Re: [PATCH 1/3] phy: Add driver for Exynos DP PHY

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi,

On Friday 28 June 2013 11:24 AM, Jingoo Han wrote:
> On Friday, June 28, 2013 2:31 PM, Kishon Vijay Abraham I wrote:
>>
>> Hi,
>>
>> On Friday 28 June 2013 10:52 AM, Jingoo Han wrote:
>>> Add a PHY provider driver for the Samsung Exynos SoC DP PHY.
>>>
>>> Signed-off-by: Jingoo Han <jg1.han@samsung.com>
>>> ---
>>>    .../phy/samsung,exynos5250-dp-video-phy.txt        |    7 ++
>>>    drivers/phy/Kconfig                                |    8 ++
>>>    drivers/phy/Makefile                               |    3 +-
>>>    drivers/phy/phy-exynos-dp-video.c                  |  130 ++++++++++++++++++++
>>>    4 files changed, 147 insertions(+), 1 deletion(-)
>>>    create mode 100644 Documentation/devicetree/bindings/phy/samsung,exynos5250-dp-video-phy.txt
>>>    create mode 100644 drivers/phy/phy-exynos-dp-video.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/phy/samsung,exynos5250-dp-video-phy.txt
>>> b/Documentation/devicetree/bindings/phy/samsung,exynos5250-dp-video-phy.txt
>>> new file mode 100644
>>> index 0000000..8b6fa79
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/phy/samsung,exynos5250-dp-video-phy.txt
>>> @@ -0,0 +1,7 @@
>>> +Samsung EXYNOS SoC series DP PHY
>>> +-------------------------------------------------
>>> +
>>> +Required properties:
>>> +- compatible : should be "samsung,exynos5250-dp-video-phy";
>>> +- reg : offset and length of the DP PHY register set;
>>> +- #phy-cells : from the generic phy bindings, must be 1;
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index 5f85909..6d10e3b 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -11,3 +11,11 @@ menuconfig GENERIC_PHY
>>>    	  devices present in the kernel. This layer will have the generic
>>>    	  API by which phy drivers can create PHY using the phy framework and
>>>    	  phy users can obtain reference to the PHY.
>>> +
>>> +if GENERIC_PHY
>>> +
>>> +config PHY_EXYNOS_DP_VIDEO
>>> +	tristate "EXYNOS SoC series DP PHY driver"
>>> +	help
>>> +	  Support for DP PHY found on Samsung EXYNOS SoCs.
>>> +endif
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index 9e9560f..d8d861c 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -2,4 +2,5 @@
>>>    # Makefile for the phy drivers.
>>>    #
>>>
>>> -obj-$(CONFIG_GENERIC_PHY)	+= phy-core.o
>>> +obj-$(CONFIG_GENERIC_PHY)		+= phy-core.o
>>> +obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)	+= phy-exynos-dp-video.o
>>> diff --git a/drivers/phy/phy-exynos-dp-video.c b/drivers/phy/phy-exynos-dp-video.c
>>> new file mode 100644
>>> index 0000000..376b3bc2
>>> --- /dev/null
>>> +++ b/drivers/phy/phy-exynos-dp-video.c
>>> @@ -0,0 +1,130 @@
>>> +/*
>>> + * Samsung EXYNOS SoC series DP PHY driver
>>> + *
>>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>>> + * Author: Jingoo Han <jg1.han@samsung.com>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 as
>>> + * published by the Free Software Foundation.
>>> + */
>>> +
>>> +#include <linux/delay.h>
>>
>> this header file is not needed here.
>
> OK, I will remove it.
>
>>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/spinlock.h>
>>> +
>>> +/* DPTX_PHY_CONTROL register */
>>> +#define EXYNOS_DPTX_PHY_ENABLE		(1 << 0)
>>> +
>>> +struct exynos_dp_video_phy {
>>> +	spinlock_t slock;
>>> +	struct phy *phys;
