From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jingoo Han <jg1.han@samsung.com>
Date: Thu, 20 Sep 2012 11:46:52 +0000
Subject: Re: [PATCH] video: exynos_dp: Add device tree support to DP driver
Message-Id: <008d01cd9725$a096e480$e1c4ad80$%han@samsung.com>
List-Id: <linux-fbdev.vger.kernel.org>
References: <1347561592-29400-1-git-send-email-ajaykumar.rs@samsung.com>
In-Reply-To: <1347561592-29400-1-git-send-email-ajaykumar.rs@samsung.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: 'Ajay Kumar' <ajaykumar.rs@samsung.com>
Cc: FlorianSchandinat@gmx.de, linux-samsung-soc@vger.kernel.org, linux-fbdev@vger.kernel.org, thomas.ab@samsung.com, 'Leela Krishna Amudala' <l.krishna@samsung.com>, 'Jingoo Han' <jg1.han@samsung.com>

On Friday, September 14, 2012 3:40 AM Ajay Kumar wrote
> 
> This patch enables device tree based discovery support for DP driver.
> The driver is modified to handle platform data in both the cases:
> with DT and non-DT.
> 
> DP-PHY should be regarded as a seperate device node while
> being passed from device tree list, and device node for
> DP should contain DP-PHY as child node with property name "dp-phy"
> associated with it.

Hi Ajay,

Thank you for sending the patch for Device Tree support.
I tested the patch with Exynos5250.

As Leela Krishna Amudala mentioned, please post the documentation
for the bindings.

Also, I added some comments for minor fix.

Best regards,
Jingoo Han

> 
> Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
> ---
>  drivers/video/exynos/exynos_dp_core.c |  156 +++++++++++++++++++++++++++++++--
>  drivers/video/exynos/exynos_dp_core.h |    2 +
>  2 files changed, 151 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c
> index f57c915..15887bd 100644
> --- a/drivers/video/exynos/exynos_dp_core.c
> +++ b/drivers/video/exynos/exynos_dp_core.c
> @@ -18,6 +18,7 @@
>  #include <linux/io.h>
>  #include <linux/interrupt.h>
>  #include <linux/delay.h>
> +#include <linux/of.h>
> 
>  #include <video/exynos_dp.h>
> 
> @@ -856,20 +857,117 @@ static irqreturn_t exynos_dp_irq_handler(int irq, void *arg)
>  	return IRQ_HANDLED;
>  }
> 
> +#ifdef CONFIG_OF
> +struct exynos_dp_platdata *exynos_dp_dt_parse_pdata(struct device *dev)
> +{
> +	struct device_node *dp_node = dev->of_node;
> +	struct exynos_dp_platdata *pd;
> +	struct video_info *dp_video_config;
> +
> +	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
> +	if (!pd) {
> +		dev_err(dev, "memory allocation for pdata failed\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +	dp_video_config = devm_kzalloc(dev,
> +				sizeof(*dp_video_config), GFP_KERNEL);
> +
> +	if (!dp_video_config) {
> +		dev_err(dev, "memory allocation for video config failed\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +	pd->video_info = dp_video_config;
> +
> +	if (of_get_property(dp_node, "samsung,h-sync-polarity", NULL))
> +		dp_video_config->h_sync_polarity = 1;
> +
> +	if (of_get_property(dp_node, "samsung,v-sync-polarity", NULL))
> +		dp_video_config->v_sync_polarity = 1;
> +
> +	if (of_get_property(dp_node, "samsung,interlaced", NULL))
> +		dp_video_config->interlaced = 1;
> +
> +	of_property_read_u32(dp_node, "samsung,color_space",
> +				&dp_video_config->color_space);
> +
> +	of_property_read_u32(dp_node, "samsung,dynamic_range",
> +				&dp_video_config->dynamic_range);
> +
> +	of_property_read_u32(dp_node, "samsung,ycbcr_coeff",
> +				&dp_video_config->ycbcr_coeff);
> +
> +	of_property_read_u32(dp_node, "samsung,color_depth",
> +				&dp_video_config->color_depth);
> +
> +	of_property_read_u32(dp_node, "samsung,link_rate",
> +				&dp_video_config->link_rate);
> +
> +	of_property_read_u32(dp_node, "samsung,lane_count",
> +				&dp_video_config->lane_count);
> +	return pd;
> +}
> +
> +void exynos_dp_dt_parse_phydata(struct exynos_dp_device *dp)
> +{
> +	struct device_node *dp_phy_node;
> +
> +	const __be32 *parp;
> +
> +	u32 phy_base;
> +
> +	void *virt_phy_base;

