki]

On 22.11.2021 00:27, Sam Protsenko wrote:
> Some clocks shouldn't be automatically disabled in clk_disable_unused(),
> otherwise kernel hangs. Mark those clocks with:
>   - CLK_IS_CRITICAL flag, when there won't be any consumers for that
>     clock, but system can't function when it's gated
>   - CLK_IGNORE_UNUSED flag, when consumer driver will be probably added
>     later
> 
> That makes it possible to run the kernel without passing the
> "clk_ignore_unused" param.

Applied, thanks.