drivers/usb/misc/usb3503.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Driver for SMSC USB3503 USB 2.0 hub controller driver
   4  *
   5  * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/i2c.h>
  10 #include <linux/gpio.h>
  11 #include <linux/delay.h>
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/of_gpio.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/platform_data/usb3503.h>
  17 #include <linux/regmap.h>
  18
  19 #define USB3503_VIDL            0x00
  20 #define USB3503_VIDM            0x01
  21 #define USB3503_PIDL            0x02
  22 #define USB3503_PIDM            0x03
  23 #define USB3503_DIDL            0x04
  24 #define USB3503_DIDM            0x05
  25
  26 #define USB3503_CFG1            0x06
  27 #define USB3503_SELF_BUS_PWR    (1 << 7)
  28
  29 #define USB3503_CFG2            0x07
  30 #define USB3503_CFG3            0x08
  31 #define USB3503_NRD             0x09
  32
  33 #define USB3503_PDS             0x0a
  34
  35 #define USB3503_SP_ILOCK        0xe7
  36 #define USB3503_SPILOCK_CONNECT (1 << 1)
  37 #define USB3503_SPILOCK_CONFIG  (1 << 0)
  38
  39 #define USB3503_CFGP            0xee
  40 #define USB3503_CLKSUSP         (1 << 7)
  41
  42 #define USB3503_RESET           0xff
  43
  44 struct usb3503 {
  45         enum usb3503_mode       mode;
  46         struct regmap           *regmap;
  47         struct device           *dev;
  48         struct clk              *clk;
  49         u8      port_off_mask;
  50         int     gpio_intn;
  51         int     gpio_reset;
  52         int     gpio_connect;
  53         bool    secondary_ref_clk;
  54 };
  55
  56 static int usb3503_reset(struct usb3503 *hub, int state)
  57 {
  58         if (!state && gpio_is_valid(hub->gpio_connect))
  59                 gpio_set_value_cansleep(hub->gpio_connect, 0);
  60
  61         if (gpio_is_valid(hub->gpio_reset))
  62                 gpio_set_value_cansleep(hub->gpio_reset, state);
  63
  64         /* Wait T_HUBINIT == 4ms for hub logic to stabilize */
  65         if (state)
  66                 usleep_range(4000, 10000);
  67
  68         return 0;
  69 }
  70
  71 static int usb3503_connect(struct usb3503 *hub)
  72 {
  73         struct device *dev = hub->dev;
  74         int err;
  75
  76         usb3503_reset(hub, 1);
  77
  78         if (hub->regmap) {
  79                 /* SP_ILOCK: set connect_n, config_n for config */
  80                 err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
  81                            (USB3503_SPILOCK_CONNECT
  82                                  | USB3503_SPILOCK_CONFIG));
  83                 if (err < 0) {
  84                         dev_err(dev, "SP_ILOCK failed (%d)\n", err);
  85                         return err;
  86                 }
  87
  88                 /* PDS : Set the ports which are disabled in self-powered mode. */
  89                 if (hub->port_off_mask) {
  90                         err = regmap_update_bits(hub->regmap, USB3503_PDS,
  91                                         hub->port_off_mask,
  92                                         hub->port_off_mask);
  93                         if (err < 0) {
  94                                 dev_err(dev, "PDS failed (%d)\n", err);
  95                                 return err;
  96                         }
  97                 }
  98
  99                 /* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
 100                 err = regmap_update_bits(hub->regmap, USB3503_CFG1,
 101                                          USB3503_SELF_BUS_PWR,
 102                                          USB3503_SELF_BUS_PWR);
 103                 if (err < 0) {
 104                         dev_err(dev, "CFG1 failed (%d)\n", err);
 105                         return err;
 106                 }
 107
 108                 /* SP_LOCK: clear connect_n, config_n for hub connect */
 109                 err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
 110                                          (USB3503_SPILOCK_CONNECT
 111                                           | USB3503_SPILOCK_CONFIG), 0);
 112                 if (err < 0) {
