d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add iicbus_transfer_excl(), a helper routine to do an i2c bus transaction

Browse Source 
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.
This commit is contained in:
Ian Lepore 2015-10-22 00:54:59 +00:00
parent 7f1636b75e
commit 4c1e5d32b2
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=289726
2 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
sys/dev/iicbus/iiconf.c
View File

@ -395,6 +395,21 @@ iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
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

2
sys/dev/iicbus/iiconf.h
View File

@ -129,6 +129,8 @@ extern int iicbus_block_read(device_t, u_char, char *, int, int *);
/* 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