linux/Documentation/devicetree/bindings/spi/sh-msiof.txt
Simon Horman 4286db8456 spi: sh-msiof: Add R-Car Gen 2 and 3 fallback bindings
In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 2 and Gen 3. But beyond that it's not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7790 is older than r8a7791 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme is being adopted for
drivers for Renesas SoCs.

Also:
* Deprecate renesas,sh-msiof. It seems poorly named as it is only
  compatible with SH-Mobile. It also appears unused in mainline.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-12-14 17:38:18 +00:00

81 lines
2.9 KiB
Plaintext

Renesas MSIOF spi controller
Required properties:
- compatible : "renesas,msiof-r8a7790" (R-Car H2)
"renesas,msiof-r8a7791" (R-Car M2-W)
"renesas,msiof-r8a7792" (R-Car V2H)
"renesas,msiof-r8a7793" (R-Car M2-N)
"renesas,msiof-r8a7794" (R-Car E2)
"renesas,msiof-r8a7796" (R-Car M3-W)
"renesas,msiof-sh73a0" (SH-Mobile AG5)
"renesas,sh-mobile-msiof" (generic SH-Mobile compatibile device)
"renesas,rcar-gen2-msiof" (generic R-Car Gen2 compatible device)
"renesas,rcar-gen3-msiof" (generic R-Car Gen3 compatible device)
"renesas,sh-msiof" (deprecated)
When compatible with the generic version, nodes
must list the SoC-specific version corresponding
to the platform first followed by the generic
version.
- reg : A list of offsets and lengths of the register sets for
the device.
If only one register set is present, it is to be used
by both the CPU and the DMA engine.
If two register sets are present, the first is to be
used by the CPU, and the second is to be used by the
DMA engine.
- interrupt-parent : The phandle for the interrupt controller that
services interrupts for this device
- interrupts : Interrupt specifier
- #address-cells : Must be <1>
- #size-cells : Must be <0>
Optional properties:
- clocks : Must contain a reference to the functional clock.
- num-cs : Total number of chip-selects (default is 1)
- dmas : Must contain a list of two references to DMA
specifiers, one for transmission, and one for
reception.
- dma-names : Must contain a list of two DMA names, "tx" and "rx".
- renesas,dtdl : delay sync signal (setup) in transmit mode.
Must contain one of the following values:
0 (no bit delay)
50 (0.5-clock-cycle delay)
100 (1-clock-cycle delay)
150 (1.5-clock-cycle delay)
200 (2-clock-cycle delay)
- renesas,syncdl : delay sync signal (hold) in transmit mode.
Must contain one of the following values:
0 (no bit delay)
50 (0.5-clock-cycle delay)
100 (1-clock-cycle delay)
150 (1.5-clock-cycle delay)
200 (2-clock-cycle delay)
300 (3-clock-cycle delay)
Optional properties, deprecated for soctype-specific bindings:
- renesas,tx-fifo-size : Overrides the default tx fifo size given in words
(default is 64)
- renesas,rx-fifo-size : Overrides the default rx fifo size given in words
(default is 64)
Pinctrl properties might be needed, too. See
Documentation/devicetree/bindings/pinctrl/renesas,*.
Example:
msiof0: spi@e6e20000 {
compatible = "renesas,msiof-r8a7791",
"renesas,rcar-gen2-msiof";
reg = <0 0xe6e20000 0 0x0064>;
interrupts = <0 156 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&mstp0_clks R8A7791_CLK_MSIOF0>;
dmas = <&dmac0 0x51>, <&dmac0 0x52>;
dma-names = "tx", "rx";
#address-cells = <1>;
#size-cells = <0>;
status = "disabled";
};