Also adding a note to the user if they misconfigure the device's external
reference.
Signed-off-by: Sam Povilus <kernel.development@xxxxxxxx>
---
Documentation/devicetree/bindings/hwmon/ads7828.txt | 18 ++++++++++++++++++
.../devicetree/bindings/i2c/trivial-devices.txt | 2 --
drivers/hwmon/ads7828.c | 15 +++++++++++++++
3 files changed, 33 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/hwmon/ads7828.txt
diff --git a/Documentation/devicetree/bindings/hwmon/ads7828.txt b/Documentation/devicetree/bindings/hwmon/ads7828.txt
new file mode 100644
index 000000000000..7cd786585b51
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ads7828.txt
@@ -0,0 +1,18 @@
+ads7828 properties
+
+Required properties:
+- compatible:
+ Should be one of
+ ti,ads7828
+ ti,ads7830
+- reg: I2C address
+
+Optional properties:
+
+- diff_input
+ Set to use the device in differential mode.
+- ext_vref
+ Set to enable the external voltage reference on the device.
+- vref_mv
+ The external reference on the device is set to this as an unsigned integer in
+ milivolts. Must use "ext_vref" for this to have any meaning.
diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index cdd7b48826c3..87648909f6ce 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -163,8 +163,6 @@ st,m41t00 Serial real-time clock (RTC)
st,m41t62 Serial real-time clock (RTC) with alarm
st,m41t80 M41T80 - SERIAL ACCESS RTC WITH ALARMS
taos,tsl2550 Ambient Light Sensor with SMBUS/Two Wire Serial Interface
-ti,ads7828 8-Channels, 12-bit ADC
-ti,ads7830 8-Channels, 8-bit ADC
ti,tsc2003 I2C Touch-Screen Controller
ti,tmp102 Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface
ti,tmp103 Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index ee396ff167d9..05fc0ac06c06 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -118,6 +118,7 @@ static int ads7828_probe(struct i2c_client *client,
struct ads7828_data *data;
struct device *hwmon_dev;
unsigned int vref_mv = ADS7828_INT_VREF_MV;
+ unsigned int vref_mv_tmp;
bool diff_input = false;
bool ext_vref = false;
unsigned int regval;
@@ -131,11 +132,25 @@ static int ads7828_probe(struct i2c_client *client,
ext_vref = pdata->ext_vref;
if (ext_vref && pdata->vref_mv)
vref_mv = pdata->vref_mv;
+ } else if (dev->of_node) {
+ if (of_get_property(dev->of_node, "diff_input", NULL))
+ diff_input = true;
+ if (of_get_property(dev->of_node, "ext_vref", NULL))
+ ext_vref = true;
+ if (!of_property_read_u32(dev->of_node, "vref_mv", &vref_mv_tmp)
+ && ext_vref)
+ vref_mv = vref_mv_tmp;
}
/* Bound Vref with min/max values */
+ vref_mv_tmp = vref_mv;
vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
ADS7828_EXT_VREF_MV_MAX);
+ if (vref_mv_tmp != vref_mv) {
+ pr_info("You used and invalid external vref,"
+ " it has been clamped to %u",
+ vref_mv);
+ }
/* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
if (id->driver_data == ads7828) {
--
2.11.0
--
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