| Message ID | 20240722160022.454226-1-valentin.caron@foss.st.com |
|---|---|
| Headers | show |
| Series | rtc: stm32: add pinctrl interface to handle RTC outs | expand |
Hi Valentin, On Mon, Jul 22, 2024 at 6:02 PM Valentin Caron <valentin.caron@foss.st.com> wrote: > This series adds a pinctrl/pinmux interface to control STM32 RTC outputs. Interesting! I think it is the first pin controller outside on drivers/pinctrl in the kernel tree. Please include me and the linux-gpio@vger.kernel.org list in subsequent postings, I want to be sure what gets merged here and I only noticed this from the LWN driver patches summary. > As device-trees will be upstreamed separately, here is an example: > > stm32-pinctrl { > rtc_rsvd_pins_a: rtc-rsvd-0 { > pins { > pinmux = <STM32_PINMUX('B', 2, AF1)>, /* OUT2 */ > <STM32_PINMUX('I', 8, ANALOG)>; /* OUT2_RMP */ > }; > }; > }; > > stm32-rtc { > pinctrl-0 = <&rtc_rsvd_pins_a &rtc_alarma_pins_a>; So the first one is a generic pin control setting and the second one is a hog for the pins defined by the device itself. It's clever, and works. Nice work! (There should probably be a comment in the device tree to say what is going on so people reading it are not confused.) > /* Enable by foo-device */ > rtc_lsco_pins_a: rtc-lsco-0 { > pins = "out2_rmp"; > function = "lsco"; > }; > > /* Enable by stm32-rtc hog */ > rtc_alarma_pins_a: rtc-alarma-0 { > pins = "out2"; > function = "alarm-a"; > }; Yours, Linus Walleij
Hello Linus, On 26/07/2024 22:37:21+0200, Linus Walleij wrote: > On Mon, Jul 22, 2024 at 6:02 PM Valentin Caron > <valentin.caron@foss.st.com> wrote: > > > This series adds a pinctrl/pinmux interface to control STM32 RTC outputs. > > Interesting! I think it is the first pin controller outside on > drivers/pinctrl in the kernel tree. Actually, we have rtc-omap which does this too. I've been pushing for more RTC to do this instead of defining custom dt bindings to do what boils down to pinmuxing. > > Please include me and the linux-gpio@vger.kernel.org list in > subsequent postings, I want to be sure what gets merged here > and I only noticed this from the LWN driver patches summary. I'll also ensure you get copied on pinctrl related patches.
On Mon, 22 Jul 2024 18:00:18 +0200, Valentin Caron wrote: > This series adds a pinctrl/pinmux interface to control STM32 RTC outputs. > > Theses two signals output are possible: > - LSCO (Low Speed Clock Output) that allow to output LSE clock on a pin. > On STM32MPU Discovery boards, this feature is used to generate a clock > to Wifi/Bluetooth module. > - Alarm out that allow to send a pulse on a pin when alarm A of the RTC > expires. > > [...] Applied, thanks! [1/4] dt-bindings: rtc: stm32: describe pinmux nodes https://git.kernel.org/abelloni/c/5b19519d4e6f [2/4] rtc: stm32: add pinctrl and pinmux interfaces https://git.kernel.org/abelloni/c/16ad2bc09efb [3/4] rtc: stm32: add Low Speed Clock Output (LSCO) support https://git.kernel.org/abelloni/c/bb7b0df2be5c [4/4] rtc: stm32: add alarm A out feature https://git.kernel.org/abelloni/c/04dcadb87da6 Best regards,
This series adds a pinctrl/pinmux interface to control STM32 RTC outputs. Theses two signals output are possible: - LSCO (Low Speed Clock Output) that allow to output LSE clock on a pin. On STM32MPU Discovery boards, this feature is used to generate a clock to Wifi/Bluetooth module. - Alarm out that allow to send a pulse on a pin when alarm A of the RTC expires. First attempt [1] was based on 'st,' vendor properties, this one is based on pinctrl and pinmux framework. As device-trees will be upstreamed separately, here is an example: stm32-pinctrl { rtc_rsvd_pins_a: rtc-rsvd-0 { pins { pinmux = <STM32_PINMUX('B', 2, AF1)>, /* OUT2 */ <STM32_PINMUX('I', 8, ANALOG)>; /* OUT2_RMP */ }; }; }; stm32-rtc { pinctrl-0 = <&rtc_rsvd_pins_a &rtc_alarma_pins_a>; /* Enable by foo-device */ rtc_lsco_pins_a: rtc-lsco-0 { pins = "out2_rmp"; function = "lsco"; }; /* Enable by stm32-rtc hog */ rtc_alarma_pins_a: rtc-alarma-0 { pins = "out2"; function = "alarm-a"; }; }; foo-device { pinctrl-0 = <&rtc_lsco_pins_a>; }; [1] https://lore.kernel.org/linux-arm-kernel/20220504130617.331290-5-valentin.caron@foss.st.com/t/#m37935e92315e22bbe085775096175afc05b7ff09 Since v2: - Modify Kconfig after (a lot of) robots alert: + https://lore.kernel.org/oe-kbuild-all/202407190654.I3RI7WfP-lkp@intel.com/ + https://lore.kernel.org/oe-kbuild-all/202407191258.1oitwwMV-lkp@intel.com/ + https://lore.kernel.org/oe-kbuild-all/202407200400.NnW2fJ0q-lkp@intel.com/ + https://lore.kernel.org/oe-kbuild-all/202407181525.BRNKqmNf-lkp@intel.com/ + https://lore.kernel.org/oe-kbuild-all/202407191830.8bh5dJ09-lkp@intel.com/ Make RTC_DRV_STM32 depends on OF, PINCTRL and COMMON_CLK as they are menuconfig entry. Make RTC_DRV_STM32 select PINCONF, PINCONF_GENERIC and PINMUX as they config entry. Since v1: - Select PINMUX and PINCONF_GENERIC to solve: https://lore.kernel.org/oe-kbuild-all/202407130943.ie6n2Orh-lkp@intel.com/ - Make stm32_rtc_pinctrl_pins as static to solve: https://lore.kernel.org/oe-kbuild-all/202407130612.OEicZbNE-lkp@intel.com/ - Change "depends on" to "select" COMMON_CLK config - Modify regex in dt-binding to avoid properties like "rtc--123" as valid ones. Valentin Caron (4): dt-bindings: rtc: stm32: describe pinmux nodes rtc: stm32: add pinctrl and pinmux interfaces rtc: stm32: add Low Speed Clock Output (LSCO) support rtc: stm32: add alarm A out feature .../devicetree/bindings/rtc/st,stm32-rtc.yaml | 28 ++ drivers/rtc/Kconfig | 6 + drivers/rtc/rtc-stm32.c | 281 ++++++++++++++++++ 3 files changed, 315 insertions(+)