Re: [RFC v2 3/5] clk: use struct clk only for external API

From: Tomeu Vizoso
Date: Thu Jul 10 2014 - 05:16:46 EST

On 07/09/2014 10:12 PM, Tomasz Figa wrote:
Actually few more comments, see inline.

On 03.07.2014 16:38, Tomeu Vizoso wrote:
From: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>

In order to provide per-user accounting, this separates the struct clk
used in the common clock framework into two structures 'struct clk_core'
and 'struct clk'. struct clk_core will be used for internal
manipulation and struct clk will be used in the clock API


diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 8f57154..5f2aba9 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -5,6 +5,7 @@

#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/gfp.h>
@@ -14,15 +15,15 @@ static void devm_clk_release(struct device *dev, void *res)
clk_put(*(struct clk **)res);

This function still expects to get a (struct clk *) here, but...


-struct clk *devm_clk_get(struct device *dev, const char *id)
+struct clk_core *devm_clk_provider_get(struct device *dev, const char *id)
- struct clk **ptr, *clk;
+ struct clk_core **ptr, *clk;

ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);

- clk = clk_get(dev, id);
+ clk = clk_provider_get(dev, id);
if (!IS_ERR(clk)) {
*ptr = clk; a (struct clk_core *) is stored.

Thanks, well spotted.

devres_add(dev, ptr);


diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h
index d278572..c69f4fe 100644
--- a/drivers/clk/clk.h
+++ b/drivers/clk/clk.h
@@ -15,3 +15,7 @@ struct clk_core *__of_clk_get_from_provider(struct of_phandle_args *clkspec);
void of_clk_lock(void);
void of_clk_unlock(void);
+#if defined(CONFIG_COMMON_CLK)
+#define clk_to_clk_core(clk) (clk->core)

Making this a static inline will benefit you with type checking at
compilation time.

Good point.



+#define clk_core_to_clk(core) ((struct clk *)(core))

Hmm, I'm not following. clk_to_clk_core() returns clk->core, while
clk_core_to_clk() simply casts whatever the former returns into a
pointer to struct clk?

Yeah, this is totally wrong, v3 will be fixing this, I have tested it on an Odroid U2, so the most embarrassing issues have been fixed.



Also this should be a static inline to benefit from compiler type checking.

Best regards,

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