Hi
On Thu, 9 Oct 2014, Tomi Valkeinen wrote:
> Add parent_hwmod pointer to omap_hwmod. This can be set to point to a
> "parent" hwmod that needs to be enabled for the "child" hwmod to work.
>
> This is used at hwmod setup time: when doing the initial setup and
> reset, first enable the parent hwmod, and after setup and reset is done,
> restore the parent hwmod to postsetup_state.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
This one has been updated here to add some kerneldoc documentation.
Please let me know if you have any objections.
- Paul
From: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Date: Thu, 9 Oct 2014 17:03:14 +0300
Subject: [PATCH] ARM: OMAP2+: hwmod: add parent_hwmod support
Add parent_hwmod pointer to omap_hwmod. This can be set to point to a
"parent" hwmod that needs to be enabled for the "child" hwmod to work.
This is used at hwmod setup time: when doing the initial setup and
reset, first enable the parent hwmod, and after setup and reset is done,
restore the parent hwmod to postsetup_state.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Reviewed-by: Archit Taneja <archit.taneja@xxxxxxxxx>
[paul@xxxxxxxxx: add kerneldoc documentation for parent_hwmod; note that it
is a temporary workaround]
Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
---
arch/arm/mach-omap2/omap_hwmod.c | 22 ++++++++++++++++++++++
arch/arm/mach-omap2/omap_hwmod.h | 8 ++++++++
2 files changed, 30 insertions(+)
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index acae6d5d1151..a2c7b300fe89 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2719,11 +2719,33 @@ static int __init _setup(struct omap_hwmod *oh, void *data)
if (oh->_state != _HWMOD_STATE_INITIALIZED)
return 0;
+ if (oh->parent_hwmod) {
+ int r;
+
+ r = _enable(oh->parent_hwmod);
+ WARN(r, "hwmod: %s: setup: failed to enable parent hwmod %s\n",
+ oh->name, oh->parent_hwmod->name);
+ }
+
_setup_iclk_autoidle(oh);
if (!_setup_reset(oh))
_setup_postsetup(oh);
+ if (oh->parent_hwmod) {
+ u8 postsetup_state;
+
+ postsetup_state = oh->parent_hwmod->_postsetup_state;
+
+ if (postsetup_state == _HWMOD_STATE_IDLE)
+ _idle(oh->parent_hwmod);
+ else if (postsetup_state == _HWMOD_STATE_DISABLED)
+ _shutdown(oh->parent_hwmod);
+ else if (postsetup_state != _HWMOD_STATE_ENABLED)
+ WARN(1, "hwmod: %s: unknown postsetup state %d! defaulting to enabled\n",
+ oh->parent_hwmod->name, postsetup_state);
+ }
+
return 0;
}
diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
index 512f809a3f4d..35ca6efbec31 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/arch/arm/mach-omap2/omap_hwmod.h
@@ -633,6 +633,7 @@ struct omap_hwmod_link {
* @flags: hwmod flags (documented below)
* @_lock: spinlock serializing operations on this hwmod
* @node: list node for hwmod list (internal use)
+ * @parent_hwmod: (temporary) a pointer to the hierarchical parent of this hwmod
*
* @main_clk refers to this module's "main clock," which for our
* purposes is defined as "the functional clock needed for register
@@ -643,6 +644,12 @@ struct omap_hwmod_link {
* the omap_hwmod code and should not be set during initialization.
*
* @masters and @slaves are now deprecated.
+ *
+ * @parent_hwmod is temporary; there should be no need for it, as this
+ * information should already be expressed in the OCP interface
+ * structures. @parent_hwmod is present as a workaround until we improve
+ * handling for hwmods with multiple parents (e.g., OMAP4+ DSS with
+ * multiple register targets across different interconnects).
*/
struct omap_hwmod {
const char *name;
@@ -680,6 +687,7 @@ struct omap_hwmod {
u8 _int_flags;
u8 _state;
u8 _postsetup_state;
+ struct omap_hwmod *parent_hwmod;
};
struct omap_hwmod *omap_hwmod_lookup(const char *name);
--
2.1.3
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