Add NAU7802 ADC driver

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Add nau7802 to dt

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Disable one more ADC
Polling works
Cleanup the mess
gpio: pca953x: fix irq_domain_add_simple usage

We actually have to pass chip as the host_data parameter of
irq_domain_add_simple() as later on, it is used to initialize chip_data
in pca953x_gpio_irq_map(). Failing to do so is leading to a NULL pointer
dereference after calling irq_data_get_irq_chip_data() in
pca953x_irq_mask(), pca953x_irq_unmask(), pca953x_irq_bus_lock(),
pca953x_irq_bus_sync_unlock() and pca953x_irq_set_type().

Fixes regression introduced by commit
0e8f2fdacf1d44651aa7e57063c76142d1f4988b (gpio: pca953x: use simple
irqdomain)

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
ARM: mxs: Slow down the I2C clock speed

Slow down the I2C clock speed on M28 and SPS1 as it turns out the
I2C block in i.MX28 can not operate stable enough with the bus
running at 400kHz. Note that the driver used by Freescale runs
the bus at 250kHz when 400kHz speed is selected, but the mainline
Linux kernel runs the bus at actual 400kHz and that's where it is
occasionally unstable. Play safe and run the bus at 100kHz.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Don't use 400kHZ, it is not working reliably
Debug !
polling is back

almost working but still a lot ot timeouts on the i2c bus