drivers/extcon/extcon-intel-cht-wc.c

   1 /*
   2  * Extcon charger detection driver for Intel Cherrytrail Whiskey Cove PMIC
   3  * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
   4  *
   5  * Based on various non upstream patches to support the CHT Whiskey Cove PMIC:
   6  * Copyright (C) 2013-2015 Intel Corporation. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  */
  17
  18 #include <linux/extcon.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mfd/intel_soc_pmic.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/slab.h>
  26
  27 #define CHT_WC_PHYCTRL                  0x5e07
  28
  29 #define CHT_WC_CHGRCTRL0                0x5e16
  30 #define CHT_WC_CHGRCTRL0_CHGRRESET      BIT(0)
  31 #define CHT_WC_CHGRCTRL0_EMRGCHREN      BIT(1)
  32 #define CHT_WC_CHGRCTRL0_EXTCHRDIS      BIT(2)
  33 #define CHT_WC_CHGRCTRL0_SWCONTROL      BIT(3)
  34 #define CHT_WC_CHGRCTRL0_TTLCK_MASK     BIT(4)
  35 #define CHT_WC_CHGRCTRL0_CCSM_OFF_MASK  BIT(5)
  36 #define CHT_WC_CHGRCTRL0_DBPOFF_MASK    BIT(6)
  37 #define CHT_WC_CHGRCTRL0_WDT_NOKICK     BIT(7)
  38
  39 #define CHT_WC_CHGRCTRL1                0x5e17
  40
  41 #define CHT_WC_USBSRC                   0x5e29
  42 #define CHT_WC_USBSRC_STS_MASK          GENMASK(1, 0)
  43 #define CHT_WC_USBSRC_STS_SUCCESS       2
  44 #define CHT_WC_USBSRC_STS_FAIL          3
  45 #define CHT_WC_USBSRC_TYPE_SHIFT        2
  46 #define CHT_WC_USBSRC_TYPE_MASK         GENMASK(5, 2)
  47 #define CHT_WC_USBSRC_TYPE_NONE         0
  48 #define CHT_WC_USBSRC_TYPE_SDP          1
  49 #define CHT_WC_USBSRC_TYPE_DCP          2
  50 #define CHT_WC_USBSRC_TYPE_CDP          3
  51 #define CHT_WC_USBSRC_TYPE_ACA          4
  52 #define CHT_WC_USBSRC_TYPE_SE1          5
  53 #define CHT_WC_USBSRC_TYPE_MHL          6
  54 #define CHT_WC_USBSRC_TYPE_FLOAT_DP_DN  7
  55 #define CHT_WC_USBSRC_TYPE_OTHER        8
  56 #define CHT_WC_USBSRC_TYPE_DCP_EXTPHY   9
  57
  58 #define CHT_WC_PWRSRC_IRQ               0x6e03
  59 #define CHT_WC_PWRSRC_IRQ_MASK          0x6e0f
  60 #define CHT_WC_PWRSRC_STS               0x6e1e
  61 #define CHT_WC_PWRSRC_VBUS              BIT(0)
  62 #define CHT_WC_PWRSRC_DC                BIT(1)
  63 #define CHT_WC_PWRSRC_BAT               BIT(2)
  64 #define CHT_WC_PWRSRC_ID_GND            BIT(3)
  65 #define CHT_WC_PWRSRC_ID_FLOAT          BIT(4)
  66
  67 #define CHT_WC_VBUS_GPIO_CTLO           0x6e2d
  68 #define CHT_WC_VBUS_GPIO_CTLO_OUTPUT    BIT(0)
  69
  70 enum cht_wc_usb_id {
  71         USB_ID_OTG,
  72         USB_ID_GND,
  73         USB_ID_FLOAT,
  74         USB_RID_A,
  75         USB_RID_B,
  76         USB_RID_C,
  77 };
  78
  79 enum cht_wc_mux_select {
  80         MUX_SEL_PMIC = 0,
  81         MUX_SEL_SOC,
  82 };
  83
  84 static const unsigned int cht_wc_extcon_cables[] = {
  85         EXTCON_USB,
  86         EXTCON_USB_HOST,
  87         EXTCON_CHG_USB_SDP,
  88         EXTCON_CHG_USB_CDP,
  89         EXTCON_CHG_USB_DCP,
  90         EXTCON_CHG_USB_ACA,
  91         EXTCON_NONE,
  92 };
  93
  94 struct cht_wc_extcon_data {
  95         struct device *dev;
  96         struct regmap *regmap;
  97         struct extcon_dev *edev;
  98         unsigned int previous_cable;
  99         bool usb_host;
 100 };
 101
 102 static int cht_wc_extcon_get_id(struct cht_wc_extcon_data *ext, int pwrsrc_sts)
 103 {
 104         if (pwrsrc_sts & CHT_WC_PWRSRC_ID_GND)
 105                 return USB_ID_GND;
 106         if (pwrsrc_sts & CHT_WC_PWRSRC_ID_FLOAT)
 107                 return USB_ID_FLOAT;
 108
 109         /*
 110          * Once we have iio support for the gpadc we should read the USBID
 111          * gpadc channel here and determine ACA role based on that.
