From: Andrej Picej <andrej.picej@norik.com>
Make i.MX93 ADC calibration parameters:
- AVGEN: Enable calibration averaging function,
- NRSMPL: Select number of calibration samples,
- TSAMP: Select sample time of calibration conversions,
in the MCR register configurable with the corresponding device-tree
properties:
- nxp,calib-avg-en,
- nxp,calib-nr-samples and
- nxp,calib-t-sample.
Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
---
drivers/iio/adc/imx93_adc.c | 75 ++++++++++++++++++++++++++++++++++---
1 file changed, 70 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/adc/imx93_adc.c b/drivers/iio/adc/imx93_adc.c
index 7feaafd2316f..da9b5c179240 100644
--- a/drivers/iio/adc/imx93_adc.c
+++ b/drivers/iio/adc/imx93_adc.c
@@ -18,6 +18,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
+#include <linux/property.h>
#define IMX93_ADC_DRIVER_NAME "imx93-adc"
@@ -43,6 +44,9 @@
#define IMX93_ADC_MCR_MODE_MASK BIT(29)
#define IMX93_ADC_MCR_NSTART_MASK BIT(24)
#define IMX93_ADC_MCR_CALSTART_MASK BIT(14)
+#define IMX93_ADC_MCR_AVGEN_MASK BIT(13)
+#define IMX93_ADC_MCR_NRSMPL_MASK GENMASK(12, 11)
+#define IMX93_ADC_MCR_TSAMP_MASK GENMASK(10, 9)
#define IMX93_ADC_MCR_ADCLKSE_MASK BIT(8)
#define IMX93_ADC_MCR_PWDN_MASK BIT(0)
#define IMX93_ADC_MSR_CALFAIL_MASK BIT(30)
@@ -145,7 +149,7 @@ static void imx93_adc_config_ad_clk(struct imx93_adc *adc)
static int imx93_adc_calibration(struct imx93_adc *adc)
{
- u32 mcr, msr;
+ u32 mcr, msr, val, reg;
int ret;
/* make sure ADC in power down mode */
@@ -156,12 +160,73 @@ static int imx93_adc_calibration(struct imx93_adc *adc)
mcr &= ~FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1);
writel(mcr, adc->regs + IMX93_ADC_MCR);
- imx93_adc_power_up(adc);
-
/*
- * TODO: we use the default TSAMP/NRSMPL/AVGEN in MCR,
- * can add the setting of these bit if need in future.
+ * Optionally configure desired ADC calibration settings in MCR
+ * - MCR[AVGEN]: Enable/disable calibration averaging function (default: on)
+ * - MCR[NRSMPL]: Select the number of calibration samples (default: 512)
+ * - MCR[TSAMP]: Select sample time of calibration conversions (default: 22)
*/
+ ret = device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
+ if (!ret) {
+ if (val != 0 && val != 1) {
+ dev_err(adc->dev, "invalid nxp,calib-avg-en: %d\n", val);
+ return -EINVAL;
+ }
+ reg = val;
+ mcr &= ~IMX93_ADC_MCR_AVGEN_MASK;
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_AVGEN_MASK, reg);
+ }
+
+ ret = device_property_read_u32(adc->dev, "nxp,calib-nr-samples", &val);
+ if (!ret) {
+ switch (val) {
+ case 16:
+ reg = 0x0;
+ break;
+ case 32:
+ reg = 0x1;
+ break;
+ case 128:
+ reg = 0x2;
+ break;
+ case 512:
+ reg = 0x3;
+ break;
+ default:
+ dev_err(adc->dev, "invalid nxp,calib-nr-samples: %d\n", val);
+ return -EINVAL;
+ }
+ mcr &= ~IMX93_ADC_MCR_NRSMPL_MASK;
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_NRSMPL_MASK, reg);
+ }
+
+ ret = device_property_read_u32(adc->dev, "nxp,calib-t-sample", &val);
+ if (!ret) {
+ switch (val) {
+ case 8:
+ reg = 0x1;
+ break;
+ case 16:
+ reg = 0x2;
+ break;
+ case 22:
+ reg = 0x0;
+ break;
+ case 32:
+ reg = 0x3;
+ break;
+ default:
+ dev_err(adc->dev, "invalid nxp,calib-t-sample: %d\n", val);
+ return -EINVAL;
+ }
+ mcr &= ~IMX93_ADC_MCR_TSAMP_MASK;
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_TSAMP_MASK, reg);
+ }
+
+ /* write calibration settings to MCR */
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ imx93_adc_power_up(adc);
/* run calibration */
mcr = readl(adc->regs + IMX93_ADC_MCR);
--
2.34.1On Thu, Jul 10, 2025 at 09:39:04AM +0200, Primoz Fiser wrote:
>
> Make i.MX93 ADC calibration parameters:
> - AVGEN: Enable calibration averaging function,
> - NRSMPL: Select number of calibration samples,
> - TSAMP: Select sample time of calibration conversions,
>
> in the MCR register configurable with the corresponding device-tree
> properties:
> - nxp,calib-avg-en,
> - nxp,calib-nr-samples and
> - nxp,calib-t-sample.
