ARM: OMAP2+ hwmod: Allow modules to disable HW_AUTO

Introduce HWMOD_CLKDM_NOAUTO flag that allows the hwmod's
clockdomain to be prevented from HW_AUTO while the hwmod is active.

This is needed to workaround some modules which don't function
correctly with HW_AUTO. e.g. DCAN on DRA7.

Signed-off-by: Roger Quadros <rogerq@ti.com>
[nsekhar@ti.com: rebased to v4.9 kernel]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap_hwmod.c

@@ -2027,7 +2027,7 @@ static int _enable(struct omap_hwmod *oh)
 
 	r = (soc_ops.wait_target_ready) ? soc_ops.wait_target_ready(oh) :
 		-EINVAL;
-	if (oh->clkdm)
+	if (oh->clkdm && !(oh->flags & HWMOD_CLKDM_NOAUTO))
 		clkdm_allow_idle(oh->clkdm);
 
 	if (!r) {
@@ -2084,7 +2084,12 @@ static int _idle(struct omap_hwmod *oh)
 		_idle_sysc(oh);
 	_del_initiator_dep(oh, mpu_oh);
 
-	if (oh->clkdm)
+	/*
+	 * If HWMOD_CLKDM_NOAUTO is set then we don't
+	 * deny idle the clkdm again since idle was already denied
+	 * in _enable()
+	 */
+	if (oh->clkdm && !(oh->flags & HWMOD_CLKDM_NOAUTO))
 		clkdm_deny_idle(oh->clkdm);
 
 	if (oh->flags & HWMOD_BLOCK_WFI)

arch/arm/mach-omap2/omap_hwmod.h

@@ -531,6 +531,10 @@ struct omap_hwmod_omap4_prcm {
  *     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.
+ * HWMOD_CLKDM_NOAUTO: Allows the hwmod's clockdomain to be prevented from
+ *     entering HW_AUTO while hwmod is active. This is needed to workaround
+ *     some modules which don't function correctly with HW_AUTO. For example,
+ *     DCAN on DRA7x SoC needs this to workaround errata i893.
  */
 #define HWMOD_SWSUP_SIDLE			(1 << 0)
 #define HWMOD_SWSUP_MSTANDBY			(1 << 1)
@@ -548,6 +552,7 @@ struct omap_hwmod_omap4_prcm {
 #define HWMOD_RECONFIG_IO_CHAIN			(1 << 13)
 #define HWMOD_OPT_CLKS_NEEDED			(1 << 14)
 #define HWMOD_NO_IDLE				(1 << 15)
+#define HWMOD_CLKDM_NOAUTO			(1 << 16)
 
 /*
  * omap_hwmod._int_flags definitions