 113                         dev_err(dev, "SP_ILOCK failed (%d)\n", err);
 114                         return err;
 115                 }
 116         }
 117
 118         if (gpio_is_valid(hub->gpio_connect))
 119                 gpio_set_value_cansleep(hub->gpio_connect, 1);
 120
 121         hub->mode = USB3503_MODE_HUB;
 122         dev_info(dev, "switched to HUB mode\n");
 123
 124         return 0;
 125 }
 126
 127 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
 128 {
 129         struct device *dev = hub->dev;
 130         int err = 0;
 131
 132         switch (mode) {
 133         case USB3503_MODE_HUB:
 134                 err = usb3503_connect(hub);
 135                 break;
 136
 137         case USB3503_MODE_STANDBY:
 138                 usb3503_reset(hub, 0);
 139                 dev_info(dev, "switched to STANDBY mode\n");
 140                 break;
 141
 142         default:
 143                 dev_err(dev, "unknown mode is requested\n");
 144                 err = -EINVAL;
 145                 break;
 146         }
 147
 148         return err;
 149 }
 150
 151 static const struct regmap_config usb3503_regmap_config = {
 152         .reg_bits = 8,
 153         .val_bits = 8,
 154
 155         .max_register = USB3503_RESET,
 156 };
 157
 158 static int usb3503_probe(struct usb3503 *hub)
 159 {
 160         struct device *dev = hub->dev;
 161         struct usb3503_platform_data *pdata = dev_get_platdata(dev);
 162         struct device_node *np = dev->of_node;
 163         int err;
 164         u32 mode = USB3503_MODE_HUB;
 165         const u32 *property;
 166         int len;
 167
 168         if (pdata) {
 169                 hub->port_off_mask      = pdata->port_off_mask;
 170                 hub->gpio_intn          = pdata->gpio_intn;
 171                 hub->gpio_connect       = pdata->gpio_connect;
 172                 hub->gpio_reset         = pdata->gpio_reset;
 173                 hub->mode               = pdata->initial_mode;
 174         } else if (np) {
 175                 struct clk *clk;
 176                 u32 rate = 0;
 177                 hub->port_off_mask = 0;
 178
 179                 if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
 180                         switch (rate) {
 181                         case 38400000:
 182                         case 26000000:
 183                         case 19200000:
 184                         case 12000000:
 185                                 hub->secondary_ref_clk = 0;
 186                                 break;
 187                         case 24000000:
 188                         case 27000000:
 189                         case 25000000:
 190                         case 50000000:
 191                                 hub->secondary_ref_clk = 1;
 192                                 break;
 193                         default:
 194                                 dev_err(dev,
 195                                         "unsupported reference clock rate (%d)\n",
 196                                         (int) rate);
 197                                 return -EINVAL;
 198                         }
 199                 }
 200
 201                 clk = devm_clk_get(dev, "refclk");
 202                 if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
 203                         dev_err(dev, "unable to request refclk (%ld)\n",
 204                                         PTR_ERR(clk));
 205                         return PTR_ERR(clk);
 206                 }
 207
 208                 if (!IS_ERR(clk)) {
 209                         hub->clk = clk;
 210
 211                         if (rate != 0) {
 212                                 err = clk_set_rate(hub->clk, rate);
 213                                 if (err) {
 214                                         dev_err(dev,
 215                                                 "unable to set reference clock rate to %d\n",
 216                                                 (int) rate);
 217                                         return err;
 218                                 }
 219                         }
 220
 221                         err = clk_prepare_enable(hub->clk);
