| Message ID | 20211214213630.14819-1-tharvey@gateworks.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: dts: imx8mm-venice-gw73xx-0x: add dt overlays for serial modes | expand |
On Tue, Dec 14, 2021 at 1:36 PM Tim Harvey <tharvey@gateworks.com> wrote: > > The imx8mm-venice-gw73xx-0x som+baseboard combination has a multi-protocol > RS-232/RS-485/RS-422 transceiver to an off-board connector which > can be configured in a number of ways via UART and GPIO configuration. > > The default configuration per the imx8mm-venice-gw73xx-0x dts is for > UART2 TX/RX and UART4 TX/RX to be available as RS-232: > J15.1 UART2 TX out > J15.2 UART2 RX in > J15.3 UART4 TX out > J15.4 UART4 RX in > J15.5 GND > > Add dt overlays to allow additional the modes of operation: > > rs232-rts (UART2 RS-232 with RTS/CTS hardware flow control) > J15.1 TX out > J15.2 RX in > J15.3 RTS out > J15.4 CTS in > J15.5 GND > > rs485 (UART2 RS-485 half duplex) > J15.1 TXRX- > J15.2 N/C > J15.3 TXRX+ > J15.4 N/C > J15.5 GND > > rs422 (UART2 RS-422 full duplex) > J15.1 TX- > J15.2 RX+ > J15.3 TX+ > J15.4 RX- > J15.5 GND > > Signed-off-by: Tim Harvey <tharvey@gateworks.com> > --- > arch/arm64/boot/dts/freescale/Makefile | 3 + > .../imx8mm-venice-gw73xx-0x-rs232-rts.dts | 53 ++++++++++++++++ > .../imx8mm-venice-gw73xx-0x-rs422.dts | 61 +++++++++++++++++++ > .../imx8mm-venice-gw73xx-0x-rs485.dts | 61 +++++++++++++++++++ > 4 files changed, 178 insertions(+) > create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts > create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts > create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > > diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile > index a14a6173b765..5ec8d59347b6 100644 > --- a/arch/arm64/boot/dts/freescale/Makefile > +++ b/arch/arm64/boot/dts/freescale/Makefile > @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-var-som-symphony.dtb > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb > dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts > new file mode 100644 > index 000000000000..c184cf4aea4e > --- /dev/null > +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts > @@ -0,0 +1,53 @@ > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > +/* > + * Copyright 2021 Gateworks Corporation > + * > + * GW73xx RS232 with RTS/CTS hardware flow control: > + * - GPIO4_0 rs485_en needs to be driven low (in-active) > + * - UART4_TX becomes RTS > + * - UART4_RX becomes CTS > + */ > + > +#include <dt-bindings/gpio/gpio.h> > + > +#include "imx8mm-pinfunc.h" > + > +/dts-v1/; > +/plugin/; > + > +&{/} { > + compatible = "gw,imx8mm-gw73xx-0x"; > +}; > + > +&gpio4 { > + rs485_en { > + gpio-hog; > + gpios = <0 GPIO_ACTIVE_HIGH>; > + output-low; > + line-name = "rs485_en"; > + }; > +}; > + > +&uart2 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_uart2>; > + rts-gpios = <&gpio5 29 GPIO_ACTIVE_LOW>; > + cts-gpios = <&gpio5 28 GPIO_ACTIVE_LOW>; > + uart-has-rtscts; > + status = "okay"; > +}; > + > +&uart4 { > + status = "disabled"; > +}; > + > +&iomuxc { > + pinctrl_uart2: uart2grp { > + fsl,pins = < > + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 > + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 > + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 > + MX8MM_IOMUXC_UART4_RXD_GPIO5_IO28 0x140 > + >; > + }; > +}; > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts > new file mode 100644 > index 000000000000..3e6404340d52 > --- /dev/null > +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts > @@ -0,0 +1,61 @@ > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > +/* > + * Copyright 2021 Gateworks Corporation > + * > + * GW73xx RS422 (RS485 full duplex): > + * - GPIO1_0 rs485_term selects on-chip termination > + * - GPIO4_0 