Re: [PATCH V3 3/3] video: exynos_dp: Use the generic PHY driver

Sylwester Nawrocki
2013-07-01T19:35:42Z

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.

> 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.

> #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.

> 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 ?

> - 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