diff mbox

[v4,07/10] exynos4-is: Add clock provider for the SCLK_CAM clock outputs

Message ID 1392925237-31394-9-git-send-email-s.nawrocki@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

This patch adds clock provider so the the SCLK_CAM0/1 output clocks
can be accessed by image sensor devices through the clk API.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Changes since v3:
 - use clock-output-names DT property instead of hard coding names
   of registered clocks in the driver; first two entries of the
   clock-names property value are used to specify parent clocks of
   cam_{a,b}_clkout clocks, rather than hard coding it to sclk_cam{0,1}
   in the driver.
 - addressed issues pointed out in review by Mauro.

Changes since v2:
 - use 'camera' DT node drirectly as clock provider node, rather than
  creating additional clock-controller child node.
 - DT binding documentation moved to a separate patch.
---
 drivers/media/platform/exynos4-is/media-dev.c |  110 +++++++++++++++++++++++++
 drivers/media/platform/exynos4-is/media-dev.h |   19 ++++-
 2 files changed, 128 insertions(+), 1 deletion(-)

Comments

Mark Rutland Feb. 21, 2014, 4:05 p.m. UTC | #1
On Thu, Feb 20, 2014 at 07:40:34PM +0000, Sylwester Nawrocki wrote:
> This patch adds clock provider so the the SCLK_CAM0/1 output clocks
> can be accessed by image sensor devices through the clk API.
> 
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
> Changes since v3:
>  - use clock-output-names DT property instead of hard coding names
>    of registered clocks in the driver; first two entries of the
>    clock-names property value are used to specify parent clocks of
>    cam_{a,b}_clkout clocks, rather than hard coding it to sclk_cam{0,1}
>    in the driver.
>  - addressed issues pointed out in review by Mauro.
> 
> Changes since v2:
>  - use 'camera' DT node drirectly as clock provider node, rather than
>   creating additional clock-controller child node.
>  - DT binding documentation moved to a separate patch.
> ---
>  drivers/media/platform/exynos4-is/media-dev.c |  110 +++++++++++++++++++++++++
>  drivers/media/platform/exynos4-is/media-dev.h |   19 ++++-
>  2 files changed, 128 insertions(+), 1 deletion(-)

[...]

> +static int fimc_md_register_clk_provider(struct fimc_md *fmd)
> +{
> +	struct cam_clk_provider *cp = &fmd->clk_provider;
> +	struct device *dev = &fmd->pdev->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(cp->clks); i++) {
> +		struct cam_clk *camclk = &cp->camclk[i];
> +		struct clk_init_data init;
> +
> +		ret = of_property_read_string_index(dev->of_node,
> +					"clock-output-names", i, &init.name);

Are there not well-defined names for the clock outputs of the block?

> +		if (ret < 0)
> +			break;
> +
> +		ret = of_property_read_string_index(dev->of_node,
> +					"clock-names", i, init.parent_names);

This shouldn't be a parent name. It should be the input line name.

I don't think this makes sense.

Why do you need the name of the parent clock?

> +		if (ret < 0)
> +			break;
> +
> +		init.num_parents = 1;
> +		init.ops = &cam_clk_ops;
> +		init.flags = CLK_SET_RATE_PARENT;
> +		camclk->hw.init = &init;
> +		camclk->fmd = fmd;
> +
> +		cp->clks[i] = clk_register(NULL, &camclk->hw);
> +		if (IS_ERR(cp->clks[i])) {
> +			dev_err(dev, "failed to register clock: %s (%ld)\n",
> +					init.name, PTR_ERR(cp->clks[i]));
> +			ret = PTR_ERR(cp->clks[i]);
> +			goto err;
> +		}
> +		cp->num_clocks++;
> +	}
> +
> +	if (cp->num_clocks == 0) {
> +		dev_warn(dev, "clk provider not registered\n");
> +		return 0;
> +	}
> +
> +	cp->clk_data.clks = cp->clks;
> +	cp->clk_data.clk_num = cp->num_clocks;
> +	cp->of_node = dev->of_node;
> +	ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
> +				  &cp->clk_data);

Are _all_ of the input clock lines available to children in hardware?

The binding and commit message(s) implied only two clocks were, so
what's the point in exporting clocks which aren't available?

Thanks,
Mark.
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Sylwester Nawrocki Feb. 22, 2014, 10:18 p.m. UTC | #2
On 02/21/2014 05:05 PM, Mark Rutland wrote:
>> ---
>>   drivers/media/platform/exynos4-is/media-dev.c |  110 +++++++++++++++++++++++++
>>   drivers/media/platform/exynos4-is/media-dev.h |   19 ++++-
>>   2 files changed, 128 insertions(+), 1 deletion(-)
...
>
>> +static int fimc_md_register_clk_provider(struct fimc_md *fmd)
>> +{
>> +	struct cam_clk_provider *cp =&fmd->clk_provider;
>> +	struct device *dev =&fmd->pdev->dev;
>> +	int i, ret;
>> +
>> +	for (i = 0; i<  ARRAY_SIZE(cp->clks); i++) {
>> +		struct cam_clk *camclk =&cp->camclk[i];
>> +		struct clk_init_data init;
>> +
>> +		ret = of_property_read_string_index(dev->of_node,
>> +					"clock-output-names", i,&init.name);
>
> Are there not well-defined names for the clock outputs of the block?

