[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: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/v4l2-core/v4l2-clk.c b/drivers/media/v4l2-core/v4l2-clk.c
index b67de86..e18cc04 100644
--- a/drivers/media/v4l2-core/v4l2-clk.c
+++ b/drivers/media/v4l2-core/v4l2-clk.c
@@ -240,3 +240,42 @@
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);
diff --git a/include/media/v4l2-clk.h b/include/media/v4l2-clk.h
index 0503a90..a354a9d 100644
--- a/include/media/v4l2-clk.h
+++ b/include/media/v4l2-clk.h
@@ -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 @@
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