readl_poll_timeout() calls usleep_range(), but
regmap_atmel_hlcdc_reg_write() is called in atomic context (regmap
spinlock held).

Replace the readl_poll_timeout() call by readl_poll_timeout_atomic().

Cc: <stable@vger.kernel.org>
Fixes: ea31c0cf ("mfd: atmel-hlcdc: Implement config synchronization")
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Use devm_mfd_add_devices() for MFD devices registration and get
rid of .remove callback to remove MFD child-devices. This is done
by managed device framework.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Add the compatible strings for the at91sam9x5, at91sam9n12, sama5d4 and
sama5d2 SoCs.
Update the documentation accordingly.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Some HLCDC registers cannot be written until the hardware has finished
applying the previous configuration request. If they are written while
an action is still in progress, the new configuration might be silently
ignored, resulting in unpredictable behavior.

Hide the config synchronization stuff in a regmap implementation and use
this implementation instead of the generic mmio one.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

The HLCDC IP available on some Atmel SoCs (i.e. at91sam9n12, at91sam9x5
family or sama5d3 family) exposes 2 subdevices:
- a display controller (controlled by a DRM driver)
- a PWM chip

The MFD device provides a regmap and several clocks (those connected
to this hardware block) to its subdevices.

This way concurrent accesses to the iomem range are handled by the regmap
framework, and each subdevice can safely access HLCDC registers.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NAnthony Harivel <anthony.harivel@emtrion.de>
Tested-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>