On Tue, 20 Nov 2018 11:12:30 +0100
Fabrice Gasnier <fabrice.gasn...@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.gasn...@st.com>
one trivial point inline. Otherwise seems a sensible bit of refactoring.
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,
