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authorPaul Walmsley <paul@pwsan.com>2011-10-07 03:18:45 +0400
committerKevin Hilman <khilman@ti.com>2011-10-08 00:41:49 +0400
commitb02b917211d50ad5dc13e49c933ef916b10e0d00 (patch)
tree138707c1aab31b0263cb1bd02ba4678c6a7d80f5 /arch/arm/plat-omap/include/plat/cpu.h
parentff2f8e5ffb23de6e2284f31651447cb80a4c9d1b (diff)
downloadlinux-b02b917211d50ad5dc13e49c933ef916b10e0d00.tar.xz
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 <dhylands@gmail.com> for reporting this problem and doing some testing to help isolate the cause. Thanks to Steve Sakoman <sakoman@gmail.com> for catching a bug in the first version of this patch. Thanks to Russell King <linux@arm.linux.org.uk> for comments. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Dave Hylands <dhylands@gmail.com> Cc: Steve Sakoman <sakoman@gmail.com> Tested-by: Steve Sakoman <sakoman@gmail.com> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Kevin Hilman <khilman@ti.com>
Diffstat (limited to 'arch/arm/plat-omap/include/plat/cpu.h')
-rw-r--r--arch/arm/plat-omap/include/plat/cpu.h17
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/arm/plat-omap/include/plat/cpu.h b/arch/arm/plat-omap/include/plat/cpu.h
index 67b3d75884cd..3a280aaf9675 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) \
{ \