svn commit: r289726 - head/sys/dev/iicbus

[Ian Lepore]

Author: ian
Date: Thu Oct 22 00:54:59 2015
New Revision: 289726
URL: https://svnweb.freebsd.org/changeset/base/289726

Log:
  Add iicbus_transfer_excl(), a helper routine to do an i2c bus transaction
  while holding exclusive ownership of the bus.  This is the routine most
  slave drivers should use unless they have a need to acquire and hold the
  bus across a series of related operations that involves multiple transfers.

Modified:
  head/sys/dev/iicbus/iiconf.c
  head/sys/dev/iicbus/iiconf.h

Modified: head/sys/dev/iicbus/iiconf.c
==============================================================================
--- head/sys/dev/iicbus/iiconf.c	Thu Oct 22 00:07:48 2015	(r289725)
+++ head/sys/dev/iicbus/iiconf.c	Thu Oct 22 00:54:59 2015	(r289726)
@@ -395,6 +395,21 @@ iicbus_transfer(device_t bus, struct iic
 	return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
 }
 
+int
+iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
+    int how)
+{
+	device_t bus;
+	int error;
+
+	bus = device_get_parent(dev);
+	error = iicbus_request_bus(bus, dev, how);
+	if (error == 0)
+		error = IICBUS_TRANSFER(bus, msgs, nmsgs);
+	iicbus_release_bus(bus, dev);
+	return (error);
+}
+
 /*
  * Generic version of iicbus_transfer that calls the appropriate
  * routines to accomplish this.  See note above about acceptable

Modified: head/sys/dev/iicbus/iiconf.h
==============================================================================
--- head/sys/dev/iicbus/iiconf.h	Thu Oct 22 00:07:48 2015	(r289725)
+++ head/sys/dev/iicbus/iiconf.h	Thu Oct 22 00:54:59 2015	(r289726)
@@ -129,6 +129,8 @@ extern int iicbus_block_read(device_t, u
 
 /* vectors of iic operations to pass to bridge */
 int iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs);
+int iicbus_transfer_excl(device_t bus, struct iic_msg *msgs, uint32_t nmsgs,
+    int how);
 int iicbus_transfer_gen(device_t bus, struct iic_msg *msgs, uint32_t nmsgs);
 
 #define IICBUS_MODVER	1