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[1/2] dt-bindings: spi: Document the STM32 SPI bindings

Message ID 1498055526-6918-2-git-send-email-amelie.delaunay@st.com
State Changes Requested, archived
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Commit Message

Amelie DELAUNAY June 21, 2017, 2:32 p.m. UTC
This patch adds the documentation of device tree bindings
for the STM32 SPI controller.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
---
 .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt

Comments

Neil Armstrong June 21, 2017, 3:20 p.m. UTC | #1
On 06/21/2017 04:32 PM, Amelie Delaunay wrote:
> This patch adds the documentation of device tree bindings
> for the STM32 SPI controller.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> ---
>  .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> new file mode 100644
> index 0000000..3958bf6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> @@ -0,0 +1,60 @@
> +STMicroelectronics STM32 SPI Controller
> +
> +The STM32 SPI controller is used to communicate with external devices using
> +the Serial Peripheral Interface. It supports full-duplex, half-duplex and
> +simplex synchronous serial communication with external devices. It supports
> +from 4 to 32-bit data size. Although it can be configured as master or slave,
> +only master is supported by the driver.
> +
> +Required properties:
> +- compatible: Must be "st,stm32-spi".

Hi Amelie,

What about the gen1 SPI devices like the F4 ?

It should have been better to use SoC specific compatible, or specify the SPI HW gen like gen1 or gen2.

Neil

> +- reg: Offset and length of the device's register set.
> +- interrupts: Must contain the interrupt id.
> +- clocks: Must contain an entry for spiclk (which feeds the internal clock
> +	  generator).
> +- #address-cells:  Number of cells required to define a chip select address.
> +- #size-cells: Should be zero.
> +
> +Optional properties:
> +- resets: Must contain the phandle to the reset controller.
> +- A pinctrl state named "default" may be defined to set pins in mode of
> +  operation for SPI transfer.
> +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
> +  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
> +- dma-names: DMA request names should include "tx" and "rx" if present.
> +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
> +  Documentation/devicetree/bindings/spi/spi-bus.txt
> +
> +
> +Child nodes represent devices on the SPI bus
> +  See ../spi/spi-bus.txt
> +
> +Optional properties:
> +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
> +		  nanoseconds inserted between two consecutive data frames.
> +
> +
> +Example:
> +	spi2: spi@40003800 {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		compatible = "st,stm32-spi";
> +		reg = <0x40003800 0x400>;
> +		interrupts = <36>;
> +		clocks = <&rcc SPI2_CK>;
> +		resets = <&rcc 1166>;
> +		dmas = <&dmamux1 0 39 0x400 0x01>,
> +		       <&dmamux1 1 40 0x400 0x01>;
> +		dma-names = "rx", "tx";
> +		pinctrl-0 = <&spi2_pins_b>;
> +		pinctrl-names = "default";
> +		status = "okay";
> +		cs-gpios = <&gpioa 11 0>;
> +
> +		spidev@0 {
> +			compatible = "spidev";
> +			reg = <0>;
> +			spi-max-frequency = <4000000>;
> +			st,spi-midi = <4000>;
> +		};
> +	};
> 

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Amelie DELAUNAY June 22, 2017, 11:51 a.m. UTC | #2
On 06/21/2017 05:20 PM, Neil Armstrong wrote:
> On 06/21/2017 04:32 PM, Amelie Delaunay wrote:
>> This patch adds the documentation of device tree bindings
>> for the STM32 SPI controller.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>> ---
>>   .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
>>   1 file changed, 60 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt
>>
>> diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
>> new file mode 100644
>> index 0000000..3958bf6
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
>> @@ -0,0 +1,60 @@
>> +STMicroelectronics STM32 SPI Controller
>> +
>> +The STM32 SPI controller is used to communicate with external devices using
>> +the Serial Peripheral Interface. It supports full-duplex, half-duplex and
>> +simplex synchronous serial communication with external devices. It supports
>> +from 4 to 32-bit data size. Although it can be configured as master or slave,
>> +only master is supported by the driver.
>> +
>> +Required properties:
>> +- compatible: Must be "st,stm32-spi".
> 
> Hi Amelie,
> 
> What about the gen1 SPI devices like the F4 ?
> 
> It should have been better to use SoC specific compatible, or specify the SPI HW gen like gen1 or gen2.
> 
> Neil
> 

Hi Neil,

The gen1 SPI controller embedded on F4/F7 is different from gen2 
embedded on H7 and just to illustrate this, there are 5 main registers 
(16-bit) on gen1 versus 10 main registers on gen2 (32-bit)! Their 
operating modes are different, fifo management and so on... Moreover, I 
know that the community is working on an SPI driver for F4.

