Expand SMBUS API to add smbus_trans() function.

Differential Revision:	https://reviews.freebsd.org/D1955
Reviewed by:	adrian, jhb, wblock
Approved by:	adrian, jhb

1 files changed, 69 insertions, 30 deletions

diff --git a/share/man/man4/smb.4 b/share/man/man4/smb.4
index afe4605b449f..ba0e8f13b101 100644
--- a/share/man/man4/smb.4
+++ b/share/man/man4/smb.4
@@ -1,5 +1,6 @@
 .\" Copyright (c) 1998, Nicolas Souchu
 .\" Copyright (c) 2004, Joerg Wunsch
+.\" Copyright (c) 2015, Michael Gmelin <freebsd@grem.de>
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -25,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 6, 2009
+.Dd April 25, 2015
 .Dt SMB 4
 .Os
 .Sh NAME
@@ -49,21 +50,24 @@ as its argument.
 #include <sys/types.h>
 
 struct smbcmd {
-	char cmd;
-	int count;
-	u_char slave;
+	u_char cmd;
+	u_char reserved;
+	u_short op;
 	union {
-		char byte;
-		short word;
-
-		char *byte_ptr;
-		short *word_ptr;
-
-		struct {
-			short sdata;
-			short *rdata;
-		} process;
-	} data;
+		char    byte;
+		char    buf[2];
+		short   word;
+	} wdata;
+	union {
+		char    byte;
+		char    buf[2];
+		short   word;
+	} rdata;
+	int  slave;
+	char *wbuf;     /* use wdata if NULL */
+	int  wcount;
+	char *rbuf;     /* use rdata if NULL */
+	int  rcount;
 };
 .Ed
 .Pp
@@ -107,14 +111,14 @@ The
 command first sends the byte from the
 .Fa cmd
 field to the device, followed by the byte given in
-.Fa data.byte .
+.Fa wdata.byte .
 .It Dv SMB_WRITEW Ta
 The
 .Em WriteWord
 command first sends the byte from the
 .Fa cmd
 field to the device, followed by the word given in
-.Fa data.word .
+.Fa wdata.word .
 Note that the SMBus byte-order is little-endian by definition.
 .It Dv SMB_READB Ta
 The
@@ -123,8 +127,8 @@ command first sends the byte from the
 .Fa cmd
 field to the device, and then reads one byte of data from
 the device.
-The returned data will be stored in the location pointed to by
-.Fa data.byte_ptr .
+The returned data will be stored in
+.Fa rdata.byte .
 .It Dv SMB_READW Ta
 The
 .Em ReadWord
@@ -132,29 +136,33 @@ command first sends the byte from the
 .Fa cmd
 field to the device, and then reads one word of data from
 the device.
-The returned data will be stored in the location pointed to by
-.Fa data.word_ptr .
+The returned data will be stored in
+.Fa rdata.word .
 .It Dv SMB_PCALL Ta
 The
 .Em ProcedureCall
 command first sends the byte from the
 .Fa cmd
 field to the device, followed by the word provided in
-.Fa data.process.sdata .
+.Fa wdata.word .
 It then reads one word of data from the device, and returns it
-in the location pointed to by
-.Fa data.process.rdata .
+in
+.Fa rdata.word .
 .It Dv SMB_BWRITE Ta
 The
 .Em BlockWrite
 command first sends the byte from the
 .Fa cmd
 field to the device, followed by
-.Fa count
+.Fa wcount
 bytes of data that are taken from the buffer pointed to by
-.Fa data.byte_ptr .
+.Fa wbuf .
 The SMBus specification mandates that no more than 32 bytes of
-data can be transferred in a single block read or write command.
+data can be transferred in a single block read or write command,
+but since
+.Xr smbus 4
+is also used to access I2C devices, the limit has been increased
+to 1024.
 This value is available in the constant
 .Dv SMB_MAXBLOCKSIZE .
 .It Dv SMB_BREAD Ta
@@ -163,10 +171,38 @@ The
 command first sends the byte from the
 .Fa cmd
 field to the device, and then reads
-.Fa count
+.Fa rcount
+bytes of data that from the device.
+These data will be returned in the buffer pointed to by
+.Fa rbuf .
+.It Dv SMB_TRANS Ta
+The
+.Em Trans
+command sends an SMB roll-up transaction with flags that also allow it to
+be used for (mostly) I2C pass-through and with with 10-bit addresses.
+This function can be used to roll up all of the above functions.
+It first sends the byte from the
+.Fa cmd
+field to the device, followed by
+.Fa wcount
+bytes of data that are taken from the buffer pointed to by
+.Fa wbuf ,
+then reads
+.Fa rcount
 bytes of data that from the device.
 These data will be returned in the buffer pointed to by
-.Fa data.byte_ptr .
+.Fa rbuf .
+.Pp
+The following flags are allowed in
+.Fa op :
+.Pp
+.Bd -literal -compact
+SMB_TRANS_NOSTOP  Do not send STOP at end
+SMB_TRANS_NOCMD   Ignore cmd field (do not tx)
+SMB_TRANS_NOCNT   Do not tx or rx count field
+SMB_TRANS_7BIT    Change address mode to 7-bit
+SMB_TRANS_10BIT   Change address mode to 10-bit
+.Ed
 .El
 .Pp
 The
@@ -201,4 +237,7 @@ manual page first appeared in
 .Sh AUTHORS
 This
 manual page was written by
-.An Nicolas Souchu .
+.An Nicolas Souchu
+and extended by
+.An Michael Gmelin Aq freebsd@grem.de
+.