Hi Uffe,

-----Original Message-----
From: Ulf Hansson <redacted>
Sent: Wednesday, June 19, 2019 7:09 PM
To: Manish Narani <redacted>
Cc: Michal Simek <redacted>; Rob Herring <robh+dt@kernel.org>;
Mark Rutland [off-list ref]; Adrian Hunter
[off-list ref]; Rajan Vaja [off-list ref]; Jolly Shah
[off-list ref]; Nava kishore Manne [off-list ref]; Olof
Johansson [off-list ref]; linux-mmc@vger.kernel.org; DTML
[off-list ref]; Linux Kernel Mailing List <linux-
kernel@vger.kernel.org>; Linux ARM [off-list ref]
Subject: Re: [PATCH 3/3] mmc: sdhci-of-arasan: Add support for ZynqMP
Platform Tap Delays Setup

On Wed, 19 Jun 2019 at 10:40, Manish Narani [off-list ref] wrote:

quoted

Hi Uffe,

quoted

-----Original Message-----
From: Ulf Hansson <redacted>
Sent: Monday, June 17, 2019 5:51 PM

[...]

quoted

The "const struct zynqmp_eemi_ops *eemi_ops; should then be moved into
a clock provider specific struct, which is assigned when calling
sdhci_arasan_register_sdclk. I understand that all the clock data is
folded into struct sdhci_arasan_data today, but I think that should be
moved into a "sub-struct" for the clock specifics.

Moreover, when registering the clock, we should convert from using
devm_clk_register() into devm_clk_hw_register() as the first one is
now deprecated.

Just a query here:
When we switch to using devm_clk_hw_register() here, it will register the

clk_hw and return int.

quoted

Is there a way we can get the clk (related to the clk_hw registered) from the
clock framework?
I am asking this because we will need that clk pointer while calling

clk_set_phase() function.

I assume devm_clk_get() should work fine?

This clock does not come through ZynqMP Clock framework. We are initializing it in this 'sdhci-of-arasan' driver and getting only the clock name from "clock_output_names" property. So I think devm_clk_get() will not work here for our case.
I have gone through the clock framework and I found one function which may be used to create clock from clock hw, that is ' clk_hw_create_clk()' which can be used from our driver, however this needs change in the clock framework as below :

---

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index aa51756..4dc69ff 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c

@@ -3420,6 +3420,7 @@ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
 
        return clk;
 }
+EXPORT_SYMBOL_GPL(clk_hw_create_clk);
 
 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
 {

diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h
index d8400d6..2319899 100644
--- a/drivers/clk/clk.h
+++ b/drivers/clk/clk.h

@@ -22,17 +22,9 @@ static inline struct clk_hw *of_clk_get_hw(struct device_node *np,
 struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id);
 
 #ifdef CONFIG_COMMON_CLK
-struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
-                             const char *dev_id, const char *con_id);
 void __clk_put(struct clk *clk);
 #else
 /* All these casts to avoid ifdefs in clkdev... */
-static inline struct clk *
-clk_hw_create_clk(struct device *dev, struct clk_hw *hw, const char *dev_id,
-                 const char *con_id)
-{
-       return (struct clk *)hw;
-}
 static struct clk_hw *__clk_get_hw(struct clk *clk)
 {
        return (struct clk_hw *)clk;

diff --git a/include/linux/clk.h b/include/linux/clk.h
index f689fc5..d3f60fe 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h

@@ -18,6 +18,7 @@
 
 struct device;
 struct clk;
+struct clk_hw;
 struct device_node;
 struct of_phandle_args;
 

@@ -934,4 +935,15 @@ static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clksp
 }
 #endif
 
+#ifdef CONFIG_COMMON_CLK
+struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
+                             const char *dev_id, const char *con_id);
+#else
+static inline struct clk *
+clk_hw_create_clk(struct device *dev, struct clk_hw *hw, const char *dev_id,
+                 const char *con_id)
+{
+       return (struct clk *)hw;
+}
+#endif
 #endif
---

This change should help other drivers (outside 'drivers/clk/') as well for getting the clock created from clk_hw.
Is this fine to do?

Thanks,
Manish
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel