On 24/03/16 13:18, Linus Walleij wrote:
> Some types of ST Sensors can be connected to the same IRQ line
> as other peripherals using open drain. Add a device tree binding
> and a sensor data property to flip the right bit in the interrupt
> control register to enable open drain mode on the INT line.
>
> If the line is set to be open drain, also tag on IRQF_SHARED
> to the IRQ flags when requesting the interrupt, as the whole
> point of using open drain interrupt lines is to share them with
> more than one peripheral (wire-or).
>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: Giuseppe Barba <giuseppe.barba@xxxxxx>
> Cc: Denis Ciocca <denis.ciocca@xxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Few comments inline but looks fine to me. Ideally again an
ack from Denis would be good. Mostly this one is stalled behind the earlier
ones.
Jonathan
> ---
> ChangeLog v2->v3:
> - Rebase on top of the patches fixing the other issues (handling
> IRQ status check and channel reading bug).
> ChangeLog v1->v2:
> - Rebased to fit the new patch order.
> ---
> Documentation/devicetree/bindings/iio/st-sensors.txt | 3 +++
> drivers/iio/accel/st_accel_core.c | 8 ++++++++
> drivers/iio/common/st_sensors/st_sensors_core.c | 20 ++++++++++++++++++++
> drivers/iio/common/st_sensors/st_sensors_trigger.c | 13 +++++++++++++
> drivers/iio/pressure/st_pressure_core.c | 8 ++++++++
> include/linux/iio/common/st_sensors.h | 6 ++++++
> include/linux/platform_data/st_sensors_pdata.h | 2 ++
> 7 files changed, 60 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/st-sensors.txt b/Documentation/devicetree/bindings/iio/st-sensors.txt
> index d4b87cc1e446..accb5681fbbb 100644
> --- a/Documentation/devicetree/bindings/iio/st-sensors.txt
> +++ b/Documentation/devicetree/bindings/iio/st-sensors.txt
> @@ -16,6 +16,9 @@ Optional properties:
> - st,drdy-int-pin: the pin on the package that will be used to signal
> "data ready" (valid values: 1 or 2). This property is not configurable
> on all sensors.
> +- st,int-pin-open-drain: the interrupt/data ready line will be configured
> + as open drain, which is useful if several sensors share the same
> + interrupt line.
Really feels like this one ought to be more generic.. Mind you so does
drdy-int-pin!
Hmm. Looks like most open drain controls are chip specific - other than
your pinctrl ones and that doesn't really map to here I guess.
>
> Sensors may also have applicable pin control settings, those use the
> standard bindings from pinctrl/pinctrl-bindings.txt.
> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
> index 4df4c278af23..f06f4329db5b 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -96,6 +96,8 @@
> #define ST_ACCEL_2_DRDY_IRQ_INT2_MASK 0x10
> #define ST_ACCEL_2_IHL_IRQ_ADDR 0x22
> #define ST_ACCEL_2_IHL_IRQ_MASK 0x80
> +#define ST_ACCEL_2_OD_IRQ_ADDR 0x22
> +#define ST_ACCEL_2_OD_IRQ_MASK 0x40
> #define ST_ACCEL_2_MULTIREAD_BIT true
>
> /* CUSTOM VALUES FOR SENSOR 3 */
> @@ -177,6 +179,8 @@
> #define ST_ACCEL_5_DRDY_IRQ_INT2_MASK 0x20
> #define ST_ACCEL_5_IHL_IRQ_ADDR 0x22
> #define ST_ACCEL_5_IHL_IRQ_MASK 0x80
> +#define ST_ACCEL_5_OD_IRQ_ADDR 0x22
> +#define ST_ACCEL_5_OD_IRQ_MASK 0x40
> #define ST_ACCEL_5_IG1_EN_ADDR 0x21
> #define ST_ACCEL_5_IG1_EN_MASK 0x08
> #define ST_ACCEL_5_MULTIREAD_BIT false
> @@ -368,6 +372,8 @@ static const struct st_sensor_settings st_accel_sensors_settings[] = {
> .mask_int2 = ST_ACCEL_2_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_ACCEL_2_IHL_IRQ_ADDR,
> .mask_ihl = ST_ACCEL_2_IHL_IRQ_MASK,
> + .addr_od = ST_ACCEL_2_OD_IRQ_ADDR,
> + .mask_od = ST_ACCEL_2_OD_IRQ_MASK,
