Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
Documentation/devicetree/bindings/iio/max1363.txt | 54 +++++++++++++++++++++
drivers/iio/adc/max1363.c | 54 ++++++++++++++++-----
2 files changed, 95 insertions(+), 13 deletions(-)
create mode 100644 Documentation/devicetree/bindings/iio/max1363.txt
diff --git a/Documentation/devicetree/bindings/iio/max1363.txt b/Documentation/devicetree/bindings/iio/max1363.txt
new file mode 100644
index 0000000..6d22861
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/max1363.txt
@@ -0,0 +1,54 @@
+Device Tree bindings for MAX1363 and compatible ADC controllers
+
+This binding uses the common IIO binding[1].
+
+[1] Documentation/devicetree/bindings/iio/iio-bindings.txt
+
+Required properties:
+
+- compatible, shall be one of the following:
+ "maxim,max1361"
+ "maxim,max1362"
+ "maxim,max1363"
+ "maxim,max1364"
+ "maxim,max1036"
+ "maxim,max1037"
+ "maxim,max1038"
+ "maxim,max1039"
+ "maxim,max1136"
+ "maxim,max1137"
+ "maxim,max1138"
+ "maxim,max1139"
+ "maxim,max1236"
+ "maxim,max1237"
+ "maxim,max1238"
+ "maxim,max1239"
+ "maxim,max11600"
+ "maxim,max11601"
+ "maxim,max11602"
+ "maxim,max11603"
+ "maxim,max11604"
+ "maxim,max11605"
+ "maxim,max11606"
+ "maxim,max11607"
+ "maxim,max11608"
+ "maxim,max11609"
+ "maxim,max11610"
+ "maxim,max11611"
+ "maxim,max11612"
+ "maxim,max11613"
+ "maxim,max11614"
+ "maxim,max11615"
+ "maxim,max11616"
+ "maxim,max11617"
+
+- reg: shall be the I2C device address
+
+Required properties for IIO bindings:
+- #io-channel-cells: from common IIO bindings; shall be set to 1.
+
+Optional properties:
+- vref: Reference voltage in mV. If the provided reference voltage matches
+ the internal reference voltage, the internal reference voltage is used.
+ Otherwise it is assumed that an external reference voltage is used,
+ and the chip is programmed accordingly.
diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c
index 51165d6..cf49a20 100644
--- a/drivers/iio/adc/max1363.c
+++ b/drivers/iio/adc/max1363.c
@@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -162,6 +163,7 @@ struct max1363_chip_info {
* @mask_low: bitmask for enabled low thresholds
* @thresh_high: high threshold values
* @thresh_low: low threshold values
+ * @vref_mv: Actual (external or internal) reference voltage
*/
struct max1363_state {
struct i2c_client *client;
@@ -181,6 +183,7 @@ struct max1363_state {
/* 4x unipolar first then the fours bipolar ones */
s16 thresh_high[8];
s16 thresh_low[8];
+ u16 vref_mv;
};
#define MAX1363_MODE_SINGLE(_num, _mask) { \
@@ -392,6 +395,8 @@ 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);
@@ -399,16 +404,10 @@ 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_mv * 1000) >> st->chip_info->bits;
+ *val = scale_uv / 1000;
+ *val2 = (scale_uv % 1000) * 1000;
+ return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
@@ -1389,12 +1388,16 @@ 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_mv != st->chip_info->int_vref_mv)
+ 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];
@@ -1526,6 +1529,26 @@ static void max1363_buffer_cleanup(struct iio_dev *indio_dev)
iio_kfifo_free(indio_dev->buffer);
}
+#ifdef CONFIG_OF
+static int max1363_parse_of(struct device *dev, struct max1363_state *st)
+{
+ struct device_node *np = dev->of_node;
+ u32 vref_mv;
+
+ if (!of_property_read_u32(np, "vref", &vref_mv)) {
+ if (vref_mv == 0 || vref_mv > USHRT_MAX)
+ return -EINVAL;
+ st->vref_mv = vref_mv;
+ }
+ return 0;
+}
+#else
+static int max1363_parse_of(struct device *dev, struct max1363_state *st)
+{
+ return 0;
+}
+#endif
+
static int max1363_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -1562,6 +1585,11 @@ static int max1363_probe(struct i2c_client *client,
st->chip_info = &max1363_chip_info_tbl[id->driver_data];
st->client = client;
+ st->vref_mv = st->chip_info->int_vref_mv;
+ ret = max1363_parse_of(&client->dev, st);
+ if (ret)
+ goto error_disable_reg;
+
ret = max1363_alloc_scan_masks(indio_dev);
if (ret)
goto error_disable_reg;
--
1.7.9.7
--
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