diff mbox

[1/4] dt-bindings: media: Binding document for Qualcomm Camera Control Interface driver

Message ID 1506953613-23875-2-git-send-email-todor.tomov@linaro.org (mailing list archive)
State Deferred
Delegated to: Andy Gross
Headers show

Commit Message

Todor Tomov Oct. 2, 2017, 2:13 p.m. UTC
Add DT binding document for Qualcomm Camera Control Interface driver

CC: Rob Herring <robh+dt@kernel.org>
CC: Mark Rutland <mark.rutland@arm.com>
CC: devicetree@vger.kernel.org
Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
---
 .../devicetree/bindings/i2c/i2c-qcom-cci.txt       | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt

Comments

Bjorn Andersson Oct. 6, 2017, 5:29 a.m. UTC | #1
On Mon 02 Oct 07:13 PDT 2017, Todor Tomov wrote:
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
> new file mode 100644
> index 0000000..f4c5338
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
> @@ -0,0 +1,55 @@
> +Qualcomm Camera Control Interface I2C controller

Well, it's not a I2C controller, it is a MIPI CCI controller.

> +
> +Required properties:
> + - compatible: Should be one of:
> +   - "qcom,cci-v1.0.8" for 8916;
> +   - "qcom,cci-v1.4.0" for 8996.
> + - #address-cells: Should be <1>.
> + - #size-cells: Should be <0>.
> + - reg: Base address of the controller and length of memory mapped region.
> + - reg-names: Should be "cci".

No need for reg-names, as we only have one.

> + - interrupts: Specifier for CCI interrupt.
> + - interrupt-names: Should be "cci".

No need for interrupt-names, as we only have one.

> + - clocks: List of clock specifiers, one for each entry in clock-names.
> + - clock-names: Should contain:
> +   - "mmss_mmagic_ahb" - on 8996 only;
> +   - "camss_top_ahb";
> +   - "cci_ahb";
> +   - "cci";
> +   - "camss_ahb".
> + - pinctrl-names: Should contain only one value - "default".
> + - pinctrl-0: Pin control group to be used for this controller.

No need to document that the node can have the default pinctrl
properties.

> +
> +
> +Required properties on 8996:
> + - power-domains: Power domain specifier.
> +
> +Optional:
> + - clock-frequency: Desired I2C bus clock frequency in Hz, defaults to 100 kHz
> +   if omitted.
> +
> +Example:
> +
> +                cci: qcom,cci@a0c000 {

Don't do qcom, in the node name, and there's probably no reason to have
a label for this node either. So just make it

		   cci@a0c000 {

> +                        compatible = "qcom,cci-v1.4.0";
> +                        #address-cells = <1>;
> +                        #size-cells = <0>;
> +                        reg = <0xa0c000 0x1000>;
> +                        reg-names = "cci";
> +                        interrupts = <GIC_SPI 295 IRQ_TYPE_EDGE_RISING>;
> +                        interrupt-names = "cci";
> +                        power-domains = <&mmcc CAMSS_GDSC>;
> +                        clocks = <&mmcc MMSS_MMAGIC_AHB_CLK>,
> +                                        <&mmcc CAMSS_TOP_AHB_CLK>,
> +                                        <&mmcc CAMSS_CCI_AHB_CLK>,
> +                                        <&mmcc CAMSS_CCI_CLK>,
> +                                        <&mmcc CAMSS_AHB_CLK>;
> +                        clock-names = "mmss_mmagic_ahb",
> +                                        "camss_top_ahb",
> +                                        "cci_ahb",
> +                                        "cci",
> +                                        "camss_ahb";
> +                        pinctrl-names = "default";
> +                        pinctrl-0 = <&cci0_default>;
> +                        clock-frequency = <400000>;
> +                };

In the case of this single cci block having two masters we need a way to
describe the two sets of clients. I think the two options we have are:

cci {
	client {
		reg = <0 0x2c>;
	};
};

The reg here being <master address>

or:

cci {
	master0 {
		client {
			reg = <0x2c>;
		};
	};
};

The name "master0" could be made significant and picked up by name, and
in the case of single-master this level could be omitted.


I like the first one, but it looks really hard to get implemented in
Linux, based on the i2c core's expectation that #address-cells is 1. So
I think the latter is the favourable option.

Regards,
Bjorn
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Todor Tomov Oct. 12, 2017, 2:50 p.m. UTC | #2
Hi Bjorn,

Thank you for the review.

