[v5,1/5] usb: phy: samsung: Introducing usb phy driver for hsotg

Commit Message

[e-mail] Sept. 12, 2012, 10:45 a.m. UTC

This driver uses usb_phy interface to interact with s3c-hsotg. Supports
phy_init and phy_shutdown functions to enable/disable phy. Tested with
smdk6410 and smdkv310. More SoCs can be brought under later.

Signed-off-by: Praveen Paneri <[e-mail]>
Acked-by: Heiko Stuebner <[e-mail]>
---
 .../devicetree/bindings/usb/samsung-usbphy.txt     |    9 +
 drivers/usb/phy/Kconfig                            |    8 +
 drivers/usb/phy/Makefile                           |    1 +
 drivers/usb/phy/samsung-usbphy.c                   |  371 ++++++++++++++++++++
 include/linux/platform_data/samsung-usbphy.h       |   27 ++
 5 files changed, 416 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/usb/samsung-usbphy.txt
 create mode 100644 drivers/usb/phy/samsung-usbphy.c
 create mode 100644 include/linux/platform_data/samsung-usbphy.h

Comments

Marc Kleine-Budde Sept. 12, 2012, 11:08 a.m. UTC | #1

On 09/12/2012 12:45 PM, Praveen Paneri wrote:
> This driver uses usb_phy interface to interact with s3c-hsotg. Supports
> phy_init and phy_shutdown functions to enable/disable phy. Tested with
> smdk6410 and smdkv310. More SoCs can be brought under later.
> 
> Signed-off-by: Praveen Paneri <[e-mail]>
> Acked-by: Heiko Stuebner <[e-mail]>
> ---
>  .../devicetree/bindings/usb/samsung-usbphy.txt     |    9 +
>  drivers/usb/phy/Kconfig                            |    8 +
>  drivers/usb/phy/Makefile                           |    1 +
>  drivers/usb/phy/samsung-usbphy.c                   |  371 ++++++++++++++++++++
>  include/linux/platform_data/samsung-usbphy.h       |   27 ++
>  5 files changed, 416 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>  create mode 100644 drivers/usb/phy/samsung-usbphy.c
>  create mode 100644 include/linux/platform_data/samsung-usbphy.h
> 
> diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> new file mode 100644
> index 0000000..fefd9c8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> @@ -0,0 +1,9 @@
> +* Samsung's usb phy transceiver
> +
> +The Samsung's phy transceiver is used for controlling usb otg phy for
> +s3c-hsotg usb device controller.
> +
> +Required properties:
> +- compatible : should be "samsung,exynos4210-usbphy"
> +- reg : base physical address of the phy registers and length of memory mapped
> +	region.
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index 63c339b..313685f 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -32,3 +32,11 @@ config MV_U3D_PHY
>  	help
>  	  Enable this to support Marvell USB 3.0 phy controller for Marvell
>  	  SoC.
> +
> +config SAMSUNG_USBPHY
> +	bool "Samsung USB PHY controller Driver"
> +	depends on USB_S3C_HSOTG
> +	select USB_OTG_UTILS
> +	help
> +	  Enable this to support Samsung USB phy controller for samsung
> +	  SoCs.
> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
> index b069f29..55dcfc1 100644
> --- a/drivers/usb/phy/Makefile
> +++ b/drivers/usb/phy/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_OMAP_USB2)			+= omap-usb2.o
>  obj-$(CONFIG_USB_ISP1301)		+= isp1301.o
>  obj-$(CONFIG_MV_U3D_PHY)		+= mv_u3d_phy.o
>  obj-$(CONFIG_USB_EHCI_TEGRA)	+= tegra_usb_phy.o
> +obj-$(CONFIG_SAMSUNG_USBPHY)		+= samsung-usbphy.o
> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
> new file mode 100644
> index 0000000..b00d01b
> --- /dev/null
> +++ b/drivers/usb/phy/samsung-usbphy.c
> @@ -0,0 +1,371 @@
> +/* linux/drivers/usb/phy/samsung-usbphy.c
> + *
> + * Copyright (c) 2012 Samsung Electronics Co., Ltd.
> + *              http://www.samsung.com
> + *
> + * Author: Praveen Paneri <[e-mail]>
> + *
> + * Samsung USB2.0 High-speed OTG transceiver, talks to S3C HS OTG controller
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/usb/otg.h>
> +#include <linux/platform_data/samsung-usbphy.h>
> +
> +/* Register definitions */
> +
> +#define S3C_PHYPWR				(0x00)
> +
> +#define S3C_PHYPWR_NORMAL_MASK			(0x19 << 0)
> +#define S3C_PHYPWR_OTG_DISABLE			(1 << 4)
> +#define S3C_PHYPWR_ANALOG_POWERDOWN		(1 << 3)
> +#define S3C_PHYPWR_FORCE_SUSPEND		(1 << 1)
> +/* For Exynos4 */
> +#define EXYNOS4_PHYPWR_NORMAL_MASK		(0x39 << 0)
> +#define EXYNOS4_PHYPWR_SLEEP			(1 << 5)
> +
> +#define S3C_PHYCLK				(0x04)
> +
> +#define S3C_PHYCLK_MODE_SERIAL			(1 << 6)
> +#define S3C_PHYCLK_EXT_OSC			(1 << 5)
> +#define S3C_PHYCLK_COMMON_ON_N			(1 << 4)
> +#define S3C_PHYCLK_ID_PULL			(1 << 2)
> +#define S3C_PHYCLK_CLKSEL_MASK			(0x3 << 0)
> +#define S3C_PHYCLK_CLKSEL_SHIFT			(0)
> +#define S3C_PHYCLK_CLKSEL_48M			(0x0 << 0)
> +#define S3C_PHYCLK_CLKSEL_12M			(0x2 << 0)
> +#define S3C_PHYCLK_CLKSEL_24M			(0x3 << 0)
> +
> +#define S3C_RSTCON				(0x08)
> +
> +#define S3C_RSTCON_PHYCLK			(1 << 2)
> +#define S3C_RSTCON_HCLK				(1 << 1)
> +#define S3C_RSTCON_PHY				(1 << 0)
> +
> +#ifndef MHZ
> +#define MHZ (1000*1000)
> +#endif
> +
> +enum samsung_cpu_type {
> +	TYPE_S3C64XX,
> +	TYPE_EXYNOS4210,
> +};
> +
> +/*
> + * struct samsung_usbphy - transceiver driver state
> + * @phy: transceiver structure
> + * @plat: platform data
> + * @dev: The parent device supplied to the probe function
> + * @clk: usb phy clock
> + * @regs: usb phy register memory base
> + * @cpu_type: machine identifier
> + */
> +struct samsung_usbphy {
> +	struct usb_phy	phy;
> +	struct samsung_usbphy_data *plat;
> +	struct device	*dev;
> +	struct clk	*clk;
> +	void __iomem	*regs;
> +	int		cpu_type;
> +};
> +
> +#define phy_to_sphy(x)		container_of((x), struct samsung_usbphy, phy)
> +
> +/*
> + * Enables or disables the phy clock
> + * returns 0 on success else the error
> + */
> +static int samsung_usbphy_clk_control(struct samsung_usbphy *sphy, bool on)
> +{
> +	if (on) {
> +		if (!sphy->clk) {
> +			sphy->clk = clk_get(sphy->dev, "otg");

Why don't you get the clock in the probe function?