Please, remove unnecessary spaces between variables.


> +
> +	parp = of_get_property(dp->dev->of_node, "dp_phy", NULL);
> +	if (!parp) {
> +		dp->dp_phy_addr = NULL;
> +		return;
> +	}
> +
> +	dp_phy_node = of_find_node_by_phandle(be32_to_cpup(parp));
> +	if (!dp_phy_node) {
> +		dp->dp_phy_addr = NULL;
> +		return;
> +	}
> +
> +	of_property_read_u32(dp_phy_node, "samsung,dptx_phy_reg", &phy_base);
> +	of_property_read_u32(dp_phy_node, "samsung,enable_bit",
> +							&dp->enable_bit);
> +	virt_phy_base = ioremap(phy_base, SZ_4);
> +	if (!virt_phy_base) {
> +		dev_err(dp->dev, "failed to ioremap dp-phy\n");
> +		dp->dp_phy_addr = NULL;
> +		return;
> +	}
> +	dp->dp_phy_addr = virt_phy_base;
> +}
> +
> +void dp_phy_init(struct exynos_dp_device *dp)

Use exynos_dp_phy_init.

> +{
> +	u32 reg;
> +
> +	reg = __raw_readl(dp->dp_phy_addr);
> +	reg |= dp->enable_bit;
> +	__raw_writel(reg, dp->dp_phy_addr);
> +}
> +
> +void dp_phy_exit(struct exynos_dp_device *dp)

Use exynos_dp_phy_exit.

> +{
> +	u32 reg;
> +
> +	reg = __raw_readl(dp->dp_phy_addr);
> +	reg &= ~(dp->enable_bit);
> +	__raw_writel(reg, dp->dp_phy_addr);
> +}
> +#endif /* CONFIG_OF */
> +
>  static int __devinit exynos_dp_probe(struct platform_device *pdev)
>  {
>  	struct resource *res;
>  	struct exynos_dp_device *dp;
> -	struct exynos_dp_platdata *pdata;
> +	struct exynos_dp_platdata *pdata = pdev->dev.platform_data;
> 
>  	int ret = 0;
> 
> -	pdata = pdev->dev.platform_data;
> -	if (!pdata) {
> -		dev_err(&pdev->dev, "no platform data\n");
> -		return -EINVAL;
> -	}
> -
>  	dp = devm_kzalloc(&pdev->dev, sizeof(struct exynos_dp_device),
>  				GFP_KERNEL);
>  	if (!dp) {
> @@ -879,6 +982,19 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
> 
>  	dp->dev = &pdev->dev;
> 
> +	if (pdev->dev.of_node) {
> +		pdata = exynos_dp_dt_parse_pdata(&pdev->dev);
> +		if (IS_ERR(pdata))
> +			return PTR_ERR(pdata);
> +
> +		exynos_dp_dt_parse_phydata(dp);
> +	}

I would like to use the style as follows.

if (pdev->dev.of_node) {
	DT case
else
	Non-DT case

Could you modify it as follows?

