cpu/cc2538: fix build errors when UART1 or the 32 kHz crystal is enabled

[hexluthor]

4780b5c introduced a couple of build errors that aren't apparent unless UART_1_EN=1 or SYS_CTRL_OSC32K_USE_XTAL=1. This patch fixes both.

[OlegHahm]

Oops, sorry!

[kYc0o]

let's test this tomorrow ;-)

[OlegHahm]

Did you?

[kYc0o]

I'm on it ;)

[kYc0o]

On which hardware did you tested? I'm trying with cc2538dk and remote without success...

[hexluthor]

@kYc0o I tested this on a custom PCB (similar to cc2538dk, but with two dedicated UARTs). But the patch is intended primarily to fix a compile-time issue. Please try the following.

Test 1

Modify boards/cc2538dk/include/periph_conf.h:

#define UART_NUMOF    2
#define UART_1_EN     1
#define UART_1_TX_PIN GPIO_UNDEF
#define UART_1_RX_PIN GPIO_UNDEF

Then

git checkout a553fe0^
make -C examples/default BOARD=cc2538dk clean all

This build fails.

git checkout a553fe0
make -C examples/default BOARD=cc2538dk clean all

This build succeeds.

Test 2

Add CFLAGS += -DSYS_CTRL_OSC32K_USE_XTAL=1 to examples/default/Makefile, then:

git checkout a553fe0^
make -C examples/default BOARD=cc2538dk clean all

This build fails.

git checkout a553fe0
make -C examples/default BOARD=cc2538dk clean all

This build succeeds.

[haukepetersen]

@kYc0o: are you still on it?

[kYc0o]

Ok yeah, sorry for the delay I forgot it... I'll test this now

[kYc0o]

Tests succeed. There's a small error on the board's definition but I'll PR it afterwards. So ACK and since Murdock is ok we can merge it ASAP. @haukepetersen everything's ok for you too?

[kYc0o]

Murdock and Travis are OK -> GO!

[miri64]

Needs backport.