Re: [PATCH v4] iio: mma8452: support either of the available interrupt pins

From: Martin Kepplinger
Date: Thu Oct 22 2015 - 11:24:23 EST


Am 2015-10-20 um 13:03 schrieb Martin Kepplinger:
> Am 2015-10-15 um 15:10 schrieb Martin Kepplinger:
>> This change is important in order for everyone to be easily able to use the
>> driver for one of the supported accelerometer chips!
>>
>> Until now, the driver blindly assumed that the INT1 interrupt line is wired
>> on a user's board. But these devices have 2 interrupt lines and can route
>> their interrupt sources to one of them. Now, if "INT2" is found and matches
>> i2c_client->irq, INT2 will be used.
>>
>> The chip's default actually is INT2, which is why probably many boards will
>> have it wired and can make use of this.
>>
>> Of course, this also falls back to assuming INT1, so for existing users
>> nothing will break. The new functionality is described in the bindings doc.
>>
>> Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxxxxxxxxxxxxxxxx>
>> ---
>> changelog:
>> v4: use irq that matches client->irq, backwards compatible
>> v3: correctly assign irq if both pins are described in DT
>> v2: don't warn but normally handle if both pins are described in dts
>> thanks Mark Rutland
>> v1: initial post
>>
>> .../devicetree/bindings/iio/accel/mma8452.txt | 6 ++++++
>> drivers/iio/accel/mma8452.c | 21 +++++++++++++++------
>> 2 files changed, 21 insertions(+), 6 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/iio/accel/mma8452.txt b/Documentation/devicetree/bindings/iio/accel/mma8452.txt
>> index e3c3746..3c10e85 100644
>> --- a/Documentation/devicetree/bindings/iio/accel/mma8452.txt
>> +++ b/Documentation/devicetree/bindings/iio/accel/mma8452.txt
>> @@ -7,13 +7,18 @@ Required properties:
>> * "fsl,mma8453"
>> * "fsl,mma8652"
>> * "fsl,mma8653"
>> +
>> - reg: the I2C address of the chip
>>
>> Optional properties:
>>
>> - interrupt-parent: should be the phandle for the interrupt controller
>> +
>> - interrupts: interrupt mapping for GPIO IRQ
>>
>> + - interrupt-names: should contain "INT1" and/or "INT2", the accelerometer's
>> + interrupt line in use.
>> +
>> Example:
>>
>> mma8453fc@1d {
>> @@ -21,4 +26,5 @@ Example:
>> reg = <0x1d>;
>> interrupt-parent = <&gpio1>;
>> interrupts = <5 0>;
>> + interrupt-names = "INT2";
>> };
>> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
>> index 1eccc2d..116a6e4 100644
>> --- a/drivers/iio/accel/mma8452.c
>> +++ b/drivers/iio/accel/mma8452.c
>> @@ -29,6 +29,7 @@
>> #include <linux/iio/events.h>
>> #include <linux/delay.h>
>> #include <linux/of_device.h>
>> +#include <linux/of_irq.h>
>>
>> #define MMA8452_STATUS 0x00
>> #define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
>> @@ -1130,13 +1131,21 @@ static int mma8452_probe(struct i2c_client *client,
>> MMA8452_INT_FF_MT;
>> int enabled_interrupts = MMA8452_INT_TRANS |
>> MMA8452_INT_FF_MT;
>> + int irq2;
>>
>> - /* Assume wired to INT1 pin */
>> - ret = i2c_smbus_write_byte_data(client,
>> - MMA8452_CTRL_REG5,
>> - supported_interrupts);
>> - if (ret < 0)
>> - return ret;
>> + irq2 = of_irq_get_byname(client->dev.of_node, "INT2");
>> +
>> + if (irq2 == client->irq) {
>> + dev_dbg(&client->dev, "using interrupt line INT2\n");
>> + } else {
>> + ret = i2c_smbus_write_byte_data(client,
>> + MMA8452_CTRL_REG5,
>> + supported_interrupts);
>> + if (ret < 0)
>> + return ret;
>> +
>> + dev_dbg(&client->dev, "using interrupt line INT1\n");
>> + }
>>
>> ret = i2c_smbus_write_byte_data(client,
>> MMA8452_CTRL_REG4,
>>
>
> This works fine and would be convenient to have. Any objections?
>
> thanks
> martin

yes, no, maybe?

thanks
martin


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