Add lock protection from race conditions to the 104-quad-8 counter
driver for filter clock prescaler code changes. Mutex calls used for
protection.

Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Fixes: de65d0556343 ("counter: 104-quad-8: Support Filter Clock Prescaler")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add lock protection from race conditions to 104-quad-8 counter driver
for differential encoder status code changes. Mutex lock calls used for
protection.

Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Fixes: 954ab5cc5f3e ("counter: 104-quad-8: Support Differential Encoder Cable Status")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add lock protection from race conditions to 104-quad-8 counter driver
generic interface code changes. Mutex calls used for protection.

Fixes: f1d8a071d45b ("counter: 104-quad-8: Add Generic Counter interface support")

Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The ACCES 104-QUAD-8 series provides status information about the
connection state of the differential encoder cable inputs. This patch
implements support to expose such information from these devices.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The ACCES 104-QUAD-8 series does active filtering on the quadrature
input signals via the PC/104 bus clock (OSC 14.318 MHz). This patch
exposes the filter clock prescaler available on each channel.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The stm32-timer-cnt driver doesn't use the iio interface. The iio headers
aren't relevant and can be removed as reported by William in [1].
With this change, mod_devicetable.h needs to be added to define the
'of_device_id' struct.

[1] https://lkml.org/lkml/2020/2/10/1516

Reported-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add suspend/resume PM sleep ops. When going to low power, enforce the
counter isn't active. Gracefully restore its state upon resume in case
it's been left enabled prior to suspend.

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The count_read and count_write callbacks are simplified to pass val as
unsigned long rather than as an opaque data structure. The opaque
counter_count_read_value and counter_count_write_value structures,
counter_count_value_type enum, and relevant counter_count_read_value_set
and counter_count_write_value_get functions, are removed as they are no
longer used.

Cc: Patrick Havelange <patrick.havelange@essensium.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Immutable branch being merged in.  Created as this also involves
moving some dependencies around, outside of the counter subsystem.
It's possible it will want to be pulled into other trees.

This adds a new counter driver for the Texas Instruments Enhanced
Quadrature Encoder Pulse (eQEP) module.

Only very basic functionality is currently implemented - only enough to
be able to read the position. The actual device has many more features
which can be added to the driver on an as-needed basis.

It is not possible to read the QEPA/B signal values in hardware, so
that feature is omitted.

The TI_PWMSS kernel option is selected in Kconfig to enable the parent
bus, which is needed for power management.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>