Hi all
I am still waiting for your response.....
2013/7/5 James Lebron <leileishangchina@xxxxxxxxx>:
> Hi guys,
>
> Any comments?
>
> 2013/7/2 James Lebron <leileishangchina@xxxxxxxxx>:
>> Hi Wolfram
>>
>> Have you finished reading datasheet?
>>
>> 2013/6/15 Wolfram Sang <wsa@xxxxxxxxxxxxx>:
>>> Hi,
>>>
>>> On Fri, Jun 07, 2013 at 02:38:17PM +0800, Leilei Shang wrote:
>>>> To enter high speed mode, following steps should be done:
>>>> 1. When running in high speed mode, i2c clock rate is different
>>>> from standard mode. Clock rate must be set according to
>>>> specification first.
>>>> 2. When i2c controller sends a master code and wins arbitration,
>>>> high speed mode is entered.
>>>>
>>>> If you want to enable high speed mode, the following members of
>>>> platform data should be set to proper value:
>>>
>>> I couldn't find any support for hs-mode in pxa2xx and pxa3xx. So it
>>> shouldn't be set in platform data, but depending on checks if this is
>>> supported on this device at all. And why don't simply switch to it if
>>> rate is bigger than what is supported without hs-mode?
>>>
>>
>> 1. High speed mode is hardware feature, you can't read it from
>> software. It's similar to fast mode, and fast mode is set in platform
>> data.
>>
>> The only method I can think of is to add a platform, like pxa910.
>> And if you enable hs mode and platform is not pxa910, we'll set it to
>> normal mode. Is this OK?
>>
>> 2. About hs mode clock setting. We don't know whether currently hs
>> mode clock will be changed in future. Do you think below code is OK?
>>
>> if (i2c->rate)
>> clk_set_rate(i2c->clk, i2c->rate);
>> else
>> clk_set_rate(i2c->clk, 62400000);
>>
>> pr_info("i2c: <%s> set rate to %ld\n",
>> i2c->adap.name, clk_get_rate(i2c->clk));
>>
>>>> 1. "high_mode" should be set to "1".
>>>> 2. "master_code" should be set to "8'b 0000_1xxx"(x is 0 or 1).
>>>> If no master_code is set, set to default value 0xe.
>>>> 3. "rate" should be set according to specification.
>>>
>>> Note that you should fall back to full-speed mode after sending the stop
>>> bit in high-speed mode. I can't find this in the code?
>>>
>>
>> 3. Will fall back to normal mode when stop bit is sent.
>>
>>>>
>>>> Signed-off-by: Leilei Shang <shangll@xxxxxxxxxxx>
>>>
>>> Which SoC supports this? I'd like to have a look at the datasheet.
>>>
>>> Thanks,
>>>
>>> Wolfram
>>>
>>
>> Hope you can reply soon!
>>
>> Best regards
>> Leilei
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