mxs-auart: redefine AUART_LINECTRL_WLEN to accept bits count

It's a bit illogical to take magic constants in AUART_LINECTRL_WLEN.
Like in auart_console_get_options(), 2 means 7 bits. Switch
AUART_LINECTRL_WLEN to accept bit length, i.e. let it subtract 5 from
the parameter before doing the logic.

This will ease conversion from CSIZE to bits in mxs_auart_settermios()
in the next patch.

Signed-off-by: Jiri Slaby <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/mxs-auart.c

···
 #define AUART_LINECTRL_BAUD_DIVFRAC(v)		(((v) & 0x3f) << 8)
 #define AUART_LINECTRL_SPS			(1 << 7)
 #define AUART_LINECTRL_WLEN_MASK		0x00000060
-#define AUART_LINECTRL_WLEN(v)			(((v) & 0x3) << 5)
+#define AUART_LINECTRL_WLEN(v)			((((v) - 5) & 0x3) << 5)
 #define AUART_LINECTRL_FEN			(1 << 4)
 #define AUART_LINECTRL_STP2			(1 << 3)
 #define AUART_LINECTRL_EPS			(1 << 2)
···
 	/* byte size */
 	switch (cflag & CSIZE) {
 	case CS5:
-		bm = 0;
+		bm = 5;
 		break;
 	case CS6:
-		bm = 1;
+		bm = 6;
 		break;
 	case CS7:
-		bm = 2;
+		bm = 7;
 		break;
 	case CS8:
-		bm = 3;
+		bm = 8;
 		break;
 	default:
 		return;
···
 			*parity = 'o';
 	}
 
-	if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2))
+	if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(7))
 		*bits = 7;
 	else
 		*bits = 8;