Re: [PATCH 1/2] V4L: remove clock name from v4l2_clk API

Josh Wu <josh.wu@xxxxxxxxx> · Wed, 7 Jan 2015 10:16:27 +0800

Hi, Guennadi

On 1/7/2015 6:17 AM, Guennadi Liakhovetski wrote:
Hi Josh,

On Tue, 6 Jan 2015, Josh Wu wrote:

Hi, Guennadi

After look deep into this patch, I found you miss one line that should be
changed as well.
It's In function v4l2_clk_get(), there still has one line code called
v4l2_clk_find(dev_id, id).
You need to change it to v4l2_clk_find(dev_id, NULL) as well.
Otherwise the code that many sensor used: v4l2_clk_get(&client->dev, "mclk")
cannot acquired the "mclk" clock.

After above changes, this patch works for me.
I think you're right, in fact, since we now don't store CCF-based v4l2_clk
wrappers on the list, this can be simplified even further, I'll update the
patch. Did you only test this patch or both?
I tested both patches with Atmel-isi driver. For the 2/2 patch I applied 
the modification Laurent suggested.
Those patches works for me.

The only concern is in ov2640 I still need to acquired two v4l2 clocks:
   "xvclk"  that will get the xvclk CCF clock directly.
   "mclk"  that make ISI driver call his clock_start()/stop() to 
enable/disable ISI's peripheral clock.
If I only get xvclk clock, then the camera capture will be failed with a 
ISI timeout error.

But I think this is acceptable as we will keep go forward. Finally we'll 
switch to CCF and removed the v4l2_clock then we will move the 
clock_start()/stop() caller code to soc_camera.c.

Best Regards,
Josh Wu


Thanks
Guennadi

On 1/2/2015 7:48 PM, Guennadi Liakhovetski wrote:
All uses of the v4l2_clk API so far only register one clock with a fixed
name. This allows us to get rid of it, which also will make CCF and DT
integration easier.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
---
   drivers/media/platform/soc_camera/soc_camera.c |  6 +++---
   drivers/media/usb/em28xx/em28xx-camera.c       |  2 +-
   drivers/media/v4l2-core/v4l2-clk.c             | 24
+++++++++++-------------
   include/media/v4l2-clk.h                       |  7 +++----
   4 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/drivers/media/platform/soc_camera/soc_camera.c
b/drivers/media/platform/soc_camera/soc_camera.c
index f4be2a1..ce192b6 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -1380,7 +1380,7 @@ static int soc_camera_i2c_init(struct
soc_camera_device *icd,
   	snprintf(clk_name, sizeof(clk_name), "%d-%04x",
   		 shd->i2c_adapter_id, shd->board_info->addr);
   -	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, "mclk",
icd);
+	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, icd);
   	if (IS_ERR(icd->clk)) {
   		ret = PTR_ERR(icd->clk);
   		goto eclkreg;
@@ -1561,7 +1561,7 @@ static int scan_async_group(struct soc_camera_host
*ici,
   	snprintf(clk_name, sizeof(clk_name), "%d-%04x",
   		 sasd->asd.match.i2c.adapter_id, sasd->asd.match.i2c.address);
   -	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, "mclk",
icd);
+	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, icd);
   	if (IS_ERR(icd->clk)) {
   		ret = PTR_ERR(icd->clk);
   		goto eclkreg;
@@ -1666,7 +1666,7 @@ static int soc_of_bind(struct soc_camera_host *ici,
   		snprintf(clk_name, sizeof(clk_name), "of-%s",
   			 of_node_full_name(remote));
   -	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, "mclk",
icd);
+	icd->clk = v4l2_clk_register(&soc_camera_clk_ops, clk_name, icd);
   	if (IS_ERR(icd->clk)) {
   		ret = PTR_ERR(icd->clk);
   		goto eclkreg;
diff --git a/drivers/media/usb/em28xx/em28xx-camera.c
b/drivers/media/usb/em28xx/em28xx-camera.c
index 7be661f..a4b22c2 100644
--- a/drivers/media/usb/em28xx/em28xx-camera.c
+++ b/drivers/media/usb/em28xx/em28xx-camera.c
@@ -330,7 +330,7 @@ int em28xx_init_camera(struct em28xx *dev)
     	v4l2_clk_name_i2c(clk_name, sizeof(clk_name),
   			  i2c_adapter_id(adap), client->addr);
-	v4l2->clk = v4l2_clk_register_fixed(clk_name, "mclk", -EINVAL);
+	v4l2->clk = v4l2_clk_register_fixed(clk_name, -EINVAL);
   	if (IS_ERR(v4l2->clk))
   		return PTR_ERR(v4l2->clk);
   diff --git a/drivers/media/v4l2-core/v4l2-clk.c
b/drivers/media/v4l2-core/v4l2-clk.c
index e18cc04..c210906 100644
--- a/drivers/media/v4l2-core/v4l2-clk.c
+++ b/drivers/media/v4l2-core/v4l2-clk.c
@@ -31,7 +31,8 @@ static struct v4l2_clk *v4l2_clk_find(const char *dev_id,
const char *id)
   		if (strcmp(dev_id, clk->dev_id))
   			continue;
   -		if (!id || !clk->id || !strcmp(clk->id, id))
+		if ((!id && !clk->id) ||
+		    (id && clk->id && !strcmp(clk->id, id)))
   			return clk;
   	}
   @@ -127,8 +128,8 @@ void v4l2_clk_disable(struct v4l2_clk *clk)
   	mutex_lock(&clk->lock);
     	enable = --clk->enable;
-	if (WARN(enable < 0, "Unbalanced %s() on %s:%s!\n", __func__,
-		 clk->dev_id, clk->id))
+	if (WARN(enable < 0, "Unbalanced %s() on %s!\n", __func__,
+		 clk->dev_id))
   		clk->enable++;
   	else if (!enable && clk->ops->disable)
   		clk->ops->disable(clk);
@@ -181,7 +182,7 @@ EXPORT_SYMBOL(v4l2_clk_set_rate);
     struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops,
   				   const char *dev_id,
-				   const char *id, void *priv)
+				   void *priv)
   {
   	struct v4l2_clk *clk;
   	int ret;
@@ -193,9 +194,8 @@ struct v4l2_clk *v4l2_clk_register(const struct
v4l2_clk_ops *ops,
   	if (!clk)
   		return ERR_PTR(-ENOMEM);
   -	clk->id = kstrdup(id, GFP_KERNEL);
   	clk->dev_id = kstrdup(dev_id, GFP_KERNEL);
-	if ((id && !clk->id) || !clk->dev_id) {
+	if (!clk->dev_id) {
   		ret = -ENOMEM;
   		goto ealloc;
   	}
@@ -205,7 +205,7 @@ struct v4l2_clk *v4l2_clk_register(const struct
v4l2_clk_ops *ops,
   	mutex_init(&clk->lock);
     	mutex_lock(&clk_lock);
-	if (!IS_ERR(v4l2_clk_find(dev_id, id))) {
+	if (!IS_ERR(v4l2_clk_find(dev_id, NULL))) {
like mentioned in the beginning of the mail, you need to do same change in
v4l2_clk_get().

