[PATCH v5 1/5] phy: add a driver for the Rockchip SoC internal USB2.0 PHY

Yunzhi Li lyz at rock-chips.com
Wed Dec 10 22:52:22 PST 2014


On 2014/12/11 14:37, Joe Perches wrote:
> On Thu, 2014-12-11 at 11:57 +0530, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Thursday 11 December 2014 11:42 AM, Joe Perches wrote:
>>> On Thu, 2014-12-11 at 11:32 +0530, Kishon Vijay Abraham I wrote:
>>>> On Wednesday 10 December 2014 04:16 PM, Yunzhi Li wrote:
>>>>> diff --git a/drivers/phy/phy-rockchip-usb.c b/drivers/phy/phy-rockchip-usb.c
>>> []
>>>>> +/*
>>>>> + * The higher 16-bit of this register is used for write protection
>>>>> + * only if BIT(13 + 16) set to 1 the BIT(13) can be written.
>>>>> + */
>>>>> +#define SIDDQ_MSK		BIT(13 + 16)
>>> huh?
>>>
>>> This #define looks _very_ odd.
>>>
>>> Is this supposed to be a single bit 29 or
>>> some range?
>>  From what I understood, the most significant 16 bits are write locks to the
>> least significant 16 bits.
>>
>> So If I have to write something on bit 0, I have to set bit 16.
>> If I have to write something on bit 1, I have to set bit 17.
>> If I have to write something on bit 2, I have to set bit 18.
>> and so on.
> To me it'd look better to use another << rather than a plus
Like (BIT(13) << 16)? It looks strange, or could I just use ((1 << 13) 
<< 16) to describe this bit ?

---
Yunzhi Li @ rockchip






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