[V6 PATCH 01/16] usb: phy: mv_usb2: add PHY driver for marvell usb2 controller

kishon kishon at ti.com
Wed Feb 6 05:35:46 EST 2013


Hi,

On Wednesday 06 February 2013 01:48 PM, Chao Xie wrote:
> On Wed, Feb 6, 2013 at 4:10 PM, kishon <kishon at ti.com> wrote:
>> Hi,
>>
>>
>> On Wednesday 06 February 2013 12:53 PM, Chao Xie wrote:
>>>
>>> The PHY is seperated from usb controller.
>>> The usb controller used in marvell pxa168/pxa910/mmp2 are same,
>>> but PHY initialization may be different.
>>> the usb controller can support udc/otg/ehci, and for each of
>>> the mode, it need PHY to initialized before use the controller.
>>> Direclty writing the phy driver will make the usb controller
>>> driver to be simple and portable.
>>> The PHY driver will be used by marvell udc/otg/ehci.
>>>
>>> Signed-off-by: Chao Xie <chao.xie at marvell.com>
>>> ---
>>>    drivers/usb/phy/Kconfig              |    7 +
>>>    drivers/usb/phy/Makefile             |    1 +
>>>    drivers/usb/phy/mv_usb2_phy.c        |  454
>>> ++++++++++++++++++++++++++++++++++
>>>    include/linux/platform_data/mv_usb.h |    9 +-
>>>    include/linux/usb/mv_usb2.h          |   43 ++++
>>>    5 files changed, 511 insertions(+), 3 deletions(-)
>>>    create mode 100644 drivers/usb/phy/mv_usb2_phy.c
>>>    create mode 100644 include/linux/usb/mv_usb2.h
>>>
>>> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
>>> index 65217a5..5479760 100644
>>> --- a/drivers/usb/phy/Kconfig
>>> +++ b/drivers/usb/phy/Kconfig
>>> @@ -73,3 +73,10 @@ config SAMSUNG_USBPHY
>>>          help
>>>            Enable this to support Samsung USB phy controller for samsung
>>>            SoCs.
>>> +
>>> +config MV_USB2_PHY
>>> +       tristate "Marvell USB 2.0 PHY Driver"
>>> +       depends on USB || USB_GADGET
>>> +       help
>>> +         Enable this to support Marvell USB 2.0 phy driver for Marvell
>>> +         SoC.
>>> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
>>> index b13faa1..3835316 100644
>>> --- a/drivers/usb/phy/Makefile
>>> +++ b/drivers/usb/phy/Makefile
>>> @@ -12,3 +12,4 @@ obj-$(CONFIG_MV_U3D_PHY)              += mv_u3d_phy.o
>>>    obj-$(CONFIG_USB_EHCI_TEGRA)  += tegra_usb_phy.o
>>>    obj-$(CONFIG_USB_RCAR_PHY)            += rcar-phy.o
>>>    obj-$(CONFIG_SAMSUNG_USBPHY)          += samsung-usbphy.o
>>> +obj-$(CONFIG_MV_USB2_PHY)              += mv_usb2_phy.o
>>> diff --git a/drivers/usb/phy/mv_usb2_phy.c b/drivers/usb/phy/mv_usb2_phy.c
>>> new file mode 100644
>>> index 0000000..c2bccae
>>> --- /dev/null
>>> +++ b/drivers/usb/phy/mv_usb2_phy.c
>>> @@ -0,0 +1,454 @@
>>> +/*
>>> + * Copyright (C) 2010 Google, Inc.
>>> + *
>>> + * Author:
>>> + *     Chao Xie <xiechao.mail at gmail.com>
>>> + *
>>> + * This software is licensed under the terms of the GNU General Public
>>> + * License version 2, as published by the Free Software Foundation, and
>>> + * may be copied, distributed, and modified under those terms.
