[PATCH RESEND v10 3/4] PHY: add APM X-Gene SoC 15Gbps Multi-purpose PHY driver

[Loc Ho]

Hi,

>>
>> +config PHY_XGENE
>> +       tristate "APM X-Gene 15Gbps PHY support"
>> +       depends on ARM64 || COMPILE_TEST
>> +       select GENERIC_PHY
>
>
> depends on HAS_IOMEM and CONFIG_OF..

I will make it depends as "HAS_IOMEM && OF && (ARM64 || COMPILE_TEST)

>>
>> +/* PLL Clock Macro Unit (CMU) CSR accessing from SDS indirectly */
>> +#define CMU_REG0                       0x00000
>> +#define  CMU_REG0_PLL_REF_SEL_MASK     0x00002000
>> +#define  CMU_REG0_PLL_REF_SEL_SET(dst, src)    \
>> +               (((dst) & ~0x00002000) | (((u32)(src) << 0xd) & 0x00002000))
>
>
> using decimals for shift value would be better. No strong feeling though.

I will change to integer value.

>> +/*
>> + * For chip earlier than A3 version, enable this flag.
>> + * To enable, pass boot argument phy_xgene.preA3Chip=1
>> + */
>> +static int preA3Chip;
>> +MODULE_PARM_DESC(preA3Chip, "Enable pre-A3 chip support (1=enable 0=disable)");
>> +module_param_named(preA3Chip, preA3Chip, int, 0444);
>
>
> Do we need to have module param for this? I mean we can differentiate between
> different chip versions in dt data only.

This is only required for the short term. Once all the pre-A3 system
are replaced, there isn't an need for this. For those who still has an
pre-A3 silicon system, this would provide an short term solution for
them. DT isn't quite correct here. This is an global thing. I guess I
can OR all node. If it is still better to put in the DT, let me know
and I will move it.

>> +
>> +static void sds_wr(void __iomem *csr_base, u32 indirect_cmd_reg,
>> +                  u32 indirect_data_reg, u32 addr, u32 data)
>> +{
>> +       u32 val;
>> +       u32 cmd;
>> +
>> +       cmd = CFG_IND_WR_CMD_MASK | CFG_IND_CMD_DONE_MASK;
>> +       cmd = CFG_IND_ADDR_SET(cmd, addr);
>
>
> This looks hacky. If 'CFG_IND_WR_CMD_MASK | CFG_IND_CMD_DONE_MASK' should be set then it should be part of the second argument. From the macro 'CFG_IND_ADDR_SET' the first argument should be more like the current value present in the register right? I feel the macro (CFG_IND_ADDR_SET) is not used in the way it is intended to.

The macro XXX_SET is intended to update an field within the register.
The update field is returned. The first assignment lines are setting
another field. Those two lines can be written as:

cmd = 0;
cmd |= CFG_IND_WR_CMD_MASK;            ==> Set the CMD bit
cmd |= CFG_IND_CMD_DONE_MASK;        ==> Set the DONE bit
cmd = CFG_IND_ADDR_SET(cmd, addr);    ===> Set the field ADDR
(multiple bit) to value from addr

Is this clear?

>> +       ctx->dev = &pdev->dev;
>> +       platform_set_drvdata(pdev, ctx);
>> +
>> +       phy_provider = devm_of_phy_provider_register(ctx->dev,
>> +                                                    xgene_phy_xlate);
>> +       if (IS_ERR(phy_provider)) {
>> +               rc = PTR_ERR(phy_provider);
>> +               goto error;
>> +       }
>
>
> phy_provider_register should be the last step in registering the PHY with the framework.

I will move to after devm_phy_create. BTW, other driver is before.

-Loc