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_specific_cable_nb vbus_dev;
  34        struct extcon_specific_cable_nb id_dev;
  35        struct notifier_block           vbus_nb;
  36        struct notifier_block           id_nb;
  37};
  38
  39#define OMAP_OTG_CTRL           0x0c
  40#define OMAP_OTG_ASESSVLD       (1 << 20)
  41#define OMAP_OTG_BSESSEND       (1 << 19)
  42#define OMAP_OTG_BSESSVLD       (1 << 18)
  43#define OMAP_OTG_VBUSVLD        (1 << 17)
  44#define OMAP_OTG_ID             (1 << 16)
  45#define OMAP_OTG_XCEIV_OUTPUTS \
  46        (OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
  47         OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
  48
  49static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
  50{
  51        u32 l;
  52
  53        l = readl(otg_dev->base + OMAP_OTG_CTRL);
  54        l &= ~OMAP_OTG_XCEIV_OUTPUTS;
  55        l |= outputs;
  56        writel(l, otg_dev->base + OMAP_OTG_CTRL);
  57}
  58
  59static void omap_otg_set_mode(struct otg_device *otg_dev)
  60{
  61        if (!otg_dev->id && otg_dev->vbus)
  62                /* Set B-session valid. */
  63                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
  64        else if (otg_dev->vbus)
  65                /* Set A-session valid. */
  66                omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
  67        else if (!otg_dev->id)
  68                /* Set B-session end to indicate no VBUS. */
  69                omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
  70}
  71
  72static int omap_otg_id_notifier(struct notifier_block *nb,
  73                                unsigned long event, void *ptr)
  74{
  75        struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
  76
  77        otg_dev->id = event;
  78        omap_otg_set_mode(otg_dev);
  79
  80        return NOTIFY_DONE;
  81}
  82
  83static int omap_otg_vbus_notifier(struct notifier_block *nb,
  84                                  unsigned long event, void *ptr)
  85{
  86        struct otg_device *otg_dev = container_of(nb, struct otg_device,
  87                                                  vbus_nb);
  88
  89        otg_dev->vbus = event;
  90        omap_otg_set_mode(otg_dev);
  91
  92        return NOTIFY_DONE;
  93}
  94
  95static int omap_otg_probe(struct platform_device *pdev)
  96{
  97        const struct omap_usb_config *config = pdev->dev.platform_data;
  98        struct otg_device *otg_dev;
  99        struct extcon_dev *extcon;
 100        int ret;
 101        u32 rev;
 102
 103        if (!config || !config->extcon)
 104                return -ENODEV;
 105
 106        extcon = extcon_get_extcon_dev(config->extcon);
 107        if (!extcon)
 108                return -EPROBE_DEFER;
 109
 110        otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
 111        if (!otg_dev)
 112                return -ENOMEM;
 113
 114        otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
 115        if (IS_ERR(otg_dev->base))
 116                return PTR_ERR(otg_dev->base);
 117
 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 = extcon_register_interest(&otg_dev->id_dev, config->extcon,
 122                                       "USB-HOST", &otg_dev->id_nb);
 123        if (ret)
 124                return ret;
 125
 126        ret = extcon_register_interest(&otg_dev->vbus_dev, config->extcon,
 127                                       "USB", &otg_dev->vbus_nb);
 128        if (ret) {
 129                extcon_unregister_interest(&otg_dev->id_dev);
 130                return ret;
 131        }
 132
 133        otg_dev->id = extcon_get_cable_state(extcon, "USB-HOST");
 134        otg_dev->vbus = extcon_get_cable_state(extcon, "USB");
 135        omap_otg_set_mode(otg_dev);
 136
 137        rev = readl(otg_dev->base);
 138
 139        dev_info(&pdev->dev,
 140                 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
 141                 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
 142                 otg_dev->vbus);
 143
 144        return 0;
 145}
 146
 147static int omap_otg_remove(struct platform_device *pdev)
 148{
 149        struct otg_device *otg_dev = platform_get_drvdata(pdev);
 150
 151        extcon_unregister_interest(&otg_dev->id_dev);
 152        extcon_unregister_interest(&otg_dev->vbus_dev);
 153
 154        return 0;
 155}
 156
 157static struct platform_driver omap_otg_driver = {
 158        .probe          = omap_otg_probe,
 159        .remove         = omap_otg_remove,
 160        .driver         = {
 161                .name   = "omap_otg",
 162        },
 163};
 164module_platform_driver(omap_otg_driver);
 165
 166MODULE_DESCRIPTION("OMAP USB OTG controller driver");
 167MODULE_LICENSE("GPL");
 168MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 169
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