[PATCH 2/4] ARM: OMAP2+ hwmod: Allow modules to disable HW_AUTO

From: Roger Quadros
Date: Tue Feb 07 2017 - 06:22:57 EST


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@xxxxxx>
[nsekhar@xxxxxx: rebased to v4.9 kernel]
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
---
v2:
- add comment explaining why we don't call clkdm_deny_idle() in _idle()

arch/arm/mach-omap2/omap_hwmod.c | 9 +++++++--
arch/arm/mach-omap2/omap_hwmod.h | 5 +++++
2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 0da4f2e..360fded 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2092,7 +2092,7 @@ 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) {
@@ -2149,7 +2149,12 @@ 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)
diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
index 9e1c4ed..cda553a 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/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
--
2.7.4