 112          */
 113         return USB_ID_FLOAT;
 114 }
 115
 116 static int cht_wc_extcon_get_charger(struct cht_wc_extcon_data *ext,
 117                                      bool ignore_errors)
 118 {
 119         int ret, usbsrc, status;
 120         unsigned long timeout;
 121
 122         /* Charger detection can take upto 600ms, wait 800ms max. */
 123         timeout = jiffies + msecs_to_jiffies(800);
 124         do {
 125                 ret = regmap_read(ext->regmap, CHT_WC_USBSRC, &usbsrc);
 126                 if (ret) {
 127                         dev_err(ext->dev, "Error reading usbsrc: %d\n", ret);
 128                         return ret;
 129                 }
 130
 131                 status = usbsrc & CHT_WC_USBSRC_STS_MASK;
 132                 if (status == CHT_WC_USBSRC_STS_SUCCESS ||
 133                     status == CHT_WC_USBSRC_STS_FAIL)
 134                         break;
 135
 136                 msleep(50); /* Wait a bit before retrying */
 137         } while (time_before(jiffies, timeout));
 138
 139         if (status != CHT_WC_USBSRC_STS_SUCCESS) {
 140                 if (ignore_errors)
 141                         return EXTCON_CHG_USB_SDP; /* Save fallback */
 142
 143                 if (status == CHT_WC_USBSRC_STS_FAIL)
 144                         dev_warn(ext->dev, "Could not detect charger type\n");
 145                 else
 146                         dev_warn(ext->dev, "Timeout detecting charger type\n");
 147                 return EXTCON_CHG_USB_SDP; /* Save fallback */
 148         }
 149
 150         usbsrc = (usbsrc & CHT_WC_USBSRC_TYPE_MASK) >> CHT_WC_USBSRC_TYPE_SHIFT;
 151         switch (usbsrc) {
 152         default:
 153                 dev_warn(ext->dev,
 154                         "Unhandled charger type %d, defaulting to SDP\n",
 155                          ret);
 156                 /* Fall through, treat as SDP */
 157         case CHT_WC_USBSRC_TYPE_SDP:
 158         case CHT_WC_USBSRC_TYPE_FLOAT_DP_DN:
 159         case CHT_WC_USBSRC_TYPE_OTHER:
 160                 return EXTCON_CHG_USB_SDP;
 161         case CHT_WC_USBSRC_TYPE_CDP:
 162                 return EXTCON_CHG_USB_CDP;
 163         case CHT_WC_USBSRC_TYPE_DCP:
 164         case CHT_WC_USBSRC_TYPE_DCP_EXTPHY:
 165         case CHT_WC_USBSRC_TYPE_MHL: /* MHL2+ delivers upto 2A, treat as DCP */
 166                 return EXTCON_CHG_USB_DCP;
 167         case CHT_WC_USBSRC_TYPE_ACA:
 168                 return EXTCON_CHG_USB_ACA;
 169         }
 170 }
 171
 172 static void cht_wc_extcon_set_phymux(struct cht_wc_extcon_data *ext, u8 state)
 173 {
 174         int ret;
 175
 176         ret = regmap_write(ext->regmap, CHT_WC_PHYCTRL, state);
 177         if (ret)
 178                 dev_err(ext->dev, "Error writing phyctrl: %d\n", ret);
 179 }
 180
 181 static void cht_wc_extcon_set_5v_boost(struct cht_wc_extcon_data *ext,
 182                                        bool enable)
 183 {
 184         int ret, val;
 185
 186         val = enable ? CHT_WC_VBUS_GPIO_CTLO_OUTPUT : 0;
 187
 188         /*
 189          * The 5V boost converter is enabled through a gpio on the PMIC, since
 190          * there currently is no gpio driver we access the gpio reg directly.