rs485_en needs to be driven high (active) > + * - GPIO4_2 rs485_hd needs to be driven low (in-active) > + * - UART4_TX is DE for RS485 transmitter > + * - RS485_EN needs to be pulled high > + * - RS485_HALF needs to be low > + */ > + > +#include <dt-bindings/gpio/gpio.h> > + > +#include "imx8mm-pinfunc.h" > + > +/dts-v1/; > +/plugin/; > + > +&{/} { > + compatible = "gw,imx8mm-gw73xx-0x"; > +}; > + > +&gpio4 { > + rs485_en { > + gpio-hog; > + gpios = <0 GPIO_ACTIVE_HIGH>; > + output-high; > + line-name = "rs485_en"; > + }; > + > + rs485_hd { > + gpio-hog; > + gpios = <2 GPIO_ACTIVE_HIGH>; > + output-low; > + line-name = "rs485_hd"; > + }; > +}; > + > +&uart2 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_uart2>; > + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; > + linux,rs485-enabled-at-boot-time; > + status = "okay"; > +}; > + > +&uart4 { > + status = "disabled"; > +}; > + > +&iomuxc { > + pinctrl_uart2: uart2grp { > + fsl,pins = < > + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 > + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 > + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 > + >; > + }; > +}; > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > new file mode 100644 > index 000000000000..97f19c15c3d0 > --- /dev/null > +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > @@ -0,0 +1,61 @@ > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > +/* > + * Copyright 2021 Gateworks Corporation > + * > + * GW73xx RS485 HD: > + * - GPIO1_0 rs485_term selects on-chip termination > + * - GPIO4_0 rs485_en needs to be driven high (active) > + * - GPIO4_2 rs485_hd needs to be driven high (active) > + * - UART4_TX is DE for RS485 transmitter > + * - RS485_EN needs to be pulled high > + * - RS485_HALF needs to be pulled high > + */ > + > +#include <dt-bindings/gpio/gpio.h> > + > +#include "imx8mm-pinfunc.h" > + > +/dts-v1/; > +/plugin/; > + > +&{/} { > + compatible = "gw,imx8mm-gw73xx-0x"; > +}; > + > +&gpio4 { > + rs485_en { > + gpio-hog; > + gpios = <0 GPIO_ACTIVE_HIGH>; > + output-high; > + line-name = "rs485_en"; > + }; > + > + rs485_hd { > + gpio-hog; > + gpios = <2 GPIO_ACTIVE_HIGH>; > + output-high; > + line-name = "rs485_hd"; > + }; > +}; > + > +&uart2 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_uart2>; > + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; > + linux,rs485-enabled-at-boot-time; > + status = "okay"; > +}; > + > +&uart4 { > + status = "disabled"; > +}; > + > +&iomuxc { > + pinctrl_uart2: uast2grp { > + fsl,pins = < > + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 > + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 > + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 > + >; > + }; > +}; > -- > 2.17.1 > gentle ping. I'm mostly interested to see if my approach to dt fragments here and the naming of the files makes sense to others. This patch causes the kernel to build dtbo files for: arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dtbo arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dtbo arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dtbo The intention is that these files are used by boot firmware (U-Boot) to adjust the dtb before passing it to the kernel. Best regards, Tim
