Dear Hector Palacios,
> Adds in_voltageX_scale_available file for every channel to read
> the different available scales.
> There are two scales per channel:
> [0] = divider_by_two disabled (default)
> [1] = divider_by_two enabled
>
> Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx>
> ---
> drivers/staging/iio/adc/mxs-lradc.c | 115
> +++++++++++++++++++++++++++++++++++- 1 file changed, 114 insertions(+), 1
> deletion(-)
>
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c
> b/drivers/staging/iio/adc/mxs-lradc.c index 012c42e..7f98c99 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -37,6 +37,7 @@
> #include <linux/input.h>
>
> #include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> #include <linux/iio/buffer.h>
> #include <linux/iio/trigger.h>
> #include <linux/iio/trigger_consumer.h>
> @@ -186,6 +187,7 @@ struct mxs_lradc {
> struct completion completion;
>
> const int *vref_mv;
> + unsigned int scale_avail[LRADC_MAX_TOTAL_CHANS][2][2];
>
> /*
> * Touchscreen LRADC channels receives a private slot in the CTRL4
> @@ -362,9 +364,99 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> return ret;
> }
>
> +static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
> + struct device_attribute *attr,
> + char *buf,
> + int ch)
> +{
> + struct iio_dev *iio = dev_to_iio_dev(dev);
> + struct mxs_lradc *lradc = iio_priv(iio);
> + int i, len = 0;
> +
> + for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
> + len += sprintf(buf + len, "%d.%09u ",
> + lradc->scale_avail[ch][i][0],
> + lradc->scale_avail[ch][i][1]);
> +
> + len += sprintf(buf + len, "\n");
> +
> + return len;
> +}
> +
> +#define SHOW_SCALE_AVAILABLE_FUNC(ch)
\
> +static ssize_t mxs_lradc_show_scale_available##ch(struct device *dev,
\
> + struct device_attribute *attr, \
> + char *buf) \
> +{ \
> + return mxs_lradc_show_scale_available_ch(dev, attr, buf, ch); \
> +}
> +
> +SHOW_SCALE_AVAILABLE_FUNC(0)
> +SHOW_SCALE_AVAILABLE_FUNC(1)
> +SHOW_SCALE_AVAILABLE_FUNC(2)
> +SHOW_SCALE_AVAILABLE_FUNC(3)
> +SHOW_SCALE_AVAILABLE_FUNC(4)
> +SHOW_SCALE_AVAILABLE_FUNC(5)
> +SHOW_SCALE_AVAILABLE_FUNC(6)
> +SHOW_SCALE_AVAILABLE_FUNC(7)
> +SHOW_SCALE_AVAILABLE_FUNC(8)
> +SHOW_SCALE_AVAILABLE_FUNC(9)
> +SHOW_SCALE_AVAILABLE_FUNC(10)
> +SHOW_SCALE_AVAILABLE_FUNC(11)
> +SHOW_SCALE_AVAILABLE_FUNC(12)
> +SHOW_SCALE_AVAILABLE_FUNC(13)
> +SHOW_SCALE_AVAILABLE_FUNC(14)
> +SHOW_SCALE_AVAILABLE_FUNC(15)
> +
> +#define SHOW_SCALE_AVAILABLE_ATTR(ch)
\
> +static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
> + mxs_lradc_show_scale_available##ch, NULL, 0)
> +
> +SHOW_SCALE_AVAILABLE_ATTR(0);
> +SHOW_SCALE_AVAILABLE_ATTR(1);
> +SHOW_SCALE_AVAILABLE_ATTR(2);
> +SHOW_SCALE_AVAILABLE_ATTR(3);
> +SHOW_SCALE_AVAILABLE_ATTR(4);
> +SHOW_SCALE_AVAILABLE_ATTR(5);
> +SHOW_SCALE_AVAILABLE_ATTR(6);
> +SHOW_SCALE_AVAILABLE_ATTR(7);
> +SHOW_SCALE_AVAILABLE_ATTR(8);
> +SHOW_SCALE_AVAILABLE_ATTR(9);
> +SHOW_SCALE_AVAILABLE_ATTR(10);
> +SHOW_SCALE_AVAILABLE_ATTR(11);
> +SHOW_SCALE_AVAILABLE_ATTR(12);
> +SHOW_SCALE_AVAILABLE_ATTR(13);
> +SHOW_SCALE_AVAILABLE_ATTR(14);
> +SHOW_SCALE_AVAILABLE_ATTR(15);
> +
> +static struct attribute *mxs_lradc_attributes[] = {
> + &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage8_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage9_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
> + &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group mxs_lradc_attribute_group = {
> + .attrs = mxs_lradc_attributes,
> +};
> +
> static const struct iio_info mxs_lradc_iio_info = {
> .driver_module = THIS_MODULE,
> .read_raw = mxs_lradc_read_raw,
> + .attrs = &mxs_lradc_attribute_group,
> };
>
> /*
> @@ -968,7 +1060,8 @@ static int mxs_lradc_probe(struct platform_device
> *pdev) struct resource *iores;
> uint32_t ts_wires = 0;
> int ret = 0;
> - int i;
> + int i, s;
> + unsigned int scale_uv;
>
> /* Allocate the IIO device. */
> iio = iio_device_alloc(sizeof(*lradc));
> @@ -1043,6 +1136,26 @@ static int mxs_lradc_probe(struct platform_device
> *pdev) if (ret)
> goto err_trig;
>
> + /* Populate available ADC input ranges */
> + for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
> + for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
> + /*
> + * [0] = optional divider by two disabled (default)
> + * [1] = optional divider by two enabled
> + *
> + * The scale is calculated by doing:
> + * Vref >> (realbits - s)
> + * which multiplies by two on the second component
> + * of the array.
> + */
> + scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
> + (iio->channels[i].scan_type.realbits - s);
Given that you do have a table of values already, can this table not be computed
at compile-time as well?
> + lradc->scale_avail[i][s][1] = do_div(scale_uv,
> + 100000000) * 10;
> + lradc->scale_avail[i][s][0] = scale_uv;
Is this correct? Why is one set to "scale_uv" and the other set to scale_uv /
100000000 ? Maybe I just don't understand what each of the fields in the array
stand for.
> + }
> + }
> +
> /* Configure the hardware. */
> mxs_lradc_hw_init(lradc);
Best regards,
Marek Vasut
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