linux/drivers/power/isp1704_charger.c
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   1/*
   2 * ISP1704 USB Charger Detection driver
   3 *
   4 * Copyright (C) 2010 Nokia Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 */
  20
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23#include <linux/err.h>
  24#include <linux/init.h>
  25#include <linux/types.h>
  26#include <linux/device.h>
  27#include <linux/sysfs.h>
  28#include <linux/platform_device.h>
  29#include <linux/power_supply.h>
  30#include <linux/delay.h>
  31
  32#include <linux/usb/otg.h>
  33#include <linux/usb/ulpi.h>
  34#include <linux/usb/ch9.h>
  35#include <linux/usb/gadget.h>
  36
  37/* Vendor specific Power Control register */
  38#define ISP1704_PWR_CTRL                0x3d
  39#define ISP1704_PWR_CTRL_SWCTRL         (1 << 0)
  40#define ISP1704_PWR_CTRL_DET_COMP       (1 << 1)
  41#define ISP1704_PWR_CTRL_BVALID_RISE    (1 << 2)
  42#define ISP1704_PWR_CTRL_BVALID_FALL    (1 << 3)
  43#define ISP1704_PWR_CTRL_DP_WKPU_EN     (1 << 4)
  44#define ISP1704_PWR_CTRL_VDAT_DET       (1 << 5)
  45#define ISP1704_PWR_CTRL_DPVSRC_EN      (1 << 6)
  46#define ISP1704_PWR_CTRL_HWDETECT       (1 << 7)
  47
  48#define NXP_VENDOR_ID                   0x04cc
  49
  50static u16 isp170x_id[] = {
  51        0x1704,
  52        0x1707,
  53};
  54
  55struct isp1704_charger {
  56        struct device           *dev;
  57        struct power_supply     psy;
  58        struct otg_transceiver  *otg;
  59        struct notifier_block   nb;
  60        struct work_struct      work;
  61
  62        char                    model[7];
  63        unsigned                present:1;
  64};
  65
  66/*
  67 * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
  68 * is actually a dedicated charger, the following steps need to be taken.
  69 */
  70static inline int isp1704_charger_verify(struct isp1704_charger *isp)
  71{
  72        int     ret = 0;
  73        u8      r;
  74
  75        /* Reset the transceiver */
  76        r = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
  77        r |= ULPI_FUNC_CTRL_RESET;
  78        otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
  79        usleep_range(1000, 2000);
  80
  81        /* Set normal mode */
  82        r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
  83        otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
  84
  85        /* Clear the DP and DM pull-down bits */
  86        r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
  87        otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), r);
  88
  89        /* Enable strong pull-up on DP (1.5K) and reset */
  90        r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
  91        otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), r);
  92        usleep_range(1000, 2000);
  93
  94        /* Read the line state */
  95        if (!otg_io_read(isp->otg, ULPI_DEBUG)) {
  96                /* Disable strong pull-up on DP (1.5K) */
  97                otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
  98                                ULPI_FUNC_CTRL_TERMSELECT);
  99                return 1;
 100        }
 101
 102        /* Is it a charger or PS/2 connection */
 103
 104        /* Enable weak pull-up resistor on DP */
 105        otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
 106                        ISP1704_PWR_CTRL_DP_WKPU_EN);
 107
 108        /* Disable strong pull-up on DP (1.5K) */
 109        otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 110                        ULPI_FUNC_CTRL_TERMSELECT);
 111
 112        /* Enable weak pull-down resistor on DM */
 113        otg_io_write(isp->otg, ULPI_SET(ULPI_OTG_CTRL),
 114                        ULPI_OTG_CTRL_DM_PULLDOWN);
 115
 116        /* It's a charger if the line states are clear */
 117        if (!(otg_io_read(isp->otg, ULPI_DEBUG)))
 118                ret = 1;
 119
 120        /* Disable weak pull-up resistor on DP */
 121        otg_io_write(isp->otg, ULPI_CLR(ISP1704_PWR_CTRL),
 122                        ISP1704_PWR_CTRL_DP_WKPU_EN);
