Skip to contentSkip to conversation

lm87: Allow LM87_REG_CHANNEL_MODE to be set via DT

PATCH In review Jason Gunthorpe 2 participants 3 messages Nov 10, 2016 – Nov 11, 2016

Subsystems (2)
Device tree bindings Hardware monitoring
lore
Share & tools
lore

Jason Gunthorpe

author
#0 lore raw

PATCH 1/1 lm87: Allow LM87_REG_CHANNEL_MODE to be set via DT

This compliments the existing scheme that lets it be set via platform_data.

Signed-off-by Jason Gunthorpe <[email protected]>
---
 Documentation/devicetree/bindings/hwmon/lm87.txt | 27 ++++++++++++++++++++++++
 drivers/hwmon/lm87.c                             |  8 ++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/lm87.txt
Documentation/devicetree/bindings/hwmon/lm87.txt new file +27 -0
new file mode 100644
index 00000000000000..4ea2646ce8d2f0
@@ -0,0 +1,27 @@
+* LM87 I2C Temperature and Fan sensor
+
+Required properties:
+- compatible: should contain one of
+		* "national,lm87"
+		* "ti,lm87"
+
+Optional properties:
+- channel-mode: Write the specified value to register 0x16. If not specified
+                the driver will read the value from the chip at startup.
+
+		The value controls how the driver operates certain multi-use
+		pins, eg bit 2 will select between temp_input3 or
+		in0&in5 operation.
+
+See Documentation/devicetree/bindings/i2c/i2c.txt for more required and
+optional properties.
+
+Example:
+
+i2c_master {
+	temperature-sensor@0 {
+		compatible = "ti,lm87";
+		channel-mode = <0x4>;
+		reg = <0>;
+	};
+};
drivers/hwmon/lm87.c +7 -1
index 81cb898245a107..ccc0c913b4534e 100644
@@ -853,9 +853,15 @@ static void lm87_restore_config(void *arg)
 static int lm87_init_client(struct i2c_client *client)
 {
 	struct lm87_data *data = i2c_get_clientdata(client);
+	u32 channel;
 	int rc;
 
-	if (dev_get_platdata(&client->dev)) {
+	if (client->dev.of_node &&
+	    !of_property_read_u32(client->dev.of_node, "channel-mode",
+				  &channel)) {
+		data->channel = channel;
+		lm87_write_value(client, LM87_REG_CHANNEL_MODE, data->channel);
+	} else if (dev_get_platdata(&client->dev)) {
 		data->channel = *(u8 *)dev_get_platdata(&client->dev);
 		lm87_write_value(client,
 				 LM87_REG_CHANNEL_MODE, data->channel);
Signature · 1 line
2.7.4
maintainer
#1 lore raw
Quoted 4 lines · Jason Gunthorpe

This compliments the existing scheme that lets it be set via platform_data.

Signed-off-by Jason Gunthorpe <[email protected]>

I would prefer https://www.spinics.net/lists/devicetree/msg148819.html
which appears to address the same problem and is less cryptic.

NACK unless someone convinces me otherwise.

Guenter

Quoted 62 lines
---
 Documentation/devicetree/bindings/hwmon/lm87.txt | 27 ++++++++++++++++++++++++
 drivers/hwmon/lm87.c                             |  8 ++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/lm87.txt
Documentation/devicetree/bindings/hwmon/lm87.txt new file +27 -0
new file mode 100644
index 00000000000000..4ea2646ce8d2f0
@@ -0,0 +1,27 @@
+* LM87 I2C Temperature and Fan sensor
+
+Required properties:
+- compatible: should contain one of
+		* "national,lm87"
+		* "ti,lm87"
+
+Optional properties:
+- channel-mode: Write the specified value to register 0x16. If not specified
+                the driver will read the value from the chip at startup.
+
+		The value controls how the driver operates certain multi-use
+		pins, eg bit 2 will select between temp_input3 or
+		in0&in5 operation.
+
+See Documentation/devicetree/bindings/i2c/i2c.txt for more required and
+optional properties.
+
+Example:
+
+i2c_master {
+	temperature-sensor@0 {
+		compatible = "ti,lm87";
+		channel-mode = <0x4>;
+		reg = <0>;
+	};
+};
drivers/hwmon/lm87.c +7 -1
index 81cb898245a107..ccc0c913b4534e 100644
@@ -853,9 +853,15 @@ static void lm87_restore_config(void *arg)
 static int lm87_init_client(struct i2c_client *client)
 {
 	struct lm87_data *data = i2c_get_clientdata(client);
+	u32 channel;
 	int rc;
 
-	if (dev_get_platdata(&client->dev)) {
+	if (client->dev.of_node &&
+	    !of_property_read_u32(client->dev.of_node, "channel-mode",
+				  &channel)) {
+		data->channel = channel;
+		lm87_write_value(client, LM87_REG_CHANNEL_MODE, data->channel);
+	} else if (dev_get_platdata(&client->dev)) {
 		data->channel = *(u8 *)dev_get_platdata(&client->dev);
 		lm87_write_value(client,
 				 LM87_REG_CHANNEL_MODE, data->channel);
Signature · 1 line
2.7.4
author
#2 lore raw
Quoted 8 lines · Guenter Roeck
Quoted 4 lines · Jason Gunthorpe

This compliments the existing scheme that lets it be set via platform_data.

Signed-off-by Jason Gunthorpe <[email protected]>

I would prefer https://www.spinics.net/lists/devicetree/msg148819.html
which appears to address the same problem and is less cryptic.

Is there a patch someplace that implements that proposed DT binding? I couldn't find anything.

Quoted 1 line

NACK unless someone convinces me otherwise.

*shrug* both styles of definition seem to be used in various device tree bindings.

The downside with Mahoda's proposal is that it only covers 3 of the 8 configuration bits, and will require alot of code for parsing. It seems really clunky, and why is a regulator involved to set the A/D sensitivity? Weird.

But I only need has-temp3, so if a patch appears please cc me and I'll review it here..

Regards,
Jason