diff options
author | Guenter Roeck <linux@roeck-us.net> | 2013-02-03 00:59:00 (GMT) |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2013-02-06 18:38:40 (GMT) |
commit | a405b00e4470b15ed062de97c4ce552d41a0a60b (patch) | |
tree | c3a8efd5c7ab535628fe82500e403d3a079bd34e | |
parent | 7c3e8675f37503337d901dc254cba253326b572a (diff) | |
download | linux-fsl-qoriq-a405b00e4470b15ed062de97c4ce552d41a0a60b.tar.xz |
iio/adc: (max1363) Add support for external reference voltage
Implement external reference voltage as regulator named "vref".
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r-- | drivers/iio/adc/max1363.c | 52 |
1 files changed, 39 insertions, 13 deletions
diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c index c5e46c6..6c1cfb7 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]; @@ -1491,6 +1495,7 @@ 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) { @@ -1521,6 +1526,23 @@ 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; @@ -1562,6 +1584,8 @@ 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); @@ -1578,6 +1602,8 @@ 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); |