Re: [PATCH v3] usb: phy: samsung: Add support to set pmu isolation

[Vivek Gautam]

Hi Doug,


On Fri, Dec 21, 2012 at 10:35 PM, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> Vivek,
>
> Nothing really serious below and things look good to me, but figured
> I'd put a few nits in (sorry!).
>
>
> On Fri, Dec 21, 2012 at 12:16 AM, Vivek Gautam <gautam.vivek@xxxxxxxxxxx> wrote:
>> diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>> index 7b26e2d..09f06f8 100644
>> --- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>> +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>> @@ -9,3 +9,31 @@ Required properties:
>>  - compatible : should be "samsung,exynos4210-usbphy"
>>  - reg : base physical address of the phy registers and length of memory mapped
>>         region.
>> +- #address-cells: should be 1.
>> +- #size-cells: should be 0.
>
> Doesn't match your example.  Probably should be 1.

Oops !! true it is 1, will amend this.

>
>> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
>> index 5c5e1bb5..2260029 100644
>> --- a/drivers/usb/phy/samsung-usbphy.c
>> +++ b/drivers/usb/phy/samsung-usbphy.c
>>  /*
>> + * struct samsung_usbphy_drvdata - driver data for various SoC variants
>> + * @cpu_type: machine identifier
>> + * @devphy_en_mask: device phy enable mask for PHY CONTROL register
>> + * @hostphy_en_mask: host phy enable mask for PHY CONTROL register
>> + *
>> + *     having different mask for host and device type phy
>> + *     helps in setting independent masks in case of SoCs like
>> + *     S5PV210 in which PHY0 and PHY1 enable bits belong to same
>> + *     register placed at [0] and [1] respectively.
>> + *     Although for newer SoCs like exynos these bits belong to
>> + *     different registers altogether placed at [0].
>> + */
>> +struct samsung_usbphy_drvdata {
>> +       int cpu_type;
>> +       int devphy_en_mask;
>
> This is really a "devphy_dis_mask", isn't it?  AKA: setting to 1
> disables the phy and setting to 0 enables the phy.

This is actually 'devphy_en_mask' only. We use it this way:
When pmu_isolation is true, meaning usbphy is isolated from pmu
so we are resetting this bit to disable usbphy, as there in
samsung_usbphy_set_isolation().

>
>> +       int hostphy_en_mask;
>
> Code below always uses devphy and only ever inits devphy.  I assume
> future code will init / use hostphy?  Worth moving the hostphy part in
> that patch?
>
Sure will move this in forthcoming  patch for host phy.

>>  struct samsung_usbphy {
>>         struct usb_phy  phy;
>> @@ -81,12 +104,66 @@ struct samsung_usbphy {
>>         struct device   *dev;
>>         struct clk      *clk;
>>         void __iomem    *regs;
>> +       void __iomem    *phyctrl_pmureg;
>>         int             ref_clk_freq;
>> -       int             cpu_type;
>> +       struct samsung_usbphy_drvdata *drv_data;
>
> nit: const

Will make it const.
>
>> +static int samsung_usbphy_parse_dt_param(struct samsung_usbphy *sphy)
>> +{
>> +       struct device_node *usbphy_pmu;
>> +       u32 reg[2];
>> +       int ret;
>> +
>> +       if (!sphy->dev->of_node) {
>> +               dev_err(sphy->dev, "Can't get usb-phy node\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       usbphy_pmu = of_get_child_by_name(sphy->dev->of_node, "usbphy-pmu");
>> +       if (!usbphy_pmu)
>> +               dev_warn(sphy->dev, "Can't get usb-phy pmu control node\n");
>> +
>> +       ret = of_property_read_u32_array(usbphy_pmu, "reg", reg, 2);
>
> nit: use ARRAY_SIZE(reg)
>
Sure will amend this.

>> +       if (!ret)
>> +               sphy->phyctrl_pmureg = ioremap(reg[0], reg[1]);
>> +
>> +       of_node_put(usbphy_pmu);
>> +
>> +       if (IS_ERR_OR_NULL(sphy->phyctrl_pmureg)) {
>> +               dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");
>
> I don't think there's any cases where it matters (you'll error out of
> the driver if you return an error here), but seems like it might be
> nice to set sphy->phyctrl_pmureg to NULL here since other places test
> this member against NULL only.
>
Isn't devm_kzallocing the memory for sphy setting sphy->phyctrl_pmureg to NULL ?
Then, does checking here for IS_ERR_OR_NULL(sphy->phyctrl_pmureg) has
a problem ?
Probably i am not getting what is expected here. :-(

>> +static inline struct samsung_usbphy_drvdata
>> +*samsung_usbphy_get_driver_data(struct platform_device *pdev)
>>  {
>>         if (pdev->dev.of_node) {
>>                 const struct of_device_id *match;
>>                 match = of_match_node(samsung_usbphy_dt_match,
>>                                                         pdev->dev.of_node);
>> -               return (int) match->data;
>> +               return (struct samsung_usbphy_drvdata *) match->data;
>
> nit: no need for a cast here, I believe.
>
"samsung_usbphy_get_driver_data()" is returning (struct
samsung_usbphy_drvdata *)
and the data is actually (void *). So won't we need a cast here.
I am actually getting compile time warnings.

>>         }
>>
>> -       return platform_get_device_id(pdev)->driver_data;
>> +       return ((struct samsung_usbphy_drvdata *)
>> +                               platform_get_device_id(pdev)->driver_data);
>
> nit: no need for a cast here, I believe.
>
ditto here, the driver data for non dt is (unsigned long). So ?

>> +static struct samsung_usbphy_drvdata usbphy_s3c64xx = {
>> +       .cpu_type               = TYPE_S3C64XX,
>> +       .devphy_en_mask         = S3C64XX_USBPHY_ENABLE,
>> +};
>> +
>> +static struct samsung_usbphy_drvdata usbphy_exynos4 = {
>> +       .cpu_type               = TYPE_EXYNOS4210,
>> +       .devphy_en_mask         = EXYNOS_USBPHY_ENABLE,
>> +};
>> +
>
> nit: static const for these structs?

Sure will make them const. no harm.
>
>
>
> -Doug
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss@xxxxxxxxxxxxxxxx
> https://lists.ozlabs.org/listinfo/devicetree-discuss



-- 
Thanks & Regards
Vivek
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/