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SubjectRe: [PATCH 1/3] iio: adc: stm32-adc: move self-calibration to prepare routine
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On 11/25/18 2:14 PM, Jonathan Cameron wrote:
> On Sun, 25 Nov 2018 13:03:39 +0000
> Jonathan Cameron <jic23@kernel.org> wrote:
>
>> On Tue, 20 Nov 2018 11:12:30 +0100
>> Fabrice Gasnier <fabrice.gasnier@st.com> wrote:
>>
>>> Move self-calibration routine to prepare routine.
>>> - This is precursor patch to ease power management handling.
>>> - This also allow to factorize few error cases (error handling).
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
>> one trivial point inline. Otherwise seems a sensible bit of refactoring.
> Given this was the only 'issue' I found in the whole set I've
> just applied it with that changed.

Hi Jonathan,

Many thanks.

Best Regards,
Fabrice
>
> Applied to the togreg branch of iio.git and pushed out as testing
> for the autobuilders to play with it.
>
> Thanks,
>
> Jonathan
>
>>
>> Thanks,
>>
>> Jonathan
>>
>>> ---
>>> drivers/iio/adc/stm32-adc.c | 59 ++++++++++++++++++---------------------------
>>> 1 file changed, 24 insertions(+), 35 deletions(-)
>>>
>>> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
>>> index 3784118..dca8733 100644
>>> --- a/drivers/iio/adc/stm32-adc.c
>>> +++ b/drivers/iio/adc/stm32-adc.c
>>> @@ -199,11 +199,13 @@ struct stm32_adc_trig_info {
>>> * @calfact_s: Calibration offset for single ended channels
>>> * @calfact_d: Calibration offset in differential
>>> * @lincalfact: Linearity calibration factor
>>> + * @calibrated: Indicates calibration status
>>> */
>>> struct stm32_adc_calib {
>>> u32 calfact_s;
>>> u32 calfact_d;
>>> u32 lincalfact[STM32H7_LINCALFACT_NUM];
>>> + bool calibrated;
>>> };
>>>
>>> /**
>>> @@ -251,7 +253,6 @@ struct stm32_adc_regspec {
>>> * @trigs: external trigger sources
>>> * @clk_required: clock is required
>>> * @has_vregready: vregready status flag presence
>>> - * @selfcalib: optional routine for self-calibration
>>> * @prepare: optional prepare routine (power-up, enable)
>>> * @start_conv: routine to start conversions
>>> * @stop_conv: routine to stop conversions
>>> @@ -264,7 +265,6 @@ struct stm32_adc_cfg {
>>> struct stm32_adc_trig_info *trigs;
>>> bool clk_required;
>>> bool has_vregready;
>>> - int (*selfcalib)(struct stm32_adc *);
>>> int (*prepare)(struct stm32_adc *);
>>> void (*start_conv)(struct stm32_adc *, bool dma);
>>> void (*stop_conv)(struct stm32_adc *);
>>> @@ -777,6 +777,7 @@ static void stm32h7_adc_disable(struct stm32_adc *adc)
>>> /**
>>> * stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result
>>> * @adc: stm32 adc instance
>>> + * Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are writable
>>> */
>>> static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
>>> {
>>> @@ -784,11 +785,6 @@ static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
>>> int i, ret;
>>> u32 lincalrdyw_mask, val;
>>>
>>> - /* Enable adc so LINCALRDYW1..6 bits are writable */
>>> - ret = stm32h7_adc_enable(adc);
>>> - if (ret)
>>> - return ret;
>>> -
>>> /* Read linearity calibration */
>>> lincalrdyw_mask = STM32H7_LINCALRDYW6;
>>> for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
>>> @@ -801,7 +797,7 @@ static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
>>> 100, STM32_ADC_TIMEOUT_US);
>>> if (ret) {
>>> dev_err(&indio_dev->dev, "Failed to read calfact\n");
>>> - goto disable;
>>> + return ret;
>>> }
>>>
>>> val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
>>> @@ -817,11 +813,9 @@ static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
>>> adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT;
>>> adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK);
