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-rw-r--r--Documentation/devicetree/bindings/arm/omap/omap.txt1
-rw-r--r--arch/arm/boot/dts/dra7.dtsi10
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.c9
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.h3
4 files changed, 22 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt
index a2bd593881ca..66422d663184 100644
--- a/Documentation/devicetree/bindings/arm/omap/omap.txt
+++ b/Documentation/devicetree/bindings/arm/omap/omap.txt
@@ -23,6 +23,7 @@ Optional properties:
during suspend.
- ti,no-reset-on-init: When present, the module should not be reset at init
- ti,no-idle-on-init: When present, the module should not be idled at init
+- ti,no-idle: When present, the module is never allowed to idle.
Example:
diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
index c4d9175b90dc..f82aa44c3cee 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -1500,6 +1500,16 @@
0x48485200 0x2E00>;
#address-cells = <1>;
#size-cells = <1>;
+
+ /*
+ * Do not allow gating of cpsw clock as workaround
+ * for errata i877. Keeping internal clock disabled
+ * causes the device switching characteristics
+ * to degrade over time and eventually fail to meet
+ * the data manual delay time/skew specs.
+ */
+ ti,no-idle;
+
/*
* rx_thresh_pend
* rx_pend
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index e9f65fec55c0..b6d62e4cdfdd 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2200,6 +2200,11 @@ static int _enable(struct omap_hwmod *oh)
*/
static int _idle(struct omap_hwmod *oh)
{
+ if (oh->flags & HWMOD_NO_IDLE) {
+ oh->_int_flags |= _HWMOD_SKIP_ENABLE;
+ return 0;
+ }
+
pr_debug("omap_hwmod: %s: idling\n", oh->name);
if (oh->_state != _HWMOD_STATE_ENABLED) {
@@ -2504,6 +2509,8 @@ static int __init _init(struct omap_hwmod *oh, void *data)
oh->flags |= HWMOD_INIT_NO_RESET;
if (of_find_property(np, "ti,no-idle-on-init", NULL))
oh->flags |= HWMOD_INIT_NO_IDLE;
+ if (of_find_property(np, "ti,no-idle", NULL))
+ oh->flags |= HWMOD_NO_IDLE;
}
oh->_state = _HWMOD_STATE_INITIALIZED;
@@ -2630,7 +2637,7 @@ static void __init _setup_postsetup(struct omap_hwmod *oh)
* XXX HWMOD_INIT_NO_IDLE does not belong in hwmod data -
* it should be set by the core code as a runtime flag during startup
*/
- if ((oh->flags & HWMOD_INIT_NO_IDLE) &&
+ if ((oh->flags & (HWMOD_INIT_NO_IDLE | HWMOD_NO_IDLE)) &&
(postsetup_state == _HWMOD_STATE_IDLE)) {
oh->_int_flags |= _HWMOD_SKIP_ENABLE;
postsetup_state = _HWMOD_STATE_ENABLED;
diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
index 76bce11c85a4..7c7a31169475 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/arch/arm/mach-omap2/omap_hwmod.h
@@ -525,6 +525,8 @@ struct omap_hwmod_omap4_prcm {
* or idled.
* HWMOD_OPT_CLKS_NEEDED: The optional clocks are needed for the module to
* operate and they need to be handled at the same time as the main_clk.
+ * HWMOD_NO_IDLE: Do not idle the hwmod at all. Useful to handle certain
+ * IPs like CPSW on DRA7, where clocks to this module cannot be disabled.
*/
#define HWMOD_SWSUP_SIDLE (1 << 0)
#define HWMOD_SWSUP_MSTANDBY (1 << 1)
@@ -541,6 +543,7 @@ struct omap_hwmod_omap4_prcm {
#define HWMOD_SWSUP_SIDLE_ACT (1 << 12)
#define HWMOD_RECONFIG_IO_CHAIN (1 << 13)
#define HWMOD_OPT_CLKS_NEEDED (1 << 14)
+#define HWMOD_NO_IDLE (1 << 15)
/*
* omap_hwmod._int_flags definitions