[PATCH v6 1/5] usb: phy: samsung: Introducing usb phy driver for hsotg

Praveen Paneri p.paneri at samsung.com
Wed Sep 26 03:22:34 EDT 2012


On Tue, Sep 25, 2012 at 4:59 PM, Marc Kleine-Budde <mkl at pengutronix.de> wrote:
> On 09/24/2012 11:38 AM, Praveen Paneri wrote:
>> Hi Kishon, Felipe,
>>
>> Any further comments on these patches? Can they be merged now?
>
> One nitpick inline.
>
> Marc
>>
>> Thanks,
>> Praveen
>>
>> On Mon, Sep 17, 2012 at 6:24 PM, Praveen Paneri <p.paneri at samsung.com> 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 <p.paneri at samsung.com>
>>> Acked-by: Heiko Stuebner <heiko at sntech.de>
>>> ---
>>>  .../devicetree/bindings/usb/samsung-usbphy.txt     |    9 +
>>>  drivers/usb/phy/Kconfig                            |    8 +
>>>  drivers/usb/phy/Makefile                           |    1 +
>>>  drivers/usb/phy/samsung-usbphy.c                   |  360 ++++++++++++++++++++
>>>  include/linux/platform_data/samsung-usbphy.h       |   27 ++
>>>  5 files changed, 405 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..95ec4d0
>>> --- /dev/null
>>> +++ b/drivers/usb/phy/samsung-usbphy.c
>>> @@ -0,0 +1,360 @@
>>> +/* linux/drivers/usb/phy/samsung-usbphy.c
>>> + *
>>> + * Copyright (c) 2012 Samsung Electronics Co., Ltd.
>>> + *              http://www.samsung.com
>>> + *
>>> + * Author: Praveen Paneri <p.paneri at samsung.com>
>>> + *
>>> + * 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
>>> + * @ref_clk_freq: reference clock frequency selection
>>> + * @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             ref_clk_freq;
>>> +       int             cpu_type;
>>> +};
>>> +
>>> +#define phy_to_sphy(x)         container_of((x), struct samsung_usbphy, phy)
>>> +
>>> +/*
>>> + * Returns reference clock frequency selection value
>>> + */
>>> +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 = sphy->ref_clk_freq;
>>> +       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 = clk_prepare_enable(sphy->clk);
>>> +       if (ret) {
>>> +               dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
>>> +               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);
>>> +
>>> +       /* Disable the phy clock */
>>> +       clk_disable_unprepare(sphy->clk);
>>> +       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);
>>> +
>>> +       if (clk_prepare_enable(sphy->clk)) {
>>> +               dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
>>> +               return;
>>> +       }
>>> +
>>> +       /* De-initialize usb phy registers */
>>> +       samsung_usbphy_disable(sphy);
>>> +
>>> +       /* Enable phy isolation */
>>> +       if (sphy->plat && sphy->plat->pmu_isolation)
>>> +               sphy->plat->pmu_isolation(true);
>>> +
>>> +       clk_disable_unprepare(sphy->clk);
>>> +}
>>> +
>>> +static const struct of_device_id samsung_usbphy_dt_match[];
>>> +
>>> +static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
>>> +{
>>> +       if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
>>> +               int data;
>>> +               const struct of_device_id *match;
>>> +               match = of_match_node(samsung_usbphy_dt_match,
>>> +                                                       pdev->dev.of_node);
>>> +               data = (int) match->data;
>>> +               return data;
>>> +       }
>>> +
>>> +       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;
>>> +       struct clk *clk;
>>> +       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;
>>> +
>>> +       clk = devm_clk_get(dev, "otg");
>>> +       if (IS_ERR(clk)) {
>>> +               dev_err(dev, "Failed to get otg clock\n");
>>> +               return PTR_ERR(clk);
>>> +       }
>>> +
>>> +       sphy->dev               = &pdev->dev;
>>> +       sphy->plat              = pdata;
>>> +       sphy->regs              = phy_base;
>>> +       sphy->clk               = clk;
>>> +       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);
>>> +       sphy->ref_clk_freq      = samsung_usbphy_get_refclk_freq(sphy);
>>> +
>>> +       ret = usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB2);
>>> +       if (ret)
>>> +               goto err;
>>> +
>>> +       platform_set_drvdata(pdev, sphy);
>
> To avoid potential race conditions, you should first setup
> platform_set_drvdata(), then add the phy.
It will not be the case as driver_data is not used as of now, may be I
can just remove the platform_set_drvdata() call from here.
>
>>> +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);
>>> +
>>> +       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 <p.paneri at samsung.com>");
>>> +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 <p.paneri at samsung.com>
>>> + *
>>> + * 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 */
>>> --
>>> 1.7.1
>>>
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>
>
> --
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
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