From 951d21de88e4df3449b063180ddec0c668b64c53 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Mon, 22 May 2017 17:51:45 -0700 Subject: iio: adc: cpcap: Fix die temperature It seems that "MC13783 Power Management and Audio Ciruit User's Guide" MC1378UG.pdf documents several similar components as in the CPCAP PMIC. Chapter "9.5.5 Die Temperature and UID" says that the die temperature value is 282 at 25C with LSB of -1.14C. Converting CPCAP PMIC channel3 values with following seems to produce values that make sense for a PMIC die: temperature = 25000 + ((regval - 282) * 114) As we don't have any other documentation, let's assume the die temperature is unconfigured in the Motorola mapphone Linux kernel and the current temperature conversion table should be only used for the battery thermistor and not for the die temperature. Cc: Marcel Partap Cc: Michael Scott Cc: Sebastian Reichel Signed-off-by: Tony Lindgren Signed-off-by: Jonathan Cameron --- drivers/iio/adc/cpcap-adc.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) (limited to 'drivers/iio') diff --git a/drivers/iio/adc/cpcap-adc.c b/drivers/iio/adc/cpcap-adc.c index 73cf7964a5fe..11e65852725a 100644 --- a/drivers/iio/adc/cpcap-adc.c +++ b/drivers/iio/adc/cpcap-adc.c @@ -874,6 +874,22 @@ static int cpcap_adc_init_request(struct cpcap_adc_request *req, return 0; } +static int cpcap_adc_read_st_die_temp(struct cpcap_adc *ddata, + int addr, int *val) +{ + int error; + + error = regmap_read(ddata->reg, addr, val); + if (error) + return error; + + *val -= 282; + *val *= 114; + *val += 25000; + + return 0; +} + static int cpcap_adc_read(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) @@ -905,9 +921,18 @@ static int cpcap_adc_read(struct iio_dev *indio_dev, error = cpcap_adc_start_bank(ddata, &req); if (error) goto err_unlock; - error = cpcap_adc_read_bank_scaled(ddata, &req); - if (error) - goto err_unlock; + if ((ddata->vendor == CPCAP_VENDOR_ST) && + (chan->channel == CPCAP_ADC_AD3)) { + error = cpcap_adc_read_st_die_temp(ddata, + chan->address, + &req.result); + if (error) + goto err_unlock; + } else { + error = cpcap_adc_read_bank_scaled(ddata, &req); + if (error) + goto err_unlock; + } error = cpcap_adc_stop_bank(ddata); if (error) goto err_unlock; -- cgit v1.2.3-59-g8ed1b