On 03/20/2017 08:24 PM, Sam Povilus wrote:
Adding the ability for the ads7828 and ads7830 to use the device tree to
get their optional parameters, instead of using platform devices. This
allows people using custom boards to also use the ads7828 in a non-default
manner.
v2: conforming to coding style
v3: changing from "_" to "-" for device tree entries
v4: using regulator subsystem for voltage source, renaming differential
input property
v5: checking for invalid vref values sooner and returning error if they are
bad, not warning user.
Signed-off-by: Sam Povilus <kernel.development@xxxxxxxx>
---
.../devicetree/bindings/hwmon/ads7828.txt | 26 ++++++++++++++++++++++
.../devicetree/bindings/i2c/trivial-devices.txt | 2 --
drivers/hwmon/ads7828.c | 21 +++++++++++++++++
3 files changed, 47 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..5a0c4a7c6144
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ads7828.txt
@@ -0,0 +1,26 @@
+ads7828 properties
+
+Required properties:
+- compatible: Should be one of
+ ti,ads7828
+ ti,ads7830
+- reg: I2C address
+
+Optional properties:
+
+- ti,differential-input
+ Set to use the device in differential mode.
+- vref
+ The external reference on the device is set to this regulators output. If it
+ does not exists the internal reference will be used and output by the ads78xx
+ on the "external vref" pin.
+
+ Example ADS7828 node:
+
+ ads7828: ads@48 {
+ comatible = "ti,ads7828";
s/comatible/compatible/
+ reg = <0x48>;
+ vref = <&vref>;
Looking into the source of of_get_regulator(), either this has to be vref-supply
or I am missing something.
Didn't I mention all this before ?
+ ti,differential-input;
+ };
+
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..0be4804a9e59 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -34,6 +34,9 @@
#include <linux/platform_data/ads7828.h>
#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
alphabetic order please
+
+#define MV_TO_UV 1000
/* The ADS7828 registers */
#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
@@ -118,9 +121,12 @@ 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_uv;
bool diff_input = false;
bool ext_vref = false;
unsigned int regval;
+ struct regulator *reg;
+
Please no double empty lines.
data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
if (!data)
@@ -131,6 +137,21 @@ 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, "ti,differential-input",
+ NULL))
+ diff_input = true;
+ reg = devm_regulator_get_optional(dev, "vref");
+ if (!IS_ERR(reg)) {
+ vref_uv = regulator_get_voltage(reg);
+ if ((vref_uv >= ADS7828_EXT_VREF_MV_MIN * MV_TO_UV) &&
+ (vref_uv <= ADS7828_EXT_VREF_MV_MAX * MV_TO_UV)) {
+ vref_mv = DIV_ROUND_CLOSEST(vref_uv, MV_TO_UV);
+ ext_vref = true;
+ } else {
+ return -EINVAL;
+ }
Easier would be
vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000);
if (vref_mv < ADS7828_EXT_VREF_MV_MIN ||
vref_mv > ADS7828_EXT_VREF_MV_MAX)
return -EINVAL;
ext_vref = true;
I don't think we need the MV_TO_UV define.
+ }
}
/* Bound Vref with min/max values */
--
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