linux-kernel - [PATCH 4.2.y-ckt 71/98] ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property

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Message-Id: <1458084692-23100-72-git-send-email-kamal@canonical.com>
Date:	Tue, 15 Mar 2016 16:31:05 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Lokesh Vutla <lokeshvutla@...com>, Sekhar Nori <nsekhar@...com>,
	Dave Gerlach <d-gerlach@...com>,
	Paul Walmsley <paul@...an.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 4.2.y-ckt 71/98] ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property

4.2.8-ckt6 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Lokesh Vutla <lokeshvutla@...com>

commit 2e18f5a1bc18e8af7031b3b26efde25307014837 upstream.

Introduce a dt property, ti,no-idle, that prevents an IP to idle at any
point. This is to handle Errata i877, which tells that GMAC clocks
cannot be disabled.

Acked-by: Roger Quadros <rogerq@...com>
Tested-by: Mugunthan V N <mugunthanvnm@...com>
Signed-off-by: Lokesh Vutla <lokeshvutla@...com>
Signed-off-by: Sekhar Nori <nsekhar@...com>
Signed-off-by: Dave Gerlach <d-gerlach@...com>
Acked-by: Rob Herring <robh@...nel.org>
Signed-off-by: Paul Walmsley <paul@...an.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 Documentation/devicetree/bindings/arm/omap/omap.txt | 1 +
 arch/arm/mach-omap2/omap_hwmod.c                    | 9 ++++++++-
 arch/arm/mach-omap2/omap_hwmod.h                    | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt
index 4f6a82c..cbe35b3 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/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 486cc4d..573da0d 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2180,6 +2180,11 @@ 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) {
@@ -2484,6 +2489,8 @@ 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;
@@ -2610,7 +2617,7 @@ 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 b5d27ec..1681310 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/arch/arm/mach-omap2/omap_hwmod.h
@@ -523,6 +523,8 @@ struct omap_hwmod_omap4_prcm {
  * HWMOD_RECONFIG_IO_CHAIN: omap_hwmod code needs to reconfigure wake-up 
  *     events by calling _reconfigure_io_chain() when a device is enabled
  *     or idled.
+ * 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)
@@ -538,6 +540,7 @@ struct omap_hwmod_omap4_prcm {
 #define HWMOD_FORCE_MSTANDBY			(1 << 11)
 #define HWMOD_SWSUP_SIDLE_ACT			(1 << 12)
 #define HWMOD_RECONFIG_IO_CHAIN			(1 << 13)
+#define HWMOD_NO_IDLE				(1 << 15)
 
 /*
  * omap_hwmod._int_flags definitions
-- 
2.7.0