There are, but this driver handles multiple SoCs so I thought it's better
to define these names in devicetree. They are supposed to be unique. Isn't
that what the clock-output-names property is for ?

>> +		if (ret<  0)
>> +			break;
>> +
>> +		ret = of_property_read_string_index(dev->of_node,
>> +					"clock-names", i, init.parent_names);
>
> This shouldn't be a parent name. It should be the input line name.
>
> I don't think this makes sense.
>
> Why do you need the name of the parent clock?

As explained in previous e-mail, it is needed to maintain the clock tree,
the parent clock names must be set properly. As the above is not correct
I could hard code these names or retrieve with __clk_get_name() from proper
input clocks. of_clk_get_parent_name() cannot be used.

>> +		if (ret<  0)
>> +			break;
>> +
>> +		init.num_parents = 1;
>> +		init.ops =&cam_clk_ops;
>> +		init.flags = CLK_SET_RATE_PARENT;
>> +		camclk->hw.init =&init;
>> +		camclk->fmd = fmd;
>> +
>> +		cp->clks[i] = clk_register(NULL,&camclk->hw);
>> +		if (IS_ERR(cp->clks[i])) {
>> +			dev_err(dev, "failed to register clock: %s (%ld)\n",
>> +					init.name, PTR_ERR(cp->clks[i]));
>> +			ret = PTR_ERR(cp->clks[i]);
>> +			goto err;
>> +		}
>> +		cp->num_clocks++;
>> +	}
>> +
>> +	if (cp->num_clocks == 0) {
>> +		dev_warn(dev, "clk provider not registered\n");
>> +		return 0;
>> +	}
>> +
>> +	cp->clk_data.clks = cp->clks;
>> +	cp->clk_data.clk_num = cp->num_clocks;
>> +	cp->of_node = dev->of_node;
>> +	ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
>> +				&cp->clk_data);
>
> Are _all_ of the input clock lines available to children in hardware?

This code is only for two clocks, ARRAY_SIZE(cp->clks) == 2 and
cp->num_clocks can't be greater than 2. Nevertheless, for some SoC
variants this driver handles (e.g. S5PV210) there can be only up to
two clocks listed in the camera node.

The camera interface IP block doesn't generate the clock itself, it just
passes it through when is active, i.e. its other clocks are enabled and
the power domain activated.

> The binding and commit message(s) implied only two clocks were, so
> what's the point in exporting clocks which aren't available?

I'm not sure what makes you think there is more than two ?

--
Regards,
Sylwester
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diff mbox

Patch

diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c
index c1bce17..dfc3131 100644
--- a/drivers/media/platform/exynos4-is/media-dev.c
+++ b/drivers/media/platform/exynos4-is/media-dev.c
@@ -11,6 +11,8 @@ 
  */
 
 #include <linux/bug.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
@@ -1437,6 +1439,103 @@  static int fimc_md_get_pinctrl(struct fimc_md *fmd)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static int cam_clk_prepare(struct clk_hw *hw)
+{
+	struct cam_clk *camclk = to_cam_clk(hw);
+	int ret;
+
+	if (camclk->fmd->pmf == NULL)
+		return -ENODEV;
+
+	ret = pm_runtime_get_sync(camclk->fmd->pmf);
+	return ret < 0 ? ret : 0;
+}
+
+static void cam_clk_unprepare(struct clk_hw *hw)
+{
+	struct cam_clk *camclk = to_cam_clk(hw);
+
+	if (camclk->fmd->pmf == NULL)
+		return;
+
+	pm_runtime_put_sync(camclk->fmd->pmf);
+}
+
+static const struct clk_ops cam_clk_ops = {
+	.prepare = cam_clk_prepare,
+	.unprepare = cam_clk_unprepare,
+};
+
+static void fimc_md_unregister_clk_provider(struct fimc_md *fmd)
+{
+	struct cam_clk_provider *cp = &fmd->clk_provider;
+	unsigned int i;
+
+	if (cp->of_node)
+		of_clk_del_provider(cp->of_node);
+
+	for (i = 0; i < cp->num_clocks; i++)
+		clk_unregister(cp->clks[i]);
+}
+
+static int fimc_md_register_clk_provider(struct fimc_md *fmd)
+{
+	struct cam_clk_provider *cp = &fmd->clk_provider;
+	struct device *dev = &fmd->pdev->dev;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(cp->clks); i++) {
+		struct cam_clk *camclk = &cp->camclk[i];
+		struct clk_init_data init;
+
+		ret = of_property_read_string_index(dev->of_node,
+					"clock-output-names", i, &init.name);
+		if (ret < 0)
+			break;
+
+		ret = of_property_read_string_index(dev->of_node,
+					"clock-names", i, init.parent_names);
+		if (ret < 0)
+			break;
+
+		init.num_parents = 1;
+		init.ops = &cam_clk_ops;
+		init.flags = CLK_SET_RATE_PARENT;
+		camclk->hw.init = &init;
+		camclk->fmd = fmd;
+
+		cp->clks[i] = clk_register(NULL, &camclk->hw);
+		if (IS_ERR(cp->clks[i])) {
+			dev_err(dev, "failed to register clock: %s (%ld)\n",
+					init.name, PTR_ERR(cp->clks[i]));
+			ret = PTR_ERR(cp->clks[i]);
+			goto err;
+		}
+		cp->num_clocks++;
+	}
+
+	if (cp->num_clocks == 0) {
+		dev_warn(dev, "clk provider not registered\n");
+		return 0;
+	}
+
+	cp->clk_data.clks = cp->clks;
+	cp->clk_data.clk_num = cp->num_clocks;
+	cp->of_node = dev->of_node;
+	ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
+				  &cp->clk_data);
+	if (ret == 0)
+		return 0;
+err:
+	fimc_md_unregister_clk_provider(fmd);
+	return ret;
+}
+#else
+#define fimc_md_register_clk_provider(fmd) (0)
+#define fimc_md_unregister_clk_provider(fmd) (0)
+#endif
+
 static int fimc_md_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1464,16 +1563,24 @@  static int fimc_md_probe(struct platform_device *pdev)
 
