On 07/16/2013 03:22 PM, Maxime Ripard wrote:
Hi Maxime,
Hi Jacek,
I find myself needing these bindings as well, so I'm definitely
interested by your patches.
On Tue, Jul 02, 2013 at 02:15:38PM +0200, Lukasz Czerwinski wrote:
From: Jacek Anaszewski<j.anaszewski@xxxxxxxxxxx>
This patch adds DT support for the lps331ap barometer
sensor.
Signed-off-by: Jacek Anaszewski<j.anaszewski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park<kyungmin.park@xxxxxxxxxxx>
---
.../bindings/iio/pressure/st_pressure.txt | 41 ++++++++++++++++++++
drivers/iio/pressure/st_pressure_i2c.c | 9 +++++
drivers/iio/pressure/st_pressure_spi.c | 9 +++++
3 files changed, 59 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/pressure/st_pressure.txt
diff --git a/Documentation/devicetree/bindings/iio/pressure/st_pressure.txt b/Documentation/devicetree/bindings/iio/pressure/st_pressure.txt
new file mode 100644
index 0000000..73a4b7d
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/pressure/st_pressure.txt
@@ -0,0 +1,41 @@
+* STMicroelectronics LPS331AP barometer sensor
+
+Required properties:
+
+ - compatible : should be "lps331ap"
+ - reg : the I2C address of the barometer
+
+Optional properties:
+
+ - drdy-int-pin : redirect DRDY on pin INT1 (1) or pin INT2 (2) (u8)
+ - interrupt-parent : phandle to the interrupt map subnode
+ - interrupts : interrupt mapping for LPS331AP interrupt sources:
+ 2 sources: 0 - INT1, 1 - INT2
Maybe you could use interrupts-names here, instead of requiring to
hardcode the interrupt index.
From what I've figured out in order to obtain the interrupt id
by name the function
platform_get_irq_by_name(struct platform_device *dev, const char *name)
has to be exploited. Unfortunately required platform_device structure
is not available in the struct i2c_client that is passed to the
probe function of an i2c driver. The interrupt-names property would be
indeed neater here, if only it was usable from i2c driver.
Plus, I guess that it's assuming that you
can only use INT2 when you already use INT1?
As I see now the binding documentation file I submitted is confusing.
I fixed it in the second version of the patch. Currently description
of the interrupt map elements is as follows:
0 - data ready interrupt
1 - threshold interrupt
which means that you can use INT2 even though you don't use INT1.
This is the case I have on my board - I have only INT2 pin of
lps331ap device routed to the CPU. I define interrupt map
with only one element with index 0 (which means that I want
it to act as a data ready interrupt) and I assign 2 to the
drdy-int-pin property which instructs the driver to configure
data ready interrupt on the INT2 pin.
+ - irq-map : irq sub-node defining interrupt map
+ (all properties listed below are required):
+ - #interrupt-cells : should be 1
+ - #address-cells : should be 0
+ - #size-cells : should be 0
+ - interrupt-map : table of entries consisting of three child elements:
+ - unit_interrupt_specifier - 0 : INT1, 1 : INT2
+ - interrupt parent phandle
+ - parent unit interrupt specifier consisiting of two elements:
+ - index of the interrupt within the controller
+ - flags : should be 0
I don't really get why it's needed. Isn't that redundant with the
interrupt parent and the interrupt number already defined by
interrupt-parent and interrupts in the top node?
I'm aware that this adds much noise but I couldn't have found
other solution which would allow to define more than one interrupts
for the i2c device.
Thanks,
Jacek
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