 222                         if (err) {
 223                                 dev_err(dev,
 224                                         "unable to enable reference clock\n");
 225                                 return err;
 226                         }
 227                 }
 228
 229                 property = of_get_property(np, "disabled-ports", &len);
 230                 if (property && (len / sizeof(u32)) > 0) {
 231                         int i;
 232                         for (i = 0; i < len / sizeof(u32); i++) {
 233                                 u32 port = be32_to_cpu(property[i]);
 234                                 if ((1 <= port) && (port <= 3))
 235                                         hub->port_off_mask |= (1 << port);
 236                         }
 237                 }
 238
 239                 hub->gpio_intn  = of_get_named_gpio(np, "intn-gpios", 0);
 240                 if (hub->gpio_intn == -EPROBE_DEFER)
 241                         return -EPROBE_DEFER;
 242                 hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
 243                 if (hub->gpio_connect == -EPROBE_DEFER)
 244                         return -EPROBE_DEFER;
 245                 hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
 246                 if (hub->gpio_reset == -EPROBE_DEFER)
 247                         return -EPROBE_DEFER;
 248                 of_property_read_u32(np, "initial-mode", &mode);
 249                 hub->mode = mode;
 250         }
 251
 252         if (hub->port_off_mask && !hub->regmap)
 253                 dev_err(dev, "Ports disabled with no control interface\n");
 254
 255         if (gpio_is_valid(hub->gpio_intn)) {
 256                 int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
 257                                                    GPIOF_OUT_INIT_HIGH;
 258                 err = devm_gpio_request_one(dev, hub->gpio_intn, val,
 259                                             "usb3503 intn");
 260                 if (err) {
 261                         dev_err(dev,
 262                                 "unable to request GPIO %d as interrupt pin (%d)\n",
 263                                 hub->gpio_intn, err);
 264                         return err;
 265                 }
 266         }
 267
 268         if (gpio_is_valid(hub->gpio_connect)) {
 269                 err = devm_gpio_request_one(dev, hub->gpio_connect,
 270                                 GPIOF_OUT_INIT_LOW, "usb3503 connect");
 271                 if (err) {
 272                         dev_err(dev,
 273                                 "unable to request GPIO %d as connect pin (%d)\n",
 274                                 hub->gpio_connect, err);
 275                         return err;
 276                 }
 277         }
 278
 279         if (gpio_is_valid(hub->gpio_reset)) {
 280                 err = devm_gpio_request_one(dev, hub->gpio_reset,
 281                                 GPIOF_OUT_INIT_LOW, "usb3503 reset");
 282                 /* Datasheet defines a hardware reset to be at least 100us */
 283                 usleep_range(100, 10000);
 284                 if (err) {
 285                         dev_err(dev,
 286                                 "unable to request GPIO %d as reset pin (%d)\n",
 287                                 hub->gpio_reset, err);
 288                         return err;
 289                 }
 290         }
 291
 292         usb3503_switch_mode(hub, hub->mode);
 293
 294         dev_info(dev, "%s: probed in %s mode\n", __func__,
 295                         (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
 296
 297         return 0;
 298 }
 299
 300 static int usb3503_i2c_probe(struct i2c_client *i2c,
 301                              const struct i2c_device_id *id)
 302 {
 303         struct usb3503 *hub;
 304         int err;
 305
 306         hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
 307         if (!hub)
 308                 return -ENOMEM;
 309
 310         i2c_set_clientdata(i2c, hub);
 311         hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
 312         if (IS_ERR(hub->regmap)) {