Am Dienstag, 11. Januar 2022, 01:00:21 CET schrieb Tim Harvey: > [SNIP] > > diff --git a/arch/arm64/boot/dts/freescale/Makefile > > b/arch/arm64/boot/dts/freescale/Makefile index a14a6173b765..5ec8d59347b6 > > 100644 > > --- a/arch/arm64/boot/dts/freescale/Makefile > > +++ b/arch/arm64/boot/dts/freescale/Makefile > > @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-var-som-symphony.dtb > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb > > dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb > > > [SNIP] > I'm mostly interested to see if my approach to dt fragments here and > the naming of the files makes sense to others. > > This patch causes the kernel to build dtbo files for: > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dtbo > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dtbo > > The intention is that these files are used by boot firmware (U-Boot) > to adjust the dtb before passing it to the kernel. Hi Tim, do these dtbo actually work? I'm wondering because I was trying to useoverlays myself and noticed that the had to be compiled with -@ for u-boot to be able to apply them. Apparently there are 2 possibilities: * Set "DTC_FLAGS_[dtb] := -@" yourself See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ commit/?id=e426d63e752bdbe7d5ba2d872319dde9ab844a07 * Use dedicated overlay target See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ commit/?id=15d16d6dadf6947ac7f9a686c615995c5a426ce2 You use neither of them. IIRC just naming the target file .dtbo will not apply symbols (-Q) during dtc call. Can you verify using 'V=1' Also I'm wondering which way is the best to go. Best regards, Alexander
Hi, On Mon, 10 Jan 2022 16:00:21 -0800 Tim Harvey wrote: > On Tue, Dec 14, 2021 at 1:36 PM Tim Harvey <tharvey@gateworks.com> wrote: > > [...] > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > > new file mode 100644 > > index 000000000000..97f19c15c3d0 > > --- /dev/null > > +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > > @@ -0,0 +1,61 @@ > > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > > +/* > > + * Copyright 2021 Gateworks Corporation > > + * > > + * GW73xx RS485 HD: > > + * - GPIO1_0 rs485_term selects on-chip termination > > + * - GPIO4_0 rs485_en needs to be driven high (active) > > + * - GPIO4_2 rs485_hd needs to be driven high (active) > > + * - UART4_TX is DE for RS485 transmitter > > + * - RS485_EN needs to be pulled high > > + * - RS485_HALF needs to be pulled high > > + */ > > + > > +#include <dt-bindings/gpio/gpio.h> > > + > > +#include "imx8mm-pinfunc.h" > > + > > +/dts-v1/; > > +/plugin/; > > + > > +&{/} { > > + compatible = "gw,imx8mm-gw73xx-0x"; > > +}; > > + > > +&gpio4 { > > + rs485_en { > > + gpio-hog; > > + gpios = <0 GPIO_ACTIVE_HIGH>; > > + output-high; > > + line-name = "rs485_en"; > > + }; > > + > > + rs485_hd { > > + gpio-hog; > > + gpios = <2 GPIO_ACTIVE_HIGH>; > > + output-high; > > + line-name = "rs485_hd"; > > + }; > > +}; > > + > > +&uart2 { > > + pinctrl-names = "default"; > > + pinctrl-0 = <&pinctrl_uart2>; > > + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; > > + linux,rs485-enabled-at-boot-time; > > + status = "okay"; > > +}; > > + > > +&uart4 { > > + status = "disabled"; > > +}; > > + > > +&iomuxc { > > + pinctrl_uart2: uast2grp { > s/uast/uart/ Lothar Waßmann
On Mon, Jan 10, 2022 at 11:20 PM Alexander Stein <alexander.stein@ew.tq-group.com> wrote: > > Am Dienstag, 11. Januar 2022, 01:00:21 CET schrieb Tim Harvey: > > [SNIP] > > > diff --git a/arch/arm64/boot/dts/freescale/Makefile > > > b/arch/arm64/boot/dts/freescale/Makefile index a14a6173b765..5ec8d59347b6 > > > 100644 > > > --- a/arch/arm64/boot/dts/freescale/Makefile > > > +++ b/arch/arm64/boot/dts/freescale/Makefile > > > @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-var-som-symphony.dtb > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb > > > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb > > > dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb > > > > > [SNIP] > > I'm mostly interested to see if my approach to dt fragments here and > > the naming of the files makes sense to others. > > > > This patch causes the kernel to build dtbo files for: > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dtbo > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > The intention is that these files are used by boot firmware (U-Boot) > > to adjust the dtb before passing it to the kernel. > > Hi Tim, > > do these dtbo actually work? I'm wondering because I was trying to useoverlays > myself and noticed that the had to be compiled with -@ for u-boot to be able > to apply them. Apparently there are 2 possibilities: Alexander, Yes, they work, but I do manually set DTC_FLAGS=-@ when building kernel dtbs to make them work. > * Set "DTC_FLAGS_[dtb] := -@" yourself > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > commit/?id=e426d63e752bdbe7d5ba2d872319dde9ab844a07 > > * Use dedicated overlay target > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > commit/?id=15d16d6dadf6947ac7f9a686c615995c5a426ce2 > > You use neither of them. IIRC just naming the target file .dtbo will not apply > symbols (-Q) during dtc call. Can you verify using 'V=1' > Also I'm wondering which way is the best to go. > I wasn't aware there was a way to do this via Makefiles. It seems that perhaps Rob's approach with 'kbuild: Add generic rule to apply fdtoverlay' is a way to avoid having to add them all manually in the first approach? I must admit I'm not sure how to use that. Best regards, Tim
Am Dienstag, 11. Januar 2022, 18:53:29 CET schrieb Tim Harvey: > On Mon, Jan 10, 2022 at 11:20 PM Alexander Stein > > <alexander.stein@ew.tq-group.com> wrote: > > Am Dienstag, 11. Januar 2022, 01:00:21 CET schrieb Tim Harvey: > > > [SNIP] > > > > > > > diff --git a/arch/arm64/boot/dts/freescale/Makefile > > > > b/arch/arm64/boot/dts/freescale/Makefile index > > > > a14a6173b765..5ec8d59347b6 > > > > 100644 > > > > --- a/arch/arm64/boot/dts/freescale/Makefile > > > > +++ b/arch/arm64/boot/dts/freescale/Makefile > > > > @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += > > > > imx8mm-var-som-symphony.dtb > > > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb > > > > > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb > > > > > > [SNIP] > > > I'm mostly interested to see if my approach to dt fragments here and > > > the naming of the files makes sense to others. > > > > > > This patch causes the kernel to build dtbo files for: > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dtbo > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > > > The intention is that these files are used by boot firmware (U-Boot) > > > to adjust the dtb before passing it to the kernel. > > > > Hi Tim, > > > > do these dtbo actually work? I'm wondering because I was trying to > > useoverlays myself and noticed that the had to be compiled with -@ for > > u-boot to be able > > to apply them. Apparently there are 2 possibilities: > Alexander, > > Yes, they work, but I do manually set DTC_FLAGS=-@ when building > kernel dtbs to make them work. I see, I expected something like this. That's why I responded to you. > > * Set "DTC_FLAGS_[dtb] := -@" yourself > > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > commit/?id=e426d63e752bdbe7d5ba2d872319dde9ab844a07 > > > > * Use dedicated overlay target > > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > commit/?id=15d16d6dadf6947ac7f9a686c615995c5a426ce2 > > > > You use neither of them. IIRC just naming the target file .dtbo will not > > apply symbols (-Q) during dtc call. Can you verify using 'V=1' > > Also I'm wondering which way is the best to go. > > I wasn't aware there was a way to do this via Makefiles. It seems that > perhaps Rob's approach with 'kbuild: Add generic rule to apply > fdtoverlay' is a way to avoid having to add them all manually in the > first approach? I must admit I'm not sure how to use that. I tried using this myself for my custom board. I feel it is a bit cumbersome to get it right. See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/ arch/arm64/boot/dts/xilinx/Makefile for an example. Essentially you define your .dtb as before and add another target (e.g. sm- k26-revA-sck-kv-g-revA-dtbs) where you add your .dtbo _after_ the original .dtb. This target needs to be added to 'dtb-y' as before. I suspect this way is needed to check the .dtbo against the base .dtb if it actually matches. HTH Alexander