>>> + *
>>> + * 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/resource.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/io.h>
>>> +#include <linux/err.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/export.h>
>>> +#include <linux/module.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/platform_data/mv_usb.h>
>>> +#include <linux/usb/mv_usb2.h>
>>> +
>>> +/* phy regs */
>>> +#define UTMI_REVISION          0x0
>>> +#define UTMI_CTRL              0x4
>>> +#define UTMI_PLL               0x8
>>> +#define UTMI_TX                        0xc
>>> +#define UTMI_RX                        0x10
>>> +#define UTMI_IVREF             0x14
>>> +#define UTMI_T0                        0x18
>>> +#define UTMI_T1                        0x1c
>>> +#define UTMI_T2                        0x20
>>> +#define UTMI_T3                        0x24
>>> +#define UTMI_T4                        0x28
>>> +#define UTMI_T5                        0x2c
>>> +#define UTMI_RESERVE           0x30
>>> +#define UTMI_USB_INT           0x34
>>> +#define UTMI_DBG_CTL           0x38
>>> +#define UTMI_OTG_ADDON         0x3c
>>> +
>>> +/* For UTMICTRL Register */
>>> +#define UTMI_CTRL_USB_CLK_EN                    (1 << 31)
>>> +/* pxa168 */
>>> +#define UTMI_CTRL_SUSPEND_SET1                  (1 << 30)
>>> +#define UTMI_CTRL_SUSPEND_SET2                  (1 << 29)
>>> +#define UTMI_CTRL_RXBUF_PDWN                    (1 << 24)
>>> +#define UTMI_CTRL_TXBUF_PDWN                    (1 << 11)
>>> +
>>> +#define UTMI_CTRL_INPKT_DELAY_SHIFT             30
>>> +#define UTMI_CTRL_INPKT_DELAY_SOF_SHIFT                28
>>> +#define UTMI_CTRL_PU_REF_SHIFT                 20
>>> +#define UTMI_CTRL_ARC_PULLDN_SHIFT              12
>>> +#define UTMI_CTRL_PLL_PWR_UP_SHIFT              1
>>> +#define UTMI_CTRL_PWR_UP_SHIFT                  0
>>> +
>>> +/* For UTMI_PLL Register */
>>> +#define UTMI_PLL_PLLCALI12_SHIFT               29
>>> +#define UTMI_PLL_PLLCALI12_MASK                        (0x3 << 29)
>>> +
>>> +#define UTMI_PLL_PLLVDD18_SHIFT                        27
>>> +#define UTMI_PLL_PLLVDD18_MASK                 (0x3 << 27)
>>> +
>>> +#define UTMI_PLL_PLLVDD12_SHIFT                        25
>>> +#define UTMI_PLL_PLLVDD12_MASK                 (0x3 << 25)
>>> +
>>> +#define UTMI_PLL_CLK_BLK_EN_SHIFT               24
>>> +#define CLK_BLK_EN                              (0x1 << 24)
>>> +#define PLL_READY                               (0x1 << 23)
>>> +#define KVCO_EXT                                (0x1 << 22)
>>> +#define VCOCAL_START                            (0x1 << 21)
>>> +
>>> +#define UTMI_PLL_KVCO_SHIFT                    15
>>> +#define UTMI_PLL_KVCO_MASK                      (0x7 << 15)
>>> +
>>> +#define UTMI_PLL_ICP_SHIFT                     12
>>> +#define UTMI_PLL_ICP_MASK                       (0x7 << 12)
>>> +
>>> +#define UTMI_PLL_FBDIV_SHIFT                    4
>>> +#define UTMI_PLL_FBDIV_MASK                     (0xFF << 4)
>>> +
>>> +#define UTMI_PLL_REFDIV_SHIFT                   0
>>> +#define UTMI_PLL_REFDIV_MASK                    (0xF << 0)
>>> +
>>> +/* For UTMI_TX Register */
>>> +#define UTMI_TX_REG_EXT_FS_RCAL_SHIFT          27
>>> +#define UTMI_TX_REG_EXT_FS_RCAL_MASK           (0xf << 27)
>>> +
>>> +#define UTMI_TX_REG_EXT_FS_RCAL_EN_SHIFT       26