 191          */
 192         ret = regmap_update_bits(ext->regmap, CHT_WC_VBUS_GPIO_CTLO,
 193                                  CHT_WC_VBUS_GPIO_CTLO_OUTPUT, val);
 194         if (ret)
 195                 dev_err(ext->dev, "Error writing Vbus GPIO CTLO: %d\n", ret);
 196 }
 197
 198 /* Small helper to sync EXTCON_CHG_USB_SDP and EXTCON_USB state */
 199 static void cht_wc_extcon_set_state(struct cht_wc_extcon_data *ext,
 200                                     unsigned int cable, bool state)
 201 {
 202         extcon_set_state_sync(ext->edev, cable, state);
 203         if (cable == EXTCON_CHG_USB_SDP)
 204                 extcon_set_state_sync(ext->edev, EXTCON_USB, state);
 205 }
 206
 207 static void cht_wc_extcon_pwrsrc_event(struct cht_wc_extcon_data *ext)
 208 {
 209         int ret, pwrsrc_sts, id;
 210         unsigned int cable = EXTCON_NONE;
 211         /* Ignore errors in host mode, as the 5v boost converter is on then */
 212         bool ignore_get_charger_errors = ext->usb_host;
 213
 214         ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_STS, &pwrsrc_sts);
 215         if (ret) {
 216                 dev_err(ext->dev, "Error reading pwrsrc status: %d\n", ret);
 217                 return;
 218         }
 219
 220         id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
 221         if (id == USB_ID_GND) {
 222                 /* The 5v boost causes a false VBUS / SDP detect, skip */
 223                 goto charger_det_done;
 224         }
 225
 226         /* Plugged into a host/charger or not connected? */
 227         if (!(pwrsrc_sts & CHT_WC_PWRSRC_VBUS)) {
 228                 /* Route D+ and D- to PMIC for future charger detection */
 229                 cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
 230                 goto set_state;
 231         }
 232
 233         ret = cht_wc_extcon_get_charger(ext, ignore_get_charger_errors);
 234         if (ret >= 0)
 235                 cable = ret;
 236
 237 charger_det_done:
 238         /* Route D+ and D- to SoC for the host or gadget controller */
 239         cht_wc_extcon_set_phymux(ext, MUX_SEL_SOC);
 240
 241 set_state:
 242         if (cable != ext->previous_cable) {
 243                 cht_wc_extcon_set_state(ext, cable, true);
 244                 cht_wc_extcon_set_state(ext, ext->previous_cable, false);
 245                 ext->previous_cable = cable;
 246         }
 247
 248         ext->usb_host = ((id == USB_ID_GND) || (id == USB_RID_A));
 249         extcon_set_state_sync(ext->edev, EXTCON_USB_HOST, ext->usb_host);
 250 }
 251
 252 static irqreturn_t cht_wc_extcon_isr(int irq, void *data)
 253 {
 254         struct cht_wc_extcon_data *ext = data;
 255         int ret, irqs;
 256
 257         ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_IRQ, &irqs);
 258         if (ret) {
 259                 dev_err(ext->dev, "Error reading irqs: %d\n", ret);
 260                 return IRQ_NONE;
 261         }
 262
 263         cht_wc_extcon_pwrsrc_event(ext);
 264
 265         ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ, irqs);
 266         if (ret) {
 267                 dev_err(ext->dev, "Error writing irqs: %d\n", ret);
 268                 return IRQ_NONE;
 269         }
 270
 271         return IRQ_HANDLED;
 272 }
 273
 274 static int cht_wc_extcon_sw_control(struct cht_wc_extcon_data *ext, bool enable)
 275 {
 276         int ret, mask, val;
 277
 278         mask = CHT_WC_CHGRCTRL0_SWCONTROL | CHT_WC_CHGRCTRL0_CCSM_OFF_MASK;
 279         val = enable ? mask : 0;
 280         ret = regmap_update_bits(ext->regmap, CHT_WC_CHGRCTRL0, mask, val);
 281         if (ret)
 282                 dev_err(ext->dev, "Error setting sw control: %d\n", ret);
 283
 284         return ret;
 285 }
 286
 287 static int cht_wc_extcon_probe(struct platform_device *pdev)
 288 {
 289         struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 290         struct cht_wc_extcon_data *ext;
 291         int irq, ret;
 292
 293         irq = platform_get_irq(pdev, 0);
 294         if (irq < 0)
 295                 return irq;
 296
 297         ext = devm_kzalloc(&pdev->dev, sizeof(*ext), GFP_KERNEL);
 298         if (!ext)
 299                 return -ENOMEM;
 300
 301         ext->dev = &pdev->dev;
 302         ext->regmap = pmic->regmap;
 303         ext->previous_cable = EXTCON_NONE;
 304
 305         /* Initialize extcon device */
 306         ext->edev = devm_extcon_dev_allocate(ext->dev, cht_wc_extcon_cables);
 307         if (IS_ERR(ext->edev))
 308                 return PTR_ERR(ext->edev);
 309
 310         /*
 311          * When a host-cable is detected the BIOS enables an external 5v boost
 312          * converter to power connected devices there are 2 problems with this:
 313          * 1) This gets seen by the external battery charger as a valid Vbus
 314          *    supply and it then tries to feed Vsys from this creating a
 315          *    feedback loop which causes aprox. 300 mA extra battery drain
 316          *    (and unless we drive the external-charger-disable pin high it
 317          *    also tries to charge the battery causing even more feedback).