 123
 124        return ret;
 125}
 126
 127static inline int isp1704_charger_detect(struct isp1704_charger *isp)
 128{
 129        unsigned long   timeout;
 130        u8              r;
 131        int             ret = 0;
 132
 133        /* set SW control bit in PWR_CTRL register */
 134        otg_io_write(isp->otg, ISP1704_PWR_CTRL,
 135                        ISP1704_PWR_CTRL_SWCTRL);
 136
 137        /* enable manual charger detection */
 138        r = (ISP1704_PWR_CTRL_SWCTRL | ISP1704_PWR_CTRL_DPVSRC_EN);
 139        otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL), r);
 140        usleep_range(1000, 2000);
 141
 142        timeout = jiffies + msecs_to_jiffies(300);
 143        do {
 144                /* Check if there is a charger */
 145                if (otg_io_read(isp->otg, ISP1704_PWR_CTRL)
 146                                & ISP1704_PWR_CTRL_VDAT_DET) {
 147                        ret = isp1704_charger_verify(isp);
 148                        break;
 149                }
 150        } while (!time_after(jiffies, timeout));
 151
 152        return ret;
 153}
 154
 155static void isp1704_charger_work(struct work_struct *data)
 156{
 157        int                     detect;
 158        struct isp1704_charger  *isp =
 159                container_of(data, struct isp1704_charger, work);
 160
 161        /*
 162         * FIXME Only supporting dedicated chargers even though isp1704 can
 163         * detect HUB and HOST chargers. If the device has already been
 164         * enumerated, the detection will break the connection.
 165         */
 166        if (isp->otg->state != OTG_STATE_B_IDLE)
 167                return;
 168
 169        /* disable data pullups */
 170        if (isp->otg->gadget)
 171                usb_gadget_disconnect(isp->otg->gadget);
 172
 173        /* detect charger */
 174        detect = isp1704_charger_detect(isp);
 175        if (detect) {
 176                isp->present = detect;
 177                power_supply_changed(&isp->psy);
 178        }
 179
 180        /* enable data pullups */
 181        if (isp->otg->gadget)
 182                usb_gadget_connect(isp->otg->gadget);
 183}
 184
 185static int isp1704_notifier_call(struct notifier_block *nb,
 186                unsigned long event, void *unused)
 187{
 188        struct isp1704_charger *isp =
 189                container_of(nb, struct isp1704_charger, nb);
 190
 191        switch (event) {
 192        case USB_EVENT_VBUS:
 193                schedule_work(&isp->work);
 194                break;
 195        case USB_EVENT_NONE:
 196                if (isp->present) {
 197                        isp->present = 0;
 198                        power_supply_changed(&isp->psy);
 199                }
 200                break;
 201        default:
 202                return NOTIFY_DONE;
 203        }
 204
 205        return NOTIFY_OK;
 206}
 207
 208static int isp1704_charger_get_property(struct power_supply *psy,
 209                                enum power_supply_property psp,
 210                                union power_supply_propval *val)
 211{
 212        struct isp1704_charger *isp =
 213                container_of(psy, struct isp1704_charger, psy);
 214
 215        switch (psp) {
 216        case POWER_SUPPLY_PROP_PRESENT:
 217                val->intval = isp->present;
 218                break;
 219        case POWER_SUPPLY_PROP_MODEL_NAME:
 220                val->strval = isp->model;
 221                break;
 222        case POWER_SUPPLY_PROP_MANUFACTURER:
 223                val->strval = "NXP";
 224                break;
 225        default:
 226                return -EINVAL;
 227        }
 228        return 0;
 229}
 230
 231static enum power_supply_property power_props[] = {
 232        POWER_SUPPLY_PROP_PRESENT,
 233        POWER_SUPPLY_PROP_MODEL_NAME,
 234        POWER_SUPPLY_PROP_MANUFACTURER,
 235};
 236
 237static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
 238{
 239        int vendor;
 240        int product;
 241        int i;
 242        int ret = -ENODEV;