>>> +#define UTMI_TX_REG_EXT_FS_RCAL_EN_MASK                (0x1 << 26)
>>> +
>>> +#define UTMI_TX_TXVDD12_SHIFT                   22
>>> +#define UTMI_TX_TXVDD12_MASK                    (0x3 << 22)
>>> +
>>> +#define UTMI_TX_CK60_PHSEL_SHIFT                17
>>> +#define UTMI_TX_CK60_PHSEL_MASK                 (0xf << 17)
>>> +
>>> +#define UTMI_TX_IMPCAL_VTH_SHIFT                14
>>> +#define UTMI_TX_IMPCAL_VTH_MASK                 (0x7 << 14)
>>> +
>>> +#define REG_RCAL_START                          (0x1 << 12)
>>> +
>>> +#define UTMI_TX_LOW_VDD_EN_SHIFT                11
>>> +
>>> +#define UTMI_TX_AMP_SHIFT                      0
>>> +#define UTMI_TX_AMP_MASK                       (0x7 << 0)
>>> +
>>> +/* For UTMI_RX Register */
>>> +#define UTMI_REG_SQ_LENGTH_SHIFT                15
>>> +#define UTMI_REG_SQ_LENGTH_MASK                 (0x3 << 15)
>>> +
>>> +#define UTMI_RX_SQ_THRESH_SHIFT                 4
>>> +#define UTMI_RX_SQ_THRESH_MASK                  (0xf << 4)
>>> +
>>> +#define UTMI_OTG_ADDON_OTG_ON                  (1 << 0)
>>> +
>>> +enum mv_usb2_phy_type {
>>> +       PXA168_USB,
>>> +       PXA910_USB,
>>> +       MMP2_USB,
>>> +};
>>> +
>>> +static struct mv_usb2_phy *the_phy;
>>> +
>>> +struct mv_usb2_phy *mv_usb2_get_phy(void)
>>> +{
>>> +       return the_phy;
>>> +}
>>> +EXPORT_SYMBOL(mv_usb2_get_phy);
>>> +
>>> +static unsigned int u2o_get(void __iomem *base, unsigned int offset)
>>> +{
>>> +       return readl(base + offset);
>>> +}
>>> +
>>> +static void u2o_set(void __iomem *base, unsigned int offset,
>>> +               unsigned int value)
>>> +{
>>> +       u32 reg;
>>> +
>>> +       reg = readl(base + offset);
>>> +       reg |= value;
>>> +       writel(reg, base + offset);
>>> +       readl(base + offset);
>>> +}
>>> +
>>> +static void u2o_clear(void __iomem *base, unsigned int offset,
>>> +               unsigned int value)
>>> +{
>>> +       u32 reg;
>>> +
>>> +       reg = readl(base + offset);
>>> +       reg &= ~value;
>>> +       writel(reg, base + offset);
>>> +       readl(base + offset);
>>> +}
>>> +
>>> +static void u2o_write(void __iomem *base, unsigned int offset,
>>> +               unsigned int value)
>>> +{
>>> +       writel(value, base + offset);
>>> +       readl(base + offset);
>>> +}
>>> +
>>> +static int _usb_phy_init(struct mv_usb2_phy *mv_phy)
>>> +{
>>> +       struct platform_device *pdev = mv_phy->pdev;
>>> +       unsigned int loops = 0;
>>> +       void __iomem *base = mv_phy->base;
>>> +
>>> +       dev_dbg(&pdev->dev, "phy init\n");
>>> +
>>> +       /* Initialize the USB PHY power */
>>> +       if (mv_phy->type == PXA910_USB) {
>>> +               u2o_set(base, UTMI_CTRL,
>>> (1<<UTMI_CTRL_INPKT_DELAY_SOF_SHIFT)
>>> +                       | (1<<UTMI_CTRL_PU_REF_SHIFT));
>>> +       }
>>> +
>>> +       u2o_set(base, UTMI_CTRL, 1<<UTMI_CTRL_PLL_PWR_UP_SHIFT);
>>> +       u2o_set(base, UTMI_CTRL, 1<<UTMI_CTRL_PWR_UP_SHIFT);
>>> +
>>> +       /* UTMI_PLL settings */
>>> +       u2o_clear(base, UTMI_PLL, UTMI_PLL_PLLVDD18_MASK
>>> +               | UTMI_PLL_PLLVDD12_MASK | UTMI_PLL_PLLCALI12_MASK
>>> +               | UTMI_PLL_FBDIV_MASK | UTMI_PLL_REFDIV_MASK
>>> +               | UTMI_PLL_ICP_MASK | UTMI_PLL_KVCO_MASK);
>>> +
