Re: [PATCH v3 2/3] iio:adc:palmas: add DT support

[Jonathan Cameron]

On 16/10/15 13:53, H. Nikolaus Schaller wrote:
> From: Marek Belisko 
> 
> Code was found at:
> https://android.googlesource.com/kernel/tegra/+/a90856a6626d502d42c6e7abccbdf9d730b36270%5E%21/#F1
> 
> Signed-off-by: Laxman Dewangan 
> Signed-off-by: Marek Belisko  [Fixed minor typos + add 
> channels list to documentation]
I am happy with your responses to Lars and that kind of covers what Mark raised 
as well.

One typo correction applied.

Applied to the togreg branch of iio.git

Thanks,

Jonathan
> ---
>  .../devicetree/bindings/iio/adc/palmas-gpadc.txt   | 48 
>  drivers/iio/adc/palmas_gpadc.c | 52 
> +++---
>  2 files changed, 95 insertions(+), 5 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt 
> b/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt
> new file mode 100644
> index 000..a6de996
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt
> @@ -0,0 +1,48 @@
> +* Palmas general purpose ADC IP block devicetree bindings
> +
> +Channels list:
> + 0 battery type
> + 1 battery temp NTC (optional current source)
> + 2 GP
> + 3 temp (with ext. diode, optional current source)
> + 4 GP
> + 5 GP
> + 6 VBAT_SENSE
> + 7 VCC_SENSE
> + 8 Backup Battery voltage
> + 9 external charger (VCHG)
> + 10 VBUS
> + 11 DC-DC current probe (how does this work?)
> + 12 internal die temp
> + 13 internal die temp
> + 14 USB ID pin voltage
> + 15 test network
> +
> +Required properties:
> +- compatible : Must be "ti,palmas-gpadc".
> +- #io-channel-cells: Should be set to <1>.
> +
> +Optional sub-nodes:
> +ti,channel0-current-microamp: Channel 0 current in uA.
> + Values are rounded to derive 0uA, 5uA, 15uA, 20uA.
> +ti,channel3-current-microamp: Channel 3 current in uA.
> + Valid are rounded to derive 0uA, 10uA, 400uA, 800uA.
Values

> +ti,enable-extended-delay: Enable extended delay.
> +
> +Example:
> +
> +pmic {
> + compatible = "ti,twl6035-pmic", "ti,palmas-pmic";
> + ...
> + gpadc {
> + compatible = "ti,palmas-gpadc";
> + interrupts = <18 0
> +   16 0
> +   17 0>;
> + #io-channel-cells = <1>;
> + ti,channel0-current-microamp = <5>;
> + ti,channel3-current-microamp = <10>;
> + };
> + };
> + ...
> +};
> diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
> index 71763c5..f42eb8a 100644
> --- a/drivers/iio/adc/palmas_gpadc.c
> +++ b/drivers/iio/adc/palmas_gpadc.c
> @@ -21,6 +21,8 @@
>  #include 
>  #include 
>  #include 
> +#include 
> +#include 
>  #include 
>  #include 
>  #include 
> @@ -460,6 +462,34 @@ static const struct iio_chan_spec 
> palmas_gpadc_iio_channel[] = {
>   PALMAS_ADC_CHAN_IIO(IN15, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
>  };
>  
> +static int palmas_gpadc_get_adc_dt_data(struct platform_device *pdev,
> + struct palmas_gpadc_platform_data **gpadc_pdata)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct palmas_gpadc_platform_data *gp_data;
> + int ret;
> + u32 pval;
> +
> + gp_data = devm_kzalloc(>dev, sizeof(*gp_data), GFP_KERNEL);
> + if (!gp_data)
> + return -ENOMEM;
> +
> + ret = of_property_read_u32(np, "ti,channel0-current-microamp", );
> + if (!ret)
> + gp_data->ch0_current = pval;
> +
> + ret = of_property_read_u32(np, "ti,channel3-current-microamp", );
> + if (!ret)
> + gp_data->ch3_current = pval;
> +
> + gp_data->extended_delay = of_property_read_bool(np,
> + "ti,enable-extended-delay");
> +
> + *gpadc_pdata = gp_data;
> +
> + return 0;
> +}
> +
>  static int palmas_gpadc_probe(struct platform_device *pdev)
>  {
>   struct palmas_gpadc *adc;
> @@ -469,12 +499,17 @@ static int palmas_gpadc_probe(struct platform_device 
> *pdev)
>   int ret, i;
>  
>   pdata = dev_get_platdata(pdev->dev.parent);
> - if (!pdata || !pdata->gpadc_pdata) {
> - dev_err(>dev, "No platform data\n");
> - return -ENODEV;
> - }
>  
> - gpadc_pdata = pdata->gpadc_pdata;
> + if (pdata && pdata->gpadc_pdata)
> + gpadc_pdata = pdata->gpadc_pdata;
> +
> + if (!gpadc_pdata && pdev->dev.of_node) {
> + ret = palmas_gpadc_get_adc_dt_data(pdev, _pdata);
> + if (ret < 0)
> + return ret;
> + }
> + if (!gpadc_pdata)
> + return -EINVAL;
>  
>   indio_dev = devm_iio_device_alloc(>dev, sizeof(*adc));
>   if (!indio_dev) {
> @@ -790,12 +825,19 @@ static const struct dev_pm_ops palmas_pm_ops = {
>   palmas_gpadc_resume)

Re: [PATCH v3 2/3] iio:adc:palmas: add DT support

[H. Nikolaus Schaller]

Am 19.10.2015 um 13:57 schrieb Lars-Peter Clausen :

> On 10/16/2015 02:53 PM, H. Nikolaus Schaller wrote:
> [...]
>> +Optional sub-nodes:
>> +ti,channel0-current-microamp: Channel 0 current in uA.
>> +Values are rounded to derive 0uA, 5uA, 15uA, 20uA.
>> +ti,channel3-current-microamp: Channel 3 current in uA.
>> +Valid are rounded to derive 0uA, 10uA, 400uA, 800uA.
>> +ti,enable-extended-delay: Enable extended delay.
> 
> Those three above sound more like configuration policy, rather than hardware
> description. What influence which values should be chosen?

e.g. the nominal value of the NTC that can be connected if the Palmas
is hooked up in a standard way.

If a board has no NTC and uses channel0 for a different purpose one
should choose 0uA.

If it is let's say 10kOhm it should probably be 20uA to give a nominal voltage
reading of 200mV.

100kOhm will give 2V which is at the limit of the ADC input range and
therefore it would be better to choose 15uA or 5uA.

I think choosing extended delay depends on the noisiness of the input
signal but I am not a specialist for this feature.

So I would say the board hardware mandates some specific value.

BR,
Nikolaus

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3 2/3] iio:adc:palmas: add DT support

[Lars-Peter Clausen]

On 10/16/2015 02:53 PM, H. Nikolaus Schaller wrote:
[...]
> +Optional sub-nodes:
> +ti,channel0-current-microamp: Channel 0 current in uA.
> + Values are rounded to derive 0uA, 5uA, 15uA, 20uA.
> +ti,channel3-current-microamp: Channel 3 current in uA.
> + Valid are rounded to derive 0uA, 10uA, 400uA, 800uA.
> +ti,enable-extended-delay: Enable extended delay.

Those three above sound more like configuration policy, rather than hardware
description. What influence which values should be chosen?


--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html