Re: [PATCH v2 2/5] MFD: RK808: Add new mfd driver for RK808

[Chris Zhong <zyw@rock-chips.com>]

On 08/26/2014 08:23 PM, Lee Jones wrote:
> On Tue, 26 Aug 2014, Chris Zhong wrote:
>> On 08/26/2014 07:20 PM, Lee Jones wrote:
>>> On Tue, 26 Aug 2014, Chris Zhong wrote:
>>>> On 08/26/2014 06:20 PM, Lee Jones wrote:
>>>>> On Tue, 26 Aug 2014, Chris Zhong wrote:
>>>>>> On 08/26/2014 05:22 PM, Lee Jones wrote:
>>>>>>> On Mon, 25 Aug 2014, Chris Zhong wrote:
>>>>>>>> On 08/20/2014 05:21 PM, Lee Jones wrote:
>>>>>>>>> On Wed, 20 Aug 2014, Chris Zhong wrote:
>>>>>>>>>
>>>>>>>>>> The RK808 chip is a power management IC for multimedia and handheld
>>>>>>>>>> devices. It contains the following components:
>>>>>>>>>>
>>>>>>>>>> - Regulators
>>>>>>>>>> - RTC
>>>>>>>>>>
>>>>>>>>>> The rk808 core driver is registered as a platform driver and provides
>>>>>>>>>> communication through I2C with the host device for the different
>>>>>>>>>> components.
>>>>>>>>>>
>>>>>>>>>> Signed-off-by: Chris Zhong <zyw@rock-chips.com>
>>>>>>>>>> ---
>>>>>>> [...]
>>>>>>>
>>>>>>>>>> +	rk808->pdata = pdata;
>>>>>>>>> Remove pdata from 'struct rk808'.  You can obtain it from dev.
>>>>>>>> Can I keep this pdata in rk808, because it is used in the regulator driver.
>>>>>>>> The one obtain from dev maybe empty.
>>>>>>> If the one in dev is empty, you should populate that instead.
>>>>>> So, should I malloc a pada, and assign it to client->dev?
>>>>> If client->dev.pdata is NULL, yes.
>>>>>
>>>>> But actually, I have more important questions that need to be answered
>>>>> first.  Ones which I would normally be able to answer myself if the
>>>>> patch-set had been sent as one (i.e. threaded) instead of as
>>>>> individual patches:
>>>>>
>>>>> - What are you using pdata for?
>>>> For save some properties,
>>>>
>>>> like "rockchip,system-power-controller" in MFD
>>>> and some regulator properties in regulator/rk808...
>>>>
>>>>> - Where is pdata populated?
>>>> It is populated in probe in mfd/rk808.c
>>>>
>>>> actually, I copy it from tps65910.c
>>>>
>>>>
>>>>> - Where is pdata used?
>>>> pdata is used in mfd and regulator
>>> I'm still a little confused.  I see it being populated in the MFD
>>> driver, then I only see the attributes populated in the MFD driver
>>> used in the MFD driver and nowhere else?  I do see other attributes
>>> used in the regulator driver i.e. .of_node[], but these are then used
>>> only in the regulator driver, thus they shouldn't really be pdata.
>>>
>>> Let me put it another way:
>>>
>>> struct rk808_board {
>>> +       int irq;
>>> +       int irq_base;
>>> +       int wakeup;
>>> +       bool pm_off;
>>> +       struct regulator_init_data *rk808_init_data[rk808_NUM_REGULATORS];
>>> +       struct device_node *of_node[rk808_NUM_REGULATORS];
>>> +       int pmic_sleep_gpio;
>>> +       unsigned int dcdc_slp_voltage[3]; /* buckx_voltage in uV */
>>> +       unsigned int ldo_slp_voltage[7];
>>> +};
>>>
>>> For each of the above:
>>>
>>> - Can it be passed from platform data i.e. arch/<arch>/{plat,mach}-*?
>>> - Can it use local (not passed from driver to driver) variable instead?
>>>
>>> If the answer to the first question is 'no' and/or if the answer to
>>> the second question is 'yes', then it shouldn't be platform data.
>> Yes, if we have no dts file, these value can pass from mach-rk***.
>>
>> It can be filled with all user setting of rk808, in a struct.
>>
>> the latest struct is:
>>
>> struct rk808_board {
>>
>>      int wakeup;
>>
>>      bool pm_off;
>>
>>      struct regulator_init_data *rk808_init_data[RK808_NUM_REGULATORS];
>>
>>      struct device_node *of_node[RK808_NUM_REGULATORS];
>>
>>      unsigned int dcdc_slp_voltage[3]; /* buckx_voltage in uV */
>>
>>      unsigned int ldo_slp_voltage[7];
>>
>> };
> This version looks much more acceptable.
>
> Although, I am concerned about of_node[].  Isn't that only populated
> and used in the regulator driver?

Yes, it only used in regulator driver

Well, it might be better to delete the pdata from MFD.