> +			if (IS_ERR(sphy->clk)) {
> +				dev_err(sphy->dev, "Failed to get otg clock\n");
> +				return PTR_ERR(sphy->clk);
> +			}
> +		}
> +		clk_enable(sphy->clk);

I think you have to prepare the clock, too. Thus better use:
clk_prepare_enable();

> +	} else {
> +		clk_disable(sphy->clk);

clk_disable_unprepare()

> +		clk_put(sphy->clk);

Move this to you remove function.

> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * Returns reference clock frequency
> + */
> +static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
> +{
> +	struct clk *ref_clk;
> +	int refclk_freq = 0;
> +
> +	ref_clk = clk_get(sphy->dev, "xusbxti");

Can you move the samsung_usbphy_get_refclk_freq to your probe function
and save refclock in your private data?

> +	if (IS_ERR(ref_clk)) {
> +		dev_err(sphy->dev, "Failed to get reference clock\n");
> +		return PTR_ERR(ref_clk);
> +	}
> +
> +	switch (clk_get_rate(ref_clk)) {
> +	case 12 * MHZ:
> +		refclk_freq |= S3C_PHYCLK_CLKSEL_12M;
> +		break;
> +	case 24 * MHZ:
> +		refclk_freq |= S3C_PHYCLK_CLKSEL_24M;
> +		break;
> +	default:
> +	case 48 * MHZ:
> +		/* default reference clock */
> +		refclk_freq |= S3C_PHYCLK_CLKSEL_48M;
> +		break;
> +	}
> +	clk_put(ref_clk);
> +
> +	return refclk_freq;
> +}
> +
> +static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
> +{
> +	void __iomem *regs = sphy->regs;
> +	u32 phypwr;
> +	u32 phyclk;
> +	u32 rstcon;
> +
> +	/* set clock frequency for PLL */
> +	phyclk = samsung_usbphy_get_refclk_freq(sphy);
> +	phypwr = readl(regs + S3C_PHYPWR);
> +	rstcon = readl(regs + S3C_RSTCON);
> +
> +	switch (sphy->cpu_type) {
> +	case TYPE_S3C64XX:
> +		phyclk &= ~(S3C_PHYCLK_COMMON_ON_N);
> +		phypwr &= ~S3C_PHYPWR_NORMAL_MASK;
> +		rstcon |= S3C_RSTCON_PHY;
> +		break;
> +	case TYPE_EXYNOS4210:
> +		phypwr &= ~EXYNOS4_PHYPWR_NORMAL_MASK;
> +		rstcon |= S3C_RSTCON_PHY;
> +	default:
> +		break;
> +	}
> +
> +	writel(phyclk, regs + S3C_PHYCLK);
> +	/* set to normal of PHY0 */
> +	writel(phypwr, regs + S3C_PHYPWR);
> +	/* reset all ports of PHY and Link */
> +	writel(rstcon, regs + S3C_RSTCON);
> +	udelay(10);
> +	rstcon &= ~S3C_RSTCON_PHY;
> +	writel(rstcon, regs + S3C_RSTCON);
> +}
> +
> +static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
> +{
> +	void __iomem *regs = sphy->regs;
> +	u32 phypwr;
> +
> +	phypwr = readl(regs + S3C_PHYPWR);
> +
> +	switch (sphy->cpu_type) {
> +	case TYPE_S3C64XX:
> +		phypwr |= S3C_PHYPWR_NORMAL_MASK;
> +		break;
> +	case TYPE_EXYNOS4210:
> +		phypwr |= EXYNOS4_PHYPWR_NORMAL_MASK;
> +	default:
> +		break;
> +	}
> +
> +	/* unset to normal of PHY0 */
> +	writel(phypwr, regs + S3C_PHYPWR);
> +}
> +
> +/*
> + * The function passed to the usb driver for phy initialization
> + */
> +static int samsung_usbphy_init(struct usb_phy *phy)
> +{
> +	struct samsung_usbphy *sphy;
> +	int ret = 0;
> +
> +	sphy = phy_to_sphy(phy);
> +
> +	/* Enable the phy clock */
> +	ret = samsung_usbphy_clk_control(sphy, true);
> +	if (ret) {
> +		dev_err(sphy->dev, "phy clock enable failed\n");
> +		return ret;
> +	}
> +
> +	/* Disable phy isolation */
> +	if (sphy->plat && sphy->plat->pmu_isolation)
> +		sphy->plat->pmu_isolation(false);
> +
> +	/* Initialize usb phy registers */
> +	samsung_usbphy_enable(sphy);
> +	return ret;
> +}
> +
> +/*
> + * The function passed to the usb driver for phy shutdown
> + */
> +static void samsung_usbphy_shutdown(struct usb_phy *phy)
> +{
> +	struct samsung_usbphy *sphy;
> +
> +	sphy = phy_to_sphy(phy);
> +
> +	/* De-initialize usb phy registers */
> +	samsung_usbphy_disable(sphy);
> +
> +	/* Enable phy isolation */
> +	if (sphy->plat && sphy->plat->pmu_isolation)
> +		sphy->plat->pmu_isolation(true);
> +
> +	/* Disable the phy clock */
> +	samsung_usbphy_clk_control(sphy, false);
> +}
> +
> +static const struct of_device_id samsung_usbphy_dt_match[];
> +
> +static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
> +{
> +#ifdef CONFIG_OF

if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)

> +	int data;
> +	if (pdev->dev.of_node) {
> +		const struct of_device_id *match;
> +		match = of_match_node(samsung_usbphy_dt_match,
> +							pdev->dev.of_node);
> +		data = (int) match->data;
> +		return data;
> +	}
> +#endif
> +	return platform_get_device_id(pdev)->driver_data;
> +}
> +
> +static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
> +{
> +	struct samsung_usbphy *sphy;
> +	struct samsung_usbphy_data *pdata;
> +	struct device *dev = &pdev->dev;
> +	struct resource *phy_mem;
> +	void __iomem	*phy_base;
> +	int	ret;
> +
> +	pdata = pdev->dev.platform_data;
> +	if (!pdata) {

Do you need platform data when probed via DT, too?

