[PATCH v2 2/2] phy: exyons5-usbdrd: support HS phy for ExynosAutov920

[Krzysztof Kozlowski]

On 21/05/2025 10:47, Krzysztof Kozlowski wrote:
> On 21/05/2025 09:10, Pritam Manohar Sutar wrote:
>> Hi Krzysztof,
>>
>>> -----Original Message-----
>>> From: Krzysztof Kozlowski <krzk at kernel.org>
>>> Sent: 20 May 2025 01:13 PM
>>> To: Neil Armstrong <neil.armstrong at linaro.org>; Pritam Manohar Sutar
>>> <pritam.sutar at samsung.com>; vkoul at kernel.org; kishon at kernel.org;
>>> robh at kernel.org; krzk+dt at kernel.org; conor+dt at kernel.org;
>>> alim.akhtar at samsung.com; andre.draszik at linaro.org; peter.griffin at linaro.org;
>>> kauschluss at disroot.org; m.szyprowski at samsung.com;
>>> s.nawrocki at samsung.com
>>> Cc: linux-phy at lists.infradead.org; devicetree at vger.kernel.org; linux-
>>> kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-samsung-
>>> soc at vger.kernel.org; rosa.pila at samsung.com; dev.tailor at samsung.com;
>>> faraz.ata at samsung.com; muhammed.ali at samsung.com;
>>> selvarasu.g at samsung.com
>>> Subject: Re: [PATCH v2 2/2] phy: exyons5-usbdrd: support HS phy for
>>> ExynosAutov920
>>>
>>> On 20/05/2025 09:39, neil.armstrong at linaro.org wrote:
>>>>> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c
>>>>> b/drivers/phy/samsung/phy-exynos5-usbdrd.c
>>>>> index 634c4310c660..b440b56c6595 100644
>>>>> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
>>>>> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
>>>>> @@ -177,6 +177,9 @@
>>>>>   #define HSPHYPLLTUNE_PLL_P_TUNE			GENMASK(3,
>>> 0)
>>>>>
>>>>>   /* Exynos850: USB DRD PHY registers */
>>>>> +#define EXYNOSAUTOv920_DRD_CTRL_VER		0x00
>>>>> +#define CTRL_VER_MAJOR_VERSION			GENMASK(31,
>>> 24)
>>>>> +
>>>>>   #define EXYNOS850_DRD_LINKCTRL			0x04
>>>>>   #define LINKCTRL_FORCE_RXELECIDLE		BIT(18)
>>>>>   #define LINKCTRL_FORCE_PHYSTATUS		BIT(17)
>>>>> @@ -1772,6 +1775,10 @@ static const char * const
>>> exynos5_regulator_names[] = {
>>>>>   	"vbus", "vbus-boost",
>>>>>   };
>>>>>
>>>>> +static const char * const exynosautov920_clk_names[] = {
>>>>> +	"ext_xtal",
>>>>> +};
>>>>> +
>>>>>   static const struct exynos5_usbdrd_phy_drvdata exynos5420_usbdrd_phy =
>>> {
>>>>>   	.phy_cfg		= phy_cfg_exynos5,
>>>>>   	.phy_ops		= &exynos5_usbdrd_phy_ops,
>>>>> @@ -1847,6 +1854,81 @@ static const struct exynos5_usbdrd_phy_drvdata
>>> exynos850_usbdrd_phy = {
>>>>>   	.n_regulators		= ARRAY_SIZE(exynos5_regulator_names),
>>>>>   };
>>>>>
>>>>> +static void exynosautov920_usbdrd_utmi_init(struct
>>>>> +exynos5_usbdrd_phy *phy_drd) {
>>>>> +	u32 version;
>>>>> +
>>>>> +	version = readl(phy_drd->reg_phy +
>>> EXYNOSAUTOv920_DRD_CTRL_VER);
>>>>> +	dev_info(phy_drd->dev, "usbphy: version:0x%x\n", version);
>>>>
>>>> Please do not add mode info to boot log, use dev_dbg instead.
>>>
>>> Just drop entirely, not even worth dbg (see coding style, driver development
>>> debugging guide). It is fixed per given compatible, isn't it? If not, there is entire
>>> commit msg to explain unusual things.
>>
>> This SoC has a single USB 3.1 DRD combo v400 phy and three USB2.0 DRD phy v303
> 
> 
> That's a different device, no? Look at the compatible here - it says
> usb31drd.
> 
> What does 31 stand for?
> 
>> controllers those only support the UTMI+ interface. Currently, supporting only 
>> v303 phy in this patch-set, and planning v400 phy later (soon). Same may be 
>> also updated in commit  message. 
>>
>> If there's any issue in phy init, dbg print is needed to debug which phy caused it. 
> No, rethink rather this makes sense at all. Please read carefully
> writing bindings, which will tell you that you cannot have different
> devices under the same compatible. Unless you say these are the same
> devices and it differs by other phy? But this is a phy... so many questions.

Hm, unless you want to say devices are fully compatible, the version is
fully detectable and the driver will make use of that. That would be
fine, but should be expressed in commit msg and actually we should see
the second phy variant already in the patchset.

Best regards,
Krzysztof