Re: [PATCH 1/4] phy: miphy365x: Add Device Tree bindings for the MiPHY365x

Mark Rutland
2014-03-05T07:34:22Z

On Fri, Feb 14, 2014 at 11:23:53AM +0000, Lee Jones wrote:
> The MiPHY365x is a Generic PHY which can serve various SATA or PCIe
> devices. It has 2 ports which it can use for either; both SATA, both
> PCIe or one of each in any configuration.
>
> Cc: devicetree@vger.kernel.org
> Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> .../devicetree/bindings/phy/phy-miphy365x.txt | 54 ++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/phy/phy-miphy365x.txt
>
> diff --git a/Documentation/devicetree/bindings/phy/phy-miphy365x.txt b/Documentation/devicetree/bindings/phy/phy-miphy365x.txt
> new file mode 100644
> index 0000000..96f269f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/phy-miphy365x.txt
> @@ -0,0 +1,54 @@
> +STMicroelectronics STi MIPHY365x PHY binding
> +============================================
> +
> +This binding describes a miphy device that is used to control PHY hardware
> +for SATA and PCIe.
> +
> +Required properties:
> +- compatible: Should be "st,miphy365x-phy"
> +- #phy-cells: Should be 2 (See second example)
> + First cell is the port number; MIPHY_PORT_{0,1}
> + Second cell is device type; MIPHY_TYPE_{SATA,PCI}

Either this should refer to the header file, or specific values should
be given in the binding document.

> +- reg: Address and length of the register set for the device
> +- reg-names: The names of the register addresses corresponding to the
> + registers filled in "reg"
> + Options are; sata{0,1} and pcie{0,1} (See first example)

How about something like:

- reg: a list of offset + length pairs, one for each entry in reg-names
- reg-names: should contain some of:
* "sata0" for ...
* "sata1" for ...
* "pcie0" for ...
* "pcie1" for ...

Where ... might just be "the sata port 0 registers"

> +- st,syscfg : Should be a phandle of the system configuration register group
> + which contain the SATA, PCIe mode setting bits

I'll assume this is well-defined by some other binding.

> +
> +Optional properties:
> +- st,sata-gen : Generation of locally attached SATA IP. Expected values
> + are {1,2,3). If not supplied generation 1 hardware will
> + be expected
> +- st,pcie-tx-pol-inv : Bool property to invert the polarity PCIe Tx (Txn/Txp)
> +- st,sata-tx-pol-inv : Bool property to invert the polarity SATA Tx (Txn/Txp)

It might just be me, but the phrase "invert the polarity {SATA,PCIe} Tx"
sounds odd. What exactly is being inverted?

> +
> +Example:
> +
> + miphy365x_phy: miphy365x@0 {
> + compatible = "st,miphy365x-phy";
> + #phy-cells = <2>;
> + reg = <0xfe382000 0x100>,
> + <0xfe38a000 0x100>,
> + <0xfe394000 0x100>,
> + <0xfe804000 0x100>;
> + reg-names = "sata0", "sata1", "pcie0", "pcie1";
> + st,syscfg= <&syscfg_rear>;

Nit: missing space before '='.

> + };
> +
> +Specifying phy control of devices
> +=================================
> +
> +Device nodes should specify the configuration required in their "phys"
> +property, containing a phandle to the miphy device node, a port number
> +and a device type.
> +
> +Example:
> +
> +#include <dt-bindings/phy/phy-miphy365x.h>
> +
> + sata0: sata@fe380000 {
> + ...
> + phys = <&miphy365x_phy MIPHY_PORT_0 MIPHY_TYPE_SATA>;
> + ...
> + };

Is there not a generic phy binding we can point to? It seems a bit
redundant to do this in each phy binding.

Cheers,
Mark.