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@xxxxxxxxxxxxxx> > >>>>>>--- > >>>[...] > >>> > >>>>>>+ 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. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html