> .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
> },
> .multi_read_bit = ST_ACCEL_2_MULTIREAD_BIT,
> @@ -557,6 +563,8 @@ static const struct st_sensor_settings st_accel_sensors_settings[] = {
> .mask_int2 = ST_ACCEL_5_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_ACCEL_5_IHL_IRQ_ADDR,
> .mask_ihl = ST_ACCEL_5_IHL_IRQ_MASK,
> + .addr_od = ST_ACCEL_5_OD_IRQ_ADDR,
> + .mask_od = ST_ACCEL_5_OD_IRQ_MASK,
> .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
> },
> .multi_read_bit = ST_ACCEL_5_MULTIREAD_BIT,
> diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
> index f5a2d445d0c0..2e03c1220d1f 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_core.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_core.c
> @@ -301,6 +301,14 @@ static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> + if (pdata->open_drain) {
> + if (!sdata->sensor_settings->drdy_irq.addr_od)
> + dev_err(&indio_dev->dev,
> + "open drain requested but unsupported.\n");
> + else
> + sdata->int_pin_open_drain = true;
> + }
> +
> return 0;
> }
>
> @@ -321,6 +329,8 @@ static struct st_sensors_platform_data *st_sensors_of_probe(struct device *dev,
> else
> pdata->drdy_int_pin = defdata ? defdata->drdy_int_pin : 0;
>
> + pdata->open_drain = of_property_read_bool(np, "st,int-pin-open-drain");
> +
> return pdata;
> }
> #else
> @@ -374,6 +384,16 @@ int st_sensors_init_sensor(struct iio_dev *indio_dev,
> return err;
> }
>
> + if (sdata->int_pin_open_drain) {
> + dev_info(&indio_dev->dev,
> + "set interrupt line to open drain mode\n");
Hmm. Curriously I have a board with an lis3l02dq on it where the interrupt
is shared, but doesn't explicitly support open drain. In that case it
is done with some external circuitry.
Anyhow - I guess when I actually add support for that I'll just add a sanity
check in here that addr_od and mask_od are specified :)
> + err = st_sensors_write_data_with_mask(indio_dev,
> + sdata->sensor_settings->drdy_irq.addr_od,
> + sdata->sensor_settings->drdy_irq.mask_od, 1);
> + if (err < 0)
> + return err;
> + }
> +
> err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
>
> return err;
> diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c
> index 6a8c98327945..da72279fcf99 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c
> @@ -64,6 +64,19 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
> "rising edge\n", irq_trig);
> irq_trig = IRQF_TRIGGER_RISING;
> }
> +
> + /*
> + * If the interrupt pin is Open Drain, by definition this
> + * means that the interrupt line may be shared with other
> + * peripherals. But to do this we also need to have a status
> + * register and mask to figure out if this sensor was firing
> + * the IRQ or not, so we can tell the interrupt handle that
> + * it was "our" interrupt.
> + */
> + if (sdata->int_pin_open_drain &&
> + sdata->sensor_settings->drdy_irq.addr_stat_drdy)
> + irq_trig |= IRQF_SHARED;
> +
> err = request_threaded_irq(irq,
> iio_trigger_generic_data_rdy_poll,
> NULL,
> diff --git a/drivers/iio/pressure/st_pressure_core.c b/drivers/iio/pressure/st_pressure_core.c
> index 1cd37eaa4a57..9e9b72a8f18f 100644
> --- a/drivers/iio/pressure/st_pressure_core.c
> +++ b/drivers/iio/pressure/st_pressure_core.c
> @@ -64,6 +64,8 @@
> #define ST_PRESS_LPS331AP_DRDY_IRQ_INT2_MASK 0x20
> #define ST_PRESS_LPS331AP_IHL_IRQ_ADDR 0x22
> #define ST_PRESS_LPS331AP_IHL_IRQ_MASK 0x80
> +#define ST_PRESS_LPS331AP_OD_IRQ_ADDR 0x22
> +#define ST_PRESS_LPS331AP_OD_IRQ_MASK 0x40
> #define ST_PRESS_LPS331AP_MULTIREAD_BIT true
> #define ST_PRESS_LPS331AP_TEMP_OFFSET 42500
>
