linux/drivers/usb/misc/usb3503.c
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   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
  44struct 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
  56static 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
  71static 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
 127static 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
 151static const struct regmap_config usb3503_regmap_config = {
 152        .reg_bits = 8,
 153        .val_bits = 8,
 154
 155        .max_register = USB3503_RESET,
 156};
 157
 158static 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                u32 rate = 0;
 176                hub->port_off_mask = 0;
 177
 178                if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
 179                        switch (rate) {
 180                        case 38400000:
 181                        case 26000000:
 182                        case 19200000:
 183                        case 12000000:
 184                                hub->secondary_ref_clk = 0;
 185                                break;
 186                        case 24000000:
 187                        case 27000000:
 188                        case 25000000:
 189                        case 50000000:
 190                                hub->secondary_ref_clk = 1;
 191                                break;
 192                        default:
 193                                dev_err(dev,
 194                                        "unsupported reference clock rate (%d)\n",
 195                                        (int) rate);
 196                                return -EINVAL;
 197                        }
 198                }
 199
 200                hub->clk = devm_clk_get_optional(dev, "refclk");
 201                if (IS_ERR(hub->clk)) {
 202                        dev_err(dev, "unable to request refclk (%ld)\n",
 203                                        PTR_ERR(hub->clk));
 204                        return PTR_ERR(hub->clk);
 205                }
 206
 207                if (rate != 0) {
 208                        err = clk_set_rate(hub->clk, rate);
 209                        if (err) {
 210                                dev_err(dev,
 211                                        "unable to set reference clock rate to %d\n",
 212                                        (int)rate);
 213                                return err;
 214                        }
 215                }
 216
 217                err = clk_prepare_enable(hub->clk);
 218                if (err) {
 219                        dev_err(dev, "unable to enable reference clock\n");
 220                        return err;
 221                }
 222
 223                property = of_get_property(np, "disabled-ports", &len);
 224                if (property && (len / sizeof(u32)) > 0) {
 225                        int i;
 226                        for (i = 0; i < len / sizeof(u32); i++) {
 227                                u32 port = be32_to_cpu(property[i]);
 228                                if ((1 <= port) && (port <= 3))
 229                                        hub->port_off_mask |= (1 << port);
 230                        }
 231                }
 232
 233                hub->gpio_intn  = of_get_named_gpio(np, "intn-gpios", 0);
 234                if (hub->gpio_intn == -EPROBE_DEFER)
 235                        return -EPROBE_DEFER;
 236                hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
 237                if (hub->gpio_connect == -EPROBE_DEFER)
 238                        return -EPROBE_DEFER;
 239                hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
 240                if (hub->gpio_reset == -EPROBE_DEFER)
 241                        return -EPROBE_DEFER;
 242                of_property_read_u32(np, "initial-mode", &mode);
 243                hub->mode = mode;
 244        }
 245
 246        if (hub->port_off_mask && !hub->regmap)
 247                dev_err(dev, "Ports disabled with no control interface\n");
 248
 249        if (gpio_is_valid(hub->gpio_intn)) {
 250                int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
 251                                                   GPIOF_OUT_INIT_HIGH;
 252                err = devm_gpio_request_one(dev, hub->gpio_intn, val,
 253                                            "usb3503 intn");
 254                if (err) {
 255                        dev_err(dev,
 256                                "unable to request GPIO %d as interrupt pin (%d)\n",
 257                                hub->gpio_intn, err);
 258                        return err;
 259                }
 260        }
 261
 262        if (gpio_is_valid(hub->gpio_connect)) {
 263                err = devm_gpio_request_one(dev, hub->gpio_connect,
 264                                GPIOF_OUT_INIT_LOW, "usb3503 connect");
 265                if (err) {
 266                        dev_err(dev,
 267                                "unable to request GPIO %d as connect pin (%d)\n",
 268                                hub->gpio_connect, err);
 269                        return err;
 270                }
 271        }
 272
 273        if (gpio_is_valid(hub->gpio_reset)) {
 274                err = devm_gpio_request_one(dev, hub->gpio_reset,
 275                                GPIOF_OUT_INIT_LOW, "usb3503 reset");
 276                /* Datasheet defines a hardware reset to be at least 100us */
 277                usleep_range(100, 10000);