 243
 244        /* Test ULPI interface */
 245        ret = otg_io_write(isp->otg, ULPI_SCRATCH, 0xaa);
 246        if (ret < 0)
 247                return ret;
 248
 249        ret = otg_io_read(isp->otg, ULPI_SCRATCH);
 250        if (ret < 0)
 251                return ret;
 252
 253        if (ret != 0xaa)
 254                return -ENODEV;
 255
 256        /* Verify the product and vendor id matches */
 257        vendor = otg_io_read(isp->otg, ULPI_VENDOR_ID_LOW);
 258        vendor |= otg_io_read(isp->otg, ULPI_VENDOR_ID_HIGH) << 8;
 259        if (vendor != NXP_VENDOR_ID)
 260                return -ENODEV;
 261
 262        product = otg_io_read(isp->otg, ULPI_PRODUCT_ID_LOW);
 263        product |= otg_io_read(isp->otg, ULPI_PRODUCT_ID_HIGH) << 8;
 264
 265        for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
 266                if (product == isp170x_id[i]) {
 267                        sprintf(isp->model, "isp%x", product);
 268                        return product;
 269                }
 270        }
 271
 272        dev_err(isp->dev, "product id %x not matching known ids", product);
 273
 274        return -ENODEV;
 275}
 276
 277static int __devinit isp1704_charger_probe(struct platform_device *pdev)
 278{
 279        struct isp1704_charger  *isp;
 280        int                     ret = -ENODEV;
 281
 282        isp = kzalloc(sizeof *isp, GFP_KERNEL);
 283        if (!isp)
 284                return -ENOMEM;
 285
 286        isp->otg = otg_get_transceiver();
 287        if (!isp->otg)
 288                goto fail0;
 289
 290        ret = isp1704_test_ulpi(isp);
 291        if (ret < 0)
 292                goto fail1;
 293
 294        isp->dev = &pdev->dev;
 295        platform_set_drvdata(pdev, isp);
 296
 297        isp->psy.name           = "isp1704";
 298        isp->psy.type           = POWER_SUPPLY_TYPE_USB;
 299        isp->psy.properties     = power_props;
 300        isp->psy.num_properties = ARRAY_SIZE(power_props);
 301        isp->psy.get_property   = isp1704_charger_get_property;
 302
 303        ret = power_supply_register(isp->dev, &isp->psy);
 304        if (ret)
 305                goto fail1;
 306
 307        /*
 308         * REVISIT: using work in order to allow the otg notifications to be
 309         * made atomically in the future.
 310         */
 311        INIT_WORK(&isp->work, isp1704_charger_work);
 312
 313        isp->nb.notifier_call = isp1704_notifier_call;
 314
 315        ret = otg_register_notifier(isp->otg, &isp->nb);
 316        if (ret)
 317                goto fail2;
 318
 319        dev_info(isp->dev, "registered with product id %s\n", isp->model);
 320
 321        return 0;
 322fail2:
 323        power_supply_unregister(&isp->psy);
 324fail1:
 325        otg_put_transceiver(isp->otg);
 326fail0:
 327        kfree(isp);
 328
 329        dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 330
 331        return ret;
 332}
 333
 334static int __devexit isp1704_charger_remove(struct platform_device *pdev)
 335{
 336        struct isp1704_charger *isp = platform_get_drvdata(pdev);
 337
 338        otg_unregister_notifier(isp->otg, &isp->nb);
 339        power_supply_unregister(&isp->psy);
 340        otg_put_transceiver(isp->otg);
 341        kfree(isp);
 342
 343        return 0;
 344}
 345
 346static struct platform_driver isp1704_charger_driver = {
 347        .driver = {
 348                .name = "isp1704_charger",
 349        },
 350        .probe = isp1704_charger_probe,
 351        .remove = __devexit_p(isp1704_charger_remove),
 352};
 353
 354static int __init isp1704_charger_init(void)
 355{
 356        return platform_driver_register(&isp1704_charger_driver);
 357}
 358module_init(isp1704_charger_init);
 359
 360static void __exit isp1704_charger_exit(void)
 361{
 362        platform_driver_unregister(&isp1704_charger_driver);
 363}
 364module_exit(isp1704_charger_exit);
 365
 366MODULE_ALIAS("platform:isp1704_charger");
 367MODULE_AUTHOR("Nokia Corporation");
 368MODULE_DESCRIPTION("ISP170x USB Charger driver");
 369MODULE_LICENSE("GPL");
 370