Re: [PATCH V4 3/5] iio: adc: Add support for PMIC7 ADC

From: Andy Shevchenko
Date: Wed May 13 2020 - 05:48:20 EST


On Wed, May 13, 2020 at 12:23 PM Jishnu Prakash <jprakash@xxxxxxxxxxxxxx> wrote:
>
> The ADC architecture on PMIC7 is changed as compared to PMIC5. The
> major change from PMIC5 is that all SW communication to ADC goes through
> PMK8350, which communicates with other PMICs through PBS when the ADC
> on PMK8350 works in master mode. The SID register is used to identify the
> PMICs with which the PBS needs to communicate. Add support for the same.

> +#define ADC7_CONV_TIMEOUT msecs_to_jiffies(10)

...

> + ret = adc5_read(adc, ADC5_USR_DIG_PARAM, buf, sizeof(buf));
> + if (ret < 0)

Is ' < 0' part necessary?
Ditto for same cases in other places in the code.

> + return ret;

...

> + switch (mask) {
> + case IIO_CHAN_INFO_PROCESSED:
> + ret = adc7_do_conversion(adc, prop, chan,
> + &adc_code_volt, &adc_code_cur);
> + if (ret)
> + return ret;
> +
> + ret = qcom_adc5_hw_scale(prop->scale_fn_type,
> + &adc5_prescale_ratios[prop->prescale],
> + adc->data,
> + adc_code_volt, val);
> +
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }

> +
> + return 0;

Dead code?

...

> +static int qcom_vadc7_scale_hw_calib_die_temp(
> + const struct vadc_prescale_ratio *prescale,
> + const struct adc5_data *data,
> + u16 adc_code, int *result_mdec)
> +{
> +
> + int voltage, vtemp0, temp, i = ARRAY_SIZE(adcmap7_die_temp) - 1;

How assignment to i is useful?

> + voltage = qcom_vadc_scale_code_voltage_factor(adc_code,
> + prescale, data, 1);
> +
> + if (adcmap7_die_temp[0].x > voltage) {
> + *result_mdec = DIE_TEMP_ADC7_SCALE_1;
> + return 0;

> + } else if (adcmap7_die_temp[i].x <= voltage) {

Redundant 'else'.

> + *result_mdec = DIE_TEMP_ADC7_MAX;
> + return 0;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(adcmap7_die_temp); i++)
> + if (adcmap7_die_temp[i].x > voltage)
> + break;
> +
> + vtemp0 = adcmap7_die_temp[i - 1].x;
> + voltage = voltage - vtemp0;
> + temp = div64_s64(voltage * DIE_TEMP_ADC7_SCALE_FACTOR,
> + adcmap7_die_temp[i - 1].y);
> + temp += DIE_TEMP_ADC7_SCALE_1 + (DIE_TEMP_ADC7_SCALE_2 * (i - 1));
> + *result_mdec = temp;
> +
> + return 0;
> +}

...

> +#define RATIO_MAX_ADC7 0x4000

Hmm... Why the last is in hex? Is it related to amount of bits in the
hardware? Then probably better to use BIT().

--
With Best Regards,
Andy Shevchenko