Commit 0da98c7b authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Jonathan Cameron
Browse files

iio: adc: stm32-adc: move self-calibration to prepare routine 



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: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 7f6232e6

drivers/iio/adc/stm32-adc.c

+24 −35
Original line number Diff line number Diff line
@@ -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; 
 * @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 true;



	/*

	 * 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 @@ pwr_dwn: 
 */

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;



	/* 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 const struct stm32_adc_cfg stm32h7_adc_cfg = { 
	.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 const struct stm32_adc_cfg stm32mp1_adc_cfg = { 
	.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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