On  6.10.2017 08:29, Bjorn Andersson wrote:
> On Mon 02 Oct 07:13 PDT 2017, Todor Tomov wrote:
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
>> new file mode 100644
>> index 0000000..f4c5338
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
>> @@ -0,0 +1,55 @@
>> +Qualcomm Camera Control Interface I2C controller
> 
> Well, it's not a I2C controller, it is a MIPI CCI controller.
> 
>> +
>> +Required properties:
>> + - compatible: Should be one of:
>> +   - "qcom,cci-v1.0.8" for 8916;
>> +   - "qcom,cci-v1.4.0" for 8996.
>> + - #address-cells: Should be <1>.
>> + - #size-cells: Should be <0>.
>> + - reg: Base address of the controller and length of memory mapped region.
>> + - reg-names: Should be "cci".
> 
> No need for reg-names, as we only have one.
> 
>> + - interrupts: Specifier for CCI interrupt.
>> + - interrupt-names: Should be "cci".
> 
> No need for interrupt-names, as we only have one.
> 
>> + - clocks: List of clock specifiers, one for each entry in clock-names.
>> + - clock-names: Should contain:
>> +   - "mmss_mmagic_ahb" - on 8996 only;
>> +   - "camss_top_ahb";
>> +   - "cci_ahb";
>> +   - "cci";
>> +   - "camss_ahb".
>> + - pinctrl-names: Should contain only one value - "default".
>> + - pinctrl-0: Pin control group to be used for this controller.
> 
> No need to document that the node can have the default pinctrl
> properties.
> 
>> +
>> +
>> +Required properties on 8996:
>> + - power-domains: Power domain specifier.
>> +
>> +Optional:
>> + - clock-frequency: Desired I2C bus clock frequency in Hz, defaults to 100 kHz
>> +   if omitted.
>> +
>> +Example:
>> +
>> +                cci: qcom,cci@a0c000 {
> 
> Don't do qcom, in the node name, and there's probably no reason to have
> a label for this node either. So just make it
> 
> 		   cci@a0c000 {
> 
>> +                        compatible = "qcom,cci-v1.4.0";
>> +                        #address-cells = <1>;
>> +                        #size-cells = <0>;
>> +                        reg = <0xa0c000 0x1000>;
>> +                        reg-names = "cci";
>> +                        interrupts = <GIC_SPI 295 IRQ_TYPE_EDGE_RISING>;
>> +                        interrupt-names = "cci";
>> +                        power-domains = <&mmcc CAMSS_GDSC>;
>> +                        clocks = <&mmcc MMSS_MMAGIC_AHB_CLK>,
>> +                                        <&mmcc CAMSS_TOP_AHB_CLK>,
>> +                                        <&mmcc CAMSS_CCI_AHB_CLK>,
>> +                                        <&mmcc CAMSS_CCI_CLK>,
>> +                                        <&mmcc CAMSS_AHB_CLK>;
>> +                        clock-names = "mmss_mmagic_ahb",
>> +                                        "camss_top_ahb",
>> +                                        "cci_ahb",
>> +                                        "cci",
>> +                                        "camss_ahb";
>> +                        pinctrl-names = "default";
>> +                        pinctrl-0 = <&cci0_default>;
>> +                        clock-frequency = <400000>;
>> +                };
> 
> In the case of this single cci block having two masters we need a way to
> describe the two sets of clients. I think the two options we have are:
> 
> cci {
> 	client {
> 		reg = <0 0x2c>;
> 	};
> };
> 
> The reg here being <master address>
> 
> or:
> 
> cci {
> 	master0 {
> 		client {
> 			reg = <0x2c>;
> 		};
> 	};
> };
> 
> The name "master0" could be made significant and picked up by name, and
> in the case of single-master this level could be omitted.
> 
> 
> I like the first one, but it looks really hard to get implemented in
> Linux, based on the i2c core's expectation that #address-cells is 1. So
> I think the latter is the favourable option.

Yes, I'll try this for the version which supports the second bus. Thank
you for this suggestion.

The rest of the points I'll fix now and send a v2.

> 
> Regards,
> Bjorn
>
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
new file mode 100644
index 0000000..f4c5338
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
@@ -0,0 +1,55 @@ 
+Qualcomm Camera Control Interface I2C controller
+
+Required properties:
+ - compatible: Should be one of:
+   - "qcom,cci-v1.0.8" for 8916;
+   - "qcom,cci-v1.4.0" for 8996.
+ - #address-cells: Should be <1>.
+ - #size-cells: Should be <0>.
+ - reg: Base address of the controller and length of memory mapped region.
+ - reg-names: Should be "cci".
+ - interrupts: Specifier for CCI interrupt.
+ - interrupt-names: Should be "cci".
+ - clocks: List of clock specifiers, one for each entry in clock-names.
+ - clock-names: Should contain:
+   - "mmss_mmagic_ahb" - on 8996 only;
+   - "camss_top_ahb";
+   - "cci_ahb";
+   - "cci";
+   - "camss_ahb".
+ - pinctrl-names: Should contain only one value - "default".
+ - pinctrl-0: Pin control group to be used for this controller.
+
+
+Required properties on 8996:
+ - power-domains: Power domain specifier.
+
+Optional:
+ - clock-frequency: Desired I2C bus clock frequency in Hz, defaults to 100 kHz
+   if omitted.
+
+Example:
+
+                cci: qcom,cci@a0c000 {
+                        compatible = "qcom,cci-v1.4.0";
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+                        reg = <0xa0c000 0x1000>;
+                        reg-names = "cci";
+                        interrupts = <GIC_SPI 295 IRQ_TYPE_EDGE_RISING>;
+                        interrupt-names = "cci";
+                        power-domains = <&mmcc CAMSS_GDSC>;
+                        clocks = <&mmcc MMSS_MMAGIC_AHB_CLK>,
+                                        <&mmcc CAMSS_TOP_AHB_CLK>,
+                                        <&mmcc CAMSS_CCI_AHB_CLK>,
+                                        <&mmcc CAMSS_CCI_CLK>,
+                                        <&mmcc CAMSS_AHB_CLK>;
+                        clock-names = "mmss_mmagic_ahb",
+                                        "camss_top_ahb",
+                                        "cci_ahb",
+                                        "cci",
+                                        "camss_ahb";
+                        pinctrl-names = "default";
+                        pinctrl-0 = <&cci0_default>;
+                        clock-frequency = <400000>;
+                };