RS485: fix inconsistencies in the meaning of some variables

The crisv10.c and the atmel_serial.c serial drivers intepret the fields of the
serial_rs485 structure in a different way.

In particular, crisv10.c uses SER_RS485_RTS_AFTER_SEND and
SER_RS485_RTS_ON_SEND for the voltage of the RTS pin; atmel_serial.c,
instead, uses these values to know if a delay must be set before and
after sending.  This patch makes the usage of these variables consistent
across all drivers and fixes the Documentation as well.

From now on, SER_RS485_RTS_AFTER_SEND and SER_RS485_RTS_ON_SEND will be
used to set the voltage of the RTS pin (as in the crisv10.c driver); the
delay will be understood by looking only at the value of
delay_rts_before_send and delay_rts_after_send.

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Darron Black <darron@griffin.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 6 deletions

diff --git a/include/linux/serial.h b/include/linux/serial.h
index 97ff8e27a6cc..3d86517fe7d5 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -207,13 +207,15 @@ struct serial_icounter_struct {
 
 struct serial_rs485 {
         __u32   flags;                  /* RS485 feature flags */
-#define SER_RS485_ENABLED               (1 << 0)
-#define SER_RS485_RTS_ON_SEND           (1 << 1)
-#define SER_RS485_RTS_AFTER_SEND        (1 << 2)
-#define SER_RS485_RTS_BEFORE_SEND       (1 << 3)
+#define SER_RS485_ENABLED               (1 << 0)        /* If enabled */
+#define SER_RS485_RTS_ON_SEND           (1 << 1)        /* Logical level for
+                                                           RTS pin when
+                                                           sending */
+#define SER_RS485_RTS_AFTER_SEND        (1 << 2)        /* Logical level for
+                                                           RTS pin after sent*/
 #define SER_RS485_RX_DURING_TX          (1 << 4)
-        __u32   delay_rts_before_send;  /* Milliseconds */
-        __u32   delay_rts_after_send;   /* Milliseconds */
+        __u32   delay_rts_before_send;  /* Delay before send (milliseconds) */
+        __u32   delay_rts_after_send;   /* Delay after send (milliseconds) */
         __u32   padding[5];             /* Memory is cheap, new structs
                                            are a royal PITA .. */
 };