Best Regards,
Josh Wu


   		mutex_unlock(&clk_lock);
   		ret = -EEXIST;
   		goto eexist;
@@ -217,7 +217,6 @@ struct v4l2_clk *v4l2_clk_register(const struct
v4l2_clk_ops *ops,
     eexist:
   ealloc:
-	kfree(clk->id);
   	kfree(clk->dev_id);
   	kfree(clk);
   	return ERR_PTR(ret);
@@ -227,15 +226,14 @@ EXPORT_SYMBOL(v4l2_clk_register);
   void v4l2_clk_unregister(struct v4l2_clk *clk)
   {
   	if (WARN(atomic_read(&clk->use_count),
-		 "%s(): Refusing to unregister ref-counted %s:%s clock!\n",
-		 __func__, clk->dev_id, clk->id))
+		 "%s(): Refusing to unregister ref-counted %s clock!\n",
+		 __func__, clk->dev_id))
   		return;
     	mutex_lock(&clk_lock);
   	list_del(&clk->list);
   	mutex_unlock(&clk_lock);
   -	kfree(clk->id);
   	kfree(clk->dev_id);
   	kfree(clk);
   }
@@ -253,7 +251,7 @@ static unsigned long fixed_get_rate(struct v4l2_clk
*clk)
   }
     struct v4l2_clk *__v4l2_clk_register_fixed(const char *dev_id,
-		const char *id, unsigned long rate, struct module *owner)
+				unsigned long rate, struct module *owner)
   {
   	struct v4l2_clk *clk;
   	struct v4l2_clk_fixed *priv = kzalloc(sizeof(*priv), GFP_KERNEL);
@@ -265,7 +263,7 @@ struct v4l2_clk *__v4l2_clk_register_fixed(const char
*dev_id,
   	priv->ops.get_rate = fixed_get_rate;
   	priv->ops.owner = owner;
   -	clk = v4l2_clk_register(&priv->ops, dev_id, id, priv);
+	clk = v4l2_clk_register(&priv->ops, dev_id, priv);
   	if (IS_ERR(clk))
   		kfree(priv);
   diff --git a/include/media/v4l2-clk.h b/include/media/v4l2-clk.h
index 0b36cc1..8f06967 100644
--- a/include/media/v4l2-clk.h
+++ b/include/media/v4l2-clk.h
@@ -43,7 +43,7 @@ struct v4l2_clk_ops {
     struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops,
   				   const char *dev_name,
-				   const char *name, void *priv);
+				   void *priv);
   void v4l2_clk_unregister(struct v4l2_clk *clk);
   struct v4l2_clk *v4l2_clk_get(struct device *dev, const char *id);
   void v4l2_clk_put(struct v4l2_clk *clk);
@@ -55,14 +55,13 @@ 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);
+			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);
+	return __v4l2_clk_register_fixed(dev_id, rate, THIS_MODULE);
   }
     #define v4l2_clk_name_i2c(name, size, adap, client) snprintf(name, size,
\

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