From: Lars-Peter Clausen [mailto:lars@xxxxxxxxxx] Data: Wednesday, November 27, 2013 4:21 PM >To: Duan Fugang-B38611 >Cc: jic23@xxxxxxxxxx; sachin.kamat@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; >shawn.guo@xxxxxxxxxx; Li Frank-B20596; linux-iio@xxxxxxxxxxxxxxx >Subject: Re: [PATCH v3 2/3] iio:adc:imx: add Freescale Vybrid vf610 adc driver > >On 11/27/2013 05:44 AM, Fugang Duan wrote: >[...] >>>> + if (info->vref) >>>> + info->vref_uv = regulator_get_voltage(info->vref); >>>> + else if (of_property_read_u32(np, "fsl,adc-vref", &info->vref_uv)) >>>> + dev_err(info->dev, >>>> + "Miss adc-vref property or vref regulator in the DT.\n"); >>> >>> If you have a fixed reference voltage use the fixed voltage >>> regulator. Don't invent custom ways of specifying this. >>> >> Different boards design may use different method to supply the reference >voltage. >> There maybe fixed voltage regulator, maybe no regulator just use fixed >voltage. > >Well the voltage has to come from somewhere and that source should be described >in the DT with a fixed regulator. > Good suggestion. Thanks. >> >>>> + >>>> + if (of_property_read_u32(np, "fsl,adc-clk-div", >>>> + &info->adc_feature.clk_div_num)) { >>>> + info->adc_feature.clk_div_num = 2; >>>> + dev_info(info->dev, >>>> + "Miss adc-clk-div in dt, set divider to 2.\n"); >>>> + } >>>> + >>>> + if (of_property_read_u32(np, "fsl,adc-res", >>>> + &info->adc_feature.res_mode)) { >>>> + info->adc_feature.res_mode = 12; >>>> + dev_info(info->dev, >>>> + "Miss adc-res property in dt, use 8bit mode.\n"); >>>> + } >>>> + >>>> + if (of_property_read_u32(np, "fsl,adc-sam-time", >>>> + &info->adc_feature.sam_time)) { >>>> + info->adc_feature.sam_time = 4; >>>> + dev_info(info->dev, >>>> + "Miss adc-sam-time property in dt, set to 4.\n"); >>>> + } >>>> + >>>> + info->adc_feature.hw_average = of_property_read_bool(np, >>>> + "fsl,adc-hw-aver-en"); >>>> + if (info->adc_feature.hw_average && >>>> + of_property_read_u32(np, "fsl,adc-aver-sam-sel", >>>> + &info->adc_feature.hw_sam)) { >>>> + info->adc_feature.hw_sam = 4; >>>> + dev_info(info->dev, >>>> + "Miss adc-aver-sam-sel property in dt, set to 4.\n"); >>>> + } >>>> + >>>> + info->adc_feature.lpm = of_property_read_bool(np, >>>> +"fsl,adc-low-power- >>> mode"); >>>> + info->adc_feature.hs_oper = of_property_read_bool(np, >>>> +"fsl,adc-high-speed-conv"); >>> >>> Some of the properties look like they should be runtime configurable >>> rather then board specific settings. E.g. the resolution or the >>> sampling frequency, or whether averaging is enabled. >>> >>> >> So, I have question: >> Since the ADC have many user configurable setting, I have import some of them >from DT, and some of them use static define. >> How to set/change them in runtime for user configuration ? >> Introduce ioctl ? > >I think a lot of them already map to standard iio properties. E.g. the >samplerate. So you'd expose them as sysfs attributes. But please use standard >attributes here instead of inventing your own with cryptic names. > >- Lars Good suggestion, I will use the standard IIO interface for the ADC configuration. Thanks, Andy -- 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