+	if (pdev->dev.of_node) {
+		pdata = exynos_dp_dt_parse_pdata(&pdev->dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+
+		exynos_dp_dt_parse_phydata(dp);
+	} else {
+		pdata = pdev->dev.platform_data;
+	}


> +
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "no platform data\n");
> +		return -EINVAL;
> +	}
> +
>  	dp->clock = devm_clk_get(&pdev->dev, "dp");
>  	if (IS_ERR(dp->clock)) {
>  		dev_err(&pdev->dev, "failed to get clock\n");
> @@ -909,9 +1025,13 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
>  	}
> 
>  	dp->video_info = pdata->video_info;
>  	if (pdata->phy_init)
>  		pdata->phy_init();
> 
> +	if (pdev->dev.of_node)
> +		if (dp->dp_phy_addr)
> +			dp_phy_init(dp);
> +

Could you modify it as follows?
phy_init() and dp_phy_init(dp) cannot be used simultaneously.
So, it seems to be clearer.

-	if (pdata->phy_init)
-		pdata->phy_init();
+
+	if (pdev->dev.of_node) {
+		if (dp->dp_phy_addr)
+			dp_phy_init(dp);
+	} else {
+		if (pdata->phy_init)
+			pdata->phy_init();
+	}


>  	exynos_dp_init_dp(dp);
> 
>  	ret = exynos_dp_detect_hpd(dp);
> @@ -956,6 +1077,10 @@ static int __devexit exynos_dp_remove(struct platform_device *pdev)
>  	if (pdata && pdata->phy_exit)
>  		pdata->phy_exit();
> 
> +	if (pdev->dev.of_node)
> +		if (dp->dp_phy_addr)
> +			dp_phy_exit(dp);
> +

Same as above.

>  	clk_disable(dp->clock);
> 
>  	return 0;
> @@ -971,6 +1096,10 @@ static int exynos_dp_suspend(struct device *dev)
>  	if (pdata && pdata->phy_exit)
>  		pdata->phy_exit();
> 
> +	if (dev->of_node)
> +		if (dp->dp_phy_addr)
> +			dp_phy_exit(dp);
> +

Same as above.

>  	clk_disable(dp->clock);
> 
>  	return 0;
> @@ -985,6 +1114,10 @@ static int exynos_dp_resume(struct device *dev)
>  	if (pdata && pdata->phy_init)
>  		pdata->phy_init();
> 
> +	if (dev->of_node)
> +		if (dp->dp_phy_addr)
> +			dp_phy_init(dp);
> +

Same as above.

>  	clk_enable(dp->clock);
> 
>  	exynos_dp_init_dp(dp);
> @@ -1013,6 +1146,14 @@ static const struct dev_pm_ops exynos_dp_pm_ops = {
>  	SET_SYSTEM_SLEEP_PM_OPS(exynos_dp_suspend, exynos_dp_resume)
>  };
> 
> +#ifdef CONFIG_OF
> +static const struct of_device_id exynos_dp_match[] = {
> +	{ .compatible = "samsung,exynos5-dp" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, exynos_dp_match);
> +#endif
> +
>  static struct platform_driver exynos_dp_driver = {
>  	.probe		= exynos_dp_probe,
>  	.remove		= __devexit_p(exynos_dp_remove),
> @@ -1020,6 +1161,7 @@ static struct platform_driver exynos_dp_driver = {
>  		.name	= "exynos-dp",
>  		.owner	= THIS_MODULE,
>  		.pm	= &exynos_dp_pm_ops,
> +		.of_match_table = of_match_ptr(exynos_dp_match),
>  	},
>  };
> 
> diff --git a/drivers/video/exynos/exynos_dp_core.h b/drivers/video/exynos/exynos_dp_core.h
> index 57b8a65..49b30cb 100644
> --- a/drivers/video/exynos/exynos_dp_core.h
> +++ b/drivers/video/exynos/exynos_dp_core.h
> @@ -29,6 +29,8 @@ struct exynos_dp_device {
>  	struct clk		*clock;
>  	unsigned int		irq;
>  	void __iomem		*reg_base;
> +	void __iomem		*dp_phy_addr;
> +	int			enable_bit;

How about replacing 'int' with 'unsigned int'?
unsigned number would be better for the bit definition.

> 
>  	struct video_info	*video_info;
>  	struct link_train	link_train;
> --
> 1.7.0.4