From b02b917211d50ad5dc13e49c933ef916b10e0d00 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Thu, 6 Oct 2011 17:18:45 -0600 Subject: ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection The way that we detect which OMAP3 chips support I/O wakeup and software I/O chain clock control is broken. Currently, I/O wakeup is marked as present for all OMAP3 SoCs other than the AM3505/3517. The TI81xx family of SoCs are at present considered to be OMAP3 SoCs, but don't support I/O wakeup. To resolve this, convert the existing blacklist approach to an explicit, whitelist support, in which only SoCs which are known to support I/O wakeup are listed. (At present, this only includes OMAP34xx, OMAP3503, OMAP3515, OMAP3525, OMAP3530, and OMAP36xx.) Also, the current code incorrectly detects the presence of a software-controllable I/O chain clock on several chips that don't support it. This results in writes to reserved bitfields, unnecessary delays, and console messages on kernels running on those chips: http://www.spinics.net/lists/linux-omap/msg58735.html Convert this test to a feature test with a chip-by-chip whitelist. Thanks to Dave Hylands for reporting this problem and doing some testing to help isolate the cause. Thanks to Steve Sakoman for catching a bug in the first version of this patch. Thanks to Russell King for comments. Signed-off-by: Paul Walmsley Cc: Dave Hylands Cc: Steve Sakoman Tested-by: Steve Sakoman Cc: Russell King - ARM Linux Signed-off-by: Kevin Hilman --- arch/arm/plat-omap/include/plat/cpu.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'arch/arm/plat-omap/include/plat/cpu.h') diff --git a/arch/arm/plat-omap/include/plat/cpu.h b/arch/arm/plat-omap/include/plat/cpu.h index 67b3d75884c..3a280aaf967 100644 --- a/arch/arm/plat-omap/include/plat/cpu.h +++ b/arch/arm/plat-omap/include/plat/cpu.h @@ -477,6 +477,13 @@ void omap2_check_revision(void); /* * Runtime detection of OMAP3 features + * + * OMAP3_HAS_IO_CHAIN_CTRL: Some later members of the OMAP3 chip + * family have OS-level control over the I/O chain clock. This is + * to avoid a window during which wakeups could potentially be lost + * during powerdomain transitions. If this bit is set, it + * indicates that the chip does support OS-level control of this + * feature. */ extern u32 omap_features; @@ -488,9 +495,10 @@ extern u32 omap_features; #define OMAP3_HAS_192MHZ_CLK BIT(5) #define OMAP3_HAS_IO_WAKEUP BIT(6) #define OMAP3_HAS_SDRC BIT(7) -#define OMAP4_HAS_MPU_1GHZ BIT(8) -#define OMAP4_HAS_MPU_1_2GHZ BIT(9) -#define OMAP4_HAS_MPU_1_5GHZ BIT(10) +#define OMAP3_HAS_IO_CHAIN_CTRL BIT(8) +#define OMAP4_HAS_MPU_1GHZ BIT(9) +#define OMAP4_HAS_MPU_1_2GHZ BIT(10) +#define OMAP4_HAS_MPU_1_5GHZ BIT(11) #define OMAP3_HAS_FEATURE(feat,flag) \ @@ -507,12 +515,11 @@ OMAP3_HAS_FEATURE(isp, ISP) OMAP3_HAS_FEATURE(192mhz_clk, 192MHZ_CLK) OMAP3_HAS_FEATURE(io_wakeup, IO_WAKEUP) OMAP3_HAS_FEATURE(sdrc, SDRC) +OMAP3_HAS_FEATURE(io_chain_ctrl, IO_CHAIN_CTRL) /* * Runtime detection of OMAP4 features */ -extern u32 omap_features; - #define OMAP4_HAS_FEATURE(feat, flag) \ static inline unsigned int omap4_has_ ##feat(void) \ { \ -- cgit v1.2.3-70-g09d2