[PATCH] ina3221: add support for summation channel control

Ninad Malwade
2022-11-08T04:55:00Z

Add support to initialize summation channel control via kernel device
tree property "summation-bypass". The channel which has this property
is excluded from channel summation.

Signed-off-by: Ninad Malwade <nmalwade@nvidia.com>
---
.../devicetree/bindings/hwmon/ina3221.txt | 2 ++
drivers/hwmon/ina3221.c | 14 ++++++++++++--
2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/ina3221.txt b/Documentation/devicetree/bindings/hwmon/ina3221.txt
index fa63b6171407..c6e8e6aafcce 100644
--- a/Documentation/devicetree/bindings/hwmon/ina3221.txt
+++ b/Documentation/devicetree/bindings/hwmon/ina3221.txt
@@ -29,6 +29,7 @@ Texas Instruments INA3221 Device Tree Bindings
Optional properties:
- label: Name of the input source
- shunt-resistor-micro-ohms: Shunt resistor value in micro-Ohm
+ - summation-bypass: exclude from channel summation.

Example:

@@ -41,6 +42,7 @@ ina3221@40 {
input@0 {
reg = <0x0>;
status = "disabled";
+ summation-bypass;
};
input@1 {
reg = <0x1>;
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index 2a57f4b60c29..ba0d6da06947 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -104,6 +104,7 @@ struct ina3221_input {
const char *label;
int shunt_resistor;
bool disconnected;
+ bool summation_bypass;
};

/**
@@ -125,6 +126,7 @@ struct ina3221_data {
struct mutex lock;
u32 reg_config;
int summation_shunt_resistor;
+ u32 summation_channel_control;

bool single_shot;
};
@@ -154,7 +156,8 @@ static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
int i, shunt_resistor = 0;

for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
- if (input[i].disconnected || !input[i].shunt_resistor)
+ if (input[i].disconnected || !input[i].shunt_resistor ||
+ input[i].summation_bypass)
continue;
if (!shunt_resistor) {
/* Found the reference shunt resistor value */
@@ -786,6 +789,9 @@ static int ina3221_probe_child_from_dt(struct device *dev,
/* Save the connected input label if available */
of_property_read_string(child, "label", &input->label);

+ /* summation channel control */
+ input->summation_bypass = of_property_read_bool(child, "summation-bypass");
+
/* Overwrite default shunt resistor value optionally */
if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
if (val < 1 || val > INT_MAX) {
@@ -873,6 +879,10 @@ static int ina3221_probe(struct i2c_client *client)

/* Initialize summation_shunt_resistor for summation channel control */
ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
+ for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
+ if (!ina->inputs[i].summation_bypass)
+ ina->summation_channel_control |= (BIT(14 - i));
+ }

ina->pm_dev = dev;
mutex_init(&ina->lock);
@@ -984,7 +994,7 @@ static int ina3221_resume(struct device *dev)
*/
ret = regmap_update_bits(ina->regmap, INA3221_MASK_ENABLE,
INA3221_MASK_ENABLE_SCC_MASK,
- INA3221_MASK_ENABLE_SCC_MASK);
+ ina->summation_channel_control);
if (ret) {
dev_err(dev, "Unable to control summation channel\n");
return ret;
--
2.17.1