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authorLinus Walleij <linus.walleij@linaro.org>2016-03-24 16:18:05 +0300
committerJonathan Cameron <jic23@kernel.org>2016-04-19 21:58:12 +0300
commit97865fe41322d83dac4373fe0a0de5b1a1b318c5 (patch)
tree6d14571a7fed1c01d8e6ed74d5817aa5edd6b5d0 /drivers/iio/common/st_sensors
parent6436db37b4a5da1ae1f381e4791e17e2236fd276 (diff)
downloadlinux-97865fe41322d83dac4373fe0a0de5b1a1b318c5.tar.xz
iio: st_sensors: verify interrupt event to status
This makes all ST sensor drivers check that they actually have new data available for the requested channel(s) before claiming an IRQ, by reading the status register (which is conveniently the same for all ST sensors) and check that the channel has new data before proceeding to read it and fill the buffer. This way sensors can share an interrupt line: it can be flaged as shared and then the sensor that did not fire will return NO_IRQ, and the sensor that fired will handle the IRQ and return IRQ_HANDLED. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/common/st_sensors')
-rw-r--r--drivers/iio/common/st_sensors/st_sensors_buffer.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
index 2ce0d2a3f855..c55898543a47 100644
--- a/drivers/iio/common/st_sensors/st_sensors_buffer.c
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -58,6 +58,24 @@ irqreturn_t st_sensors_trigger_handler(int irq, void *p)
struct iio_dev *indio_dev = pf->indio_dev;
struct st_sensor_data *sdata = iio_priv(indio_dev);
+ /* If we have a status register, check if this IRQ came from us */
+ if (sdata->sensor_settings->drdy_irq.addr_stat_drdy) {
+ u8 status;
+
+ len = sdata->tf->read_byte(&sdata->tb, sdata->dev,
+ sdata->sensor_settings->drdy_irq.addr_stat_drdy,
+ &status);
+ if (len < 0)
+ dev_err(sdata->dev, "could not read channel status\n");
+
+ /*
+ * If this was not caused by any channels on this sensor,
+ * return IRQ_NONE
+ */
+ if (!(status & (u8)indio_dev->active_scan_mask[0]))
+ return IRQ_NONE;
+ }
+
len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
if (len < 0)
goto st_sensors_get_buffer_element_error;