> +		dev_err(&pdev->dev, "%s: no platform data defined\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!phy_mem) {
> +		dev_err(dev, "%s: missing mem resource\n", __func__);
> +		return -ENODEV;
> +	}
> +
> +	phy_base = devm_request_and_ioremap(dev, phy_mem);
> +	if (!phy_base) {
> +		dev_err(dev, "%s: register mapping failed\n", __func__);
> +		return -ENXIO;
> +	}
> +
> +	sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
> +	if (!sphy)
> +		return -ENOMEM;
> +
> +	sphy->dev		= &pdev->dev;
> +	sphy->plat		= pdata;
> +	sphy->regs		= phy_base;
> +	sphy->phy.dev		= sphy->dev;
> +	sphy->phy.label		= "samsung-usbphy";
> +	sphy->phy.init		= samsung_usbphy_init;
> +	sphy->phy.shutdown	= samsung_usbphy_shutdown;
> +	sphy->cpu_type		= samsung_usbphy_get_driver_data(pdev);
> +
> +	ret = usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB2);
> +	if (ret)
> +		goto err;
> +
> +	platform_set_drvdata(pdev, sphy);
> +err:
> +	return ret;
> +}
> +
> +static int __exit samsung_usbphy_remove(struct platform_device *pdev)
> +{
> +	struct samsung_usbphy *sphy = platform_get_drvdata(pdev);
> +
> +	usb_remove_phy(&sphy->phy);
> +
> +	if (sphy->clk) {
> +		clk_put(sphy->clk);

Are you sure that your clk_put is balanced?

> +		sphy->clk = NULL;
> +	}
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id samsung_usbphy_dt_match[] = {
> +	{
> +		.compatible = "samsung,s3c64xx-usbphy",
> +		.data = (void *)TYPE_S3C64XX,
> +	}, {
> +		.compatible = "samsung,exynos4210-usbphy",
> +		.data = (void *)TYPE_EXYNOS4210,
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
> +#else
> +#define samsung_usbphy_dt_match NULL
> +#endif
> +
> +static struct platform_device_id samsung_usbphy_driver_ids[] = {
> +	{
> +		.name		= "s3c64xx-usbphy",
> +		.driver_data	= TYPE_S3C64XX,
> +	}, {
> +		.name		= "exynos4210-usbphy",
> +		.driver_data	= TYPE_EXYNOS4210,
> +	},
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(platform, samsung_usbphy_driver_ids);
> +
> +static struct platform_driver samsung_usbphy_driver = {
> +	.probe		= samsung_usbphy_probe,
> +	.remove		= __devexit_p(samsung_usbphy_remove),
> +	.id_table	= samsung_usbphy_driver_ids,
> +	.driver		= {
> +		.name	= "samsung-usbphy",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = samsung_usbphy_dt_match,
> +	},
> +};
> +
> +module_platform_driver(samsung_usbphy_driver);
> +
> +MODULE_DESCRIPTION("Samsung USB phy controller");
> +MODULE_AUTHOR("Praveen Paneri <[e-mail]>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:samsung-usbphy");
> diff --git a/include/linux/platform_data/samsung-usbphy.h b/include/linux/platform_data/samsung-usbphy.h
> new file mode 100644
> index 0000000..1bd24cb
> --- /dev/null
> +++ b/include/linux/platform_data/samsung-usbphy.h
> @@ -0,0 +1,27 @@
> +/*
> + * Copyright (C) 2012 Samsung Electronics Co.Ltd
> + *		http://www.samsung.com/
> + * Author: Praveen Paneri <[e-mail]>
> + *
> + * Defines platform data for samsung usb phy driver.
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + */
> +
> +#ifndef __SAMSUNG_USBPHY_PLATFORM_H
> +#define __SAMSUNG_USBPHY_PLATFORM_H
> +
> +/**
> + * samsung_usbphy_data - Platform data for USB PHY driver.
> + * @pmu_isolation: Function to control usb phy isolation in PMU.
> + */
> +struct samsung_usbphy_data {
> +	void (*pmu_isolation)(int on);
> +};
> +
> +extern void samsung_usbphy_set_pdata(struct samsung_usbphy_data *pd);
> +
> +#endif /* __SAMSUNG_USBPHY_PLATFORM_H */
> 
Marc

Tomasz Figa Sept. 12, 2012, 4:21 p.m. UTC | #2

Hi Praveen, Marc,

On Wednesday 12 of September 2012 13:08:26 Marc Kleine-Budde wrote:
> > +static const struct of_device_id samsung_usbphy_dt_match[];
> > +
> > +static inline int samsung_usbphy_get_driver_data(struct
> > platform_device *pdev) +{
> > +#ifdef CONFIG_OF
> 
> if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)

Is this check needed at all?

In case of CONFIG_OF disabled, of_node should always be NULL and there is a 
dummy macro provided for of_match_node, so it should compile and work just 
fine.