 313                 err = PTR_ERR(hub->regmap);
 314                 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
 315                 return err;
 316         }
 317         hub->dev = &i2c->dev;
 318
 319         return usb3503_probe(hub);
 320 }
 321
 322 static int usb3503_i2c_remove(struct i2c_client *i2c)
 323 {
 324         struct usb3503 *hub;
 325
 326         hub = i2c_get_clientdata(i2c);
 327         if (hub->clk)
 328                 clk_disable_unprepare(hub->clk);
 329
 330         return 0;
 331 }
 332
 333 static int usb3503_platform_probe(struct platform_device *pdev)
 334 {
 335         struct usb3503 *hub;
 336
 337         hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
 338         if (!hub)
 339                 return -ENOMEM;
 340         hub->dev = &pdev->dev;
 341         platform_set_drvdata(pdev, hub);
 342
 343         return usb3503_probe(hub);
 344 }
 345
 346 static int usb3503_platform_remove(struct platform_device *pdev)
 347 {
 348         struct usb3503 *hub;
 349
 350         hub = platform_get_drvdata(pdev);
 351         if (hub->clk)
 352                 clk_disable_unprepare(hub->clk);
 353
 354         return 0;
 355 }
 356
 357 #ifdef CONFIG_PM_SLEEP
 358 static int usb3503_i2c_suspend(struct device *dev)
 359 {
 360         struct i2c_client *client = to_i2c_client(dev);
 361         struct usb3503 *hub = i2c_get_clientdata(client);
 362
 363         usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
 364
 365         if (hub->clk)
 366                 clk_disable_unprepare(hub->clk);
 367
 368         return 0;
 369 }
 370
 371 static int usb3503_i2c_resume(struct device *dev)
 372 {
 373         struct i2c_client *client = to_i2c_client(dev);
 374         struct usb3503 *hub = i2c_get_clientdata(client);
 375
 376         if (hub->clk)
 377                 clk_prepare_enable(hub->clk);
 378
 379         usb3503_switch_mode(hub, hub->mode);
 380
 381         return 0;
 382 }
 383 #endif
 384
 385 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
 386                 usb3503_i2c_resume);
 387
 388 static const struct i2c_device_id usb3503_id[] = {
 389         { USB3503_I2C_NAME, 0 },
 390         { }
 391 };
 392 MODULE_DEVICE_TABLE(i2c, usb3503_id);
 393
 394 #ifdef CONFIG_OF
 395 static const struct of_device_id usb3503_of_match[] = {
 396         { .compatible = "smsc,usb3503", },
 397         { .compatible = "smsc,usb3503a", },
 398         {},
 399 };
 400 MODULE_DEVICE_TABLE(of, usb3503_of_match);
 401 #endif
 402
 403 static struct i2c_driver usb3503_i2c_driver = {
 404         .driver = {
 405                 .name = USB3503_I2C_NAME,
 406                 .pm = &usb3503_i2c_pm_ops,
 407                 .of_match_table = of_match_ptr(usb3503_of_match),
 408         },
 409         .probe          = usb3503_i2c_probe,
 410         .remove         = usb3503_i2c_remove,
 411         .id_table       = usb3503_id,
 412 };
 413
 414 static struct platform_driver usb3503_platform_driver = {
 415         .driver = {
 416                 .name = USB3503_I2C_NAME,
 417                 .of_match_table = of_match_ptr(usb3503_of_match),
 418         },
 419         .probe          = usb3503_platform_probe,
 420         .remove         = usb3503_platform_remove,
 421 };
 422
 423 static int __init usb3503_init(void)
 424 {
 425         int err;
 426
 427         err = i2c_add_driver(&usb3503_i2c_driver);
 428         if (err != 0)
 429                 pr_err("usb3503: Failed to register I2C driver: %d\n", err);
 430
 431         err = platform_driver_register(&usb3503_platform_driver);
 432         if (err != 0)
 433                 pr_err("usb3503: Failed to register platform driver: %d\n",
 434                        err);
 435
 436         return 0;
 437 }
 438 module_init(usb3503_init);
 439
 440 static void __exit usb3503_exit(void)
 441 {
 442         platform_driver_unregister(&usb3503_platform_driver);
 443         i2c_del_driver(&usb3503_i2c_driver);
 444 }
 445 module_exit(usb3503_exit);
 446
 447 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
 448 MODULE_DESCRIPTION("USB3503 USB HUB driver");
 449 MODULE_LICENSE("GPL");