On Tue, Nov 26, 2024 at 11:20:36AM +0200, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> The RZ/G3S system controller (SYSC) has registers to control signals that
> are routed to various IPs. These signals must be controlled during
> configuration of the respective IPs. One such signal is the USB PWRRDY,
> which connects the SYSC and the USB PHY. This signal must to be controlled
> before and after the power to the USB PHY is turned off/on.
>
> Other similar signals include the following (according to the RZ/G3S
> hardware manual):
>
> * PCIe:
> - ALLOW_ENTER_L1 signal controlled through the SYS_PCIE_CFG register
> - PCIE_RST_RSM_B signal controlled through the SYS_PCIE_RST_RSM_B
> register
> - MODE_RXTERMINATION signal controlled through SYS_PCIE_PHY register
>
> * SPI:
> - SEL_SPI_OCTA signal controlled through SYS_IPCONT_SEL_SPI_OCTA
> register
>
> * I2C/I3C:
> - af_bypass I2C signals controlled through SYS_I2Cx_CFG registers
> (x=0..3)
> - af_bypass I3C signal controlled through SYS_I3C_CFG register
>
> * Ethernet:
> - FEC_GIGA_ENABLE Ethernet signals controlled through SYS_GETHx_CFG
> registers (x=0..1)
>
> Add #renesas,sysc-signal-cells DT property to allow different SYSC signals
> consumers to manage these signals.
>
> The goal is to enable consumers to specify the required access data for
> these signals (through device tree) and let their respective drivers
> control these signals via the syscon regmap provided by the system
> controller driver. For example, the USB PHY will describe this relation
> using the following DT property:
>
> usb2_phy1: usb-phy@11e30200 {
> // ...
> renesas,sysc-signal = <&sysc 0xd70 0x1>;
> // ...
> };
>
> Along with it, add the syscon to the compatible list as it will be
> requested by the consumer drivers. The syscon was added to the rest of
> system controller variants as these are similar with RZ/G3S and can
> benefit from the implementation proposed in this series.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>
> Changes in v2:
> - none; this patch is new
>
>
> .../soc/renesas/renesas,rzg2l-sysc.yaml | 23 ++++++++++++++-----
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/soc/renesas/renesas,rzg2l-sysc.yaml b/Documentation/devicetree/bindings/soc/renesas/renesas,rzg2l-sysc.yaml
> index 4386b2c3fa4d..90f827e8de3e 100644
> --- a/Documentation/devicetree/bindings/soc/renesas/renesas,rzg2l-sysc.yaml
> +++ b/Documentation/devicetree/bindings/soc/renesas/renesas,rzg2l-sysc.yaml
> @@ -19,11 +19,13 @@ description:
>
> properties:
> compatible:
> - enum:
> - - renesas,r9a07g043-sysc # RZ/G2UL and RZ/Five
> - - renesas,r9a07g044-sysc # RZ/G2{L,LC}
> - - renesas,r9a07g054-sysc # RZ/V2L
> - - renesas,r9a08g045-sysc # RZ/G3S
> + items:
> + - enum:
> + - renesas,r9a07g043-sysc # RZ/G2UL and RZ/Five
> + - renesas,r9a07g044-sysc # RZ/G2{L,LC}
> + - renesas,r9a07g054-sysc # RZ/V2L
> + - renesas,r9a08g045-sysc # RZ/G3S
> + - const: syscon
>
> reg:
> maxItems: 1
> @@ -42,9 +44,17 @@ properties:
> - const: cm33stbyr_int
> - const: ca55_deny
>
> + "#renesas,sysc-signal-cells":
> + description:
> + The number of cells needed to configure a SYSC controlled signal. First
> + cell specifies the SYSC offset of the configuration register, second cell
> + specifies the bitmask in register.
> + const: 2
If there's only one possible value, then just fix the size in the users.
We don't need #foo-cells until things are really generic. Plus patch
8 already ignores this based on the schema. And there's implications to
defining them. For example, the pattern is that the consumer property
name is renesas,sysc-signals, not renesas,sysc-signal.
Maybe someone wants to create a 'h/w (signal) control' subsystem (and
binding) that is just 'read, assert, or deassert a h/w signal'. Perhaps
even the reset subsystem could be morphed into that as I think there
would be a lot of overlap. Maybe that would cut down on a lot of these
syscon phandle properties. I would find that a lot more acceptable than
the generic 'syscons' and '#syscon-cells' binding that was proposed at
some point.
> +
> required:
> - compatible
> - reg
> + - "#renesas,sysc-signal-cells"
New required properties are an ABI break.
>
> additionalProperties: false
>
> @@ -53,7 +63,7 @@ examples:
> #include <dt-bindings/interrupt-controller/arm-gic.h>
>
> sysc: system-controller@11020000 {
> - compatible = "renesas,r9a07g044-sysc";
> + compatible = "renesas,r9a07g044-sysc", "syscon";
What happens on a new kernel and a DT without this change?
Rob