 	fmd->use_isp = fimc_md_is_isp_available(dev->of_node);
 
+	ret = fimc_md_register_clk_provider(fmd);
+	if (ret < 0) {
+		v4l2_err(v4l2_dev, "clock provider registration failed\n");
+		return ret;
+	}
+
 	ret = v4l2_device_register(dev, &fmd->v4l2_dev);
 	if (ret < 0) {
 		v4l2_err(v4l2_dev, "Failed to register v4l2_device: %d\n", ret);
 		return ret;
 	}
+
 	ret = media_device_register(&fmd->media_dev);
 	if (ret < 0) {
 		v4l2_err(v4l2_dev, "Failed to register media device: %d\n", ret);
 		goto err_md;
 	}
+
 	ret = fimc_md_get_clocks(fmd);
 	if (ret)
 		goto err_clk;
@@ -1507,6 +1614,7 @@  static int fimc_md_probe(struct platform_device *pdev)
 	ret = fimc_md_create_links(fmd);
 	if (ret)
 		goto err_unlock;
+
 	ret = v4l2_device_register_subdev_nodes(&fmd->v4l2_dev);
 	if (ret)
 		goto err_unlock;
@@ -1527,6 +1635,7 @@  err_clk:
 	media_device_unregister(&fmd->media_dev);
 err_md:
 	v4l2_device_unregister(&fmd->v4l2_dev);
+	fimc_md_unregister_clk_provider(fmd);
 	return ret;
 }
 
@@ -1537,6 +1646,7 @@  static int fimc_md_remove(struct platform_device *pdev)
 	if (!fmd)
 		return 0;
 
+	fimc_md_unregister_clk_provider(fmd);
 	v4l2_device_unregister(&fmd->v4l2_dev);
 	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);
 	fimc_md_unregister_entities(fmd);
diff --git a/drivers/media/platform/exynos4-is/media-dev.h b/drivers/media/platform/exynos4-is/media-dev.h
index 62599fd..a88cee5 100644
--- a/drivers/media/platform/exynos4-is/media-dev.h
+++ b/drivers/media/platform/exynos4-is/media-dev.h
@@ -10,6 +10,7 @@ 
 #define FIMC_MDEVICE_H_
 
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -89,6 +90,12 @@  struct fimc_sensor_info {
 	struct fimc_dev *host;
 };
 
+struct cam_clk {
+	struct clk_hw hw;
+	struct fimc_md *fmd;
+};
+#define to_cam_clk(_hw) container_of(_hw, struct cam_clk, hw)
+
 /**
  * struct fimc_md - fimc media device information
  * @csis: MIPI CSIS subdevs data
@@ -105,6 +112,7 @@  struct fimc_sensor_info {
  * @pinctrl: camera port pinctrl handle
  * @state_default: pinctrl default state handle
  * @state_idle: pinctrl idle state handle
+ * @cam_clk_provider: CAMCLK clock provider structure
  * @user_subdev_api: true if subdevs are not configured by the host driver
  * @slock: spinlock protecting @sensor array
  */
@@ -122,13 +130,22 @@  struct fimc_md {
 	struct media_device media_dev;
 	struct v4l2_device v4l2_dev;
 	struct platform_device *pdev;
+
 	struct fimc_pinctrl {
 		struct pinctrl *pinctrl;
 		struct pinctrl_state *state_default;
 		struct pinctrl_state *state_idle;
 	} pinctl;
-	bool user_subdev_api;
 
+	struct cam_clk_provider {
+		struct clk *clks[FIMC_MAX_CAMCLKS];
+		struct clk_onecell_data clk_data;
+		struct device_node *of_node;
+		struct cam_clk camclk[FIMC_MAX_CAMCLKS];
+		int num_clocks;
+	} clk_provider;
+
+	bool user_subdev_api;
 	spinlock_t slock;
 	struct list_head pipelines;
 };