diff mbox

[1/2] ARM: OMAP: hwmod: partially un-reset hwmods might not be properly enabled

Message ID 1345614150-25723-2-git-send-email-omar.luna@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Omar Ramirez Luna Aug. 22, 2012, 5:42 a.m. UTC
Some IP blocks might not be using/controlling more than one
reset line, this check loosens the restriction to fully use
hwmod framework for those drivers.

E.g.: ipu has reset lines: mmu_cache, cpu0 and cpu1.
- As of now cpu1 is not used and hence (with previous check) the
  IP block isn't fully enabled by hwmod code.
- Usually ipu and dsp processors configure their mmu module first
  and then enable the processors, this involves:
    * Deasserting mmu reset line, and enabling the module.
    * Deasserting cpu0 reset line, and enabling the processor.
  The ones portrayed in this example are controlled through
  rproc_fw_boot in drivers/remoteproc/remoteproc_core.c

While at it, prevent _omap4_module_disable if all the hardreset
lines on an IP block are not under reset.

This will allow the driver to:
  a. Deassert the reset line.
  b. Enable the hwmod through runtime PM default callbacks.
  c. Do its usecase.
  d. Disable hwmod through runtime PM.
  e. Assert the reset line.

Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>
---
 arch/arm/mach-omap2/omap_hwmod.c |   37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

Comments

Paul Walmsley Sept. 21, 2012, 12:44 a.m. UTC | #1
Hi Omar

On Wed, 22 Aug 2012, Omar Ramirez Luna wrote:

> Some IP blocks might not be using/controlling more than one
> reset line, this check loosens the restriction to fully use
> hwmod framework for those drivers.
> 
> E.g.: ipu has reset lines: mmu_cache, cpu0 and cpu1.
> - As of now cpu1 is not used and hence (with previous check) the
>   IP block isn't fully enabled by hwmod code.
> - Usually ipu and dsp processors configure their mmu module first
>   and then enable the processors, this involves:
>     * Deasserting mmu reset line, and enabling the module.
>     * Deasserting cpu0 reset line, and enabling the processor.
>   The ones portrayed in this example are controlled through
>   rproc_fw_boot in drivers/remoteproc/remoteproc_core.c
> 
> While at it, prevent _omap4_module_disable if all the hardreset
> lines on an IP block are not under reset.
> 
> This will allow the driver to:
>   a. Deassert the reset line.
>   b. Enable the hwmod through runtime PM default callbacks.
>   c. Do its usecase.
>   d. Disable hwmod through runtime PM.
>   e. Assert the reset line.
> 
> Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>

Well, I don't think this is the right long-term solution, but I'd like to 
see this moving forward.  So this one has been queued for 3.7.  Hopefully 
we can figure out the right thing once the PRM driver is ready (which will 
handle the low-level hard resets).


- Paul
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diff mbox

Patch

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 6ca8e51..eaedc33 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -1558,25 +1558,28 @@  static int _read_hardreset(struct omap_hwmod *oh, const char *name)
 }
 
 /**
- * _are_any_hardreset_lines_asserted - return true if part of @oh is hard-reset
+ * _are_all_hardreset_lines_asserted - return true if the @oh is hard-reset
  * @oh: struct omap_hwmod *
  *
- * If any hardreset line associated with @oh is asserted, then return true.
- * Otherwise, if @oh has no hardreset lines associated with it, or if
- * no hardreset lines associated with @oh are asserted, then return false.
+ * If all hardreset lines associated with @oh are asserted, then return true.
+ * Otherwise, if part of @oh is out hardreset or if no hardreset lines
+ * associated with @oh are asserted, then return false.
  * This function is used to avoid executing some parts of the IP block
- * enable/disable sequence if a hardreset line is set.
+ * enable/disable sequence if its hardreset line is set.
  */
-static bool _are_any_hardreset_lines_asserted(struct omap_hwmod *oh)
+static bool _are_all_hardreset_lines_asserted(struct omap_hwmod *oh)
 {
-	int i;
+	int i, rst_cnt = 0;
 
 	if (oh->rst_lines_cnt == 0)
 		return false;
 
 	for (i = 0; i < oh->rst_lines_cnt; i++)
 		if (_read_hardreset(oh, oh->rst_lines[i].name) > 0)
-			return true;
+			rst_cnt++;
+
+	if (oh->rst_lines_cnt == rst_cnt)
+		return true;
 
 	return false;
 }
@@ -1595,6 +1598,13 @@  static int _omap4_disable_module(struct omap_hwmod *oh)
 	if (!oh->clkdm || !oh->prcm.omap4.modulemode)
 		return -EINVAL;
 
+	/*
+	 * Since integration code might still be doing something, only
+	 * disable if all lines are under hardreset.
+	 */
+	if (!_are_all_hardreset_lines_asserted(oh))
+		return 0;
+
 	pr_debug("omap_hwmod: %s: %s\n", oh->name, __func__);
 
 	omap4_cminst_module_disable(oh->clkdm->prcm_partition,
@@ -1602,9 +1612,6 @@  static int _omap4_disable_module(struct omap_hwmod *oh)
 				    oh->clkdm->clkdm_offs,
 				    oh->prcm.omap4.clkctrl_offs);
 
-	if (_are_any_hardreset_lines_asserted(oh))
-		return 0;
-
 	v = _omap4_wait_target_disable(oh);
 	if (v)
 		pr_warn("omap_hwmod: %s: _wait_target_disable failed\n",
@@ -1830,7 +1837,7 @@  static int _enable(struct omap_hwmod *oh)
 	}
 
 	/*
-	 * If an IP block contains HW reset lines and any of them are
+	 * If an IP block contains HW reset lines and all of them are
 	 * asserted, we let integration code associated with that
 	 * block handle the enable.  We've received very little
 	 * information on what those driver authors need, and until
@@ -1838,7 +1845,7 @@  static int _enable(struct omap_hwmod *oh)
 	 * posted to the public lists, this is probably the best we
 	 * can do.
 	 */
-	if (_are_any_hardreset_lines_asserted(oh))
+	if (_are_all_hardreset_lines_asserted(oh))
 		return 0;
 
 	/* Mux pins for device runtime if populated */
@@ -1918,7 +1925,7 @@  static int _idle(struct omap_hwmod *oh)
 		return -EINVAL;
 	}
 
-	if (_are_any_hardreset_lines_asserted(oh))
+	if (_are_all_hardreset_lines_asserted(oh))
 		return 0;
 
 	if (oh->class->sysc)
@@ -2006,7 +2013,7 @@  static int _shutdown(struct omap_hwmod *oh)
 		return -EINVAL;
 	}
 
-	if (_are_any_hardreset_lines_asserted(oh))
+	if (_are_all_hardreset_lines_asserted(oh))
 		return 0;
 
 	pr_debug("omap_hwmod: %s: disabling\n", oh->name);