On 02/03/2013 12:59 AM, Guenter Roeck wrote:
> Implement external reference voltage as regulator named "vref".
>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Applied to togreg branch of iio.git.
Thanks,
The remaining two patches will have sit a while.
Patch 3 effects stuff outside IIO so I'll wait to see if anyone
screams that it is going to cause merge nightmares!
Patch 4 is clearly still under discussion though a consensus seems
to have more or less been reached.
Thanks again for this work Guenter. I like the way one of my oldest
drivers is getting cleaned up along the way without me having to
do anything much ;)
> ---
> v2: Use regulator API to specify vref instead of creating new devicetree
> bindings.
> Keep reference voltage internally in uV, as this is the scale provided
> by the regulator subsystem. We need the value in uV anyway, so that does
> make some sense.
>
> drivers/iio/adc/max1363.c | 52 +++++++++++++++++++++++++++++++++------------
> 1 file changed, 39 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c
> index 1353fda..cac73d7 100644
> --- a/drivers/iio/adc/max1363.c
> +++ b/drivers/iio/adc/max1363.c
> @@ -163,6 +163,8 @@ struct max1363_chip_info {
> * @mask_low: bitmask for enabled low thresholds
> * @thresh_high: high threshold values
> * @thresh_low: low threshold values
> + * @vref: Reference voltage regulator
> + * @vref_uv: Actual (external or internal) reference voltage
> */
> struct max1363_state {
> struct i2c_client *client;
> @@ -182,6 +184,8 @@ struct max1363_state {
> /* 4x unipolar first then the fours bipolar ones */
> s16 thresh_high[8];
> s16 thresh_low[8];
> + struct regulator *vref;
> + u32 vref_uv;
> };
>
> #define MAX1363_MODE_SINGLE(_num, _mask) { \
> @@ -393,6 +397,8 @@ static int max1363_read_raw(struct iio_dev *indio_dev,
> {
> struct max1363_state *st = iio_priv(indio_dev);
> int ret;
> + unsigned long scale_uv;
> +
> switch (m) {
> case IIO_CHAN_INFO_RAW:
> ret = max1363_read_single_chan(indio_dev, chan, val, m);
> @@ -400,16 +406,10 @@ static int max1363_read_raw(struct iio_dev *indio_dev,
> return ret;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> - if ((1 << (st->chip_info->bits + 1)) >
> - st->chip_info->int_vref_mv) {
> - *val = 0;
> - *val2 = 500000;
> - return IIO_VAL_INT_PLUS_MICRO;
> - } else {
> - *val = (st->chip_info->int_vref_mv)
> - >> st->chip_info->bits;
> - return IIO_VAL_INT;
> - }
> + scale_uv = st->vref_uv >> st->chip_info->bits;
> + *val = scale_uv / 1000;
> + *val2 = (scale_uv % 1000) * 1000;
> + return IIO_VAL_INT_PLUS_MICRO;
> default:
> return -EINVAL;
> }
> @@ -1390,12 +1390,16 @@ static const struct max1363_chip_info max1363_chip_info_tbl[] = {
>
> static int max1363_initial_setup(struct max1363_state *st)
> {
> - st->setupbyte = MAX1363_SETUP_AIN3_IS_AIN3_REF_IS_VDD
> - | MAX1363_SETUP_POWER_UP_INT_REF
> - | MAX1363_SETUP_INT_CLOCK
> + st->setupbyte = MAX1363_SETUP_INT_CLOCK
> | MAX1363_SETUP_UNIPOLAR
> | MAX1363_SETUP_NORESET;
>
> + if (st->vref)
> + st->setupbyte |= MAX1363_SETUP_AIN3_IS_REF_EXT_TO_REF;
> + else
> + st->setupbyte |= MAX1363_SETUP_POWER_UP_INT_REF
> + | MAX1363_SETUP_AIN3_IS_AIN3_REF_IS_INT;
> +
> /* Set scan mode writes the config anyway so wait until then */
> st->setupbyte = MAX1363_SETUP_BYTE(st->setupbyte);
> st->current_mode = &max1363_mode_table[st->chip_info->default_mode];
> @@ -1533,6 +1537,7 @@ static int max1363_probe(struct i2c_client *client,
> int ret;
> struct max1363_state *st;
> struct iio_dev *indio_dev;
> + struct regulator *vref;
>
> indio_dev = iio_device_alloc(sizeof(struct max1363_state));
> if (indio_dev == NULL) {
> @@ -1563,6 +1568,23 @@ static int max1363_probe(struct i2c_client *client,
> st->chip_info = &max1363_chip_info_tbl[id->driver_data];
> st->client = client;
>
> + st->vref_uv = st->chip_info->int_vref_mv * 1000;
> + vref = devm_regulator_get(&client->dev, "vref");
> + if (!IS_ERR(vref)) {
> + int vref_uv;
> +
> + ret = regulator_enable(vref);
> + if (ret)
> + goto error_disable_reg;
> + st->vref = vref;
> + vref_uv = regulator_get_voltage(vref);
> + if (vref_uv <= 0) {
> + ret = -EINVAL;
> + goto error_disable_reg;
> + }
> + st->vref_uv = vref_uv;
> + }
> +
> ret = max1363_alloc_scan_masks(indio_dev);
> if (ret)
> goto error_disable_reg;
> @@ -1604,6 +1626,8 @@ static int max1363_probe(struct i2c_client *client,
> error_uninit_buffer:
> iio_triggered_buffer_cleanup(indio_dev);
> error_disable_reg:
> + if (st->vref)
> + regulator_disable(st->vref);
> regulator_disable(st->reg);
> error_unregister_map:
> iio_map_array_unregister(indio_dev);
> @@ -1620,6 +1644,8 @@ static int max1363_remove(struct i2c_client *client)
>
> iio_device_unregister(indio_dev);
> iio_triggered_buffer_cleanup(indio_dev);
> + if (st->vref)
> + regulator_disable(st->vref);
> regulator_disable(st->reg);
> iio_map_array_unregister(indio_dev);
> iio_device_free(indio_dev);
>
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