drivers/power/isp1704_charger.c

   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
  50 static u16 isp170x_id[] = {
  51         0x1704,
  52         0x1707,
  53 };
  54
  55 struct 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  */
  70 static 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
 127 static 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
 155 static 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
 185 static 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
 208 static 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
 231 static enum power_supply_property power_props[] = {
 232         POWER_SUPPLY_PROP_PRESENT,
 233         POWER_SUPPLY_PROP_MODEL_NAME,
 234         POWER_SUPPLY_PROP_MANUFACTURER,
 235 };
 236
 237 static 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
 277 static 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;
 322 fail2:
 323         power_supply_unregister(&isp->psy);
 324 fail1:
 325         otg_put_transceiver(isp->otg);
 326 fail0:
 327         kfree(isp);
 328
 329         dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 330
 331         return ret;
 332 }
 333
 334 static 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
 346 static 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
 354 static int __init isp1704_charger_init(void)
 355 {
 356         return platform_driver_register(&isp1704_charger_driver);
 357 }
 358 module_init(isp1704_charger_init);
 359
 360 static void __exit isp1704_charger_exit(void)
 361 {
 362         platform_driver_unregister(&isp1704_charger_driver);
 363 }
 364 module_exit(isp1704_charger_exit);
 365
 366 MODULE_ALIAS("platform:isp1704_charger");
 367 MODULE_AUTHOR("Nokia Corporation");
 368 MODULE_DESCRIPTION("ISP170x USB Charger driver");
 369 MODULE_LICENSE("GPL");