From: Grazvydas Ignotas <notasas@gmail.com>
Date: Mon, 11 Mar 2013 18:46:43 +0000 (+0200)
Subject: ARM: OMAP3: hwmod data: keep MIDLEMODE in force-standby for musb
X-Git-Tag: sz_154~19
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=820e9e105321853fedc793adf4d3e4a1f8b5ad74

ARM: OMAP3: hwmod data: keep MIDLEMODE in force-standby for musb

For some unknown reason, allowing hwmod to control MIDLEMODE causes
core_pwrdm to not hit idle states for musb in DM3730 at least.
I've verified that setting any MIDLEMODE value other than "force
standby" before enabling the device causes subsequent suspend
attempts to fail with core_pwrdm not entering idle states, even
if the driver is unloaded and "force standby" is restored before
suspend attempt. To recover from this, soft reset can be used, but
that's not suitable solution for suspend.

Keeping the register set at force standby (reset value) makes it work
and device still functions properly, as musb has driver-controlled
OTG_FORCESTDBY register that controls MSTANDBY signal.
Note that TI PSP kernels also have similar workarounds.

This patch also fixes HWMOD_SWSUP_MSTANDBY documentation to match the
actual flag name.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
---

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 207a2ff9a8c4..d11ef8340b1f 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -903,7 +903,9 @@ static void _enable_sysc(struct omap_hwmod *oh)
 	}
 
 	if (sf & SYSC_HAS_MIDLEMODE) {
-		if (oh->flags & HWMOD_SWSUP_MSTANDBY) {
+		if (oh->flags & HWMOD_FORCE_MSTANDBY) {
+			idlemode = HWMOD_IDLEMODE_FORCE;
+		} else if (oh->flags & HWMOD_SWSUP_MSTANDBY) {
 			idlemode = HWMOD_IDLEMODE_NO;
 		} else {
 			if (sf & SYSC_HAS_ENAWAKEUP)
@@ -970,7 +972,8 @@ static void _idle_sysc(struct omap_hwmod *oh)
 	}
 
 	if (sf & SYSC_HAS_MIDLEMODE) {
-		if (oh->flags & HWMOD_SWSUP_MSTANDBY) {
+		if ((oh->flags & HWMOD_SWSUP_MSTANDBY) ||
+		    (oh->flags & HWMOD_FORCE_MSTANDBY)) {
 			idlemode = HWMOD_IDLEMODE_FORCE;
 		} else {
 			if (sf & SYSC_HAS_ENAWAKEUP)
diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
index 363df2519040..553c1c8984cd 100644
--- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
@@ -3018,9 +3018,14 @@ static struct omap_hwmod omap3xxx_usbhsotg_hwmod = {
 	 * Erratum ID: i479  idle_req / idle_ack mechanism potentially
 	 * broken when autoidle is enabled
 	 * workaround is to disable the autoidle bit at module level.
+	 *
+	 * Enabling the device in any other MIDLEMODE setting but force-idle
+	 * causes core_pwrdm not enter idle states at least on OMAP3630.
+	 * Note that musb has OTG_FORCESTDBY register that controls MSTANDBY
+	 * signal when MIDLEMODE is set to force-idle.
 	 */
 	.flags		= HWMOD_NO_OCP_AUTOIDLE | HWMOD_SWSUP_SIDLE
-				| HWMOD_SWSUP_MSTANDBY,
+				| HWMOD_FORCE_MSTANDBY,
 };
 
 /* usb_otg_hs */
diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
index 8b372ede17c1..78747cb709e6 100644
--- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
+++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
@@ -379,8 +379,8 @@ struct omap_hwmod_omap4_prcm {
  *
  * HWMOD_SWSUP_SIDLE: omap_hwmod code should manually bring module in and out
  *     of idle, rather than relying on module smart-idle
- * HWMOD_SWSUP_MSTDBY: omap_hwmod code should manually bring module in and out
- *     of standby, rather than relying on module smart-standby
+ * HWMOD_SWSUP_MSTANDBY: omap_hwmod code should manually bring module in and
+ *     out of standby, rather than relying on module smart-standby
  * HWMOD_INIT_NO_RESET: don't reset this module at boot - important for
  *     SDRAM controller, etc. XXX probably belongs outside the main hwmod file
  *     XXX Should be HWMOD_SETUP_NO_RESET
@@ -398,6 +398,10 @@ struct omap_hwmod_omap4_prcm {
  *     in order to complete the reset. Optional clocks will be disabled
  *     again after the reset.
  * HWMOD_16BIT_REG: Module has 16bit registers
+ * HWMOD_FORCE_MSTANDBY: Always keep MIDLEMODE bits cleared so that device
+ *     is kept in force-standby mode. Failing to do so causes PM problems
+ *     with musb on OMAP3630 at least. Note that musb has a dedicated register
+ *     to control MSTANDBY signal when MIDLEMODE is set to force-standby.
  */
 #define HWMOD_SWSUP_SIDLE			(1 << 0)
 #define HWMOD_SWSUP_MSTANDBY			(1 << 1)
@@ -408,6 +412,7 @@ struct omap_hwmod_omap4_prcm {
 #define HWMOD_NO_IDLEST				(1 << 6)
 #define HWMOD_CONTROL_OPT_CLKS_IN_RESET		(1 << 7)
 #define HWMOD_16BIT_REG				(1 << 8)
+#define HWMOD_FORCE_MSTANDBY			(1 << 11)
 
 /*
  * omap_hwmod._int_flags definitions