From 45e9bda4ffc48f96e9811e158dcd610a5ec49e13 Mon Sep 17 00:00:00 2001 From: Krzysztof Adamski Date: Thu, 14 Oct 2021 15:01:09 +0200 Subject: [PATCH] hwmon: (tmp421) support disabling channels from DT The previous patch introduced per channel subnodes in DT that let us specify some channel specific properties. This built a ground for easily disabling individual channels of the sensor that may not be connected to any external diode and thus are not returning any meaningful data. This patch adds support for parsing the "status" property of channels DT subnodes and makes sure the -ENODATA is returned when disabled channels value is read. Signed-off-by: Krzysztof Adamski Link: https://lore.kernel.org/r/a85d623f0792b862870933a875bdf802f4c017f1.1634206677.git.krzysztof.adamski@nokia.com Signed-off-by: Guenter Roeck --- drivers/hwmon/tmp421.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c index 89346ca..af08bc9 100644 --- a/drivers/hwmon/tmp421.c +++ b/drivers/hwmon/tmp421.c @@ -89,6 +89,7 @@ MODULE_DEVICE_TABLE(of, tmp421_of_match); struct tmp421_channel { const char *label; + bool enabled; s16 temp; }; @@ -170,6 +171,9 @@ static int tmp421_read(struct device *dev, enum hwmon_sensor_types type, if (ret) return ret; + if (!tmp421->channel[channel].enabled) + return -ENODATA; + switch (attr) { case hwmon_temp_input: *val = temp_from_raw(tmp421->channel[channel].temp, @@ -323,6 +327,8 @@ static int tmp421_probe_child_from_dt(struct i2c_client *client, if (data->channel[i].label) data->temp_config[i] |= HWMON_T_LABEL; + data->channel[i].enabled = of_device_is_available(child); + return 0; } @@ -371,8 +377,10 @@ static int tmp421_probe(struct i2c_client *client) if (err) return err; - for (i = 0; i < data->channels; i++) + for (i = 0; i < data->channels; i++) { data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT; + data->channel[i].enabled = true; + } err = tmp421_probe_from_dt(client, data); if (err) -- 2.7.4