...
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/property.h>
Keep it in order.
...
> + ret = device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
> + if (!ret) {
> + if (val != 0 && val != 1) {
> + dev_err(adc->dev, "invalid nxp,calib-avg-en: %d\n", val);
> + return -EINVAL;
> + }
> + reg = val;
> + mcr &= ~IMX93_ADC_MCR_AVGEN_MASK;
> + mcr |= FIELD_PREP(IMX93_ADC_MCR_AVGEN_MASK, reg);
> + }
Please, since it's optional, do other way around.
val = $DEFAUTL;
device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
FIELD_MODIFY(...)
Similar approach may be used for the other properties.
...
> + /* write calibration settings to MCR */
> + writel(mcr, adc->regs + IMX93_ADC_MCR);
Please, factor out this to the function, so we won't see the direct IO in the
->probe().
--
With Best Regards,
Andy Shevchenko
Hi Andy,
On 10. 07. 25 11:22, Andy Shevchenko wrote:
> On Thu, Jul 10, 2025 at 09:39:04AM +0200, Primoz Fiser wrote:
>>
>> Make i.MX93 ADC calibration parameters:
>> - AVGEN: Enable calibration averaging function,
>> - NRSMPL: Select number of calibration samples,
>> - TSAMP: Select sample time of calibration conversions,
>>
>> in the MCR register configurable with the corresponding device-tree
>> properties:
>> - nxp,calib-avg-en,
>> - nxp,calib-nr-samples and
>> - nxp,calib-t-sample.
>
> ...
>
>> #include <linux/platform_device.h>
>> #include <linux/pm_runtime.h>
>> #include <linux/regulator/consumer.h>
>> +#include <linux/property.h>
>
> Keep it in order.
OK. Will fix for v2.
>
> ...
>
>> + ret = device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
>> + if (!ret) {
>> + if (val != 0 && val != 1) {
>> + dev_err(adc->dev, "invalid nxp,calib-avg-en: %d\n", val);
>> + return -EINVAL;
>> + }
>> + reg = val;
>> + mcr &= ~IMX93_ADC_MCR_AVGEN_MASK;
>> + mcr |= FIELD_PREP(IMX93_ADC_MCR_AVGEN_MASK, reg);
>> + }
>
> Please, since it's optional, do other way around.
>
> val = $DEFAUTL;
> device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
> FIELD_MODIFY(...)
>
> Similar approach may be used for the other properties.
OK, I guess I could implement it like you suggested to explicitly set
the default parameter values.
But in current implementation MCR values are read at the beginning of
imx93_adc_calibration(), meaning calibration parameters are register POR
defaults. With you suggestion, we put defaults in software rather than
reading them from the hw directly.
>
> ...
>
>> + /* write calibration settings to MCR */
>> + writel(mcr, adc->regs + IMX93_ADC_MCR);
>
> Please, factor out this to the function, so we won't see the direct IO in the
> ->probe().
Sorry I don't understand this part.
What do you mean by factoring out this writel()?
Do you perhaps suggest to implement function
imx93_adc_configure_calibration() and put all our changes into it?
But we are already in imx93_adc_calibration() which is separate from
probe().
Please explain.
BR,
Primoz
On Thu, Jul 10, 2025 at 12:23:58PM +0200, Primoz Fiser wrote:
> On 10. 07. 25 11:22, Andy Shevchenko wrote:
> > On Thu, Jul 10, 2025 at 09:39:04AM +0200, Primoz Fiser wrote:
...
> >> + ret = device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
> >> + if (!ret) {
> >> + if (val != 0 && val != 1) {
> >> + dev_err(adc->dev, "invalid nxp,calib-avg-en: %d\n", val);
> >> + return -EINVAL;
> >> + }
> >> + reg = val;
> >> + mcr &= ~IMX93_ADC_MCR_AVGEN_MASK;
> >> + mcr |= FIELD_PREP(IMX93_ADC_MCR_AVGEN_MASK, reg);
> >> + }
> >
> > Please, since it's optional, do other way around.
> >
> > val = $DEFAUTL;
> > device_property_read_u32(adc->dev, "nxp,calib-avg-en", &val);
> > FIELD_MODIFY(...)
> >
> > Similar approach may be used for the other properties.
>
> OK, I guess I could implement it like you suggested to explicitly set
> the default parameter values.
>
> But in current implementation MCR values are read at the beginning of
> imx93_adc_calibration(), meaning calibration parameters are register POR
> defaults. With you suggestion, we put defaults in software rather than
> reading them from the hw directly.
I see, then you need to read, do FIELD_GET()/device_property_read()/FIELD_MODIFY().
You got the idea.
...
> > Please, factor out this to the function, so we won't see the direct IO in the
> > ->probe().
>
> Sorry I don't understand this part.
>
> What do you mean by factoring out this writel()?
>
> Do you perhaps suggest to implement function
> imx93_adc_configure_calibration() and put all our changes into it?
>
> But we are already in imx93_adc_calibration() which is separate from
> probe().
Ah, sorry for the mistakenly read the function name. Ignore this comment.
--
With Best Regards,
Andy Shevchenko
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