[PATCH 2/4] ARM: imx: imx27: Introduce and use UART_BASE_ADDR(n)

[Marek Vasut <marex@denx.de>]

Introduce helper macro UART_BASE_ADDR(n), which returns Nth UART base
address. Convert all board configurations to this new macro. This is the
first step toward switching CONFIG_MXC_UART_BASE to Kconfig. This is a
clean up, no functional change.

The new macro contains compile-time test to verify N is in suitable
range. The test works such that it multiplies constant N by constant
double-negation of size of a non-empty structure, i.e. it multiplies
constant N by constant 1 in each successful compilation case.

The non-empty structure may contain C11 _Static_assert(), make use of
this and place the kernel variant of static assert in there, so that
it performs the compile-time check for N in the correct range. Note
that it is not possible to directly use static_assert in compound
statements, hence this convoluted construct.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
---
 arch/arm/include/asm/arch-mx27/imx-regs.h | 24 +++++++++++++++++------
 include/configs/imx27lite-common.h        |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/arch/arm/include/asm/arch-mx27/imx-regs.h b/arch/arm/include/asm/arch-mx27/imx-regs.h
index d39f6b03508..77794d7d03d 100644
--- a/arch/arm/include/asm/arch-mx27/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx27/imx-regs.h
@@ -179,16 +179,16 @@ struct fuse_bank0_regs {
 #define IMX_TIM2_BASE		(0x04000 + IMX_IO_BASE)
 #define IMX_TIM3_BASE		(0x05000 + IMX_IO_BASE)
 #define IMX_RTC_BASE		(0x07000 + IMX_IO_BASE)
-#define UART1_BASE		(0x0a000 + IMX_IO_BASE)
-#define UART2_BASE		(0x0b000 + IMX_IO_BASE)
-#define UART3_BASE		(0x0c000 + IMX_IO_BASE)
-#define UART4_BASE		(0x0d000 + IMX_IO_BASE)
+#define UART1_BASE_ADDR		(0x0a000 + IMX_IO_BASE)
+#define UART2_BASE_ADDR		(0x0b000 + IMX_IO_BASE)
+#define UART3_BASE_ADDR		(0x0c000 + IMX_IO_BASE)
+#define UART4_BASE_ADDR		(0x0d000 + IMX_IO_BASE)
 #define I2C1_BASE_ADDR		(0x12000 + IMX_IO_BASE)
 #define IMX_GPIO_BASE		(0x15000 + IMX_IO_BASE)
 #define IMX_TIM4_BASE		(0x19000 + IMX_IO_BASE)
 #define IMX_TIM5_BASE		(0x1a000 + IMX_IO_BASE)
-#define IMX_UART5_BASE		(0x1b000 + IMX_IO_BASE)
-#define IMX_UART6_BASE		(0x1c000 + IMX_IO_BASE)
+#define UART5_BASE_ADDR		(0x1b000 + IMX_IO_BASE)
+#define UART6_BASE_ADDR		(0x1c000 + IMX_IO_BASE)
 #define I2C2_BASE_ADDR		(0x1D000 + IMX_IO_BASE)
 #define IMX_TIM6_BASE		(0x1f000 + IMX_IO_BASE)
 #define IMX_AIPI2_BASE		(0x20000 + IMX_IO_BASE)
@@ -204,6 +204,18 @@ struct fuse_bank0_regs {
 
 #define NFC_BASE_ADDR		IMX_NFC_BASE
 
+#define UART_BASE_ADDR(n)	(			\
+	!!sizeof(struct {				\
+		static_assert((n) >= 1 && (n) <= 6);	\
+		int pad;				\
+		}) * (					\
+	(n) == 1 ? UART1_BASE_ADDR :			\
+	(n) == 2 ? UART2_BASE_ADDR :			\
+	(n) == 3 ? UART3_BASE_ADDR :			\
+	(n) == 4 ? UART4_BASE_ADDR :			\
+	(n) == 5 ? UART5_BASE_ADDR :			\
+	UART6_BASE_ADDR)				\
+	)
 
 /* FMCR System Control bit definition*/
 #define UART4_RXD_CTL	(1 << 25)
diff --git a/include/configs/imx27lite-common.h b/include/configs/imx27lite-common.h
index bb53a33a542..6790053bb8d 100644
--- a/include/configs/imx27lite-common.h
+++ b/include/configs/imx27lite-common.h
@@ -70,7 +70,7 @@
 /*
  * Serial Driver info
  */
-#define CONFIG_MXC_UART_BASE	UART1_BASE
+#define CONFIG_MXC_UART_BASE	UART_BASE_ADDR(1)
 
 /*
  * Flash & Environment
-- 
2.35.1