--
Best regards,
Tomasz Figa

[e-mail] Sept. 14, 2012, 6:24 a.m. UTC | #3

On Wed, Sep 12, 2012 at 4:38 PM, Marc Kleine-Budde <[e-mail]> wrote:
> On 09/12/2012 12:45 PM, Praveen Paneri wrote:
>> This driver uses usb_phy interface to interact with s3c-hsotg. Supports
>> phy_init and phy_shutdown functions to enable/disable phy. Tested with
>> smdk6410 and smdkv310. More SoCs can be brought under later.
>>
>> Signed-off-by: Praveen Paneri <[e-mail]>
>> Acked-by: Heiko Stuebner <[e-mail]>
>> ---
>>  .../devicetree/bindings/usb/samsung-usbphy.txt     |    9 +
>>  drivers/usb/phy/Kconfig                            |    8 +
>>  drivers/usb/phy/Makefile                           |    1 +
>>  drivers/usb/phy/samsung-usbphy.c                   |  371 ++++++++++++++++++++
>>  include/linux/platform_data/samsung-usbphy.h       |   27 ++
>>  5 files changed, 416 insertions(+), 0 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>>  create mode 100644 drivers/usb/phy/samsung-usbphy.c
>>  create mode 100644 include/linux/platform_data/samsung-usbphy.h
>>
>> diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>> new file mode 100644
>> index 0000000..fefd9c8
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
>> @@ -0,0 +1,9 @@
>> +* Samsung's usb phy transceiver
>> +
>> +The Samsung's phy transceiver is used for controlling usb otg phy for
>> +s3c-hsotg usb device controller.
>> +
>> +Required properties:
>> +- compatible : should be "samsung,exynos4210-usbphy"
>> +- reg : base physical address of the phy registers and length of memory mapped
>> +     region.
>> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
>> index 63c339b..313685f 100644
>> --- a/drivers/usb/phy/Kconfig
>> +++ b/drivers/usb/phy/Kconfig
>> @@ -32,3 +32,11 @@ config MV_U3D_PHY
>>       help
>>         Enable this to support Marvell USB 3.0 phy controller for Marvell
>>         SoC.
>> +
>> +config SAMSUNG_USBPHY
>> +     bool "Samsung USB PHY controller Driver"
>> +     depends on USB_S3C_HSOTG
>> +     select USB_OTG_UTILS
>> +     help
>> +       Enable this to support Samsung USB phy controller for samsung
>> +       SoCs.
>> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
>> index b069f29..55dcfc1 100644
>> --- a/drivers/usb/phy/Makefile
>> +++ b/drivers/usb/phy/Makefile
>> @@ -8,3 +8,4 @@ obj-$(CONFIG_OMAP_USB2)                       += omap-usb2.o
>>  obj-$(CONFIG_USB_ISP1301)            += isp1301.o
>>  obj-$(CONFIG_MV_U3D_PHY)             += mv_u3d_phy.o
>>  obj-$(CONFIG_USB_EHCI_TEGRA) += tegra_usb_phy.o
>> +obj-$(CONFIG_SAMSUNG_USBPHY)         += samsung-usbphy.o
>> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
>> new file mode 100644
>> index 0000000..b00d01b
>> --- /dev/null
>> +++ b/drivers/usb/phy/samsung-usbphy.c
>> @@ -0,0 +1,371 @@
>> +/* linux/drivers/usb/phy/samsung-usbphy.c
>> + *
>> + * Copyright (c) 2012 Samsung Electronics Co., Ltd.
>> + *              http://www.samsung.com
>> + *
>> + * Author: Praveen Paneri <[e-mail]>
>> + *
>> + * Samsung USB2.0 High-speed OTG transceiver, talks to S3C HS OTG controller
>> + *
>> + * 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.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/of.h>
>> +#include <linux/usb/otg.h>
>> +#include <linux/platform_data/samsung-usbphy.h>
>> +
>> +/* Register definitions */
>> +
>> +#define S3C_PHYPWR                           (0x00)
>> +
>> +#define S3C_PHYPWR_NORMAL_MASK                       (0x19 << 0)
>> +#define S3C_PHYPWR_OTG_DISABLE                       (1 << 4)
>> +#define S3C_PHYPWR_ANALOG_POWERDOWN          (1 << 3)
>> +#define S3C_PHYPWR_FORCE_SUSPEND             (1 << 1)
>> +/* For Exynos4 */
>> +#define EXYNOS4_PHYPWR_NORMAL_MASK           (0x39 << 0)
>> +#define EXYNOS4_PHYPWR_SLEEP                 (1 << 5)
>> +
>> +#define S3C_PHYCLK                           (0x04)
>> +
>> +#define S3C_PHYCLK_MODE_SERIAL                       (1 << 6)
>> +#define S3C_PHYCLK_EXT_OSC                   (1 << 5)
>> +#define S3C_PHYCLK_COMMON_ON_N                       (1 << 4)
>> +#define S3C_PHYCLK_ID_PULL                   (1 << 2)
>> +#define S3C_PHYCLK_CLKSEL_MASK                       (0x3 << 0)
>> +#define S3C_PHYCLK_CLKSEL_SHIFT                      (0)
>> +#define S3C_PHYCLK_CLKSEL_48M                        (0x0 << 0)
>> +#define S3C_PHYCLK_CLKSEL_12M                        (0x2 << 0)
>> +#define S3C_PHYCLK_CLKSEL_24M                        (0x3 << 0)
>> +
>> +#define S3C_RSTCON                           (0x08)
>> +
>> +#define S3C_RSTCON_PHYCLK                    (1 << 2)
>> +#define S3C_RSTCON_HCLK                              (1 << 1)
>> +#define S3C_RSTCON_PHY                               (1 << 0)
>> +
>> +#ifndef MHZ
>> +#define MHZ (1000*1000)
>> +#endif
>> +
>> +enum samsung_cpu_type {
>> +     TYPE_S3C64XX,
>> +     TYPE_EXYNOS4210,
>> +};
>> +
>> +/*
>> + * struct samsung_usbphy - transceiver driver state
>> + * @phy: transceiver structure
>> + * @plat: platform data
>> + * @dev: The parent device supplied to the probe function
>> + * @clk: usb phy clock
>> + * @regs: usb phy register memory base
>> + * @cpu_type: machine identifier
>> + */
>> +struct samsung_usbphy {
>> +     struct usb_phy  phy;
>> +     struct samsung_usbphy_data *plat;
>> +     struct device   *dev;
>> +     struct clk      *clk;
>> +     void __iomem    *regs;
>> +     int             cpu_type;
>> +};
>> +
>> +#define phy_to_sphy(x)               container_of((x), struct samsung_usbphy, phy)
