Re: [PATCH 08/11] misc: rp1: RaspberryPi RP1 misc driver

Krzysztof Kozlowski
2024-08-21T08:38:49Z

On Tue, Aug 20, 2024 at 04:36:10PM +0200, Andrea della Porta wrote:
> The RaspberryPi RP1 is ia PCI multi function device containing
> peripherals ranging from Ethernet to USB controller, I2C, SPI
> and others.
> Implement a bare minimum driver to operate the RP1, leveraging
> actual OF based driver implementations for the on-borad peripherals
> by loading a devicetree overlay during driver probe.
> The peripherals are accessed by mapping MMIO registers starting
> from PCI BAR1 region.
> As a minimum driver, the peripherals will not be added to the
> dtbo here, but in following patches.
>
> Link: https://datasheets.raspberrypi.com/rp1/rp1-peripherals.pdf
> Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
> ---
> MAINTAINERS | 2 +
> arch/arm64/boot/dts/broadcom/rp1.dtso | 152 ++++++++++++

Do not mix DTS with drivers.

These MUST be separate.

> drivers/misc/Kconfig | 1 +
> drivers/misc/Makefile | 1 +
> drivers/misc/rp1/Kconfig | 20 ++
> drivers/misc/rp1/Makefile | 3 +
> drivers/misc/rp1/rp1-pci.c | 333 ++++++++++++++++++++++++++
> drivers/misc/rp1/rp1-pci.dtso | 8 +
> drivers/pci/quirks.c | 1 +
> include/linux/pci_ids.h | 3 +
> 10 files changed, 524 insertions(+)
> create mode 100644 arch/arm64/boot/dts/broadcom/rp1.dtso
> create mode 100644 drivers/misc/rp1/Kconfig
> create mode 100644 drivers/misc/rp1/Makefile
> create mode 100644 drivers/misc/rp1/rp1-pci.c
> create mode 100644 drivers/misc/rp1/rp1-pci.dtso
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 67f460c36ea1..1359538b76e8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19119,9 +19119,11 @@ F: include/uapi/linux/media/raspberrypi/
> RASPBERRY PI RP1 PCI DRIVER
> M: Andrea della Porta <andrea.porta@suse.com>
> S: Maintained
> +F: arch/arm64/boot/dts/broadcom/rp1.dtso
> F: Documentation/devicetree/bindings/clock/raspberrypi,rp1-clocks.yaml
> F: Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml
> F: drivers/clk/clk-rp1.c
> +F: drivers/misc/rp1/
> F: drivers/pinctrl/pinctrl-rp1.c
> F: include/dt-bindings/clock/rp1.h
> F: include/dt-bindings/misc/rp1.h
> diff --git a/arch/arm64/boot/dts/broadcom/rp1.dtso b/arch/arm64/boot/dts/broadcom/rp1.dtso
> new file mode 100644
> index 000000000000..d80178a278ee
> --- /dev/null
> +++ b/arch/arm64/boot/dts/broadcom/rp1.dtso
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> +
> +#include <dt-bindings/gpio/gpio.h>
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/clock/rp1.h>
> +#include <dt-bindings/misc/rp1.h>
> +
> +/dts-v1/;
> +/plugin/;
> +
> +/ {
> + fragment@0 {
> + target-path="";
> + __overlay__ {
> + #address-cells = <3>;
> + #size-cells = <2>;
> +
> + rp1: rp1@0 {
> + compatible = "simple-bus";
> + #address-cells = <2>;
> + #size-cells = <2>;
> + interrupt-controller;
> + interrupt-parent = <&rp1>;
> + #interrupt-cells = <2>;
> +
> + // ranges and dma-ranges must be provided by the includer
> + ranges = <0xc0 0x40000000
> + 0x01/*0x02000000*/ 0x00 0x00000000
> + 0x00 0x00400000>;

Are you 100% sure you do not have here dtc W=1 warnings?

> +
> + dma-ranges =
> + // inbound RP1 1x_xxxxxxxx -> PCIe 1x_xxxxxxxx
> + <0x10 0x00000000
> + 0x43000000 0x10 0x00000000
> + 0x10 0x00000000>;
> +
> + clk_xosc: clk_xosc {

Nope, switch to DTS coding style.

> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-output-names = "xosc";
> + clock-frequency = <50000000>;
> + };
> +
> + macb_pclk: macb_pclk {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-output-names = "pclk";
> + clock-frequency = <200000000>;
> + };
> +
> + macb_hclk: macb_hclk {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-output-names = "hclk";
> + clock-frequency = <200000000>;
> + };
> +
> + rp1_clocks: clocks@c040018000 {

Why do you mix MMIO with non-MMIO nodes? This really does not look
correct.

> + compatible = "raspberrypi,rp1-clocks";
> + #clock-cells = <1>;
> + reg = <0xc0 0x40018000 0x0 0x10038>;

Wrong order of properties - see DTS coding style.

> + clocks = <&clk_xosc>;
> + clock-names = "xosc";

Best regards,
Krzysztof