Re: [PATCH 1/2] ARM: dts: bcm2*: Demux i2c0 with a pinctrl

Detlev Casanova
2022-02-09T19:26:43Z

On Wednesday, February 9, 2022 12:26:15 P.M. EST Stefan Wahren wrote:
> Hi Detlev,
>
> Am 09.02.22 um 17:25 schrieb Detlev Casanova:
> > The i2c0 device has 2 different busses controlled by a pinctrl.
> >
> > This commit separates the device node into 2 i2c devices:
> > * pin 0: Base i2c bus
> > * pin 44: DSI i2c bus
> >
> > i2c0 is renamed to i2c0if so that device-trees referencing i2c0 don't
> > break and use the i2c0 node defined in i2c0mux node.
> >
> > i2c_csi_dsi can be used to control devices via the DSI i2c bus, used for
> > DSI displays.
> >
> > Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
>
> just a note: Uwe sends a similiar approach for the RTC on CM4 [1] which
> hasn't applied yet.
>
> [1] - https://www.spinics.net/lists/arm-kernel/msg944330.html

Oh, I missed that, I'll just hav to wait for it to be merged and base the next
commit on that (Mainly name change)

> > ---
> >
> > arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 1 +
> > arch/arm/boot/dts/bcm2711.dtsi | 2 +-
> > arch/arm/boot/dts/bcm2835-rpi.dtsi | 9 ++++---
> > .../boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi | 4 +++
> > arch/arm/boot/dts/bcm283x.dtsi | 26 ++++++++++++++++++-
> > 5 files changed, 37 insertions(+), 5 deletions(-)
> > create mode 100644 arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi
> >
> > diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> > b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts index 4432412044de..5dcce58817e6
> > 100644
> > --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> > +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> > @@ -4,6 +4,7 @@
> >
> > #include "bcm2711-rpi.dtsi"
> > #include "bcm283x-rpi-usb-peripheral.dtsi"
> > #include "bcm283x-rpi-wifi-bt.dtsi"
> >
> > +#include "bcm283x-rpi-i2c0mux_0_44.dtsi"
> >
> > / {
> >
> > compatible = "raspberrypi,4-model-b", "brcm,bcm2711";
> >
> > diff --git a/arch/arm/boot/dts/bcm2711.dtsi
> > b/arch/arm/boot/dts/bcm2711.dtsi index 3b60297af7f6..bf6e8251c2c7 100644
> > --- a/arch/arm/boot/dts/bcm2711.dtsi
> > +++ b/arch/arm/boot/dts/bcm2711.dtsi
> > @@ -1037,7 +1037,7 @@ &cma {
> >
> > alloc-ranges = <0x0 0x00000000 0x40000000>;
> >
> > };
> >
> > -&i2c0 {
> > +&i2c0if {
> >
> > compatible = "brcm,bcm2711-i2c", "brcm,bcm2835-i2c";
> > interrupts = <GIC_SPI 117 IRQ_TYPE_LEVEL_HIGH>;
> >
> > };
> >
> > diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi
> > b/arch/arm/boot/dts/bcm2835-rpi.dtsi index 87ddcad76083..1e38f9f0e80e
> > 100644
> > --- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
> > +++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
> > @@ -49,13 +49,16 @@ alt0: alt0 {
> >
> > };
> >
> > };
> >
> > -&i2c0 {
> > - pinctrl-names = "default";
> > - pinctrl-0 = <&i2c0_gpio0>;
> > +&i2c0if {
> >
> > status = "okay";
> > clock-frequency = <100000>;
> >
> > };
> >
> > +&i2c0mux {
> > + pinctrl-0 = <&i2c0_gpio0>;
> > + status = "okay";
> > +};
> > +
> >
> > &i2c1 {
> >
> > pinctrl-names = "default";
> > pinctrl-0 = <&i2c1_gpio2>;
> >
> > diff --git a/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi
> > b/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi new file mode 100644
> > index 000000000000..119946d878db
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi
> > @@ -0,0 +1,4 @@
> > +&i2c0mux {
> > + pinctrl-0 = <&i2c0_gpio0>;
> > + pinctrl-1 = <&i2c0_gpio44>;
> > +};
> > diff --git a/arch/arm/boot/dts/bcm283x.dtsi
> > b/arch/arm/boot/dts/bcm283x.dtsi index a3e06b680947..06d04cde52b9 100644
> > --- a/arch/arm/boot/dts/bcm283x.dtsi
> > +++ b/arch/arm/boot/dts/bcm283x.dtsi
> > @@ -334,7 +334,7 @@ spi: spi@7e204000 {
> >
> > status = "disabled";
> >
> > };
> >
> > - i2c0: i2c@7e205000 {
> > + i2c0if: i2c@7e205000 {
> >
> > compatible = "brcm,bcm2835-i2c";
> > reg = <0x7e205000 0x200>;
> > interrupts = <2 21>;
> >
> > @@ -344,6 +344,30 @@ i2c0: i2c@7e205000 {
> >
> > status = "disabled";
> >
> > };
> >
> > + i2c0mux: i2c0mux {
> > + compatible = "i2c-mux-pinctrl";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + i2c-parent = <&i2c0if>;
> > +
> > + pinctrl-names = "i2c0", "i2c_csi_dsi";
> > +
> > + status = "disabled";
> > +
> > + i2c0: i2c@0 {
> > + reg = <0>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + };
> > +
> > + i2c_csi_dsi: i2c@1 {
> > + reg = <1>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + };
> > + };
> > +
> >
> > dpi: dpi@7e208000 {
> >
> > compatible = "brcm,bcm2835-dpi";
> > reg = <0x7e208000 0x8c>;