>> +
>> +/*
>> + * Enables or disables the phy clock
>> + * returns 0 on success else the error
>> + */
>> +static int samsung_usbphy_clk_control(struct samsung_usbphy *sphy, bool on)
>> +{
>> +     if (on) {
>> +             if (!sphy->clk) {
>> +                     sphy->clk = clk_get(sphy->dev, "otg");
>
> Why don't you get the clock in the probe function?
Yes! that can be done.
>
>> +                     if (IS_ERR(sphy->clk)) {
>> +                             dev_err(sphy->dev, "Failed to get otg clock\n");
>> +                             return PTR_ERR(sphy->clk);
>> +                     }
>> +             }
>> +             clk_enable(sphy->clk);
>
> I think you have to prepare the clock, too. Thus better use:
> clk_prepare_enable();
Will change it.
>
>> +     } else {
>> +             clk_disable(sphy->clk);
>
> clk_disable_unprepare()
>
>> +             clk_put(sphy->clk);
>
> Move this to you remove function.
>
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +/*
>> + * Returns reference clock frequency
>> + */
>> +static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
>> +{
>> +     struct clk *ref_clk;
>> +     int refclk_freq = 0;
>> +
>> +     ref_clk = clk_get(sphy->dev, "xusbxti");
>
> Can you move the samsung_usbphy_get_refclk_freq to your probe function
> and save refclock in your private data?
Sure
>
>> +     if (IS_ERR(ref_clk)) {
>> +             dev_err(sphy->dev, "Failed to get reference clock\n");
>> +             return PTR_ERR(ref_clk);
>> +     }
>> +
>> +     switch (clk_get_rate(ref_clk)) {
>> +     case 12 * MHZ:
>> +             refclk_freq |= S3C_PHYCLK_CLKSEL_12M;
>> +             break;
>> +     case 24 * MHZ:
>> +             refclk_freq |= S3C_PHYCLK_CLKSEL_24M;
>> +             break;
>> +     default:
>> +     case 48 * MHZ:
>> +             /* default reference clock */
>> +             refclk_freq |= S3C_PHYCLK_CLKSEL_48M;
>> +             break;
>> +     }
>> +     clk_put(ref_clk);
>> +
>> +     return refclk_freq;
>> +}
>> +
>> +static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
>> +{
>> +     void __iomem *regs = sphy->regs;
>> +     u32 phypwr;
>> +     u32 phyclk;
>> +     u32 rstcon;
>> +
>> +     /* set clock frequency for PLL */
>> +     phyclk = samsung_usbphy_get_refclk_freq(sphy);
>> +     phypwr = readl(regs + S3C_PHYPWR);
>> +     rstcon = readl(regs + S3C_RSTCON);
>> +
>> +     switch (sphy->cpu_type) {
>> +     case TYPE_S3C64XX:
>> +             phyclk &= ~(S3C_PHYCLK_COMMON_ON_N);
>> +             phypwr &= ~S3C_PHYPWR_NORMAL_MASK;
>> +             rstcon |= S3C_RSTCON_PHY;
>> +             break;
>> +     case TYPE_EXYNOS4210:
>> +             phypwr &= ~EXYNOS4_PHYPWR_NORMAL_MASK;
>> +             rstcon |= S3C_RSTCON_PHY;
>> +     default:
>> +             break;
>> +     }
>> +
>> +     writel(phyclk, regs + S3C_PHYCLK);
>> +     /* set to normal of PHY0 */
>> +     writel(phypwr, regs + S3C_PHYPWR);
>> +     /* reset all ports of PHY and Link */
>> +     writel(rstcon, regs + S3C_RSTCON);
>> +     udelay(10);
>> +     rstcon &= ~S3C_RSTCON_PHY;
>> +     writel(rstcon, regs + S3C_RSTCON);
>> +}
>> +
>> +static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
>> +{
>> +     void __iomem *regs = sphy->regs;
>> +     u32 phypwr;
>> +
>> +     phypwr = readl(regs + S3C_PHYPWR);
>> +
>> +     switch (sphy->cpu_type) {
>> +     case TYPE_S3C64XX:
>> +             phypwr |= S3C_PHYPWR_NORMAL_MASK;
>> +             break;
>> +     case TYPE_EXYNOS4210:
>> +             phypwr |= EXYNOS4_PHYPWR_NORMAL_MASK;
>> +     default:
>> +             break;
>> +     }
>> +
>> +     /* unset to normal of PHY0 */
>> +     writel(phypwr, regs + S3C_PHYPWR);
>> +}
>> +
>> +/*
>> + * The function passed to the usb driver for phy initialization
>> + */
>> +static int samsung_usbphy_init(struct usb_phy *phy)
>> +{
>> +     struct samsung_usbphy *sphy;
>> +     int ret = 0;
>> +
>> +     sphy = phy_to_sphy(phy);
>> +
>> +     /* Enable the phy clock */
>> +     ret = samsung_usbphy_clk_control(sphy, true);
>> +     if (ret) {
>> +             dev_err(sphy->dev, "phy clock enable failed\n");
>> +             return ret;
>> +     }
>> +
>> +     /* Disable phy isolation */
>> +     if (sphy->plat && sphy->plat->pmu_isolation)
>> +             sphy->plat->pmu_isolation(false);
>> +
>> +     /* Initialize usb phy registers */
>> +     samsung_usbphy_enable(sphy);
>> +     return ret;
>> +}
>> +
>> +/*
>> + * The function passed to the usb driver for phy shutdown
>> + */
>> +static void samsung_usbphy_shutdown(struct usb_phy *phy)
>> +{
>> +     struct samsung_usbphy *sphy;
>> +
>> +     sphy = phy_to_sphy(phy);
>> +
>> +     /* De-initialize usb phy registers */
>> +     samsung_usbphy_disable(sphy);
>> +
>> +     /* Enable phy isolation */
>> +     if (sphy->plat && sphy->plat->pmu_isolation)
>> +             sphy->plat->pmu_isolation(true);
>> +
>> +     /* Disable the phy clock */
>> +     samsung_usbphy_clk_control(sphy, false);
>> +}
>> +
>> +static const struct of_device_id samsung_usbphy_dt_match[];
>> +
>> +static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
>> +{
>> +#ifdef CONFIG_OF
>
> if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)
 I will change it.
>
>> +     int data;
>> +     if (pdev->dev.of_node) {
>> +             const struct of_device_id *match;
>> +             match = of_match_node(samsung_usbphy_dt_match,
