diff options
| -rw-r--r-- | drivers/iio/adc/stm32-adc.c | 59 |
1 files changed, 24 insertions, 35 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 378411853d75..7980c46fe37c 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; * @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; - 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 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, |