Hi Rob,
On 08/03/2017 10:21 PM, Rob Herring wrote:
On Thu, Jul 27, 2017 at 03:49:53PM +0200, Alexandre Torgue wrote:
Initially each pin was declared in "include/dt-bindings/stm32<SOC>-pinfunc.h"
and each definition contained SOC names (ex: STM32F429_PA9_FUNC_USART1_TX).
Since this approach was approved, the number of supported MCU has
increased (STM32F429/STM32F469/STM32f746/STM32H743). To avoid to add a new
file in "include/dt-bindings" each time a new STM32 SOC arrives I propose
a new approach which consist to use a macro to define pin muxing in device
tree. All STM32 will use the common macro to define pinmux. Furthermore, it
will make STM32 maintenance and integration of new SOC easier .
Signed-off-by: Alexandre TORGUE <alexandre.torgue@xxxxxx>
Reviewed-by: Vikas MANOCHA <vikas.manocha@xxxxxx>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
index d907a74..567aa72 100644
--- a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
@@ -126,22 +126,27 @@ configuration, pullups, drive, output high/low and output speed.
};
Required properties:
-- pinmux: integer array, represents gpio pin number and mux setting.
- Supported pin number and mux varies for different SoCs, and are defined in
- dt-bindings/pinctrl/<soc>-pinfunc.h directly.
- These defines are calculated as:
- ((port * 16 + line) << 8) | function
+- pinmux: integer array, represents gpio pin number and mux setting. Use
+ following macro: STM32_PINMUX(PIN_NO(port_name, line), mode) to declare it.
I would keep the above formula. It can't change because that is the ABI.
The macro is just convenience.
Is there any reason to have 2 macros? I'd just do STM32_PINMUX(port,
line, mode) and make port names defines (PA, PB, PC, etc.).
No. It has been done in this way to simplify macro definition, but it
could be done in another way. I can try to create a macro like you
propose: STM32_PINMUX(port, line, mode) if you think it is more readable.
+
With:
- - port: The gpio port index (PA = 0, PB = 1, ..., PK = 11)
- - line: The line offset within the port (PA0 = 0, PA1 = 1, ..., PA15 = 15)
- - function: The function number, can be:
- * 0 : GPIO
- * 1 : Alternate Function 0
- * 2 : Alternate Function 1
- * 3 : Alternate Function 2
+ - port_name: The gpio port name ('A', 'B', ..., 'K')
+ - line: The line offset within the port (0, 1, ..., 15)
+ - mode: The mode can be:
+ * GPIO
+ * AF0 : Alternate Function 0
+ * AF1 : Alternate Function 1
+ * AF2 : Alternate Function 2
* ...
- * 16 : Alternate Function 15
- * 17 : Analog
+ * AF15 : Alternate Function 15
+ * ANALOG
Here too, keeping the numbers is important.
Perhaps the macro description should either be its own additional
section or document it inline with the macro definition.
I agree. I can keep previous definition like it was done, and add a
section only for the new macro.
Thanks for your review.
Alex
Overall, it does seem like a nice shrinking of the header files.
+
+ Example:
+ To declare pin PA7 in mode "alternate function 7" you have to
+ declare:
+ pinmux = <STM32_PINMUX(PIN_NO('A', 9), AF7)>;
+
+ This macro is defined in dt-bindings/pinctrl/stm32-pinfunc.h
Optional properties:
- GENERIC_PINCONFIG: is the generic pinconfig options to use.
@@ -165,13 +170,13 @@ pin-controller {
...
usart1_pins_a: usart1@0 {
pins1 {
- pinmux = <STM32F429_PA9_FUNC_USART1_TX>;
+ pinmux = <STM32_PINMUX(PIN_NO('A', 9), AF7)>; /* USART1_TX */
bias-disable;
drive-push-pull;
slew-rate = <0>;
};
pins2 {
- pinmux = <STM32F429_PA10_FUNC_USART1_RX>;
+ pinmux = <STM32_PINMUX(PIN_NO('A', 10), AF7)>; /* USART1_RX */
bias-disable;
};
};
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