From 5fb3d522efca4b3a369040d37d1380103411db74 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Mon, 29 Oct 2012 22:11:50 -0600 Subject: ARM: OMAP2+: hwmod: add flag to prevent hwmod code from touching IP block during init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add HWMOD_EXT_OPT_MAIN_CLK flag to indicate that this IP block is dependent on an off-chip functional clock that is not guaranteed to be present during initialization. IP blocks marked with this flag are left in the INITIALIZED state during kernel init. This is a workaround for a hardware problem. It should be possible to guarantee that at least one clock source will be present and active for any IP block's main functional clock. This ensures that the hwmod code can enable and reset the IP block. Resetting the IP block during kernel init prevents any bogus bootloader, ROM code, or previous OS configuration from affecting the kernel. Hopefully a clock multiplexer can be added on future SoCs. N.B., at some point in the future, it should be possible to query the clock framework for this type of information. Then this flag should no longer be needed. Signed-off-by: Paul Walmsley Cc: Benoît Cousson --- arch/arm/plat-omap/include/plat/omap_hwmod.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/plat-omap/include') diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index b3349f7b1a2c..1db029438022 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -443,6 +443,11 @@ struct omap_hwmod_omap4_prcm { * in order to complete the reset. Optional clocks will be disabled * again after the reset. * HWMOD_16BIT_REG: Module has 16bit registers + * HWMOD_EXT_OPT_MAIN_CLK: The only main functional clock source for + * this IP block comes from an off-chip source and is not always + * enabled. This prevents the hwmod code from being able to + * enable and reset the IP block early. XXX Eventually it should + * be possible to query the clock framework for this information. */ #define HWMOD_SWSUP_SIDLE (1 << 0) #define HWMOD_SWSUP_MSTANDBY (1 << 1) @@ -453,6 +458,7 @@ struct omap_hwmod_omap4_prcm { #define HWMOD_NO_IDLEST (1 << 6) #define HWMOD_CONTROL_OPT_CLKS_IN_RESET (1 << 7) #define HWMOD_16BIT_REG (1 << 8) +#define HWMOD_EXT_OPT_MAIN_CLK (1 << 9) /* * omap_hwmod._int_flags definitions -- cgit v1.2.3