From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergei Shtylyov <sshtylyov-hkdhdckH98+B+jHODAdFcQ@public.gmane.org>
Subject: Re: [PATCH v2 2/4] i2c: davinci: Add helper functions
Date: Thu, 10 Dec 2009 16:02:12 +0300
Message-ID: <4B20F154.3090107@ru.mvista.com>
References: <1260267218-19406-1-git-send-email-chaithrika@ti.com>	<1260267218-19406-2-git-send-email-chaithrika@ti.com> <1260267218-19406-3-git-send-email-chaithrika@ti.com> <4B1E376F.1030808@ru.mvista.com> <005b01ca798a$20572430$61056c90$@com>
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To: Chaithrika U S <chaithrika-l0cyMroinI0@public.gmane.org>
Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org
List-Id: linux-i2c@vger.kernel.org

Hello.

Chaithrika U S wrote:

>> Hello.
>>
>> Chaithrika U S wrote:
>>
>>     
>>> Add i2c reset control and clock divider calculation functions
>>> which will be useful for power management features.
>>>
>>> Signed-off-by: Chaithrika U S <chaithrika-l0cyMroinI0@public.gmane.org>
>>>   
>>>       
>> [...]
>>
>>     
>>> @@ -138,15 +147,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
>>>  	u32 clkh;
>>>  	u32 clkl;
>>>  	u32 input_clock = clk_get_rate(dev->clk);
>>> -	u16 w;
>>> -
>>> -	if (!pdata)
>>> -		pdata = &davinci_i2c_platform_data_default;
>>> -
>>> -	/* put I2C into reset */
>>> -	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
>>> -	w &= ~DAVINCI_I2C_MDR_IRS;
>>> -	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
>>>  
>>>  	/* NOTE: I2C Clock divider programming info
>>>  	 * As per I2C specs the following formulas provide prescaler
>>> @@ -178,12 +178,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
>>>  	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
>>>  	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
>>>  
>>> +	dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
>>> +}
>>> +
>>> +/*
>>> + * This function configures I2C and brings I2C out of reset.
>>> + * This function is called during I2C init function. This function
>>> + * also gets called if I2C encounters any errors.
>>> + */
>>> +static int i2c_davinci_init(struct davinci_i2c_dev *dev)
>>> +{
>>> +	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
>>> +
>>> +	if (!pdata)
>>> +		pdata = &davinci_i2c_platform_data_default;
>>>   
>>>       
>>    The very idea of "default" platform data seems doubtful. Could we 
>> remove it?
> This platform data is used to set the default parameters in case the 
> platform is not specifying it. I am not too sure of why it is different
> from other drivers where an error is raised if the platform data is missing.
> May be this update can be made as a separate patch out of this series.
>   

   FWIW, we have removed this stuff in the internal tree...

> Regards, 
> Chaithrika

WBR, Sergei