On Mon, Jul 28, 2014 at 11:47 AM, Grygorii Strashko
[off-list ref] wrote:

Hi Grant.

On 07/28/2014 05:05 PM, Grant Likely wrote:

quoted

On Thu, 12 Jun 2014 19:53:43 +0300, Grygorii Strashko [off-list ref] wrote:

quoted

Use "clkops-clocks" property to specify clocks handled by
clock_ops domain PM domain. Only clocks defined in "clkops-clocks"
set of clocks will be handled by Runtime PM through clock_ops
Pm domain.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
  drivers/of/of_clk.c |    7 ++-----
  1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/of/of_clk.c b/drivers/of/of_clk.c
index 35f5e9f..5f9b90e 100644
--- a/drivers/of/of_clk.c
+++ b/drivers/of/of_clk.c

@@ -86,11 +86,8 @@ int of_clk_register_runtime_pm_clocks(struct device_node *np,
     struct clk *clk;
     int error;

-    for (i = 0; (clk = of_clk_get(np, i)) && !IS_ERR(clk); i++) {
-            if (!clk_may_runtime_pm(clk)) {
-                    clk_put(clk);
-                    continue;
-            }
+    for (i = 0; (clk = of_clk_get_from_set(np, "clkops", i)) &&
+                 !IS_ERR(clk); i++) {

This really looks like an ABI break to me. What happens to all the
existing platforms who don't have this new clkops-clocks in their device
tree?

Agree. This patch as is will break such platforms.
As possible solution for above problem - the NULL can be used as clock's prefix
by default and platform code can configure new value of clock's prefix during
initialization.
In addition, to make this solution full the of_clk_get_by_name() will
need to be modified too.

But note pls, this is pure RFC patches which I did to find out the answer on questions:
- What is better: maintain Runtime PM clocks configuration in DT or in code?

In code. I don't think it is workable to embed runtime PM behaviour
into the DT bindings. I think there will be too much variance in what
hardware requires. We can create helpers to make this simpler, but I
don't think it is a good idea to set it up automatically without any
control from the driver itself.

- Where and when to call of_clk_register_runtime_pm_clocks()?
  Bus notifier/ platform core/ device drivers

I would say in device drivers.

Also, May be platform dependent solution [1] can be acceptable for now?

[1] https://lkml.org/lkml/2014/7/25/630

I need to look at the series before I comment. I've flagged it and
will hopefully look at it tomorrow.

g.