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Commit cf326dfe authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Mauro Carvalho Chehab
Browse files

[media] V4L2: add v4l2-clock helpers to register and unregister a fixed-rate clock 



Many bridges and video host controllers supply fixed rate always on clocks
to their I2C devices. This patch adds two simple helpers to register and
unregister such a clock.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent d3f884a7

drivers/media/v4l2-core/v4l2-clk.c

+39 −0
Original line number Diff line number Diff line
@@ -240,3 +240,42 @@ void v4l2_clk_unregister(struct v4l2_clk *clk) 
	kfree(clk);

}

EXPORT_SYMBOL(v4l2_clk_unregister);



struct v4l2_clk_fixed {

	unsigned long rate;

	struct v4l2_clk_ops ops;

};



static unsigned long fixed_get_rate(struct v4l2_clk *clk)

{

	struct v4l2_clk_fixed *priv = clk->priv;

	return priv->rate;

}



struct v4l2_clk *__v4l2_clk_register_fixed(const char *dev_id,

		const char *id, unsigned long rate, struct module *owner)

{

	struct v4l2_clk *clk;

	struct v4l2_clk_fixed *priv = kzalloc(sizeof(*priv), GFP_KERNEL);



	if (!priv)

		return ERR_PTR(-ENOMEM);



	priv->rate = rate;

	priv->ops.get_rate = fixed_get_rate;

	priv->ops.owner = owner;



	clk = v4l2_clk_register(&priv->ops, dev_id, id, priv);

	if (IS_ERR(clk))

		kfree(priv);



	return clk;

}

EXPORT_SYMBOL(__v4l2_clk_register_fixed);



void v4l2_clk_unregister_fixed(struct v4l2_clk *clk)

{

	kfree(clk->priv);

	v4l2_clk_unregister(clk);

}

EXPORT_SYMBOL(v4l2_clk_unregister_fixed);

include/media/v4l2-clk.h

+14 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#define MEDIA_V4L2_CLK_H



#include <linux/atomic.h>

#include <linux/export.h>

#include <linux/list.h>

#include <linux/mutex.h>
@@ -51,4 +52,17 @@ void v4l2_clk_disable(struct v4l2_clk *clk); 
unsigned long v4l2_clk_get_rate(struct v4l2_clk *clk);

int v4l2_clk_set_rate(struct v4l2_clk *clk, unsigned long rate);



struct module;



struct v4l2_clk *__v4l2_clk_register_fixed(const char *dev_id,

		const char *id, unsigned long rate, struct module *owner);

void v4l2_clk_unregister_fixed(struct v4l2_clk *clk);



static inline struct v4l2_clk *v4l2_clk_register_fixed(const char *dev_id,

							const char *id,

							unsigned long rate)

{

	return __v4l2_clk_register_fixed(dev_id, id, rate, THIS_MODULE);

}



#endif