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authorTony Lindgren <tony@atomide.com>2012-07-05 02:13:04 -0700
committerTony Lindgren <tony@atomide.com>2012-07-05 02:13:04 -0700
commitac5b0ea3d00d231dd9cedd45636b29defc368a4c (patch)
tree9649d193558e7c662257063a77ab7422379ac45b /arch/arm/mach-omap2/omap_hwmod.c
parent3f96a2d90e6923e2dd1e35d2f149a70a4d0f678c (diff)
parent8cb8de5d87b75f2ecaa1189079764340ea366c0e (diff)
downloadlinux-ac5b0ea3d00d231dd9cedd45636b29defc368a4c.tar.bz2
Merge tag 'omap-devel-f-for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into cleanup-part2
Miscellaneous OMAP clock, hwmod, clockdomain, and powerdomain patches for 3.6. Mostly small infrastructure improvements, and preparation for OMAP5 and AM33xx code. Conflicts: arch/arm/mach-omap2/omap_hwmod.c arch/arm/plat-omap/include/plat/omap_hwmod.h
Diffstat (limited to 'arch/arm/mach-omap2/omap_hwmod.c')
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.c61
1 files changed, 56 insertions, 5 deletions
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index f97f0624bca0..ebdf0016e536 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -416,6 +416,49 @@ static int _set_softreset(struct omap_hwmod *oh, u32 *v)
}
/**
+ * _set_dmadisable: set OCP_SYSCONFIG.DMADISABLE bit in @v
+ * @oh: struct omap_hwmod *
+ *
+ * The DMADISABLE bit is a semi-automatic bit present in sysconfig register
+ * of some modules. When the DMA must perform read/write accesses, the
+ * DMADISABLE bit is cleared by the hardware. But when the DMA must stop
+ * for power management, software must set the DMADISABLE bit back to 1.
+ *
+ * Set the DMADISABLE bit in @v for hwmod @oh. Returns -EINVAL upon
+ * error or 0 upon success.
+ */
+static int _set_dmadisable(struct omap_hwmod *oh)
+{
+ u32 v;
+ u32 dmadisable_mask;
+
+ if (!oh->class->sysc ||
+ !(oh->class->sysc->sysc_flags & SYSC_HAS_DMADISABLE))
+ return -EINVAL;
+
+ if (!oh->class->sysc->sysc_fields) {
+ WARN(1, "omap_hwmod: %s: offset struct for sysconfig not provided in class\n", oh->name);
+ return -EINVAL;
+ }
+
+ /* clocks must be on for this operation */
+ if (oh->_state != _HWMOD_STATE_ENABLED) {
+ pr_warn("omap_hwmod: %s: dma can be disabled only from enabled state\n", oh->name);
+ return -EINVAL;
+ }
+
+ pr_debug("omap_hwmod: %s: setting DMADISABLE\n", oh->name);
+
+ v = oh->_sysc_cache;
+ dmadisable_mask =
+ (0x1 << oh->class->sysc->sysc_fields->dmadisable_shift);
+ v |= dmadisable_mask;
+ _write_sysconfig(v, oh);
+
+ return 0;
+}
+
+/**
* _set_module_autoidle: set the OCP_SYSCONFIG AUTOIDLE field in @v
* @oh: struct omap_hwmod *
* @autoidle: desired AUTOIDLE bitfield value (0 or 1)
@@ -1652,11 +1695,17 @@ dis_opt_clks:
* therefore have no OCP header registers to access. Others (like the
* IVA) have idiosyncratic reset sequences. So for these relatively
* rare cases, custom reset code can be supplied in the struct
- * omap_hwmod_class .reset function pointer. Passes along the return
- * value from either _ocp_softreset() or the custom reset function -
- * these must return -EINVAL if the hwmod cannot be reset this way or
- * if the hwmod is in the wrong state, -ETIMEDOUT if the module did
- * not reset in time, or 0 upon success.
+ * omap_hwmod_class .reset function pointer.
+ *
+ * _set_dmadisable() is called to set the DMADISABLE bit so that it
+ * does not prevent idling of the system. This is necessary for cases
+ * where ROMCODE/BOOTLOADER uses dma and transfers control to the
+ * kernel without disabling dma.
+ *
+ * Passes along the return value from either _ocp_softreset() or the
+ * custom reset function - these must return -EINVAL if the hwmod
+ * cannot be reset this way or if the hwmod is in the wrong state,
+ * -ETIMEDOUT if the module did not reset in time, or 0 upon success.
*/
static int _reset(struct omap_hwmod *oh)
{
@@ -1678,6 +1727,8 @@ static int _reset(struct omap_hwmod *oh)
}
}
+ _set_dmadisable(oh);
+
/*
* OCP_SYSCONFIG bits need to be reprogrammed after a
* softreset. The _enable() function should be split to avoid