ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property

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@ti.com>
Tested-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

3 files changed, 12 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/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