>> +                                                     pdev->dev.of_node);
>> +             data = (int) match->data;
>> +             return data;
>> +     }
>> +#endif
>> +     return platform_get_device_id(pdev)->driver_data;
>> +}
>> +
>> +static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
>> +{
>> +     struct samsung_usbphy *sphy;
>> +     struct samsung_usbphy_data *pdata;
>> +     struct device *dev = &pdev->dev;
>> +     struct resource *phy_mem;
>> +     void __iomem    *phy_base;
>> +     int     ret;
>> +
>> +     pdata = pdev->dev.platform_data;
>> +     if (!pdata) {
>
> Do you need platform data when probed via DT, too?
Yes I do need that as of now but I understand that we have to get rid
of this in the future. For more on this please look @ the discussion
after my first patch set. Do suggest an alternative, if you have in
mind, to get rid of the platform data.
>
>> +             dev_err(&pdev->dev, "%s: no platform data defined\n", __func__);
>> +             return -EINVAL;
>> +     }
>> +
>> +     phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +     if (!phy_mem) {
>> +             dev_err(dev, "%s: missing mem resource\n", __func__);
>> +             return -ENODEV;
>> +     }
>> +
>> +     phy_base = devm_request_and_ioremap(dev, phy_mem);
>> +     if (!phy_base) {
>> +             dev_err(dev, "%s: register mapping failed\n", __func__);
>> +             return -ENXIO;
>> +     }
>> +
>> +     sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
>> +     if (!sphy)
>> +             return -ENOMEM;
>> +
>> +     sphy->dev               = &pdev->dev;
>> +     sphy->plat              = pdata;
>> +     sphy->regs              = phy_base;
>> +     sphy->phy.dev           = sphy->dev;
>> +     sphy->phy.label         = "samsung-usbphy";
>> +     sphy->phy.init          = samsung_usbphy_init;
>> +     sphy->phy.shutdown      = samsung_usbphy_shutdown;
>> +     sphy->cpu_type          = samsung_usbphy_get_driver_data(pdev);
>> +
>> +     ret = usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB2);
>> +     if (ret)
>> +             goto err;
>> +
>> +     platform_set_drvdata(pdev, sphy);
>> +err:
>> +     return ret;
>> +}
>> +
>> +static int __exit samsung_usbphy_remove(struct platform_device *pdev)
>> +{
>> +     struct samsung_usbphy *sphy = platform_get_drvdata(pdev);
>> +
>> +     usb_remove_phy(&sphy->phy);
>> +
>> +     if (sphy->clk) {
>> +             clk_put(sphy->clk);
>
> Are you sure that your clk_put is balanced?
May be not, anyways I am going to move the clk_get to probe. So it
will be perfectly balanced
>
>> +             sphy->clk = NULL;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +#ifdef CONFIG_OF
>> +static const struct of_device_id samsung_usbphy_dt_match[] = {
>> +     {
>> +             .compatible = "samsung,s3c64xx-usbphy",
>> +             .data = (void *)TYPE_S3C64XX,
>> +     }, {
>> +             .compatible = "samsung,exynos4210-usbphy",
>> +             .data = (void *)TYPE_EXYNOS4210,
>> +     },
>> +     {},
>> +};
>> +MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
>> +#else
>> +#define samsung_usbphy_dt_match NULL
>> +#endif
>> +
>> +static struct platform_device_id samsung_usbphy_driver_ids[] = {
>> +     {
>> +             .name           = "s3c64xx-usbphy",
>> +             .driver_data    = TYPE_S3C64XX,
>> +     }, {
>> +             .name           = "exynos4210-usbphy",
>> +             .driver_data    = TYPE_EXYNOS4210,
>> +     },
>> +     {},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(platform, samsung_usbphy_driver_ids);
>> +
>> +static struct platform_driver samsung_usbphy_driver = {
>> +     .probe          = samsung_usbphy_probe,
>> +     .remove         = __devexit_p(samsung_usbphy_remove),
>> +     .id_table       = samsung_usbphy_driver_ids,
>> +     .driver         = {
>> +             .name   = "samsung-usbphy",
>> +             .owner  = THIS_MODULE,
>> +             .of_match_table = samsung_usbphy_dt_match,
>> +     },
>> +};
>> +
>> +module_platform_driver(samsung_usbphy_driver);
>> +
>> +MODULE_DESCRIPTION("Samsung USB phy controller");
>> +MODULE_AUTHOR("Praveen Paneri <[e-mail]>");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:samsung-usbphy");
>> diff --git a/include/linux/platform_data/samsung-usbphy.h b/include/linux/platform_data/samsung-usbphy.h
>> new file mode 100644
>> index 0000000..1bd24cb
>> --- /dev/null
>> +++ b/include/linux/platform_data/samsung-usbphy.h
>> @@ -0,0 +1,27 @@
>> +/*
>> + * Copyright (C) 2012 Samsung Electronics Co.Ltd
>> + *           http://www.samsung.com/
>> + * Author: Praveen Paneri <[e-mail]>
>> + *
>> + * Defines platform data for samsung usb phy driver.
>> + *
>> + * This program is free software; you can redistribute  it and/or modify it
>> + * under  the terms of  the GNU General  Public License as published by the
>> + * Free Software Foundation;  either version 2 of the  License, or (at your
>> + * option) any later version.
>> + */
>> +
>> +#ifndef __SAMSUNG_USBPHY_PLATFORM_H
>> +#define __SAMSUNG_USBPHY_PLATFORM_H
>> +
>> +/**
>> + * samsung_usbphy_data - Platform data for USB PHY driver.
>> + * @pmu_isolation: Function to control usb phy isolation in PMU.
>> + */
>> +struct samsung_usbphy_data {
>> +     void (*pmu_isolation)(int on);
>> +};
>> +
>> +extern void samsung_usbphy_set_pdata(struct samsung_usbphy_data *pd);
>> +
>> +#endif /* __SAMSUNG_USBPHY_PLATFORM_H */
>>