>>> +       u2o_set(base, UTMI_PLL, 0xee<<UTMI_PLL_FBDIV_SHIFT
>>> +               | 0xb<<UTMI_PLL_REFDIV_SHIFT | 3<<UTMI_PLL_PLLVDD18_SHIFT
>>> +               | 3<<UTMI_PLL_PLLVDD12_SHIFT | 3<<UTMI_PLL_PLLCALI12_SHIFT
>>> +               | 1<<UTMI_PLL_ICP_SHIFT | 3<<UTMI_PLL_KVCO_SHIFT);
>>> +
>>> +       /* UTMI_TX */
>>> +       u2o_clear(base, UTMI_TX, UTMI_TX_REG_EXT_FS_RCAL_EN_MASK
>>> +               | UTMI_TX_TXVDD12_MASK | UTMI_TX_CK60_PHSEL_MASK
>>> +               | UTMI_TX_IMPCAL_VTH_MASK | UTMI_TX_REG_EXT_FS_RCAL_MASK
>>> +               | UTMI_TX_AMP_MASK);
>>> +       u2o_set(base, UTMI_TX, 3<<UTMI_TX_TXVDD12_SHIFT
>>> +               | 4<<UTMI_TX_CK60_PHSEL_SHIFT |
>>> 4<<UTMI_TX_IMPCAL_VTH_SHIFT
>>> +               | 8<<UTMI_TX_REG_EXT_FS_RCAL_SHIFT |
>>> 3<<UTMI_TX_AMP_SHIFT);
>>> +
>>> +       /* UTMI_RX */
>>> +       u2o_clear(base, UTMI_RX, UTMI_RX_SQ_THRESH_MASK
>>> +               | UTMI_REG_SQ_LENGTH_MASK);
>>> +       u2o_set(base, UTMI_RX, 7<<UTMI_RX_SQ_THRESH_SHIFT
>>> +               | 2<<UTMI_REG_SQ_LENGTH_SHIFT);
>>> +
>>> +       /* UTMI_IVREF */
>>> +       if (mv_phy->type == PXA168_USB)
>>> +               /* fixing Microsoft Altair board interface with NEC hub
>>> issue -
>>> +                * Set UTMI_IVREF from 0x4a3 to 0x4bf */
>>> +               u2o_write(base, UTMI_IVREF, 0x4bf);
>>> +
>>> +       /* toggle VCOCAL_START bit of UTMI_PLL */
>>> +       udelay(200);
>>> +       u2o_set(base, UTMI_PLL, VCOCAL_START);
>>> +       udelay(40);
>>> +       u2o_clear(base, UTMI_PLL, VCOCAL_START);
>>> +
>>> +       /* toggle REG_RCAL_START bit of UTMI_TX */
>>> +       udelay(400);
>>> +       u2o_set(base, UTMI_TX, REG_RCAL_START);
>>> +       udelay(40);
>>> +       u2o_clear(base, UTMI_TX, REG_RCAL_START);
>>> +       udelay(400);
>>> +
>>> +       /* Make sure PHY PLL is ready */
>>> +       loops = 0;
>>> +       while ((u2o_get(base, UTMI_PLL) & PLL_READY) == 0) {
>>> +               mdelay(1);
>>> +               loops++;
>>> +               if (loops > 100) {
>>> +                       dev_warn(&pdev->dev, "calibrate timeout, UTMI_PLL
>>> %x\n",
>>> +                               u2o_get(base, UTMI_PLL));
>>> +                       break;
>>> +               }
>>> +       }
>>> +
>>> +       if (mv_phy->type == PXA168_USB) {
>>> +               u2o_set(base, UTMI_RESERVE, 1 << 5);
>>> +               /* Turn on UTMI PHY OTG extension */
>>> +               u2o_write(base, UTMI_OTG_ADDON, 1);
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int _usb_phy_shutdown(struct mv_usb2_phy *mv_phy)
>>> +{
>>> +       void __iomem *base = mv_phy->base;
>>> +
>>> +       if (mv_phy->type == PXA168_USB)
>>> +               u2o_clear(base, UTMI_OTG_ADDON, UTMI_OTG_ADDON_OTG_ON);
>>> +
>>> +       u2o_clear(base, UTMI_CTRL, UTMI_CTRL_RXBUF_PDWN);
>>> +       u2o_clear(base, UTMI_CTRL, UTMI_CTRL_TXBUF_PDWN);
>>> +       u2o_clear(base, UTMI_CTRL, UTMI_CTRL_USB_CLK_EN);
>>> +       u2o_clear(base, UTMI_CTRL, 1<<UTMI_CTRL_PWR_UP_SHIFT);
>>> +       u2o_clear(base, UTMI_CTRL, 1<<UTMI_CTRL_PLL_PWR_UP_SHIFT);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int usb_phy_init(struct mv_usb2_phy *mv_phy)
>>> +{
>>> +       int i = 0;
>>> +
>>> +       mutex_lock(&mv_phy->phy_lock);
>>> +       if (mv_phy->refcount++ == 0) {
