From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jingoo Han <jg1.han@samsung.com>
Date: Tue, 02 Jul 2013 07:05:49 +0000
Subject: Re: [PATCH V3 3/3] video: exynos_dp: Use the generic PHY driver
Message-Id: <000101ce76f2$94df04d0$be9d0e70$@samsung.com>
List-Id: <linux-fbdev.vger.kernel.org>
References: <005401ce761b$504d7090$f0e851b0$@samsung.com>
 <51D1DA07.3010803@gmail.com>
In-Reply-To: <51D1DA07.3010803@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: linux-arm-kernel@lists.infradead.org

On Tuesday, July 02, 2013 4:36 AM, Sylwester Nawrocki wrote:
> 
> Hi Jingoo,
> 
> On 07/01/2013 07:24 AM, Jingoo Han wrote:
> > Use the generic PHY API instead of the platform callback to control
> > the DP PHY. The 'phy_label' field is added to the platform data
> > structure to allow PHY lookup on non-dt platforms.
> 
> Since Exynos is currently a dt-only platform upstream, how about
> first making a pre-requisite patch that would remove support for
> non-dt platforms from this driver ? I think you could now move the
> content of file include/video/exynos_dp.h to e.g. drivers/video/
> exynos/exynos_dp_core.h and remove the public exynos_dp.h file.
> pdata->phy_init/exit could also be dropped and you wouldn't need
> to care about non-dt support with the generic PHY API.

Yes, you're right.

I will make the pre-requisite patch that would remove support for
non-dt platforms from exynos_dp_core.c.
Then, I will move the content of file include/video/exynos_dp.h
and remove 'exynos_dp.h' file.

> 
> > Signed-off-by: Jingoo Han<jg1.han@samsung.com>
> > Acked-by: Felipe Balbi<balbi@ti.com>
> > ---
> >   .../devicetree/bindings/video/exynos_dp.txt        |   23 +---
> >   drivers/video/exynos/exynos_dp_core.c              |  118 ++------------------
> >   drivers/video/exynos/exynos_dp_core.h              |    2 +
> >   include/video/exynos_dp.h                          |    6 +-
> >   4 files changed, 21 insertions(+), 128 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/video/exynos_dp.txt
> b/Documentation/devicetree/bindings/video/exynos_dp.txt
> > index 84f10c1..71645dc 100644
> > --- a/Documentation/devicetree/bindings/video/exynos_dp.txt
> > +++ b/Documentation/devicetree/bindings/video/exynos_dp.txt
> > @@ -1,17 +1,6 @@
> >   The Exynos display port interface should be configured based on
> >   the type of panel connected to it.
> >
> > -We use two nodes:
> > -	-dp-controller node
> > -	-dptx-phy node(defined inside dp-controller node)
> > -
> > -For the DP-PHY initialization, we use the dptx-phy node.
> > -Required properties for dptx-phy:
> > -	-reg:
> > -		Base address of DP PHY register.
> > -	-samsung,enable-mask:
> > -		The bit-mask used to enable/disable DP PHY.
> > -
> >   For the Panel initialization, we read data from dp-controller node.
> >   Required properties for dp-controller:
> >   	-compatible:
> > @@ -25,6 +14,10 @@ Required properties for dp-controller:
> >   		from common clock binding: handle to dp clock.
> >   	-clock-names:
> >   		from common clock binding: Shall be "dp".
> > +	-phys:
> > +		from general phy binding: the phandle for the PHY device.
> > +	-phy-names:
> > +		from general phy binding: Should be "dp".
> >   	-interrupt-parent:
> >   		phandle to Interrupt combiner node.
> >   	-samsung,color-space:
> > @@ -67,12 +60,8 @@ SOC specific portion:
> >   		interrupt-parent =<&combiner>;
> >   		clocks =<&clock 342>;
> >   		clock-names = "dp";
> > -
> > -		dptx-phy {
> > -			reg =<0x10040720>;
> > -			samsung,enable-mask =<1>;
> > -		};
> > -
> > +		phys =<&dp_phy>;
> > +		phy-names = "dp";
> >   	};
> >
> >   Board Specific portion:
> > diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c
> > index 12bbede..bac515b 100644
> > --- a/drivers/video/exynos/exynos_dp_core.c
> > +++ b/drivers/video/exynos/exynos_dp_core.c
> > @@ -19,6 +19,7 @@
> >   #include<linux/interrupt.h>
> >   #include<linux/delay.h>
> >   #include<linux/of.h>
> > +#include<linux/phy/phy.h>
> >
> >   #include<video/exynos_dp.h>
> >
> > @@ -960,84 +961,15 @@ static struct exynos_dp_platdata *exynos_dp_dt_parse_pdata(struct device *dev)
> >   		return ERR_PTR(-EINVAL);
> >   	}
> >
> > -	return pd;
> > -}
> > -
> > -static int exynos_dp_dt_parse_phydata(struct exynos_dp_device *dp)
> > -{
> > -	struct device_node *dp_phy_node = of_node_get(dp->dev->of_node);
> > -	u32 phy_base;
> > -	int ret = 0;
> > -
> > -	dp_phy_node = of_find_node_by_name(dp_phy_node, "dptx-phy");
> > -	if (!dp_phy_node) {
> > -		dev_err(dp->dev, "could not find dptx-phy node\n");
> > -		return -ENODEV;
> > -	}
> > -
> > -	if (of_property_read_u32(dp_phy_node, "reg",&phy_base)) {
> > -		dev_err(dp->dev, "failed to get reg for dptx-phy\n");
> > -		ret = -EINVAL;
> > -		goto err;
> > -	}
> > -
> > -	if (of_property_read_u32(dp_phy_node, "samsung,enable-mask",
> > -				&dp->enable_mask)) {
> > -		dev_err(dp->dev, "failed to get enable-mask for dptx-phy\n");
> > -		ret = -EINVAL;
> > -		goto err;
> > -	}
> > -
> > -	dp->phy_addr = ioremap(phy_base, SZ_4);
> > -	if (!dp->phy_addr) {
> > -		dev_err(dp->dev, "failed to ioremap dp-phy\n");
> > -		ret = -ENOMEM;
> > -		goto err;
> > -	}
> > -
> > -err:
> > -	of_node_put(dp_phy_node);
> > -
> > -	return ret;
> > -}
> > -
> > -static void exynos_dp_phy_init(struct exynos_dp_device *dp)
> > -{
> > -	u32 reg;
> > -
> > -	reg = __raw_readl(dp->phy_addr);
> > -	reg |= dp->enable_mask;
> > -	__raw_writel(reg, dp->phy_addr);
> > -}
> > -
> > -static void exynos_dp_phy_exit(struct exynos_dp_device *dp)
> > -{
> > -	u32 reg;
> > +	pd->phy_label = "dp";
> >
> > -	reg = __raw_readl(dp->phy_addr);
> > -	reg&= ~(dp->enable_mask);
> > -	__raw_writel(reg, dp->phy_addr);
> > +	return pd;
> >   }
> 
> I'm afraid you cannot simply remove the above code, the original binding
> still needs to be supported. As far as I can see Arndale and smdk5250 are
> already users of that binding in mainline now.
> 
> Thus the benefits of adding the generic PHY support to this Display Port
> controller driver are starting to be a bit questionable.

