diff mbox series

[v5,4/4] arm64: dts: qcom: Add CMN PLL node for IPQ9574 SoC

Message ID 20241028-qcom_ipq_cmnpll-v5-4-339994b0388d@quicinc.com
State Superseded
Headers show
Series Add CMN PLL clock controller driver for IPQ9574 | expand

Commit Message

Luo Jie Oct. 28, 2024, 2:04 p.m. UTC
The CMN PLL clock controller allows selection of an input clock rate
from a defined set of input clock rates. It in-turn supplies fixed
rate output clocks to the hardware blocks that provide the ethernet
functions such as PPE (Packet Process Engine) and connected switch or
PHY, and to GCC.

The reference clock of CMN PLL is routed from XO to the CMN PLL through
the internal WiFi block.
.XO (48 MHZ or 96 MHZ)-->WiFi (multiplier/divider)-->48 MHZ to CMN PLL.

The reference input clock from WiFi to CMN PLL is fully controlled by
the bootstrap pins which select the XO frequency (48 MHZ or 96 MHZ).
Based on this frequency, the divider in the internal Wi-Fi block is
automatically configured by hardware (1 for 48 MHZ, 2 for 96 MHZ), to
ensure output clock to CMN PLL is 48 MHZ.

Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
---
 arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi | 16 ++++++++++++++-
 arch/arm64/boot/dts/qcom/ipq9574.dtsi            | 26 +++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 2 deletions(-)

Comments

Dmitry Baryshkov Oct. 28, 2024, 3:39 p.m. UTC | #1
On Mon, Oct 28, 2024 at 10:04:11PM +0800, Luo Jie wrote:
> The CMN PLL clock controller allows selection of an input clock rate
> from a defined set of input clock rates. It in-turn supplies fixed
> rate output clocks to the hardware blocks that provide the ethernet
> functions such as PPE (Packet Process Engine) and connected switch or
> PHY, and to GCC.
> 
> The reference clock of CMN PLL is routed from XO to the CMN PLL through
> the internal WiFi block.
> .XO (48 MHZ or 96 MHZ)-->WiFi (multiplier/divider)-->48 MHZ to CMN PLL.
> 
> The reference input clock from WiFi to CMN PLL is fully controlled by
> the bootstrap pins which select the XO frequency (48 MHZ or 96 MHZ).
> Based on this frequency, the divider in the internal Wi-Fi block is
> automatically configured by hardware (1 for 48 MHZ, 2 for 96 MHZ), to
> ensure output clock to CMN PLL is 48 MHZ.
> 
> Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
> ---
>  arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi | 16 ++++++++++++++-
>  arch/arm64/boot/dts/qcom/ipq9574.dtsi            | 26 +++++++++++++++++++++++-
>  2 files changed, 40 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
> index 91e104b0f865..f026c2a9d0c0 100644
> --- a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
> +++ b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
> @@ -3,7 +3,7 @@
>   * IPQ9574 RDP board common device tree source
>   *
>   * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
> - * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
>   */
>  
>  /dts-v1/;
> @@ -164,6 +164,20 @@ &usb3 {
>  	status = "okay";
>  };
>  
> +/*
> + * The bootstrap pins for the board select the XO clock frequency,
> + * which automatically enables the right dividers to ensure the
> + * reference clock output to CMNPLL is 48 MHZ.
> + */
> +&cmn_pll_ref_clk {
> +	clock-div = <1>;
> +	clock-mult = <1>;
> +};
> +
>  &xo_board_clk {
>  	clock-frequency = <24000000>;
>  };
> +
> +&xo_clk {
> +	clock-frequency = <48000000>;
> +};
> diff --git a/arch/arm64/boot/dts/qcom/ipq9574.dtsi b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
> index 14c7b3a78442..ad9cdb1f76db 100644
> --- a/arch/arm64/boot/dts/qcom/ipq9574.dtsi
> +++ b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
> @@ -3,10 +3,11 @@
>   * IPQ9574 SoC device tree source
>   *
>   * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
> - * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
>   */
>  
>  #include <dt-bindings/clock/qcom,apss-ipq.h>
> +#include <dt-bindings/clock/qcom,ipq-cmn-pll.h>
>  #include <dt-bindings/clock/qcom,ipq9574-gcc.h>
>  #include <dt-bindings/interconnect/qcom,ipq9574.h>
>  #include <dt-bindings/interrupt-controller/arm-gic.h>
> @@ -19,6 +20,12 @@ / {
>  	#size-cells = <2>;
>  
>  	clocks {
> +		cmn_pll_ref_clk: cmn-pll-ref-clk {
> +			compatible = "fixed-factor-clock";
> +			clocks = <&xo_clk>;
> +			#clock-cells = <0>;
> +		};
> +
>  		sleep_clk: sleep-clk {
>  			compatible = "fixed-clock";
>  			#clock-cells = <0>;
> @@ -28,6 +35,11 @@ xo_board_clk: xo-board-clk {
>  			compatible = "fixed-clock";
>  			#clock-cells = <0>;
>  		};
> +
> +		xo_clk: xo-clk {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +		};