Thanks,
Praveen
> Marc
>
> --
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: [phone]     |
> Vertretung West/Dortmund          | Fax:   [phone]-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
>

[e-mail] Sept. 14, 2012, 9:59 a.m. UTC | #4

On Wed, Sep 12, 2012 at 9:51 PM, Tomasz Figa <[e-mail]> wrote:
> Hi Praveen, Marc,
>
> On Wednesday 12 of September 2012 13:08:26 Marc Kleine-Budde wrote:
>> > +static const struct of_device_id samsung_usbphy_dt_match[];
>> > +
>> > +static inline int samsung_usbphy_get_driver_data(struct
>> > platform_device *pdev) +{
>> > +#ifdef CONFIG_OF
>>
>> if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)
>
> Is this check needed at all?
>
> In case of CONFIG_OF disabled, of_node should always be NULL and there is a
but I guess it can also be NULL when CONFIG_OF is enabled but the
driver is probed non DT way.
> dummy macro provided for of_match_node, so it should compile and work just
> fine.
>
> --
> Best regards,
> Tomasz Figa
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to [e-mail]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
new file mode 100644
index 0000000..fefd9c8
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
@@ -0,0 +1,9 @@ 
+* Samsung's usb phy transceiver
+
+The Samsung's phy transceiver is used for controlling usb otg phy for
+s3c-hsotg usb device controller.
+
+Required properties:
+- compatible : should be "samsung,exynos4210-usbphy"
+- reg : base physical address of the phy registers and length of memory mapped
+	region.
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 63c339b..313685f 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -32,3 +32,11 @@  config MV_U3D_PHY
 	help
 	  Enable this to support Marvell USB 3.0 phy controller for Marvell
 	  SoC.
+
+config SAMSUNG_USBPHY
+	bool "Samsung USB PHY controller Driver"
+	depends on USB_S3C_HSOTG
+	select USB_OTG_UTILS
+	help
+	  Enable this to support Samsung USB phy controller for samsung
+	  SoCs.
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index b069f29..55dcfc1 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -8,3 +8,4 @@  obj-$(CONFIG_OMAP_USB2)			+= omap-usb2.o
 obj-$(CONFIG_USB_ISP1301)		+= isp1301.o
 obj-$(CONFIG_MV_U3D_PHY)		+= mv_u3d_phy.o
 obj-$(CONFIG_USB_EHCI_TEGRA)	+= tegra_usb_phy.o
+obj-$(CONFIG_SAMSUNG_USBPHY)		+= samsung-usbphy.o
diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
new file mode 100644
index 0000000..b00d01b
--- /dev/null
+++ b/drivers/usb/phy/samsung-usbphy.c
@@ -0,0 +1,371 @@ 
+/* linux/drivers/usb/phy/samsung-usbphy.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *              http://www.samsung.com
+ *
+ * Author: Praveen Paneri <[e-mail]>
+ *
+ * Samsung USB2.0 High-speed OTG transceiver, talks to S3C HS OTG controller
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/usb/otg.h>
+#include <linux/platform_data/samsung-usbphy.h>
+
+/* Register definitions */
+
+#define S3C_PHYPWR				(0x00)
+
+#define S3C_PHYPWR_NORMAL_MASK			(0x19 << 0)
+#define S3C_PHYPWR_OTG_DISABLE			(1 << 4)
+#define S3C_PHYPWR_ANALOG_POWERDOWN		(1 << 3)
+#define S3C_PHYPWR_FORCE_SUSPEND		(1 << 1)
+/* For Exynos4 */
+#define EXYNOS4_PHYPWR_NORMAL_MASK		(0x39 << 0)
+#define EXYNOS4_PHYPWR_SLEEP			(1 << 5)
+
+#define S3C_PHYCLK				(0x04)
+
+#define S3C_PHYCLK_MODE_SERIAL			(1 << 6)
+#define S3C_PHYCLK_EXT_OSC			(1 << 5)
+#define S3C_PHYCLK_COMMON_ON_N			(1 << 4)
+#define S3C_PHYCLK_ID_PULL			(1 << 2)
+#define S3C_PHYCLK_CLKSEL_MASK			(0x3 << 0)
+#define S3C_PHYCLK_CLKSEL_SHIFT			(0)
+#define S3C_PHYCLK_CLKSEL_48M			(0x0 << 0)
+#define S3C_PHYCLK_CLKSEL_12M			(0x2 << 0)
+#define S3C_PHYCLK_CLKSEL_24M			(0x3 << 0)
+
+#define S3C_RSTCON				(0x08)
+
+#define S3C_RSTCON_PHYCLK			(1 << 2)
+#define S3C_RSTCON_HCLK				(1 << 1)
+#define S3C_RSTCON_PHY				(1 << 0)
+
+#ifndef MHZ
+#define MHZ (1000*1000)
+#endif
+
+enum samsung_cpu_type {
+	TYPE_S3C64XX,
+	TYPE_EXYNOS4210,
+};
+
+/*
+ * struct samsung_usbphy - transceiver driver state
+ * @phy: transceiver structure
+ * @plat: platform data
+ * @dev: The parent device supplied to the probe function
+ * @clk: usb phy clock
+ * @regs: usb phy register memory base
+ * @cpu_type: machine identifier
+ */
+struct samsung_usbphy {
+	struct usb_phy	phy;
+	struct samsung_usbphy_data *plat;
+	struct device	*dev;
+	struct clk	*clk;
+	void __iomem	*regs;
+	int		cpu_type;
+};
+
+#define phy_to_sphy(x)		container_of((x), struct samsung_usbphy, phy)
+
+/*
+ * Enables or disables the phy clock
+ * returns 0 on success else the error
+ */
+static int samsung_usbphy_clk_control(struct samsung_usbphy *sphy, bool on)
+{
+	if (on) {
+		if (!sphy->clk) {
+			sphy->clk = clk_get(sphy->dev, "otg");
+			if (IS_ERR(sphy->clk)) {
+				dev_err(sphy->dev, "Failed to get otg clock\n");
+				return PTR_ERR(sphy->clk);
+			}
+		}
+		clk_enable(sphy->clk);
+	} else {
+		clk_disable(sphy->clk);
+		clk_put(sphy->clk);
+	}
+
+	return 0;
+}
+
+/*
+ * Returns reference clock frequency
+ */
+static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
+{
+	struct clk *ref_clk;
+	int refclk_freq = 0;
+
+	ref_clk = clk_get(sphy->dev, "xusbxti");
+	if (IS_ERR(ref_clk)) {
+		dev_err(sphy->dev, "Failed to get reference clock\n");
+		return PTR_ERR(ref_clk);
+	}
+
+	switch (clk_get_rate(ref_clk)) {
+	case 12 * MHZ:
+		refclk_freq |= S3C_PHYCLK_CLKSEL_12M;
+		break;
+	case 24 * MHZ:
+		refclk_freq |= S3C_PHYCLK_CLKSEL_24M;
+		break;
+	default:
+	case 48 * MHZ:
+		/* default reference clock */
+		refclk_freq |= S3C_PHYCLK_CLKSEL_48M;
+		break;
+	}
+	clk_put(ref_clk);
+
+	return refclk_freq;
+}
+
+static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
+{
+	void __iomem *regs = sphy->regs;
+	u32 phypwr;
+	u32 phyclk;
+	u32 rstcon;
+
+	/* set clock frequency for PLL */
+	phyclk = samsung_usbphy_get_refclk_freq(sphy);
+	phypwr = readl(regs + S3C_PHYPWR);
+	rstcon = readl(regs + S3C_RSTCON);