>>> +               for (i = 0; i < mv_phy->clks_num; i++)
>>> +                       clk_prepare_enable(mv_phy->clks[i]);
>>> +               _usb_phy_init(mv_phy);
>>> +       }
>>> +       mutex_unlock(&mv_phy->phy_lock);
>>> +       return 0;
>>> +}
>>> +
>>> +static void usb_phy_shutdown(struct mv_usb2_phy *mv_phy)
>>> +{
>>> +       int i = 0;
>>> +
>>> +       mutex_lock(&mv_phy->phy_lock);
>>> +       if (mv_phy->refcount++ == 0) {
>>> +               _usb_phy_shutdown(mv_phy);
>>> +               for (i = 0; i < mv_phy->clks_num; i++)
>>> +                       clk_disable_unprepare(mv_phy->clks[i]);
>>> +       }
>>> +       mutex_unlock(&mv_phy->phy_lock);
>>> +}
>>> +
>>> +static struct of_device_id usb_phy_dt_ids[] = {
>>> +       { .compatible = "mrvl,pxa168-usb-phy",  .data = (void
>>> *)PXA168_USB},
>>> +       { .compatible = "mrvl,pxa910-usb-phy",  .data = (void
>>> *)PXA910_USB},
>>> +       { .compatible = "mrvl,mmp2-usb-phy",    .data = (void *)MMP2_USB},
>>> +       {}
>>> +};
>>> +MODULE_DEVICE_TABLE(of, usb_phy_dt_ids);
>>> +
>>> +static int usb_phy_parse_dt(struct platform_device *pdev,
>>> +                               struct mv_usb2_phy *mv_phy)
>>> +{
>>> +       struct device_node *np = pdev->dev.of_node;
>>> +       const struct of_device_id *of_id =
>>> +                       of_match_device(usb_phy_dt_ids, &pdev->dev);
>>> +       unsigned int clks_num;
>>> +       int i, ret;
>>> +       const char *clk_name;
>>> +
>>> +       if (!np)
>>> +               return 1;
>>> +
>>> +       clks_num = of_property_count_strings(np, "clocks");
>>> +       if (clks_num < 0) {
>>> +               dev_err(&pdev->dev, "failed to get clock number\n");
>>> +               return clks_num;
>>> +       }
>>> +
>>> +       mv_phy->clks = devm_kzalloc(&pdev->dev,
>>> +               sizeof(struct clk *) * clks_num, GFP_KERNEL);
>>> +       if (mv_phy->clks == NULL) {
>>> +               dev_err(&pdev->dev,
>>> +                       "failed to allocate mempory for clocks");
>>> +               return -ENOMEM;
>>> +       }
>>> +
>>> +       for (i = 0; i < clks_num; i++) {
>>> +               ret = of_property_read_string_index(np, "clocks", i,
>>> +                       &clk_name);
>>> +               if (ret) {
>>> +                       dev_err(&pdev->dev, "failed to read clocks\n");
>>> +                       return ret;
>>> +               }
>>> +               mv_phy->clks[i] = devm_clk_get(&pdev->dev, clk_name);
>>> +               if (IS_ERR(mv_phy->clks[i])) {
>>> +                       dev_err(&pdev->dev, "failed to get clock %s\n",
>>> +                               clk_name);
>>> +                       return PTR_ERR(mv_phy->clks[i]);
>>> +               }
>>> +       }
>>> +
>>> +       mv_phy->clks_num = clks_num;
>>> +       mv_phy->type = (enum mv_usb2_phy_type)(of_id->data);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int usb_phy_probe(struct platform_device *pdev)
>>> +{
>>> +       struct mv_usb2_phy *mv_phy;
>>> +       struct resource *r;
>>> +       int ret, i;
>>> +
>>> +       mv_phy = devm_kzalloc(&pdev->dev, sizeof(*mv_phy), GFP_KERNEL);
>>> +       if (mv_phy == NULL) {
>>> +               dev_err(&pdev->dev, "failed to allocate memory\n");
>>> +               return -ENOMEM;