What is the difference between xo_clk and xo_board_clk? Are there two
different crystals?

>  	};
>  
>  	cpus {
Luo Jie Oct. 29, 2024, 1:31 p.m. UTC | #2
On 10/28/2024 11:39 PM, Dmitry Baryshkov wrote:
> On Mon, Oct 28, 2024 at 10:04:11PM +0800, Luo Jie wrote:
>> The CMN PLL clock controller allows selection of an input clock rate
>> from a defined set of input clock rates. It in-turn supplies fixed
>> rate output clocks to the hardware blocks that provide the ethernet
>> functions such as PPE (Packet Process Engine) and connected switch or
>> PHY, and to GCC.
>>
>> The reference clock of CMN PLL is routed from XO to the CMN PLL through
>> the internal WiFi block.
>> .XO (48 MHZ or 96 MHZ)-->WiFi (multiplier/divider)-->48 MHZ to CMN PLL.
>>
>> The reference input clock from WiFi to CMN PLL is fully controlled by
>> the bootstrap pins which select the XO frequency (48 MHZ or 96 MHZ).
>> Based on this frequency, the divider in the internal Wi-Fi block is
>> automatically configured by hardware (1 for 48 MHZ, 2 for 96 MHZ), to
>> ensure output clock to CMN PLL is 48 MHZ.
>>
>> Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
>> ---
>>   arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi | 16 ++++++++++++++-
>>   arch/arm64/boot/dts/qcom/ipq9574.dtsi            | 26 +++++++++++++++++++++++-
>>   2 files changed, 40 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
>> index 91e104b0f865..f026c2a9d0c0 100644
>> --- a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
>> @@ -3,7 +3,7 @@
>>    * IPQ9574 RDP board common device tree source
>>    *
>>    * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
>> - * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
>> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
>>    */
>>   
>>   /dts-v1/;
>> @@ -164,6 +164,20 @@ &usb3 {
>>   	status = "okay";
>>   };
>>   
>> +/*
>> + * The bootstrap pins for the board select the XO clock frequency,
>> + * which automatically enables the right dividers to ensure the
>> + * reference clock output to CMNPLL is 48 MHZ.
>> + */
>> +&cmn_pll_ref_clk {
>> +	clock-div = <1>;
>> +	clock-mult = <1>;
>> +};
>> +
>>   &xo_board_clk {
>>   	clock-frequency = <24000000>;
>>   };
>> +
>> +&xo_clk {
>> +	clock-frequency = <48000000>;
>> +};
>> diff --git a/arch/arm64/boot/dts/qcom/ipq9574.dtsi b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
>> index 14c7b3a78442..ad9cdb1f76db 100644
>> --- a/arch/arm64/boot/dts/qcom/ipq9574.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
>> @@ -3,10 +3,11 @@
>>    * IPQ9574 SoC device tree source
>>    *
>>    * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
>> - * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
>> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
>>    */
>>   
>>   #include <dt-bindings/clock/qcom,apss-ipq.h>
>> +#include <dt-bindings/clock/qcom,ipq-cmn-pll.h>
>>   #include <dt-bindings/clock/qcom,ipq9574-gcc.h>
>>   #include <dt-bindings/interconnect/qcom,ipq9574.h>
>>   #include <dt-bindings/interrupt-controller/arm-gic.h>
>> @@ -19,6 +20,12 @@ / {
>>   	#size-cells = <2>;
>>   
>>   	clocks {
>> +		cmn_pll_ref_clk: cmn-pll-ref-clk {
>> +			compatible = "fixed-factor-clock";
>> +			clocks = <&xo_clk>;
>> +			#clock-cells = <0>;
>> +		};
>> +
>>   		sleep_clk: sleep-clk {
>>   			compatible = "fixed-clock";
>>   			#clock-cells = <0>;
>> @@ -28,6 +35,11 @@ xo_board_clk: xo-board-clk {
>>   			compatible = "fixed-clock";
>>   			#clock-cells = <0>;
>>   		};
>> +
>> +		xo_clk: xo-clk {
>> +			compatible = "fixed-clock";
>> +			#clock-cells = <0>;
>> +		};
> 
> What is the difference between xo_clk and xo_board_clk? Are there two
> different crystals?