+
+	switch (sphy->cpu_type) {
+	case TYPE_S3C64XX:
+		phyclk &= ~(S3C_PHYCLK_COMMON_ON_N);
+		phypwr &= ~S3C_PHYPWR_NORMAL_MASK;
+		rstcon |= S3C_RSTCON_PHY;
+		break;
+	case TYPE_EXYNOS4210:
+		phypwr &= ~EXYNOS4_PHYPWR_NORMAL_MASK;
+		rstcon |= S3C_RSTCON_PHY;
+	default:
+		break;
+	}
+
+	writel(phyclk, regs + S3C_PHYCLK);
+	/* set to normal of PHY0 */
+	writel(phypwr, regs + S3C_PHYPWR);
+	/* reset all ports of PHY and Link */
+	writel(rstcon, regs + S3C_RSTCON);
+	udelay(10);
+	rstcon &= ~S3C_RSTCON_PHY;
+	writel(rstcon, regs + S3C_RSTCON);
+}
+
+static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
+{
+	void __iomem *regs = sphy->regs;
+	u32 phypwr;
+
+	phypwr = readl(regs + S3C_PHYPWR);
+
+	switch (sphy->cpu_type) {
+	case TYPE_S3C64XX:
+		phypwr |= S3C_PHYPWR_NORMAL_MASK;
+		break;
+	case TYPE_EXYNOS4210:
+		phypwr |= EXYNOS4_PHYPWR_NORMAL_MASK;
+	default:
+		break;
+	}
+
+	/* unset to normal of PHY0 */
+	writel(phypwr, regs + S3C_PHYPWR);
+}
+
+/*
+ * The function passed to the usb driver for phy initialization
+ */
+static int samsung_usbphy_init(struct usb_phy *phy)
+{
+	struct samsung_usbphy *sphy;
+	int ret = 0;
+
+	sphy = phy_to_sphy(phy);
+
+	/* Enable the phy clock */
+	ret = samsung_usbphy_clk_control(sphy, true);
+	if (ret) {
+		dev_err(sphy->dev, "phy clock enable failed\n");
+		return ret;
+	}
+
+	/* Disable phy isolation */
+	if (sphy->plat && sphy->plat->pmu_isolation)
+		sphy->plat->pmu_isolation(false);
+
+	/* Initialize usb phy registers */
+	samsung_usbphy_enable(sphy);
+	return ret;
+}
+
+/*
+ * The function passed to the usb driver for phy shutdown
+ */
+static void samsung_usbphy_shutdown(struct usb_phy *phy)
+{
+	struct samsung_usbphy *sphy;
+
+	sphy = phy_to_sphy(phy);
+
+	/* De-initialize usb phy registers */
+	samsung_usbphy_disable(sphy);
+
+	/* Enable phy isolation */
+	if (sphy->plat && sphy->plat->pmu_isolation)
+		sphy->plat->pmu_isolation(true);
+
+	/* Disable the phy clock */
+	samsung_usbphy_clk_control(sphy, false);
+}
+
+static const struct of_device_id samsung_usbphy_dt_match[];
+
+static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
+{
+#ifdef CONFIG_OF
+	int data;
+	if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(samsung_usbphy_dt_match,
+							pdev->dev.of_node);
+		data = (int) match->data;
+		return data;
+	}
+#endif
+	return platform_get_device_id(pdev)->driver_data;
+}
+
+static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
+{
+	struct samsung_usbphy *sphy;
+	struct samsung_usbphy_data *pdata;
+	struct device *dev = &pdev->dev;
+	struct resource *phy_mem;
+	void __iomem	*phy_base;
+	int	ret;
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(&pdev->dev, "%s: no platform data defined\n", __func__);
+		return -EINVAL;
+	}
+
+	phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!phy_mem) {
+		dev_err(dev, "%s: missing mem resource\n", __func__);
+		return -ENODEV;
+	}
+
+	phy_base = devm_request_and_ioremap(dev, phy_mem);
+	if (!phy_base) {
+		dev_err(dev, "%s: register mapping failed\n", __func__);
+		return -ENXIO;
+	}
+
+	sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
+	if (!sphy)
+		return -ENOMEM;
+
+	sphy->dev		= &pdev->dev;
+	sphy->plat		= pdata;
+	sphy->regs		= phy_base;
+	sphy->phy.dev		= sphy->dev;
+	sphy->phy.label		= "samsung-usbphy";
+	sphy->phy.init		= samsung_usbphy_init;
+	sphy->phy.shutdown	= samsung_usbphy_shutdown;
+	sphy->cpu_type		= samsung_usbphy_get_driver_data(pdev);
+
+	ret = usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB2);
+	if (ret)
+		goto err;
+
+	platform_set_drvdata(pdev, sphy);
+err:
+	return ret;
+}
+
+static int __exit samsung_usbphy_remove(struct platform_device *pdev)
+{
+	struct samsung_usbphy *sphy = platform_get_drvdata(pdev);
+
+	usb_remove_phy(&sphy->phy);
+
+	if (sphy->clk) {
+		clk_put(sphy->clk);
+		sphy->clk = NULL;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id samsung_usbphy_dt_match[] = {
+	{
+		.compatible = "samsung,s3c64xx-usbphy",
+		.data = (void *)TYPE_S3C64XX,
+	}, {
+		.compatible = "samsung,exynos4210-usbphy",
+		.data = (void *)TYPE_EXYNOS4210,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
+#else
+#define samsung_usbphy_dt_match NULL
+#endif
+
+static struct platform_device_id samsung_usbphy_driver_ids[] = {
+	{
+		.name		= "s3c64xx-usbphy",
+		.driver_data	= TYPE_S3C64XX,
+	}, {
+		.name		= "exynos4210-usbphy",
+		.driver_data	= TYPE_EXYNOS4210,
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(platform, samsung_usbphy_driver_ids);
+
+static struct platform_driver samsung_usbphy_driver = {
+	.probe		= samsung_usbphy_probe,
+	.remove		= __devexit_p(samsung_usbphy_remove),
+	.id_table	= samsung_usbphy_driver_ids,
+	.driver		= {
+		.name	= "samsung-usbphy",
+		.owner	= THIS_MODULE,
+		.of_match_table = samsung_usbphy_dt_match,
+	},
+};
+
+module_platform_driver(samsung_usbphy_driver);
+
+MODULE_DESCRIPTION("Samsung USB phy controller");
+MODULE_AUTHOR("Praveen Paneri <[e-mail]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:samsung-usbphy");
diff --git a/include/linux/platform_data/samsung-usbphy.h b/include/linux/platform_data/samsung-usbphy.h
new file mode 100644
index 0000000..1bd24cb
--- /dev/null
+++ b/include/linux/platform_data/samsung-usbphy.h
@@ -0,0 +1,27 @@ 
+/*
+ * Copyright (C) 2012 Samsung Electronics Co.Ltd
+ *		http://www.samsung.com/
+ * Author: Praveen Paneri <[e-mail]>
+ *
+ * Defines platform data for samsung usb phy driver.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __SAMSUNG_USBPHY_PLATFORM_H
+#define __SAMSUNG_USBPHY_PLATFORM_H
+
+/**
+ * samsung_usbphy_data - Platform data for USB PHY driver.
+ * @pmu_isolation: Function to control usb phy isolation in PMU.
+ */
+struct samsung_usbphy_data {
+	void (*pmu_isolation)(int on);
+};
+
+extern void samsung_usbphy_set_pdata(struct samsung_usbphy_data *pd);
+
+#endif /* __SAMSUNG_USBPHY_PLATFORM_H */