>>> +       }
>>> +       mutex_init(&mv_phy->phy_lock);
>>> +
>>> +       ret = usb_phy_parse_dt(pdev, mv_phy);
>>> +       /* no CONFIG_OF */
>>> +       if (ret > 0) {
>>> +               struct mv_usb_phy_platform_data *pdata
>>> +                               = pdev->dev.platform_data;
>>> +               const struct platform_device_id *id
>>> +                               = platform_get_device_id(pdev);
>>> +
>>> +               if (pdata == NULL || id == NULL) {
>>> +                       dev_err(&pdev->dev,
>>> +                               "missing platform_data or id_entry\n");
>>> +                       return -ENODEV;
>>> +               }
>>> +               mv_phy->type = (unsigned int)(id->driver_data);
>>> +               mv_phy->clks_num = pdata->clknum;
>>> +               mv_phy->clks = devm_kzalloc(&pdev->dev,
>>> +                       sizeof(struct clk *) * mv_phy->clks_num,
>>> GFP_KERNEL);
>>> +               if (mv_phy->clks == NULL) {
>>> +                       dev_err(&pdev->dev,
>>> +                               "failed to allocate mempory for clocks");
>>> +                       return -ENOMEM;
>>> +               }
>>> +               for (i = 0; i < mv_phy->clks_num; i++)
>>> +                       mv_phy->clks[i] = devm_clk_get(&pdev->dev,
>>> +
>>> pdata->clkname[i]);
>>> +                       if (IS_ERR(mv_phy->clks[i])) {
>>> +                               dev_err(&pdev->dev, "failed to get clock
>>> %s\n",
>>> +                                       pdata->clkname[i]);
>>> +                               return PTR_ERR(mv_phy->clks[i]);
>>> +                       }
>>> +       } else if (ret < 0) {
>>> +               dev_err(&pdev->dev, "error parse dt\n");
>>> +               return ret;
>>> +       }
>>> +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +       if (r == NULL) {
>>> +               dev_err(&pdev->dev, "no phy I/O memory resource
>>> defined\n");
>>> +               return -ENODEV;
>>> +       }
>>> +       mv_phy->base = devm_ioremap(&pdev->dev, r->start,
>>> resource_size(r));
>>> +       if (mv_phy->base == NULL) {
>>> +               dev_err(&pdev->dev, "error map register base\n");
>>> +               return -EBUSY;
>>> +       }
>>> +       platform_set_drvdata(pdev, mv_phy);
>>> +       mv_phy->pdev = pdev;
>>> +       mv_phy->init = usb_phy_init;
>>> +       mv_phy->shutdown = usb_phy_shutdown;
>>> +
>>> +       platform_set_drvdata(pdev, mv_phy);
>>> +
>>> +       the_phy = mv_phy;
>>
>>
>> Is there any specific reason for not using the usb phy library?
>> Please use the APIs provided in drivers/usb/otg/otg.c.
>> These APIs will be moved to phy.c soon.
>>
>> Thanks
>> Kishon
>
> The phy in driver/usb/otg/otg.c is bound to OTG. The major target of
> this APIs in OTG is help functions for OTG support.

Not really. Much of what's in otg.c is related to PHY and we have an 
action item to rename otg.c to phy.c. Sascha hauer has already sent a 
patch for it.
> I have used it and implemented it at mv_otg.c for OTG support. The
> APIs only allow one phy driver register to it.

PHY library has changed quite a bit since then. You might want to have a 
look at usb/otg/otg.c again in usb-next.

Thanks
Kishon



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