>>> +	void __iomem *regs;
>>> +};
>>> +
>>> +static int __set_phy_state(struct exynos_dp_video_phy *state, unsigned int on)
>>> +{
>>> +	void __iomem *addr;
>>> +	unsigned long flags;
>>> +	u32 reg;
>>> +
>>> +	addr = state->regs;
>>> +
>>> +	spin_lock_irqsave(&state->slock, flags);
>>> +	reg = readl(addr);
>>> +	if (on)
>>> +		reg |= EXYNOS_DPTX_PHY_ENABLE;
>>> +	else
>>> +		reg &= ~EXYNOS_DPTX_PHY_ENABLE;
>>> +	writel(reg, addr);
>>> +	spin_unlock_irqrestore(&state->slock, flags);
>>> +	return 0;
>>> +}
>>> +
>>> +static int exynos_dp_video_phy_power_on(struct phy *phy)
>>> +{
>>> +	struct exynos_dp_video_phy *state = phy_get_drvdata(phy);
>>> +
>>> +	return __set_phy_state(state, 1);
>>> +}
>>> +
>>> +static int exynos_dp_video_phy_power_off(struct phy *phy)
>>> +{
>>> +	struct exynos_dp_video_phy *state = phy_get_drvdata(phy);
>>> +
>>> +	return __set_phy_state(state, 0);
>>> +}
>>> +
>>> +static struct phy *exynos_dp_video_phy_xlate(struct device *dev,
>>> +					struct of_phandle_args *args)
>>> +{
>>> +	struct exynos_dp_video_phy *state = dev_get_drvdata(dev);
>>> +
>>> +	return state->phys;
>>
>> you can instead use of_phy_simple_xlate for such simple cases.
>
> OK, I will use of_phy_simple_xlate().
>
>>> +}
>>> +
>>> +static struct phy_ops exynos_dp_video_phy_ops = {
>>> +	.power_on	= exynos_dp_video_phy_power_on,
>>> +	.power_off	= exynos_dp_video_phy_power_off,
>>> +	.owner		= THIS_MODULE,
>>> +};
>>> +
>>> +static int exynos_dp_video_phy_probe(struct platform_device *pdev)
>>> +{
>>> +	struct exynos_dp_video_phy *state;
>>> +	struct device *dev = &pdev->dev;
>>> +	struct resource *res;
>>> +	struct phy_provider *phy_provider;
>>> +
>>> +	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
>>> +	if (!state)
>>> +		return -ENOMEM;
>>> +
>>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +
>>> +	state->regs = devm_ioremap_resource(dev, res);
>>> +	if (IS_ERR(state->regs))
>>> +		return PTR_ERR(state->regs);
>>> +
>>> +	dev_set_drvdata(dev, state);
>>> +
>>> +	phy_provider = devm_of_phy_provider_register(dev,
>>> +					exynos_dp_video_phy_xlate);
>>> +	if (IS_ERR(phy_provider))
>>> +		return PTR_ERR(phy_provider);
>>> +
>>> +	state->phys = devm_phy_create(dev, 0, &exynos_dp_video_phy_ops, "dp");
>>> +	if (IS_ERR(state->phys)) {
>>> +		dev_err(dev, "failed to create DP PHY\n");
>>> +		return PTR_ERR(state->phys);
>>> +	}
>>> +	phy_set_drvdata(state->phys, state);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct of_device_id exynos_dp_video_phy_of_match[] = {
>>> +	{ .compatible = "samsung,exynos5250-dp-video-phy" },
>>> +	{ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, exynos_dp_video_phy_of_match);
>>
>> This above should come inside #ifdef CONFIG_OF.
>
> OK, I will add '#ifdef CONFIG_OF'.
>
>>> +
>>> +static struct platform_driver exynos_dp_video_phy_driver = {
>>> +	.probe	= exynos_dp_video_phy_probe,
>>
>> missing .remove?
>
> No, it is intentional.
>
> In the exynos_dp_video_phy_probe(), only devm_*() are called as below.
>    devm_kzalloc(),
>    devm_ioremap_resource(),
>    devm_of_phy_provider_register(),
>    devm_phy_create(),
>
> Also, dev_set_drvdata(dev, NULL), phy_set_drvdata(state->phys, NULL)
> are not necessary in remove(), because driver core clears automatically
> after device_release.
>
> Thus, there is no functions in the remove().

Looks correct. Alright then.

Thanks
Kishon