On Tue, Jan 11, 2022 at 1:27 AM Lothar Waßmann <LW@karo-electronics.de> wrote: > > Hi, > > On Mon, 10 Jan 2022 16:00:21 -0800 Tim Harvey wrote: > > On Tue, Dec 14, 2021 at 1:36 PM Tim Harvey <tharvey@gateworks.com> wrote: > > > > [...] > > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > > > new file mode 100644 > > > index 000000000000..97f19c15c3d0 > > > --- /dev/null > > > +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts > > > @@ -0,0 +1,61 @@ > > > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > > > +/* > > > + * Copyright 2021 Gateworks Corporation > > > + * > > > + * GW73xx RS485 HD: > > > + * - GPIO1_0 rs485_term selects on-chip termination > > > + * - GPIO4_0 rs485_en needs to be driven high (active) > > > + * - GPIO4_2 rs485_hd needs to be driven high (active) > > > + * - UART4_TX is DE for RS485 transmitter > > > + * - RS485_EN needs to be pulled high > > > + * - RS485_HALF needs to be pulled high > > > + */ > > > + > > > +#include <dt-bindings/gpio/gpio.h> > > > + > > > +#include "imx8mm-pinfunc.h" > > > + > > > +/dts-v1/; > > > +/plugin/; > > > + > > > +&{/} { > > > + compatible = "gw,imx8mm-gw73xx-0x"; > > > +}; > > > + > > > +&gpio4 { > > > + rs485_en { > > > + gpio-hog; > > > + gpios = <0 GPIO_ACTIVE_HIGH>; > > > + output-high; > > > + line-name = "rs485_en"; > > > + }; > > > + > > > + rs485_hd { > > > + gpio-hog; > > > + gpios = <2 GPIO_ACTIVE_HIGH>; > > > + output-high; > > > + line-name = "rs485_hd"; > > > + }; > > > +}; > > > + > > > +&uart2 { > > > + pinctrl-names = "default"; > > > + pinctrl-0 = <&pinctrl_uart2>; > > > + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; > > > + linux,rs485-enabled-at-boot-time; > > > + status = "okay"; > > > +}; > > > + > > > +&uart4 { > > > + status = "disabled"; > > > +}; > > > + > > > +&iomuxc { > > > + pinctrl_uart2: uast2grp { > > > s/uast/uart/ > > Lothar, Thanks - will fix in v2. Tim
On Wed, Jan 12, 2022 at 07:58:00AM +0100, Alexander Stein wrote: > Am Dienstag, 11. Januar 2022, 18:53:29 CET schrieb Tim Harvey: > > On Mon, Jan 10, 2022 at 11:20 PM Alexander Stein > > > > <alexander.stein@ew.tq-group.com> wrote: > > > Am Dienstag, 11. Januar 2022, 01:00:21 CET schrieb Tim Harvey: > > > > [SNIP] > > > > > > > > > diff --git a/arch/arm64/boot/dts/freescale/Makefile > > > > > b/arch/arm64/boot/dts/freescale/Makefile index > > > > > a14a6173b765..5ec8d59347b6 > > > > > 100644 > > > > > --- a/arch/arm64/boot/dts/freescale/Makefile > > > > > +++ b/arch/arm64/boot/dts/freescale/Makefile > > > > > @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += > > > > > imx8mm-var-som-symphony.dtb > > > > > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb > > > > > > > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo > > > > > +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > > > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb > > > > > dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb > > > > > > > > [SNIP] > > > > I'm mostly interested to see if my approach to dt fragments here and > > > > the naming of the files makes sense to others. > > > > > > > > This patch causes the kernel to build dtbo files for: > > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dtbo > > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dtbo > > > > arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dtbo > > > > > > > > The intention is that these files are used by boot firmware (U-Boot) > > > > to adjust the dtb before passing it to the kernel. > > > > > > Hi Tim, > > > > > > do these dtbo actually work? I'm wondering because I was trying to > > > useoverlays myself and noticed that the had to be compiled with -@ for > > > u-boot to be able > > > to apply them. Apparently there are 2 possibilities: > > Alexander, > > > > Yes, they work, but I do manually set DTC_FLAGS=-@ when building > > kernel dtbs to make them work. > > I see, I expected something like this. That's why I responded to you. > > > > * Set "DTC_FLAGS_[dtb] := -@" yourself > > > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > > commit/?id=e426d63e752bdbe7d5ba2d872319dde9ab844a07 > > > > > > * Use dedicated overlay target > > > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > > commit/?id=15d16d6dadf6947ac7f9a686c615995c5a426ce2 > > > > > > You use neither of them. IIRC just naming the target file .dtbo will not > > > apply symbols (-Q) during dtc call. Can you verify using 'V=1' > > > Also I'm wondering which way is the best to go. > > > > I wasn't aware there was a way to do this via Makefiles. It seems that > > perhaps Rob's approach with 'kbuild: Add generic rule to apply > > fdtoverlay' is a way to avoid having to add them all manually in the > > first approach? I must admit I'm not sure how to use that. > > I tried using this myself for my custom board. I feel it is a bit cumbersome > to get it right. > See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/ > arch/arm64/boot/dts/xilinx/Makefile for an example. > > Essentially you define your .dtb as before and add another target (e.g. sm- > k26-revA-sck-kv-g-revA-dtbs) where you add your .dtbo _after_ the original > .dtb. This target needs to be added to 'dtb-y' as before. > > I suspect this way is needed to check the .dtbo against the base .dtb if it > actually matches. Yeah, I like this check. Tim, could you update your patch to follow this pattern? Shawn
diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile index a14a6173b765..5ec8d59347b6 100644 --- a/arch/arm64/boot/dts/freescale/Makefile +++ b/arch/arm64/boot/dts/freescale/Makefile @@ -44,6 +44,9 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-var-som-symphony.dtb dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs232-rts.dtbo +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs422.dtbo +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-rs485.dtbo dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts new file mode 100644 index 000000000000..c184cf4aea4e --- /dev/null +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) +/* + * Copyright 2021 Gateworks Corporation + * + * GW73xx RS232 with RTS/CTS hardware flow control: + * - GPIO4_0 rs485_en needs to be driven low (in-active) + * - UART4_TX becomes RTS + * - UART4_RX becomes CTS + */ + +#include <dt-bindings/gpio/gpio.h> + +#include "imx8mm-pinfunc.h" + +/dts-v1/; +/plugin/; + +&{/} { + compatible = "gw,imx8mm-gw73xx-0x"; +}; + +&gpio4 { + rs485_en { + gpio-hog; + gpios = <0 GPIO_ACTIVE_HIGH>; + output-low; + line-name = "rs485_en"; + }; +}; + +&uart2 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart2>; + rts-gpios = <&gpio5 29 GPIO_ACTIVE_LOW>; + cts-gpios = <&gpio5 28 GPIO_ACTIVE_LOW>; + uart-has-rtscts; + status = "okay"; +}; + +&uart4 { + status = "disabled"; +}; + +&iomuxc { + pinctrl_uart2: uart2grp { + fsl,pins = < + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 + MX8MM_IOMUXC_UART4_RXD_GPIO5_IO28 0x140 + >; + }; +}; diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts new file mode 100644 index 000000000000..3e6404340d52 --- /dev/null +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) +/* + * Copyright 