From 4c1e5d32b27e0745b37964505e0a368354b5d437 Mon Sep 17 00:00:00 2001 From: Ian Lepore Date: Thu, 22 Oct 2015 00:54:59 +0000 Subject: [PATCH] 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. --- sys/dev/iicbus/iiconf.c | 15 +++++++++++++++ sys/dev/iicbus/iiconf.h | 2 ++ 2 files changed, 17 insertions(+) diff --git a/sys/dev/iicbus/iiconf.c b/sys/dev/iicbus/iiconf.c index e28d341f8eef..8ac8a47c2edd 100644 --- a/sys/dev/iicbus/iiconf.c +++ b/sys/dev/iicbus/iiconf.c @@ -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 diff --git a/sys/dev/iicbus/iiconf.h b/sys/dev/iicbus/iiconf.h index aca0137d7ea0..12ac0d77319d 100644 --- a/sys/dev/iicbus/iiconf.h +++ b/sys/dev/iicbus/iiconf.h @@ -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