linux/drivers/usb/phy/phy-omap-otg.c
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   1/*
   2 * OMAP OTG controller driver
   3 *
   4 * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
   5 *
   6 * Copyright (C) 2005-2006 Nokia Corporation
   7 * Copyright (C) 2004 Texas Instruments
   8 * Copyright (C) 2004 David Brownell
   9 *
  10 * This file is subject to the terms and conditions of the GNU General
  11 * Public License. See the file "COPYING" in the main directory of this
  12 * archive for more details.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17 * GNU General Public License for more details.
  18 */
  19
  20#include <linux/io.h>
  21#include <linux/err.h>
  22#include <linux/extcon.h>
  23#include <linux/kernel.h>
  24#include <linux/module.h>
  25#include <linux/interrupt.h>
  26#include <linux/platform_device.h>
  27#include <linux/platform_data/usb-omap1.h>
  28
  29struct otg_device {
  30        void __iomem                    *base;
  31        bool                            id;
  32        bool                            vbus;
  33        struct extcon_dev               *extcon;
  34        struct notifier_block           vbus_nb;
  35        struct notifier_block           id_nb;
  36};
  37
  38#define OMAP_OTG_CTRL           0x0c
  39#define OMAP_OTG_ASESSVLD       (1 << 20)
  40#define OMAP_OTG_BSESSEND       (1 << 19)
  41#define OMAP_OTG_BSESSVLD       (1 << 18)
  42#define OMAP_OTG_VBUSVLD        (1 << 17)
  43#define OMAP_OTG_ID             (1 << 16)
  44#define OMAP_OTG_XCEIV_OUTPUTS \
  45        (OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
  46         OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
  47
  48static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
  49{
  50        u32 l;
  51
  52        l = readl(otg_dev->base + OMAP_OTG_CTRL);
  53        l &= ~OMAP_OTG_XCEIV_OUTPUTS;
  54        l |= outputs;
  55        writel(l, otg_dev->base + OMAP_OTG_CTRL);
  56}
  57
  58static void omap_otg_set_mode(struct otg_device *otg_dev)
  59{
  60        if (!otg_dev->id && otg_dev->vbus)
  61                /* Set B-session valid. */
  62                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
  63        else if (otg_dev->vbus)
  64                /* Set A-session valid. */
  65                omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
  66        else if (!otg_dev->id)
  67                /* Set B-session end to indicate no VBUS. */
  68                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
  69}
  70
  71static int omap_otg_id_notifier(struct notifier_block *nb,
  72                                unsigned long event, void *ptr)
  73{
  74        struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
  75
  76        otg_dev->id = event;
  77        omap_otg_set_mode(otg_dev);
  78
  79        return NOTIFY_DONE;
  80}
  81
  82static int omap_otg_vbus_notifier(struct notifier_block *nb,
  83                                  unsigned long event, void *ptr)
  84{
  85        struct otg_device *otg_dev = container_of(nb, struct otg_device,
  86                                                  vbus_nb);
  87
  88        otg_dev->vbus = event;
  89        omap_otg_set_mode(otg_dev);
  90
  91        return NOTIFY_DONE;
  92}
  93
  94static int omap_otg_probe(struct platform_device *pdev)
  95{
  96        const struct omap_usb_config *config = pdev->dev.platform_data;
  97        struct otg_device *otg_dev;
  98        struct extcon_dev *extcon;
  99        int ret;
 100        u32 rev;
 101
 102        if (!config || !config->extcon)
 103                return -ENODEV;
 104
 105        extcon = extcon_get_extcon_dev(config->extcon);
 106        if (!extcon)
 107                return -EPROBE_DEFER;
 108
 109        otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
 110        if (!otg_dev)
 111                return -ENOMEM;
 112
 113        otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
 114        if (IS_ERR(otg_dev->base))
 115                return PTR_ERR(otg_dev->base);
 116
 117        otg_dev->extcon = extcon;
 118        otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
 119        otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
 120
 121        ret = devm_extcon_register_notifier(&pdev->dev, extcon,
 122                                        EXTCON_USB_HOST, &otg_dev->id_nb);
 123        if (ret)
 124                return ret;
 125
 126        ret = devm_extcon_register_notifier(&pdev->dev, extcon,
 127                                        EXTCON_USB, &otg_dev->vbus_nb);
 128        if (ret) {
 129                return ret;
 130        }
 131
 132        otg_dev->id = extcon_get_state(extcon, EXTCON_USB_HOST);
 133        otg_dev->vbus = extcon_get_state(extcon, EXTCON_USB);
 134        omap_otg_set_mode(otg_dev);
 135
 136        rev = readl(otg_dev->base);
 137
 138        dev_info(&pdev->dev,
 139                 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
 140                 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
 141                 otg_dev->vbus);
 142
 143        platform_set_drvdata(pdev, otg_dev);
 144
 145        return 0;
 146}
 147
 148static struct platform_driver omap_otg_driver = {
 149        .probe          = omap_otg_probe,
 150        .driver         = {
 151                .name   = "omap_otg",
 152        },
 153};
 154module_platform_driver(omap_otg_driver);
 155
 156MODULE_DESCRIPTION("OMAP USB OTG controller driver");
 157MODULE_LICENSE("GPL");
 158MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 159