Expand SMBUS API to add smbus_trans() function.

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

share/man/man4/smb.4

@@ -1,5 +1,6 @@
 .\" Copyright (c) 1998, Nicolas Souchu
 .\" Copyright (c) 2004, Joerg Wunsch
+.\" Copyright (c) 2015, Michael Gmelin <[email protected]>
 .\" 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
@@ -123,38 +127,42 @@ 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
 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 [email protected]
+.

sys/dev/smbus/smb.c

@@ -26,10 +26,6 @@
  * $FreeBSD$
  */
 
-#ifdef HAVE_KERNEL_OPTION_HEADERS
-#include "opt_compat.h"
-#endif
-
 #include <sys/param.h>
 #include <sys/kernel.h>
 #include <sys/systm.h>
@@ -104,19 +100,24 @@ smb_identify(driver_t *driver, device_t parent)
 static int
 smb_probe(device_t dev)
 {
-	device_set_desc(dev, "SMBus generic I/O");
+	if (smbus_get_addr(dev) != -1)
+		return (ENXIO);
 
-	return (0);
+	device_set_desc(dev, "SMBus generic I/O");
+	return (BUS_PROBE_NOWILDCARD);
 }
 
 static int
 smb_attach(device_t dev)
 {
 	struct smb_softc *sc = device_get_softc(dev);
-
+	int unit;
+
+	unit = device_get_unit(dev);
 	sc->sc_dev = dev;
-	sc->sc_devnode = make_dev(&smb_cdevsw, device_get_unit(dev),
-	    UID_ROOT, GID_WHEEL, 0600, "smb%d", device_get_unit(dev));
+
+	sc->sc_devnode = make_dev(&smb_cdevsw, unit, UID_ROOT, GID_WHEEL,
+	    0600, "smb%d", unit);
 	sc->sc_devnode->si_drv1 = sc;
 	mtx_init(&sc->sc_lock, device_get_nameunit(dev), NULL, MTX_DEF);
 
@@ -174,9 +175,16 @@ smbioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *t
 	struct smb_softc *sc = dev->si_drv1;
 	device_t smbdev = sc->sc_dev;
 	int error;
-	short w;
-	u_char count;
-	char c;
+	int unit;
+	u_char bcount;
+
+	/*
+	 * If a specific slave device is being used, override any passed-in
+	 * slave.
+	 */
+	unit = dev2unit(dev);
+	if (unit & 0x0400)
+		s->slave = unit & 0x03ff;
 
 	parent = device_get_parent(smbdev);
 
@@ -208,77 +216,101 @@ smbioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *t
 
 	case SMB_WRITEB:
 		error = smbus_error(smbus_writeb(parent, s->slave, s->cmd,
-						s->data.byte));
+						s->wdata.byte));
 		break;
 
 	case SMB_WRITEW:
 		error = smbus_error(smbus_writew(parent, s->slave,
-						s->cmd, s->data.word));
+						s->cmd, s->wdata.word));
 		break;
 
 	case SMB_READB:
-		if (s->data.byte_ptr) {
-			error = smbus_error(smbus_readb(parent, s->slave,
-						s->cmd, &c));
-			if (error)
-				break;
-			error = copyout(&c, s->data.byte_ptr,
-					sizeof(*(s->data.byte_ptr)));
+		error = smbus_error(smbus_readb(parent, s->slave, s->cmd,
+		    &s->rdata.byte));
+		if (error)
+			break;
+		if (s->rbuf && s->rcount >= 1) {
+			error = copyout(&s->rdata.byte, s->rbuf, 1);
+			s->rcount = 1;
 		}
 		break;
 