I agree with you on the fact that it would be better to use a SoC 
specific compatible: I will send a v2 with "st,stm32h7-spi". This way, 
this will be aligned with what have been done for the I2S part of this 
controller: https://patchwork.kernel.org/patch/9737799/

By the way, I also noticed that my optional property "st,spi-midi-ns" 
doesn't fit with the example "st,spi-midi". I will fix that in the v2 
and keep "st,spi-midi-ns".

Regards,
Amelie

>> +- reg: Offset and length of the device's register set.
>> +- interrupts: Must contain the interrupt id.
>> +- clocks: Must contain an entry for spiclk (which feeds the internal clock
>> +	  generator).
>> +- #address-cells:  Number of cells required to define a chip select address.
>> +- #size-cells: Should be zero.
>> +
>> +Optional properties:
>> +- resets: Must contain the phandle to the reset controller.
>> +- A pinctrl state named "default" may be defined to set pins in mode of
>> +  operation for SPI transfer.
>> +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
>> +  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
>> +- dma-names: DMA request names should include "tx" and "rx" if present.
>> +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
>> +  Documentation/devicetree/bindings/spi/spi-bus.txt
>> +
>> +
>> +Child nodes represent devices on the SPI bus
>> +  See ../spi/spi-bus.txt
>> +
>> +Optional properties:
>> +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
>> +		  nanoseconds inserted between two consecutive data frames.
>> +
>> +
>> +Example:
>> +	spi2: spi@40003800 {
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +		compatible = "st,stm32-spi";
>> +		reg = <0x40003800 0x400>;
>> +		interrupts = <36>;
>> +		clocks = <&rcc SPI2_CK>;
>> +		resets = <&rcc 1166>;
>> +		dmas = <&dmamux1 0 39 0x400 0x01>,
>> +		       <&dmamux1 1 40 0x400 0x01>;
>> +		dma-names = "rx", "tx";
>> +		pinctrl-0 = <&spi2_pins_b>;
>> +		pinctrl-names = "default";
>> +		status = "okay";
>> +		cs-gpios = <&gpioa 11 0>;
>> +
>> +		spidev@0 {
>> +			compatible = "spidev";
>> +			reg = <0>;
>> +			spi-max-frequency = <4000000>;
>> +			st,spi-midi = <4000>;
>> +		};
>> +	};
>>
> 
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Rob Herring June 26, 2017, 6:21 p.m. UTC | #3
On Wed, Jun 21, 2017 at 04:32:05PM +0200, Amelie Delaunay wrote:
> This patch adds the documentation of device tree bindings
> for the STM32 SPI controller.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> ---
>  .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> new file mode 100644
> index 0000000..3958bf6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> @@ -0,0 +1,60 @@
> +STMicroelectronics STM32 SPI Controller
> +
> +The STM32 SPI controller is used to communicate with external devices using
> +the Serial Peripheral Interface. It supports full-duplex, half-duplex and
> +simplex synchronous serial communication with external devices. It supports
> +from 4 to 32-bit data size. Although it can be configured as master or slave,
> +only master is supported by the driver.
> +
> +Required properties:
> +- compatible: Must be "st,stm32-spi".
> +- reg: Offset and length of the device's register set.
> +- interrupts: Must contain the interrupt id.
> +- clocks: Must contain an entry for spiclk (which feeds the internal clock
> +	  generator).
> +- #address-cells:  Number of cells required to define a chip select address.
> +- #size-cells: Should be zero.
> +
> +Optional properties:
> +- resets: Must contain the phandle to the reset controller.
> +- A pinctrl state named "default" may be defined to set pins in mode of
> +  operation for SPI transfer.
> +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
> +  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
> +- dma-names: DMA request names should include "tx" and "rx" if present.
> +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
> +  Documentation/devicetree/bindings/spi/spi-bus.txt
> +
> +
> +Child nodes represent devices on the SPI bus
> +  See ../spi/spi-bus.txt
> +
> +Optional properties:
> +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
> +		  nanoseconds inserted between two consecutive data frames.
> +
> +
> +Example:
> +	spi2: spi@40003800 {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		compatible = "st,stm32-spi";
> +		reg = <0x40003800 0x400>;
> +		interrupts = <36>;
> +		clocks = <&rcc SPI2_CK>;
> +		resets = <&rcc 1166>;
> +		dmas = <&dmamux1 0 39 0x400 0x01>,
> +		       <&dmamux1 1 40 0x400 0x01>;
> +		dma-names = "rx", "tx";
> +		pinctrl-0 = <&spi2_pins_b>;
> +		pinctrl-names = "default";
> +		status = "okay";

Don't show status in examples.

> +		cs-gpios = <&gpioa 11 0>;
> +
> +		spidev@0 {
> +			compatible = "spidev";

This is not a valid compatible. Pick a real device.