> @@ -104,6 +106,8 @@
> #define ST_PRESS_LPS25H_DRDY_IRQ_INT2_MASK 0x10
> #define ST_PRESS_LPS25H_IHL_IRQ_ADDR 0x22
> #define ST_PRESS_LPS25H_IHL_IRQ_MASK 0x80
> +#define ST_PRESS_LPS25H_OD_IRQ_ADDR 0x22
> +#define ST_PRESS_LPS25H_OD_IRQ_MASK 0x40
> #define ST_PRESS_LPS25H_MULTIREAD_BIT true
> #define ST_PRESS_LPS25H_TEMP_OFFSET 42500
> #define ST_PRESS_LPS25H_OUT_XL_ADDR 0x28
> @@ -226,6 +230,8 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
> .mask_int2 = ST_PRESS_LPS331AP_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_PRESS_LPS331AP_IHL_IRQ_ADDR,
> .mask_ihl = ST_PRESS_LPS331AP_IHL_IRQ_MASK,
> + .addr_od = ST_PRESS_LPS331AP_OD_IRQ_ADDR,
> + .mask_od = ST_PRESS_LPS331AP_OD_IRQ_MASK,
> .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
> },
> .multi_read_bit = ST_PRESS_LPS331AP_MULTIREAD_BIT,
> @@ -313,6 +319,8 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
> .mask_int2 = ST_PRESS_LPS25H_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_PRESS_LPS25H_IHL_IRQ_ADDR,
> .mask_ihl = ST_PRESS_LPS25H_IHL_IRQ_MASK,
> + .addr_od = ST_PRESS_LPS25H_OD_IRQ_ADDR,
> + .mask_od = ST_PRESS_LPS25H_OD_IRQ_MASK,
> .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
> },
> .multi_read_bit = ST_PRESS_LPS25H_MULTIREAD_BIT,
> diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h
> index d8da075bfda0..d029ffac0d69 100644
> --- a/include/linux/iio/common/st_sensors.h
> +++ b/include/linux/iio/common/st_sensors.h
> @@ -122,6 +122,8 @@ struct st_sensor_bdu {
> * @mask_int2: mask to enable/disable IRQ on INT2 pin.
> * @addr_ihl: address to enable/disable active low on the INT lines.
> * @mask_ihl: mask to enable/disable active low on the INT lines.
> + * @addr_od: address to enable/disable Open Drain on the INT lines.
> + * @mask_od: mask to enable/disable Open Drain on the INT lines.
> * @addr_stat_drdy: address to read status of DRDY (data ready) interrupt
> * struct ig1 - represents the Interrupt Generator 1 of sensors.
> * @en_addr: address of the enable ig1 register.
> @@ -133,6 +135,8 @@ struct st_sensor_data_ready_irq {
> u8 mask_int2;
> u8 addr_ihl;
> u8 mask_ihl;
> + u8 addr_od;
> + u8 mask_od;
> u8 addr_stat_drdy;
> struct {
> u8 en_addr;
> @@ -215,6 +219,7 @@ struct st_sensor_settings {
> * @odr: Output data rate of the sensor [Hz].
> * num_data_channels: Number of data channels used in buffer.
> * @drdy_int_pin: Redirect DRDY on pin 1 (1) or pin 2 (2).
> + * @int_pin_open_drain: Set the interrupt/DRDY to open drain.
> * @get_irq_data_ready: Function to get the IRQ used for data ready signal.
> * @tf: Transfer function structure used by I/O operations.
> * @tb: Transfer buffers and mutex used by I/O operations.
> @@ -236,6 +241,7 @@ struct st_sensor_data {
> unsigned int num_data_channels;
>
> u8 drdy_int_pin;
> + bool int_pin_open_drain;
>
> unsigned int (*get_irq_data_ready) (struct iio_dev *indio_dev);
>
> diff --git a/include/linux/platform_data/st_sensors_pdata.h b/include/linux/platform_data/st_sensors_pdata.h
> index 753839187ba0..79b0e4cdb814 100644
> --- a/include/linux/platform_data/st_sensors_pdata.h
> +++ b/include/linux/platform_data/st_sensors_pdata.h
> @@ -16,9 +16,11 @@
> * @drdy_int_pin: Redirect DRDY on pin 1 (1) or pin 2 (2).
> * Available only for accelerometer and pressure sensors.
> * Accelerometer DRDY on LSM330 available only on pin 1 (see datasheet).
> + * @open_drain: set the interrupt line to be open drain if possible.
> */
> struct st_sensors_platform_data {
> u8 drdy_int_pin;
> + bool open_drain;
> };
>
> #endif /* ST_SENSORS_PDATA_H */
>
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