lkml.org 
[lkml]   [2018]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 06/16] iio: adc: sun4i-gpadc-iio: rework: support multiple sensors
From
Date


On 31.01.2018 19:42, Quentin Schulz wrote:
> Hi Philipp,
>
> On Mon, Jan 29, 2018 at 12:29:09AM +0100, Philipp Rossak wrote:
>> For adding newer sensor some basic rework of the code is necessary.
>>
>> This patch reworks the driver to be able to handle more than one
>> thermal sensor. Newer SoC like the A80 have 4 thermal sensors.
>> Because of this the maximal sensor count value was set to 4.
>>
>> The sensor_id value is set during sensor registration and is for each
>> registered sensor indiviual. This makes it able to differntiate the
>> sensors when the value is read from the register.
>>
>> In function sun4i_gpadc_read_raw(), the sensor number of the ths sensor
>> was directly set to 0 (sun4i_gpadc_temp_read(x,x,0)). This selects
>> in the temp_read function automatically sensor 0. A check for the
>> sensor_id is here not required since the old sensors only have one
>> thermal sensor. In addition to that is the sun4i_gpadc_read_raw()
>> function only used by the "older" sensors (before A33) where the
>> thermal sensor was a cobination of an adc and a thermal sensor.
>>
>> Signed-off-by: Philipp Rossak <embed3d@gmail.com>
>> ---
>> drivers/iio/adc/sun4i-gpadc-iio.c | 36 +++++++++++++++++++++++-------------
>> include/linux/mfd/sun4i-gpadc.h | 3 +++
>> 2 files changed, 26 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
>> index 51ec0104d678..ac9ad2f8232f 100644
>> --- a/drivers/iio/adc/sun4i-gpadc-iio.c
>> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
>> @@ -67,12 +67,13 @@ struct gpadc_data {
>> unsigned int tp_adc_select;
>> unsigned int (*adc_chan_select)(unsigned int chan);
>> unsigned int adc_chan_mask;
>> - unsigned int temp_data;
>> + unsigned int temp_data[MAX_SENSOR_COUNT];
>> int (*sample_start)(struct sun4i_gpadc_iio *info);
>> int (*sample_end)(struct sun4i_gpadc_iio *info);
>> bool has_bus_clk;
>> bool has_bus_rst;
>> bool has_mod_clk;
>> + int sensor_count;
>> };
>>
>
> I've noticed that for H3, A83T, A64 (at least), if DATA reg of sensor 0
> is e.g. 0x80, DATA reg of sensor N is at 0x80 + 0x04 * N.
>
> Is that verified for other SoCs? Does anyone have some input on this?
>
> We could then just use temp_data as the DATA reg "base" and increment by
> 0x4 depending on the sensor id instead of using a fixed-size array.
>

This sounds like a good idea! I will add this to the next version.

I can verify this with a table, I created during development. I will
upload it during the weekend here: [1]


>> static const struct gpadc_data sun4i_gpadc_data = {
>> @@ -82,9 +83,10 @@ static const struct gpadc_data sun4i_gpadc_data = {
>> .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
>> .adc_chan_select = &sun4i_gpadc_chan_select,
>> .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
>> - .temp_data = SUN4I_GPADC_TEMP_DATA,
>> + .temp_data = {SUN4I_GPADC_TEMP_DATA, 0, 0, 0},
>> .sample_start = sun4i_gpadc_sample_start,
>> .sample_end = sun4i_gpadc_sample_end,
>> + .sensor_count = 1,
>
> If the solution above is not desirable/possible, could we use something
> like:
>
> unsigned int sun4i_temp_data[] = {SUN4I_GPADC_TEMP_DATA,};
>
> static const struct gpadc_data sun4i_gpadc_data = {
> .temp_data = &sun4i_temp_data,
> .sensor_count = ARRAY_SIZE(sun4i_temp_data),
> };
>
> That avoids 1) inconsistencies between the array size and the array
> itself, 2) does not require to pad the array with zeroes.
>
> [...]
>
>> @@ -745,9 +752,12 @@ static int sun4i_gpadc_probe(struct platform_device *pdev)
>> pm_runtime_enable(&pdev->dev);
>>
>> if (IS_ENABLED(CONFIG_THERMAL_OF)) {
>> - info->tzd = thermal_zone_of_sensor_register(info->sensor_device,
>> - 0, info,
>> - &sun4i_ts_tz_ops);
>> + for (i = 0; i < info->data->sensor_count; i++) {
>> + info->sensor_id = i;
>> + info->tzd = thermal_zone_of_sensor_register(
>> + info->sensor_device,
>> + i, info, &sun4i_ts_tz_ops);
>> + }
>
> As Maxime said, this does not work.
>
> One way would be to have a new structure being:
> struct sun4i_sensor_info {
> struct sun4i_gpadc_iio *info;
> unsigned int sensor_id;
> };
>
> Or since we only use the iio_dev within the sun4i_gpadc_iio in the
> .get_temp function, we may replace info by struct iio_dev *indio_dev
> above.
>
> Quentin
>
I will have a closer look on this next week, when I start to work on the
next version..

Thanks,
Philipp

[1]: http://linux-sunxi.org/Thermal_Sensor

\
 
 \ /
  Last update: 2018-02-02 15:13    [W:0.169 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site