[U-Boot] [PATCH] ARC: HSDK: introduce CREG GPIO driver

[Alexey Brodkin <Alexey.Brodkin@synopsys.com>]

Hi Eugeniy,

On Fri, 2017-10-13 at 16:21 +0300, Eugeniy Paltsev wrote:
> The HSDK can manage some pins via CREG registers block.
> 
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> ---
>  MAINTAINERS                   |   6 +++
>  drivers/gpio/Kconfig          |   7 +++
>  drivers/gpio/Makefile         |   1 +
>  drivers/gpio/hsdk-creg-gpio.c | 109 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 123 insertions(+)
>  create mode 100644 drivers/gpio/hsdk-creg-gpio.c

I've got this one applied on top of today's upstream master and with
enabled HSDK GPIO driver I'm seeing this build failure:
------------------------------>8-----------------------------
  LD      cmd/built-in.o
drivers/gpio/hsdk-creg-gpio.c: In function ‘hsdk_creg_gpio_direction_input’:
drivers/gpio/hsdk-creg-gpio.c:55:2: warning: implicit declaration of function ‘error’ [-Wimplicit-function-declaration]
  error("hsdk-creg-gpio can't be used as input!\n");
  ^~~~~
  LD      drivers/gpio/built-in.o
  LD      common/built-in.o
make[2]: 'arch/arc/dts/hsdk.dtb' is up to date.
  CC      lib/display_options.o
  LD      lib/built-in.o
  LD      u-boot
drivers/gpio/built-in.o: In function `hsdk_creg_gpio_direction_input':
.../u-boot/drivers/gpio/hsdk-creg-gpio.c:55: undefined reference to `error'
.../u-boot/drivers/gpio/hsdk-creg-gpio.c:55: undefined reference to `error'
Makefile:1256: recipe for target 'u-boot' failed
------------------------------>8-----------------------------

Could you please check what's wrong there and fix it.

-Alexey