 278                if (err) {
 279                        dev_err(dev,
 280                                "unable to request GPIO %d as reset pin (%d)\n",
 281                                hub->gpio_reset, err);
 282                        return err;
 283                }
 284        }
 285
 286        usb3503_switch_mode(hub, hub->mode);
 287
 288        dev_info(dev, "%s: probed in %s mode\n", __func__,
 289                        (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
 290
 291        return 0;
 292}
 293
 294static int usb3503_i2c_probe(struct i2c_client *i2c,
 295                             const struct i2c_device_id *id)
 296{
 297        struct usb3503 *hub;
 298        int err;
 299
 300        hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
 301        if (!hub)
 302                return -ENOMEM;
 303
 304        i2c_set_clientdata(i2c, hub);
 305        hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
 306        if (IS_ERR(hub->regmap)) {
 307                err = PTR_ERR(hub->regmap);
 308                dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
 309                return err;
 310        }
 311        hub->dev = &i2c->dev;
 312
 313        return usb3503_probe(hub);
 314}
 315
 316static int usb3503_i2c_remove(struct i2c_client *i2c)
 317{
 318        struct usb3503 *hub;
 319
 320        hub = i2c_get_clientdata(i2c);
 321        clk_disable_unprepare(hub->clk);
 322
 323        return 0;
 324}
 325
 326static int usb3503_platform_probe(struct platform_device *pdev)
 327{
 328        struct usb3503 *hub;
 329
 330        hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
 331        if (!hub)
 332                return -ENOMEM;
 333        hub->dev = &pdev->dev;
 334        platform_set_drvdata(pdev, hub);
 335
 336        return usb3503_probe(hub);
 337}
 338
 339static int usb3503_platform_remove(struct platform_device *pdev)
 340{
 341        struct usb3503 *hub;
 342
 343        hub = platform_get_drvdata(pdev);
 344        clk_disable_unprepare(hub->clk);
 345
 346        return 0;
 347}
 348
 349#ifdef CONFIG_PM_SLEEP
 350static int usb3503_suspend(struct usb3503 *hub)
 351{
 352        usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
 353        clk_disable_unprepare(hub->clk);
 354
 355        return 0;
 356}
 357
 358static int usb3503_resume(struct usb3503 *hub)
 359{
 360        clk_prepare_enable(hub->clk);
 361        usb3503_switch_mode(hub, hub->mode);
 362
 363        return 0;
 364}
 365
 366static int usb3503_i2c_suspend(struct device *dev)
 367{
 368        struct i2c_client *client = to_i2c_client(dev);
 369
 370        return usb3503_suspend(i2c_get_clientdata(client));
 371}
 372
 373static int usb3503_i2c_resume(struct device *dev)
 374{
 375        struct i2c_client *client = to_i2c_client(dev);
 376
 377        return usb3503_resume(i2c_get_clientdata(client));
 378}
 379
 380static int usb3503_platform_suspend(struct device *dev)
 381{
 382        return usb3503_suspend(dev_get_drvdata(dev));
 383}
 384
 385static int usb3503_platform_resume(struct device *dev)
 386{
 387        return usb3503_resume(dev_get_drvdata(dev));
 388}
 389#endif
 390
 391static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
 392                usb3503_i2c_resume);
 393
 394static SIMPLE_DEV_PM_OPS(usb3503_platform_pm_ops, usb3503_platform_suspend,
 395                usb3503_platform_resume);
 396
 397static const struct i2c_device_id usb3503_id[] = {
 398        { USB3503_I2C_NAME, 0 },
 399        { }
 400};
 401MODULE_DEVICE_TABLE(i2c, usb3503_id);
 402
 403#ifdef CONFIG_OF
 404static const struct of_device_id usb3503_of_match[] = {
 405        { .compatible = "smsc,usb3503", },
 406        { .compatible = "smsc,usb3503a", },
 407        {},
 408};
 409MODULE_DEVICE_TABLE(of, usb3503_of_match);
 410#endif
 411
 412static struct i2c_driver usb3503_i2c_driver = {
 413        .driver = {
 414                .name = USB3503_I2C_NAME,
 415                .pm = &usb3503_i2c_pm_ops,
 416                .of_match_table = of_match_ptr(usb3503_of_match),
 417        },
 418        .probe          = usb3503_i2c_probe,
 419        .remove         = usb3503_i2c_remove,
 420        .id_table       = usb3503_id,
 421};
 422
 423static struct platform_driver usb3503_platform_driver = {
 424        .driver = {
 425                .name = USB3503_I2C_NAME,
 426                .of_match_table = of_match_ptr(usb3503_of_match),
 427                .pm = &usb3503_platform_pm_ops,
 428        },
 429        .probe          = usb3503_platform_probe,
 430        .remove         = usb3503_platform_remove,
 431};
 432
 433static int __init usb3503_init(void)
 434{
 435        int err;
 436
 437        err = i2c_add_driver(&usb3503_i2c_driver);
 438        if (err != 0)
 439                pr_err("usb3503: Failed to register I2C driver: %d\n", err);
 440
 441        err = platform_driver_register(&usb3503_platform_driver);
 442        if (err != 0)
 443                pr_err("usb3503: Failed to register platform driver: %d\n",
 444                       err);
 445
 446        return 0;
 447}
 448module_init(usb3503_init);
 449
 450static void __exit usb3503_exit(void)
 451{
 452        platform_driver_unregister(&usb3503_platform_driver);
 453        i2c_del_driver(&usb3503_i2c_driver);
 454}
 455module_exit(usb3503_exit);
 456
 457MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
 458MODULE_DESCRIPTION("USB3503 USB HUB driver");
 459MODULE_LICENSE("GPL");
 460