[U-Boot] [PATCH] include/ns16550.h: Unify structure declaration for registers

[Detlev Zundel]

Instead of special casing the different access patterns, use common
code with light macros sprinkled in to accomodate for the different
layouts of the register structure.

Note that this also changes the types of the registers for the
"positively packed (>1)" cases.  As the registers truly are unsigned
chars, this is surely the Right Thing, but it is a semantic change.
Note that for this case depending on the endianness on the bus, we may
see a change of behaviour.

Signed-off-by: Detlev Zundel <dzu at denx.de>
---
 include/ns16550.h |  130 +++++++++++++++--------------------------------------
 1 files changed, 37 insertions(+), 93 deletions(-)


Note, that I checked that the offsets are ok in the used cases
switching from the old to the new code.  They *do* shift however in
the positive packed cases, because the old code uses data types
different than unsigned char.  Note that doing this, I also noticed
that using "unsigned long" for 4 byte registers is also no longer true
on 64-bit architectures.  One more reason to change the code.

Apart from that the code was also compile tested on several
configurations using different REG_SIZES and compiles without
warnings.  The special interesting case of +4 was successfully tested
on CU824.



diff --git a/include/ns16550.h b/include/ns16550.h
index 87624bf..ce606b5 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -16,102 +16,46 @@
  * by Richard Danter (richard.danter at windriver.com), (C) 2005 Wind River Systems
  */
 
-#if (CONFIG_SYS_NS16550_REG_SIZE == 1)
-struct NS16550 {
-	unsigned char rbr;		/* 0 */
-	unsigned char ier;		/* 1 */
-	unsigned char fcr;		/* 2 */
-	unsigned char lcr;		/* 3 */
-	unsigned char mcr;		/* 4 */
-	unsigned char lsr;		/* 5 */
-	unsigned char msr;		/* 6 */
-	unsigned char scr;		/* 7 */
-#if defined(CONFIG_OMAP730)
-	unsigned char mdr1;		/* 8 */
-	unsigned char reg9;		/* 9 */
-	unsigned char regA;		/* A */
-	unsigned char regB;		/* B */
-	unsigned char regC;		/* C */
-	unsigned char regD;		/* D */
-	unsigned char regE;		/* E */
-	unsigned char regF;		/* F */
-	unsigned char reg10;		/* 10 */
-	unsigned char ssr;		/* 11*/
-#endif
-} __attribute__ ((packed));
-#elif (CONFIG_SYS_NS16550_REG_SIZE == 2)
-struct NS16550 {
-	unsigned short rbr;		/* 0 */
-	unsigned short ier;		/* 1 */
-	unsigned short fcr;		/* 2 */
-	unsigned short lcr;		/* 3 */
-	unsigned short mcr;		/* 4 */
-	unsigned short lsr;		/* 5 */
-	unsigned short msr;		/* 6 */
-	unsigned short scr;		/* 7 */
-} __attribute__ ((packed));
-#elif (CONFIG_SYS_NS16550_REG_SIZE == 4)
-struct NS16550 {
-	unsigned long rbr;		/* 0 r  */
-	unsigned long ier;		/* 1 rw */
-	unsigned long fcr;		/* 2 w  */
-	unsigned long lcr;		/* 3 rw */
-	unsigned long mcr;		/* 4 rw */
-	unsigned long lsr;		/* 5 r  */
-	unsigned long msr;		/* 6 r  */
-	unsigned long scr;		/* 7 rw */
-}; /* No need to pack an already aligned struct */
-#elif (CONFIG_SYS_NS16550_REG_SIZE == -4)
-struct NS16550 {
-	unsigned char rbr;		/* 0 */
-	int pad1:24;
-	unsigned char ier;		/* 1 */
-	int pad2:24;
-	unsigned char fcr;		/* 2 */
-	int pad3:24;
-	unsigned char lcr;		/* 3 */
-	int pad4:24;
-	unsigned char mcr;		/* 4 */
-	int pad5:24;
-	unsigned char lsr;		/* 5 */
-	int pad6:24;
-	unsigned char msr;		/* 6 */
-	int pad7:24;
-	unsigned char scr;		/* 7 */
-	int pad8:24;
-#if defined(CONFIG_OMAP)
-	unsigned char mdr1;		/* mode select reset TL16C750*/
-#endif
-#ifdef CONFIG_OMAP1510
-	int pad9:24;
-	unsigned long pad[10];
-	unsigned char osc_12m_sel;
-	int pad10:24;
-#endif
-} __attribute__ ((packed));
-#elif (CONFIG_SYS_NS16550_REG_SIZE == -8)
-struct NS16550 {
-	unsigned char rbr;		/* 0 */
-	unsigned char pad0[7];
-	unsigned char ier;		/* 1 */
-	unsigned char pad1[7];
-	unsigned char fcr;		/* 2 */
-	unsigned char pad2[7];
-	unsigned char lcr;		/* 3 */
-	unsigned char pad3[7];
-	unsigned char mcr;		/* 4 */
-	unsigned char pad4[7];
-	unsigned char lsr;		/* 5 */
-	unsigned char pad5[7];
-	unsigned char msr;		/* 6 */
-	unsigned char pad6[7];
-	unsigned char scr;		/* 7 */
-	unsigned char pad7[7];
-} __attribute__ ((packed));
-#else
+/*
+ * Note that the following macro magic uses the fact that the compiler
+ * will not allocate storage for arrays of size 0
+ */
+
+#if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
 #error "Please define NS16550 registers size."
+#elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
+#define UART_REG(x)						   \
+	unsigned char prepad_##x[CONFIG_SYS_NS16550_REG_SIZE - 1]; \
+	unsigned char x;
+#elif (CONFIG_SYS_NS16550_REG_SIZE < 0)
+#define UART_REG(x)							\
+	unsigned char x;						\
+	unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1];
 #endif
 
+struct NS16550 {
+	UART_REG(rbr);		/* 0 */
+	UART_REG(ier);		/* 1 */
+	UART_REG(fcr);		/* 2 */
+	UART_REG(lcr);		/* 3 */
+	UART_REG(mcr);		/* 4 */
+	UART_REG(lsr);		/* 5 */
+	UART_REG(msr);		/* 6 */
+	UART_REG(spr);		/* 7 */
+	UART_REG(mdr1);		/* 8 */
+	UART_REG(reg9);		/* 9 */
+	UART_REG(regA);		/* A */
+	UART_REG(regB);		/* B */
+	UART_REG(regC);		/* C */
+	UART_REG(regD);		/* D */
+	UART_REG(regE);		/* E */
+	UART_REG(uasr);		/* F */
+	UART_REG(scr);		/* 10*/
+	UART_REG(ssr);		/* 11*/
+	UART_REG(reg12);	/* 12*/
+	UART_REG(osc_12m_sel);	/* 13*/
+};
+
 #define thr rbr
 #define iir fcr
 #define dll rbr
-- 
1.6.0.6