| Message ID | 20241022155658.1647350-5-antonio.borneo@foss.st.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | pinctrl: stm32: Add new features and support for more SoC | expand |
On Tue, Oct 22, 2024 at 05:56:48PM +0200, Antonio Borneo wrote: > From: Fabien Dessenne <fabien.dessenne@foss.st.com> > > Document the RSVD (Reserved) mux function, used to reserve pins > for a coprocessor not running Linux. > > Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com> > Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> > --- > .../devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml | 8 ++++++++ > include/dt-bindings/pinctrl/stm32-pinfunc.h | 1 + > 2 files changed, 9 insertions(+) Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Best regards, Krzysztof
On Tue, Oct 22, 2024 at 05:56:48PM +0200, Antonio Borneo wrote: > From: Fabien Dessenne <fabien.dessenne@foss.st.com> > > Document the RSVD (Reserved) mux function, used to reserve pins > for a coprocessor not running Linux. > > Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com> > Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> > --- > .../devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml | 8 ++++++++ > include/dt-bindings/pinctrl/stm32-pinfunc.h | 1 + > 2 files changed, 9 insertions(+) > BTW, which *existing* SoCs use it? Aren't you adding it for the new platform? Best regards, Krzysztof
On Wed, 2024-10-23 at 10:47 +0200, Krzysztof Kozlowski wrote: > On Tue, Oct 22, 2024 at 05:56:48PM +0200, Antonio Borneo wrote: > > From: Fabien Dessenne <fabien.dessenne@foss.st.com> > > > > Document the RSVD (Reserved) mux function, used to reserve pins > > for a coprocessor not running Linux. > > > > Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com> > > Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> > > --- > > .../devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml | 8 ++++++++ > > include/dt-bindings/pinctrl/stm32-pinfunc.h | 1 + > > 2 files changed, 9 insertions(+) > > > > BTW, which *existing* SoCs use it? Aren't you adding it for the new > platform? > This is already used in ST downstream kernel for STM32MP15x In this example https://github.com/STMicroelectronics/linux/blob/v6.1-stm32mp/arch/arm/boot/dts/stm32mp157f-dk2-m4-examples.dts#L112 the GPIOs for LED and for PWM are assigned to the Cortex-M4 and Linux (on Cortex-A7) is not supposed to touch them. Regards, Antonio
On 23/10/2024 10:56, Antonio Borneo wrote: > On Wed, 2024-10-23 at 10:47 +0200, Krzysztof Kozlowski wrote: >> On Tue, Oct 22, 2024 at 05:56:48PM +0200, Antonio Borneo wrote: >>> From: Fabien Dessenne <fabien.dessenne@foss.st.com> >>> >>> Document the RSVD (Reserved) mux function, used to reserve pins >>> for a coprocessor not running Linux. >>> >>> Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com> >>> Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com> >>> --- >>> .../devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml | 8 ++++++++ >>> include/dt-bindings/pinctrl/stm32-pinfunc.h | 1 + >>> 2 files changed, 9 insertions(+) >>> >> >> BTW, which *existing* SoCs use it? Aren't you adding it for the new >> platform? >> > > This is already used in ST downstream kernel for STM32MP15x > In this example > https://github.com/STMicroelectronics/linux/blob/v6.1-stm32mp/arch/arm/boot/dts/stm32mp157f-dk2-m4-examples.dts#L112 > > the GPIOs for LED and for PWM are assigned to the Cortex-M4 and Linux (on Cortex-A7) is not supposed to touch them. I wasn't clear. Which upstream uses it? We really could not care less about downstream vendor code. Best regards, Krzysztof
diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml index a28d77748095a..5d17d6487ae9c 100644 --- a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml +++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml @@ -160,9 +160,13 @@ patternProperties: * ... * 16 : Alternate Function 15 * 17 : Analog + * 18 : Reserved To simplify the usage, macro is available to generate "pinmux" field. This macro is available here: - include/dt-bindings/pinctrl/stm32-pinfunc.h + Setting the pinmux's function to the Reserved (RSVD) value is used to inform + the driver that it shall not apply the mux setting. This can be used to + reserve some pins, for example to a co-processor not running Linux. Some examples of using macro: /* GPIO A9 set as alternate function 2 */ ... { @@ -176,6 +180,10 @@ patternProperties: ... { pinmux = <STM32_PINMUX('A', 9, ANALOG)>; }; + /* GPIO A9 reserved for co-processor */ + ... { + pinmux = <STM32_PINMUX('A', 9, RSVD)>; + }; bias-disable: type: boolean diff --git a/include/dt-bindings/pinctrl/stm32-pinfunc.h b/include/dt-bindings/pinctrl/stm32-pinfunc.h index 28ad0235086a6..af3fd388329a0 100644 --- a/include/dt-bindings/pinctrl/stm32-pinfunc.h +++ b/include/dt-bindings/pinctrl/stm32-pinfunc.h @@ -26,6 +26,7 @@ #define AF14 0xf #define AF15 0x10 #define ANALOG 0x11 +#define RSVD 0x12 /* define Pins number*/ #define PIN_NO(port, line) (((port) - 'A') * 0x10 + (line))