2021 Gateworks Corporation + * + * GW73xx RS422 (RS485 full duplex): + * - GPIO1_0 rs485_term selects on-chip termination + * - GPIO4_0 rs485_en needs to be driven high (active) + * - GPIO4_2 rs485_hd needs to be driven low (in-active) + * - UART4_TX is DE for RS485 transmitter + * - RS485_EN needs to be pulled high + * - RS485_HALF needs to be low + */ + +#include <dt-bindings/gpio/gpio.h> + +#include "imx8mm-pinfunc.h" + +/dts-v1/; +/plugin/; + +&{/} { + compatible = "gw,imx8mm-gw73xx-0x"; +}; + +&gpio4 { + rs485_en { + gpio-hog; + gpios = <0 GPIO_ACTIVE_HIGH>; + output-high; + line-name = "rs485_en"; + }; + + rs485_hd { + gpio-hog; + gpios = <2 GPIO_ACTIVE_HIGH>; + output-low; + line-name = "rs485_hd"; + }; +}; + +&uart2 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart2>; + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; + linux,rs485-enabled-at-boot-time; + status = "okay"; +}; + +&uart4 { + status = "disabled"; +}; + +&iomuxc { + pinctrl_uart2: uart2grp { + fsl,pins = < + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 + >; + }; +}; diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts new file mode 100644 index 000000000000..97f19c15c3d0 --- /dev/null +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) +/* + * Copyright 2021 Gateworks Corporation + * + * GW73xx RS485 HD: + * - GPIO1_0 rs485_term selects on-chip termination + * - GPIO4_0 rs485_en needs to be driven high (active) + * - GPIO4_2 rs485_hd needs to be driven high (active) + * - UART4_TX is DE for RS485 transmitter + * - RS485_EN needs to be pulled high + * - RS485_HALF needs to be pulled high + */ + +#include <dt-bindings/gpio/gpio.h> + +#include "imx8mm-pinfunc.h" + +/dts-v1/; +/plugin/; + +&{/} { + compatible = "gw,imx8mm-gw73xx-0x"; +}; + +&gpio4 { + rs485_en { + gpio-hog; + gpios = <0 GPIO_ACTIVE_HIGH>; + output-high; + line-name = "rs485_en"; + }; + + rs485_hd { + gpio-hog; + gpios = <2 GPIO_ACTIVE_HIGH>; + output-high; + line-name = "rs485_hd"; + }; +}; + +&uart2 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart2>; + rts-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; + linux,rs485-enabled-at-boot-time; + status = "okay"; +}; + +&uart4 { + status = "disabled"; +}; + +&iomuxc { + pinctrl_uart2: uast2grp { + fsl,pins = < + MX8MM_IOMUXC_UART2_RXD_UART2_DCE_RX 0x140 + MX8MM_IOMUXC_UART2_TXD_UART2_DCE_TX 0x140 + MX8MM_IOMUXC_UART4_TXD_GPIO5_IO29 0x140 + >; + }; +};
The imx8mm-venice-gw73xx-0x som+baseboard combination has a multi-protocol RS-232/RS-485/RS-422 transceiver to an off-board connector which can be configured in a number of ways via UART and GPIO configuration. The default configuration per the imx8mm-venice-gw73xx-0x dts is for UART2 TX/RX and UART4 TX/RX to be available as RS-232: J15.1 UART2 TX out J15.2 UART2 RX in J15.3 UART4 TX out J15.4 UART4 RX in J15.5 GND Add dt overlays to allow additional the modes of operation: rs232-rts (UART2 RS-232 with RTS/CTS hardware flow control) J15.1 TX out J15.2 RX in J15.3 RTS out J15.4 CTS in J15.5 GND rs485 (UART2 RS-485 half duplex) J15.1 TXRX- J15.2 N/C J15.3 TXRX+ J15.4 N/C J15.5 GND rs422 (UART2 RS-422 full duplex) J15.1 TX- J15.2 RX+ J15.3 TX+ J15.4 RX- J15.5 GND Signed-off-by: Tim Harvey <tharvey@gateworks.com> --- arch/arm64/boot/dts/freescale/Makefile | 3 + .../imx8mm-venice-gw73xx-0x-rs232-rts.dts | 53 ++++++++++++++++ .../imx8mm-venice-gw73xx-0x-rs422.dts | 61 +++++++++++++++++++ .../imx8mm-venice-gw73xx-0x-rs485.dts | 61 +++++++++++++++++++ 4 files changed, 178 insertions(+) create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs232-rts.dts create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs422.dts create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-rs485.dts