Fix reading trigger mode, when other bit-fields are set. SMCR register
value must be masked to read SMS (slave mode selection) only.

Fixes: 9eba381 ("iio: make stm32 trigger driver use
INDIO_HARDWARE_TRIGGERED mode")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

In order to use encoder mode, timers needs to be enabled (e.g. CEN bit)
along with peripheral clock.
Add IIO_CHAN_INFO_ENABLE attribute to handle this.
Also, in triggered mode, CEN bit is set automatically in hardware.
Then clock must be enabled before starting triggered mode.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Fixes: 4adec7da0536 ("iio: stm32 trigger: Add quadrature encoder device")

This fixes two issues:
- stm32_set_count_direction: to set down direction
- stm32_get_count_direction: to get down direction

IIO core provides/expects value to be an index of iio_enum items array.
This needs to be turned by these routines into TIM_CR1_DIR (e.g. BIT(4))
value.
Also, report error when attempting to write direction, when in encoder
mode: in this case, direction is read only (given by encoder inputs).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Fixes: 4adec7da0536 ("iio: stm32 trigger: Add quadrature encoder device")

IIO core expects zero as return value for write_raw() callback
in case of success.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Fixes: 4adec7da0536 ("iio: stm32 trigger: Add quadrature encoder device")

SMS bitfiled is mode + 1. After reset, upon boot, SMS = 0. When reading
from sysfs, stm32_get_quadrature_mode() returns -1 (e.g. -EPERM) which is
wrong error code here. So, check SMS bitfiled matches valid encoder mode,
or return -EINVAL.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add validate function to be use to use the correct trigger.
Add an attribute to configure device mode like for quadrature and
enable modes

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Add support for TRGO2 trigger that can be found on STM32F7.
Add additional master modes supported by TRGO2.
Register additional "tim[1/8]_trgo2" triggers for timer1 & timer8.
Detect TRGO2 timer capability (master mode selection 2).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Jonathan writes:

Fifth set of IIO fixes for the 4.11 cycle.

As these are rather late in the cycle, they may sneak over into 4.12.
There is a fix for a regression caused by another fix (hid sensors
hardware seems to vary a lot in how various corner cases are handled).

* ad7303
  - fix channel description. Numeric values were being passed as characters
  presumably leading to garbage from the userspace interface.
* as3935
  - the write data macro was wrong so fix it.
* bmp280
  - incorrect handling of negative values as being unsigned broke humidity
  calculation.
* hid-sensor
  - Restore the poll and hysteresis values after resume as some hardware
  doesn't do it.
* stm32-trigger
  - buglet in reading the sampling frequency

Device counting could be controlled by the level or the edges of
a trigger.
in_count0_enable_mode attibute allow to set the control mode.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

One of the features of STM32 trigger hardware block is a quadrature
encoder that can counts up/down depending of the levels and edges
of the selected external pins.

This patch allow to read/write the counter, get it direction,
set/get quadrature modes and get scale factor.

When counting up preset value is the limit of the counter.
When counting down the counter start from preset value down to 0.
This preset value could be set/get by using
/sys/bus/iio/devices/iio:deviceX/in_count0_preset attribute.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>