 	case SMB_READW:
-		if (s->data.word_ptr) {
-			error = smbus_error(smbus_readw(parent, s->slave,
-						s->cmd, &w));
-			if (error == 0) {
-				error = copyout(&w, s->data.word_ptr,
-						sizeof(*(s->data.word_ptr)));
-			}
+		error = smbus_error(smbus_readw(parent, s->slave, s->cmd,
+		    &s->rdata.word));
+		if (error)
+			break;
+		if (s->rbuf && s->rcount >= 2) {
+			buf[0] = (u_char)s->rdata.word;
+			buf[1] = (u_char)(s->rdata.word >> 8);
+			error = copyout(buf, s->rbuf, 2);
+			s->rcount = 2;
 		}
 		break;
 
 	case SMB_PCALL:
-		if (s->data.process.rdata) {
-
-			error = smbus_error(smbus_pcall(parent, s->slave, s->cmd,
-				s->data.process.sdata, &w));
-			if (error)
-				break;
-			error = copyout(&w, s->data.process.rdata,
-					sizeof(*(s->data.process.rdata)));
+		error = smbus_error(smbus_pcall(parent, s->slave, s->cmd,
+		    s->wdata.word, &s->rdata.word));
+		if (error)
+			break;
+		if (s->rbuf && s->rcount >= 2) {
+			buf[0] = (u_char)s->rdata.word;
+			buf[1] = (u_char)(s->rdata.word >> 8);
+			error = copyout(buf, s->rbuf, 2);
+			s->rcount = 2;
 		}
-		
+
 		break;
 
 	case SMB_BWRITE:
-		if (s->count && s->data.byte_ptr) {
-			if (s->count > SMB_MAXBLOCKSIZE)
-				s->count = SMB_MAXBLOCKSIZE;
-			error = copyin(s->data.byte_ptr, buf, s->count);
-			if (error)
-				break;
-			error = smbus_error(smbus_bwrite(parent, s->slave,
-						s->cmd, s->count, buf));
+		if (s->wcount < 0) {
+			error = EINVAL;
+			break;
 		}
+		if (s->wcount > SMB_MAXBLOCKSIZE)
+			s->wcount = SMB_MAXBLOCKSIZE;
+		if (s->wcount)
+			error = copyin(s->wbuf, buf, s->wcount);
+		if (error)
+			break;
+		error = smbus_error(smbus_bwrite(parent, s->slave, s->cmd,
+		    s->wcount, buf));
 		break;
 
-#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD6)
-	case SMB_OLD_BREAD:
-#endif
 	case SMB_BREAD:
-		if (s->count && s->data.byte_ptr) {
-			count = min(s->count, SMB_MAXBLOCKSIZE);
-			error = smbus_error(smbus_bread(parent, s->slave,
-						s->cmd, &count, buf));
-			if (error)
-				break;
-			error = copyout(buf, s->data.byte_ptr,
-			    min(count, s->count));
-			s->count = count;
+		if (s->rcount < 0) {
+			error = EINVAL;
+			break;
+		}
+		if (s->rcount > SMB_MAXBLOCKSIZE)
+			s->rcount = SMB_MAXBLOCKSIZE;
+		error = smbus_error(smbus_bread(parent, s->slave, s->cmd,
+		    &bcount, buf));
+		if (error)
+			break;
+		if (s->rcount > bcount)
+			s->rcount = bcount;
+		error = copyout(buf, s->rbuf, s->rcount);
+		break;
+
+	case SMB_TRANS:
+		if (s->rcount < 0 || s->wcount < 0) {
+			error = EINVAL;
+			break;
 		}
+		if (s->rcount > SMB_MAXBLOCKSIZE)
+			s->rcount = SMB_MAXBLOCKSIZE;
+		if (s->wcount > SMB_MAXBLOCKSIZE)
+			s->wcount = SMB_MAXBLOCKSIZE;
+		if (s->wcount)
+			error = copyin(s->wbuf, buf, s->wcount);
+		if (error)
+			break;
+		error = smbus_error(smbus_trans(parent, s->slave, s->cmd,
+		    s->op, buf, s->wcount, buf, s->rcount, &s->rcount));
+		if (error == 0)
+			error = copyout(buf, s->rbuf, s->rcount);
 		break;
-
 	default:
 		error = ENOTTY;
 	}