Hi Linus,
I'm not convinced about this one. If we declare sensors output as open drain,
interrupt can be shared (as you also say).
So, the irq management function should first check source registers if
interrupt is really generated by sensor or not.
Denis
On Friday, November 13, 2015 09:18:35 PM 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>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> 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 |
> 9 +++++++++ drivers/iio/gyro/st_gyro_core.c | 12
> ++++++++++++ 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 ++
> 8 files changed, 68 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/st-sensors.txt
> b/Documentation/devicetree/bindings/iio/st-sensors.txt index
> d3ccdb190c53..4ac20cb2ae8d 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.
>
> 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 1132224cbc10..888682b95693 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
> @@ -366,6 +370,8 @@ 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,
> },
> .multi_read_bit = ST_ACCEL_2_MULTIREAD_BIT,
> .bootime = 2,
> @@ -552,6 +558,8 @@ 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,
> },
> .multi_read_bit = ST_ACCEL_5_MULTIREAD_BIT,
> .bootime = 2, /* guess */
> diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c
> b/drivers/iio/common/st_sensors/st_sensors_core.c index
> ed6f54d5c932..bff469dd9583 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_core.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_core.c
> @@ -302,6 +302,14 @@ 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;
> }
>
> @@ -322,6 +330,8 @@ 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
> @@ -375,6 +385,16 @@ 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");
> + 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
> cb53d14aca94..4283468fd502 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c
> @@ -67,6 +67,15 @@ 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.
> + */
> + if (sdata->int_pin_open_drain)
> + irq_trig |= IRQF_SHARED;
> +
> err = request_any_context_irq(irq,
> iio_trigger_generic_data_rdy_poll,
> irq_trig,
> diff --git a/drivers/iio/gyro/st_gyro_core.c
> b/drivers/iio/gyro/st_gyro_core.c index 260bfe021904..d53622b0e430 100644
> --- a/drivers/iio/gyro/st_gyro_core.c
> +++ b/drivers/iio/gyro/st_gyro_core.c
> @@ -63,6 +63,8 @@
> #define ST_GYRO_1_DRDY_IRQ_INT2_MASK 0x08
> #define ST_GYRO_1_IHL_IRQ_ADDR 0x22
> #define ST_GYRO_1_IHL_IRQ_MASK 0x20
> +#define ST_GYRO_1_OD_IRQ_ADDR 0x22
> +#define ST_GYRO_1_OD_IRQ_MASK 0x10
> #define ST_GYRO_1_MULTIREAD_BIT true
>
> /* CUSTOM VALUES FOR SENSOR 2 */
> @@ -89,6 +91,8 @@
> #define ST_GYRO_2_DRDY_IRQ_INT2_MASK 0x08
> #define ST_GYRO_2_IHL_IRQ_ADDR 0x22
> #define ST_GYRO_2_IHL_IRQ_MASK 0x20
> +#define ST_GYRO_2_OD_IRQ_ADDR 0x22
> +#define ST_GYRO_2_OD_IRQ_MASK 0x10
> #define ST_GYRO_2_MULTIREAD_BIT true
>
> /* CUSTOM VALUES FOR SENSOR 3 */
> @@ -115,6 +119,8 @@
> #define ST_GYRO_3_DRDY_IRQ_INT2_MASK 0x08
> #define ST_GYRO_3_IHL_IRQ_ADDR 0x22
> #define ST_GYRO_3_IHL_IRQ_MASK 0x20
> +#define ST_GYRO_3_OD_IRQ_ADDR 0x22
> +#define ST_GYRO_3_OD_IRQ_MASK 0x10
> #define ST_GYRO_3_MULTIREAD_BIT true
>
>
> @@ -193,6 +199,8 @@ static const struct st_sensor_settings
> st_gyro_sensors_settings[] = { .mask_int2 = ST_GYRO_1_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_GYRO_1_IHL_IRQ_ADDR,
> .mask_ihl = ST_GYRO_1_IHL_IRQ_MASK,
> + .addr_od = ST_GYRO_1_OD_IRQ_ADDR,
> + .mask_od = ST_GYRO_1_OD_IRQ_MASK,
> },
> .multi_read_bit = ST_GYRO_1_MULTIREAD_BIT,
> .bootime = 2,
> @@ -258,6 +266,8 @@ static const struct st_sensor_settings
> st_gyro_sensors_settings[] = { .mask_int2 = ST_GYRO_2_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_GYRO_2_IHL_IRQ_ADDR,
> .mask_ihl = ST_GYRO_2_IHL_IRQ_MASK,
> + .addr_od = ST_GYRO_2_OD_IRQ_ADDR,
> + .mask_od = ST_GYRO_2_OD_IRQ_MASK,
> },
> .multi_read_bit = ST_GYRO_2_MULTIREAD_BIT,
> .bootime = 2,
> @@ -319,6 +329,8 @@ static const struct st_sensor_settings
> st_gyro_sensors_settings[] = { .mask_int2 = ST_GYRO_3_DRDY_IRQ_INT2_MASK,
> .addr_ihl = ST_GYRO_3_IHL_IRQ_ADDR,
> .mask_ihl = ST_GYRO_3_IHL_IRQ_MASK,
> + .addr_od = ST_GYRO_3_OD_IRQ_ADDR,
> + .mask_od = ST_GYRO_3_OD_IRQ_MASK,
> },
> .multi_read_bit = ST_GYRO_3_MULTIREAD_BIT,
> .bootime = 2,
> diff --git a/drivers/iio/pressure/st_pressure_core.c
> b/drivers/iio/pressure/st_pressure_core.c index 172393ad34af..38186288f79c
> 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,
> },
> .multi_read_bit = ST_PRESS_LPS331AP_MULTIREAD_BIT,
> .bootime = 2,
> @@ -312,6 +318,8 @@ 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,
> },
> .multi_read_bit = ST_PRESS_LPS25H_MULTIREAD_BIT,
> .bootime = 2,
> diff --git a/include/linux/iio/common/st_sensors.h
> b/include/linux/iio/common/st_sensors.h index 6670c3d25c58..8972101224d9
> 100644
> --- a/include/linux/iio/common/st_sensors.h
> +++ b/include/linux/iio/common/st_sensors.h
> @@ -121,6 +121,8 @@ 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.
> * struct ig1 - represents the Interrupt Generator 1 of sensors.
> * @en_addr: address of the enable ig1 register.
> * @en_mask: mask to write the on/off value for enable.
> @@ -131,6 +133,8 @@ struct st_sensor_data_ready_irq {
> u8 mask_int2;
> u8 addr_ihl;
> u8 mask_ihl;
> + u8 addr_od;
> + u8 mask_od;
> struct {
> u8 en_addr;
> u8 en_mask;
> @@ -212,6 +216,7 @@ 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.
> @@ -233,6 +238,7 @@ 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 */
> --
> 2.4.3
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