Rob
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Amelie DELAUNAY June 27, 2017, 7:38 a.m. UTC | #4
Hi Rob,

On 06/26/2017 08:21 PM, Rob Herring wrote:
> On Wed, Jun 21, 2017 at 04:32:05PM +0200, Amelie Delaunay wrote:
>> This patch adds the documentation of device tree bindings
>> for the STM32 SPI controller.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>> ---
>>   .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
>>   1 file changed, 60 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt
>>
>> diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
>> new file mode 100644
>> index 0000000..3958bf6
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
>> @@ -0,0 +1,60 @@
>> +STMicroelectronics STM32 SPI Controller
>> +
>> +The STM32 SPI controller is used to communicate with external devices using
>> +the Serial Peripheral Interface. It supports full-duplex, half-duplex and
>> +simplex synchronous serial communication with external devices. It supports
>> +from 4 to 32-bit data size. Although it can be configured as master or slave,
>> +only master is supported by the driver.
>> +
>> +Required properties:
>> +- compatible: Must be "st,stm32-spi".
>> +- reg: Offset and length of the device's register set.
>> +- interrupts: Must contain the interrupt id.
>> +- clocks: Must contain an entry for spiclk (which feeds the internal clock
>> +	  generator).
>> +- #address-cells:  Number of cells required to define a chip select address.
>> +- #size-cells: Should be zero.
>> +
>> +Optional properties:
>> +- resets: Must contain the phandle to the reset controller.
>> +- A pinctrl state named "default" may be defined to set pins in mode of
>> +  operation for SPI transfer.
>> +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
>> +  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
>> +- dma-names: DMA request names should include "tx" and "rx" if present.
>> +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
>> +  Documentation/devicetree/bindings/spi/spi-bus.txt
>> +
>> +
>> +Child nodes represent devices on the SPI bus
>> +  See ../spi/spi-bus.txt
>> +
>> +Optional properties:
>> +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
>> +		  nanoseconds inserted between two consecutive data frames.
>> +
>> +
>> +Example:
>> +	spi2: spi@40003800 {
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +		compatible = "st,stm32-spi";
>> +		reg = <0x40003800 0x400>;
>> +		interrupts = <36>;
>> +		clocks = <&rcc SPI2_CK>;
>> +		resets = <&rcc 1166>;
>> +		dmas = <&dmamux1 0 39 0x400 0x01>,
>> +		       <&dmamux1 1 40 0x400 0x01>;
>> +		dma-names = "rx", "tx";
>> +		pinctrl-0 = <&spi2_pins_b>;
>> +		pinctrl-names = "default";
>> +		status = "okay";
> 
> Don't show status in examples.
> 
Ok.
>> +		cs-gpios = <&gpioa 11 0>;
>> +
>> +		spidev@0 {
>> +			compatible = "spidev";
> 
> This is not a valid compatible. Pick a real device.
Ok this was just to illustrate the optional property st,spi-midi-ns.
> 
> Rob
> 

I will send a new patch to fix these issues.
Thanks,

Amelie
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
new file mode 100644
index 0000000..3958bf6
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
@@ -0,0 +1,60 @@ 
+STMicroelectronics STM32 SPI Controller
+
+The STM32 SPI controller is used to communicate with external devices using
+the Serial Peripheral Interface. It supports full-duplex, half-duplex and
+simplex synchronous serial communication with external devices. It supports
+from 4 to 32-bit data size. Although it can be configured as master or slave,
+only master is supported by the driver.
+
+Required properties:
+- compatible: Must be "st,stm32-spi".
+- reg: Offset and length of the device's register set.
+- interrupts: Must contain the interrupt id.
+- clocks: Must contain an entry for spiclk (which feeds the internal clock
+	  generator).
+- #address-cells:  Number of cells required to define a chip select address.
+- #size-cells: Should be zero.
+
+Optional properties:
+- resets: Must contain the phandle to the reset controller.
+- A pinctrl state named "default" may be defined to set pins in mode of
+  operation for SPI transfer.
+- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
+  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
+- dma-names: DMA request names should include "tx" and "rx" if present.
+- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
+  Documentation/devicetree/bindings/spi/spi-bus.txt
+
+
+Child nodes represent devices on the SPI bus
+  See ../spi/spi-bus.txt
+
+Optional properties:
+- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
+		  nanoseconds inserted between two consecutive data frames.
+
+
+Example:
+	spi2: spi@40003800 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "st,stm32-spi";
+		reg = <0x40003800 0x400>;
+		interrupts = <36>;
+		clocks = <&rcc SPI2_CK>;
+		resets = <&rcc 1166>;
+		dmas = <&dmamux1 0 39 0x400 0x01>,
+		       <&dmamux1 1 40 0x400 0x01>;
+		dma-names = "rx", "tx";
+		pinctrl-0 = <&spi2_pins_b>;
+		pinctrl-names = "default";
+		status = "okay";
+		cs-gpios = <&gpioa 11 0>;
+
+		spidev@0 {
+			compatible = "spidev";
+			reg = <0>;
+			spi-max-frequency = <4000000>;
+			st,spi-midi = <4000>;
+		};
+	};