>>> adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT;
>>> + adc->cal.calibrated = true;
>>>
>>> -disable:
>>> - stm32h7_adc_disable(adc);
>>> -
>>> - return ret;
>>> + return 0;
>>> }
>>>
>>> /**
>>> @@ -898,9 +892,9 @@ static int stm32h7_adc_restore_selfcalib(struct stm32_adc *adc)
>>> #define STM32H7_ADC_CALIB_TIMEOUT_US 100000
>>>
>>> /**
>>> - * stm32h7_adc_selfcalib() - Procedure to calibrate ADC (from power down)
>>> + * stm32h7_adc_selfcalib() - Procedure to calibrate ADC
>>> * @adc: stm32 adc instance
>>> - * Exit from power down, calibrate ADC, then return to power down.
>>> + * Note: Must be called once ADC is out of power down.
>>> */
>>> static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
>>> {
>>> @@ -908,9 +902,8 @@ static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
>>> int ret;
>>> u32 val;
>>>
>>> - ret = stm32h7_adc_exit_pwr_down(adc);
>>> - if (ret)
>>> - return ret;
>>> + if (adc->cal.calibrated)
>>> + return adc->cal.calibrated;
>> return true seems more logical given this is a boolean.
>>
>>>
>>> /*
>>> * Select calibration mode:
>>> @@ -927,7 +920,7 @@ static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
>>> STM32H7_ADC_CALIB_TIMEOUT_US);
>>> if (ret) {
>>> dev_err(&indio_dev->dev, "calibration failed\n");
>>> - goto pwr_dwn;
>>> + goto out;
>>> }
>>>
>>> /*
>>> @@ -944,18 +937,13 @@ static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
>>> STM32H7_ADC_CALIB_TIMEOUT_US);
>>> if (ret) {
>>> dev_err(&indio_dev->dev, "calibration failed\n");
>>> - goto pwr_dwn;
>>> + goto out;
>>> }
>>>
>>> +out:
>>> stm32_adc_clr_bits(adc, STM32H7_ADC_CR,
>>> STM32H7_ADCALDIF | STM32H7_ADCALLIN);
>>>
>>> - /* Read calibration result for future reference */
>>> - ret = stm32h7_adc_read_selfcalib(adc);
>>> -
>>> -pwr_dwn:
>>> - stm32h7_adc_enter_pwr_down(adc);
>>> -
>>> return ret;
>>> }
>>>
>>> @@ -972,19 +960,28 @@ static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
>>> */
>>> static int stm32h7_adc_prepare(struct stm32_adc *adc)
>>> {
>>> - int ret;
>>> + int calib, ret;
>>>
>>> ret = stm32h7_adc_exit_pwr_down(adc);
>>> if (ret)
>>> return ret;
>>>
>>> + ret = stm32h7_adc_selfcalib(adc);
>>> + if (ret < 0)
>>> + goto pwr_dwn;
>>> + calib = ret;
>>> +
>>> stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
>>>
>>> ret = stm32h7_adc_enable(adc);
>>> if (ret)
>>> goto pwr_dwn;
>>>
>>> - ret = stm32h7_adc_restore_selfcalib(adc);
>>> + /* Either restore or read calibration result for future reference */
>>> + if (calib)
>>> + ret = stm32h7_adc_restore_selfcalib(adc);
>>> + else
>>> + ret = stm32h7_adc_read_selfcalib(adc);
>>> if (ret)
>>> goto disable;
>>>
>>> @@ -1880,12 +1877,6 @@ static int stm32_adc_probe(struct platform_device *pdev)
>>> goto err_clk_disable;
>>> stm32_adc_set_res(adc);
>>>
>>> - if (adc->cfg->selfcalib) {
>>> - ret = adc->cfg->selfcalib(adc);
>>> - if (ret)
>>> - goto err_clk_disable;
>>> - }
>>> -
>>> ret = stm32_adc_chan_of_init(indio_dev);
>>> if (ret < 0)
>>> goto err_clk_disable;
>>> @@ -1961,7 +1952,6 @@ static int stm32_adc_remove(struct platform_device *pdev)
>>> .regs = &stm32h7_adc_regspec,
>>> .adc_info = &stm32h7_adc_info,
>>> .trigs = stm32h7_adc_trigs,
>>> - .selfcalib = stm32h7_adc_selfcalib,
>>> .start_conv = stm32h7_adc_start_conv,
>>> .stop_conv = stm32h7_adc_stop_conv,
>>> .prepare = stm32h7_adc_prepare,
>>> @@ -1974,7 +1964,6 @@ static int stm32_adc_remove(struct platform_device *pdev)
>>> .adc_info = &stm32h7_adc_info,
>>> .trigs = stm32h7_adc_trigs,
>>> .has_vregready = true,
>>> - .selfcalib = stm32h7_adc_selfcalib,
>>> .start_conv = stm32h7_adc_start_conv,
>>> .stop_conv = stm32h7_adc_stop_conv,
>>> .prepare = stm32h7_adc_prepare,
>>
>

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