OK.
I will keep supporting this original DT binding.

> 
> >   #else
> >   static struct exynos_dp_platdata *exynos_dp_dt_parse_pdata(struct device *dev)
> >   {
> >   	return NULL;
> >   }
> > -
> > -static int exynos_dp_dt_parse_phydata(struct exynos_dp_device *dp)
> > -{
> > -	return -EINVAL;
> > -}
> > -
> > -static void exynos_dp_phy_init(struct exynos_dp_device *dp)
> > -{
> > -	return;
> > -}
> > -
> > -static void exynos_dp_phy_exit(struct exynos_dp_device *dp)
> > -{
> > -	return;
> > -}
> >   #endif /* CONFIG_OF */
> 
> I think you could make the driver dependent on CONFIG_OF now and
> related #ifdefs and !CONFIG_OF function stubs could be removed.

OK.
I will add 'depends on OF', then remove '#ifdef CONFIG_OF'
as well as !CONFIG_OF function stubs.

> 
> >   static int exynos_dp_probe(struct platform_device *pdev)
> > @@ -1061,10 +993,6 @@ static int exynos_dp_probe(struct platform_device *pdev)
> >   		pdata = exynos_dp_dt_parse_pdata(&pdev->dev);
> >   		if (IS_ERR(pdata))
> >   			return PTR_ERR(pdata);
> > -
> > -		ret = exynos_dp_dt_parse_phydata(dp);
> > -		if (ret)
> > -			return ret;
> >   	} else {
> >   		pdata = pdev->dev.platform_data;
> >   		if (!pdata) {
> > @@ -1073,6 +1001,10 @@ static int exynos_dp_probe(struct platform_device *pdev)
> >   		}
> >   	}
> >
> > +	dp->phy = devm_phy_get(&pdev->dev, pdata->phy_label);
> > +	if (IS_ERR(dp->phy))
> > +		return PTR_ERR(dp->phy);
> > +
> >   	dp->clock = devm_clk_get(&pdev->dev, "dp");
> >   	if (IS_ERR(dp->clock)) {
> >   		dev_err(&pdev->dev, "failed to get clock\n");
> > @@ -1097,13 +1029,7 @@ static int exynos_dp_probe(struct platform_device *pdev)
> >
> >   	dp->video_info = pdata->video_info;
> >
> > -	if (pdev->dev.of_node) {
> > -		if (dp->phy_addr)
> > -			exynos_dp_phy_init(dp);
> > -	} else {
> > -		if (pdata->phy_init)
> > -			pdata->phy_init();
> > -	}
> > +	phy_power_on(dp->phy);
> >
> >   	exynos_dp_init_dp(dp);
> >
> > @@ -1121,42 +1047,27 @@ static int exynos_dp_probe(struct platform_device *pdev)
> >
> >   static int exynos_dp_remove(struct platform_device *pdev)
> >   {
> > -	struct exynos_dp_platdata *pdata = pdev->dev.platform_data;
> >   	struct exynos_dp_device *dp = platform_get_drvdata(pdev);
> >
> >   	flush_work(&dp->hotplug_work);
> >
> > -	if (pdev->dev.of_node) {
> > -		if (dp->phy_addr)
> > -			exynos_dp_phy_exit(dp);
> > -	} else {
> > -		if (pdata->phy_exit)
> > -			pdata->phy_exit();
> > -	}
> > +	phy_power_off(dp->phy);
> >
> >   	clk_disable_unprepare(dp->clock);
> >
> > -
> >   	return 0;
> >   }
> >
> >   #ifdef CONFIG_PM_SLEEP
> >   static int exynos_dp_suspend(struct device *dev)
> >   {
> > -	struct exynos_dp_platdata *pdata = dev->platform_data;
> >   	struct exynos_dp_device *dp = dev_get_drvdata(dev);
> >
> >   	disable_irq(dp->irq);
> >
> >   	flush_work(&dp->hotplug_work);
> >
> > -	if (dev->of_node) {
> > -		if (dp->phy_addr)
> > -			exynos_dp_phy_exit(dp);
> > -	} else {
> > -		if (pdata->phy_exit)
> > -			pdata->phy_exit();
> > -	}
> > +	phy_power_off(dp->phy);
> >
> >   	clk_disable_unprepare(dp->clock);
> >
> > @@ -1165,16 +1076,9 @@ static int exynos_dp_suspend(struct device *dev)
> >
> >   static int exynos_dp_resume(struct device *dev)
> >   {
> > -	struct exynos_dp_platdata *pdata = dev->platform_data;
> >   	struct exynos_dp_device *dp = dev_get_drvdata(dev);
> >
> > -	if (dev->of_node) {
> > -		if (dp->phy_addr)
> > -			exynos_dp_phy_init(dp);
> > -	} else {
> > -		if (pdata->phy_init)
> > -			pdata->phy_init();
> > -	}
> > +	phy_power_on(dp->phy);
> >
> >   	clk_prepare_enable(dp->clock);
> >
> > diff --git a/drivers/video/exynos/exynos_dp_core.h b/drivers/video/exynos/exynos_dp_core.h
> > index 6c567bbf..b3d0328 100644
> > --- a/drivers/video/exynos/exynos_dp_core.h
> > +++ b/drivers/video/exynos/exynos_dp_core.h
> > @@ -42,6 +42,8 @@ struct exynos_dp_device {
> >   	struct video_info	*video_info;
> >   	struct link_train	link_train;
> >   	struct work_struct	hotplug_work;
> > +
> > +	struct phy		*phy;
> >   };
> >
> >   /* exynos_dp_reg.c */
> > diff --git a/include/video/exynos_dp.h b/include/video/exynos_dp.h
> > index bd8cabd..f38c9af 100644
> > --- a/include/video/exynos_dp.h
> > +++ b/include/video/exynos_dp.h
> > @@ -122,10 +122,8 @@ struct video_info {
> >   };
> >
> >   struct exynos_dp_platdata {
> 
> Since Exynos doesn't support non-dt boot now this platform data structure
> is not used, is it ?

You're right.
It can be removed, if Exynos DP driver does not non-DT.

Best regards,
Jingoo Han

> 
> > -	struct video_info *video_info;
> > -
> > -	void (*phy_init)(void);
> > -	void (*phy_exit)(void);
> > +	struct video_info	*video_info;
> > +	const char		*phy_label;
> >   };
> >
> >   #endif /* _EXYNOS_DP_H */
> 
> Regards,
> Sylwester