The xo_board_clk of 24 MHZ is generated by applying another divider in
HW (by 2), on top of the same 48 MHZ clock output from internal Wi-Fi.

XO (48 MHZ or 96 MHZ)-->WiFi (mul/div)-->48 MHZ-->fixed factor divider 2 
by HW ---> xo_board_clk (24 MHZ)

We may need to correct its clock chain representation. We will update
xo_board_clk as a fixed factor (div by 2) clock, and refer to the 48 MHZ
input clock, using a separate patch after the CMN PLL patch series
review is concluded. Hope this approach is fine.

> 
>>   	};
>>   
>>   	cpus {
>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
index 91e104b0f865..f026c2a9d0c0 100644
--- a/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/ipq9574-rdp-common.dtsi
@@ -3,7 +3,7 @@ 
  * IPQ9574 RDP board common device tree source
  *
  * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
- * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 /dts-v1/;
@@ -164,6 +164,20 @@  &usb3 {
 	status = "okay";
 };
 
+/*
+ * The bootstrap pins for the board select the XO clock frequency,
+ * which automatically enables the right dividers to ensure the
+ * reference clock output to CMNPLL is 48 MHZ.
+ */
+&cmn_pll_ref_clk {
+	clock-div = <1>;
+	clock-mult = <1>;
+};
+
 &xo_board_clk {
 	clock-frequency = <24000000>;
 };
+
+&xo_clk {
+	clock-frequency = <48000000>;
+};
diff --git a/arch/arm64/boot/dts/qcom/ipq9574.dtsi b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
index 14c7b3a78442..ad9cdb1f76db 100644
--- a/arch/arm64/boot/dts/qcom/ipq9574.dtsi
+++ b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
@@ -3,10 +3,11 @@ 
  * IPQ9574 SoC device tree source
  *
  * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
- * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include <dt-bindings/clock/qcom,apss-ipq.h>
+#include <dt-bindings/clock/qcom,ipq-cmn-pll.h>
 #include <dt-bindings/clock/qcom,ipq9574-gcc.h>
 #include <dt-bindings/interconnect/qcom,ipq9574.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
@@ -19,6 +20,12 @@  / {
 	#size-cells = <2>;
 
 	clocks {
+		cmn_pll_ref_clk: cmn-pll-ref-clk {
+			compatible = "fixed-factor-clock";
+			clocks = <&xo_clk>;
+			#clock-cells = <0>;
+		};
+
 		sleep_clk: sleep-clk {
 			compatible = "fixed-clock";
 			#clock-cells = <0>;
@@ -28,6 +35,11 @@  xo_board_clk: xo-board-clk {
 			compatible = "fixed-clock";
 			#clock-cells = <0>;
 		};
+
+		xo_clk: xo-clk {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+		};
 	};
 
 	cpus {
@@ -243,6 +255,18 @@  mdio: mdio@90000 {
 			status = "disabled";
 		};
 
+		cmn_pll: clock-controller@9b000 {
+			compatible = "qcom,ipq9574-cmn-pll";
+			reg = <0x0009b000 0x800>;
+			clocks = <&cmn_pll_ref_clk>,
+				 <&gcc GCC_CMN_12GPLL_AHB_CLK>,
+				 <&gcc GCC_CMN_12GPLL_SYS_CLK>;
+			clock-names = "ref", "ahb", "sys";
+			#clock-cells = <1>;
+			assigned-clocks = <&cmn_pll CMN_PLL_CLK>;
+			assigned-clock-rates-u64 = /bits/ 64 <12000000000>;
+		};
+
 		qfprom: efuse@a4000 {
 			compatible = "qcom,ipq9574-qfprom", "qcom,qfprom";
 			reg = <0x000a4000 0x5a1>;