This message isn't an error (there can be a watchdog subnode for example)
but it shouldn't be printed unless this driver is being debugged. Demote
it to a debug print.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

The pmic_reg_read() function can return errors.  Add a check for that.

Fixes: 4e8aa0065d4b ("button: qcom-pmic: introduce Qualcomm PMIC button driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

Qualcomm PMICs include a "pon" function which handles two buttons, the
power button and "resin" button (usually volume down). Introduce a new
driver following upstream Linux DT to enable these and map them to Enter
and Down respectively to enable use in boot menus.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>