From 43b01643355672a266b95c4719f47cd1abac4680 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Thu, 10 Mar 2011 03:50:07 -0700 Subject: OMAP2+: hwmod: allow board files to prevent devices from being reset upon init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some boards can't tolerate IP blocks being reset when they are initialized. Michael Büsch cites a case with the Nokia N810: http://www.spinics.net/lists/linux-omap/msg47277.html To allow such boards to continue working normally, allow board file maintainers to mark IP blocks to prevent them from being reset upon init. This is done via a hwmod function, omap_hwmod_no_setup_reset(). Signed-off-by: Paul Walmsley Cc: Michael Buesch --- arch/arm/mach-omap2/omap_hwmod.c | 26 ++++++++++++++++++++++++++ arch/arm/plat-omap/include/plat/omap_hwmod.h | 2 ++ 2 files changed, 28 insertions(+) (limited to 'arch') diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index e282e35769fd..816aeb97ba28 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2218,3 +2218,29 @@ u32 omap_hwmod_get_context_loss_count(struct omap_hwmod *oh) return ret; } + +/** + * omap_hwmod_no_setup_reset - prevent a hwmod from being reset upon setup + * @oh: struct omap_hwmod * + * + * Prevent the hwmod @oh from being reset during the setup process. + * Intended for use by board-*.c files on boards with devices that + * cannot tolerate being reset. Must be called before the hwmod has + * been set up. Returns 0 upon success or negative error code upon + * failure. + */ +int omap_hwmod_no_setup_reset(struct omap_hwmod *oh) +{ + if (!oh) + return -EINVAL; + + if (oh->_state != _HWMOD_STATE_REGISTERED) { + pr_err("omap_hwmod: %s: cannot prevent setup reset; in wrong state\n", + oh->name); + return -EINVAL; + } + + oh->flags |= HWMOD_INIT_NO_RESET; + + return 0; +} diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index 1eee85a8abb3..bba234337d00 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -589,6 +589,8 @@ int omap_hwmod_for_each_by_class(const char *classname, int omap_hwmod_set_postsetup_state(struct omap_hwmod *oh, u8 state); u32 omap_hwmod_get_context_loss_count(struct omap_hwmod *oh); +int omap_hwmod_no_setup_reset(struct omap_hwmod *oh); + /* * Chip variant-specific hwmod init routines - XXX should be converted * to use initcalls once the initial boot ordering is straightened out -- cgit v1.2.3