 318          * 2) This gets seen by the pwrsrc block as a SDP USB Vbus supply
 319          * Since the external battery charger has its own 5v boost converter
 320          * which does not have these issues, we simply turn the separate
 321          * external 5v boost converter off and leave it off entirely.
 322          */
 323         cht_wc_extcon_set_5v_boost(ext, false);
 324
 325         /* Enable sw control */
 326         ret = cht_wc_extcon_sw_control(ext, true);
 327         if (ret)
 328                 return ret;
 329
 330         /* Register extcon device */
 331         ret = devm_extcon_dev_register(ext->dev, ext->edev);
 332         if (ret) {
 333                 dev_err(ext->dev, "Error registering extcon device: %d\n", ret);
 334                 goto disable_sw_control;
 335         }
 336
 337         /* Route D+ and D- to PMIC for initial charger detection */
 338         cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
 339
 340         /* Get initial state */
 341         cht_wc_extcon_pwrsrc_event(ext);
 342
 343         ret = devm_request_threaded_irq(ext->dev, irq, NULL, cht_wc_extcon_isr,
 344                                         IRQF_ONESHOT, pdev->name, ext);
 345         if (ret) {
 346                 dev_err(ext->dev, "Error requesting interrupt: %d\n", ret);
 347                 goto disable_sw_control;
 348         }
 349
 350         /* Unmask irqs */
 351         ret = regmap_write(ext->regmap, CHT_WC_PWRSRC_IRQ_MASK,
 352                            (int)~(CHT_WC_PWRSRC_VBUS | CHT_WC_PWRSRC_ID_GND |
 353                                   CHT_WC_PWRSRC_ID_FLOAT));
 354         if (ret) {
 355                 dev_err(ext->dev, "Error writing irq-mask: %d\n", ret);
 356                 goto disable_sw_control;
 357         }
 358
 359         platform_set_drvdata(pdev, ext);
 360
 361         return 0;
 362
 363 disable_sw_control:
 364         cht_wc_extcon_sw_control(ext, false);
 365         return ret;
 366 }
 367
 368 static int cht_wc_extcon_remove(struct platform_device *pdev)
 369 {
 370         struct cht_wc_extcon_data *ext = platform_get_drvdata(pdev);
 371
 372         cht_wc_extcon_sw_control(ext, false);
 373
 374         return 0;
 375 }
 376
 377 static const struct platform_device_id cht_wc_extcon_table[] = {
 378         { .name = "cht_wcove_pwrsrc" },
 379         {},
 380 };
 381 MODULE_DEVICE_TABLE(platform, cht_wc_extcon_table);
 382
 383 static struct platform_driver cht_wc_extcon_driver = {
 384         .probe = cht_wc_extcon_probe,
 385         .remove = cht_wc_extcon_remove,
 386         .id_table = cht_wc_extcon_table,
 387         .driver = {
 388                 .name = "cht_wcove_pwrsrc",
 389         },
 390 };
 391 module_platform_driver(cht_wc_extcon_driver);
 392
 393 MODULE_DESCRIPTION("Intel Cherrytrail Whiskey Cove PMIC extcon driver");
 394 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 395 MODULE_LICENSE("GPL v2");