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 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/clk.h> 23 #include <linux/i2c.h> 24 #include <linux/gpio.h> 25 #include <linux/delay.h> 26 #include <linux/slab.h> 27 #include <linux/module.h> 28 #include <linux/of_gpio.h> 29 #include <linux/platform_device.h> 30 #include <linux/platform_data/usb3503.h> 31 #include <linux/regmap.h> 32 33 #define USB3503_VIDL 0x00 34 #define USB3503_VIDM 0x01 35 #define USB3503_PIDL 0x02 36 #define USB3503_PIDM 0x03 37 #define USB3503_DIDL 0x04 38 #define USB3503_DIDM 0x05 39 40 #define USB3503_CFG1 0x06 41 #define USB3503_SELF_BUS_PWR (1 << 7) 42 43 #define USB3503_CFG2 0x07 44 #define USB3503_CFG3 0x08 45 #define USB3503_NRD 0x09 46 47 #define USB3503_PDS 0x0a 48 49 #define USB3503_SP_ILOCK 0xe7 50 #define USB3503_SPILOCK_CONNECT (1 << 1) 51 #define USB3503_SPILOCK_CONFIG (1 << 0) 52 53 #define USB3503_CFGP 0xee 54 #define USB3503_CLKSUSP (1 << 7) 55 56 #define USB3503_RESET 0xff 57 58 struct usb3503 { 59 enum usb3503_mode mode; 60 struct regmap *regmap; 61 struct device *dev; 62 struct clk *clk; 63 u8 port_off_mask; 64 int gpio_intn; 65 int gpio_reset; 66 int gpio_connect; 67 bool secondary_ref_clk; 68 }; 69 70 static int usb3503_reset(struct usb3503 *hub, int state) 71 { 72 if (!state && gpio_is_valid(hub->gpio_connect)) 73 gpio_set_value_cansleep(hub->gpio_connect, 0); 74 75 if (gpio_is_valid(hub->gpio_reset)) 76 gpio_set_value_cansleep(hub->gpio_reset, state); 77 78 /* Wait T_HUBINIT == 4ms for hub logic to stabilize */ 79 if (state) 80 usleep_range(4000, 10000); 81 82 return 0; 83 } 84 85 static int usb3503_connect(struct usb3503 *hub) 86 { 87 struct device *dev = hub->dev; 88 int err; 89 90 usb3503_reset(hub, 1); 91 92 if (hub->regmap) { 93 /* SP_ILOCK: set connect_n, config_n for config */ 94 err = regmap_write(hub->regmap, USB3503_SP_ILOCK, 95 (USB3503_SPILOCK_CONNECT 96 | USB3503_SPILOCK_CONFIG)); 97 if (err < 0) { 98 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 99 return err; 100 } 101 102 /* PDS : Set the ports which are disabled in self-powered mode. */ 103 if (hub->port_off_mask) { 104 err = regmap_update_bits(hub->regmap, USB3503_PDS, 105 hub->port_off_mask, 106 hub->port_off_mask); 107 if (err < 0) { 108 dev_err(dev, "PDS failed (%d)\n", err); 109 return err; 110 } 111 } 112 113 /* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */ 114 err = regmap_update_bits(hub->regmap, USB3503_CFG1, 115 USB3503_SELF_BUS_PWR, 116 USB3503_SELF_BUS_PWR); 117 if (err < 0) { 118 dev_err(dev, "CFG1 failed (%d)\n", err); 119 return err; 120 } 121 122 /* SP_LOCK: clear connect_n, config_n for hub connect */ 123 err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK, 124 (USB3503_SPILOCK_CONNECT 125 | USB3503_SPILOCK_CONFIG), 0); 126 if (err < 0) { 127 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 128 return err; 129 } 130 } 131 132 if (gpio_is_valid(hub->gpio_connect)) 133 gpio_set_value_cansleep(hub->gpio_connect, 1); 134 135 hub->mode = USB3503_MODE_HUB; 136 dev_info(dev, "switched to HUB mode\n"); 137 138 return 0; 139 } 140 141 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode) 142 { 143 struct device *dev = hub->dev; 144 int err = 0; 145 146 switch (mode) { 147 case USB3503_MODE_HUB: 148 err = usb3503_connect(hub); 149 break; 150 151 case USB3503_MODE_STANDBY: 152 usb3503_reset(hub, 0); 153 dev_info(dev, "switched to STANDBY mode\n"); 154 break; 155 156 default: 157 dev_err(dev, "unknown mode is requested\n"); 158 err = -EINVAL; 159 break; 160 } 161 162 return err; 163 } 164 165 static const struct regmap_config usb3503_regmap_config = { 166 .reg_bits = 8, 167 .val_bits = 8, 168 169 .max_register = USB3503_RESET, 170 }; 171 172 static int usb3503_probe(struct usb3503 *hub) 173 { 174 struct device *dev = hub->dev; 175 struct usb3503_platform_data *pdata = dev_get_platdata(dev); 176 struct device_node *np = dev->of_node; 177 int err; 178 u32 mode = USB3503_MODE_HUB; 179 const u32 *property; 180 int len; 181 182 if (pdata) { 183 hub->port_off_mask = pdata->port_off_mask; 184 hub->gpio_intn = pdata->gpio_intn; 185 hub->gpio_connect = pdata->gpio_connect; 186 hub->gpio_reset = pdata->gpio_reset; 187 hub->mode = pdata->initial_mode; 188 } else if (np) { 189 struct clk *clk; 190 u32 rate = 0; 191 hub->port_off_mask = 0; 192 193 if (!of_property_read_u32(np, "refclk-frequency", &rate)) { 194 switch (rate) { 195 case 38400000: 196 case 26000000: 197 case 19200000: 198 case 12000000: 199 hub->secondary_ref_clk = 0; 200 break; 201 case 24000000: 202 case 27000000: 203 case 25000000: 204 case 50000000: 205 hub->secondary_ref_clk = 1; 206 break; 207 default: 208 dev_err(dev, 209 "unsupported reference clock rate (%d)\n", 210 (int) rate); 211 return -EINVAL; 212 } 213 } 214 215 clk = devm_clk_get(dev, "refclk"); 216 if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) { 217 dev_err(dev, "unable to request refclk (%ld)\n", 218 PTR_ERR(clk)); 219 return PTR_ERR(clk); 220 } 221 222 if (!IS_ERR(clk)) { 223 hub->clk = clk; 224 225 if (rate != 0) { 226 err = clk_set_rate(hub->clk, rate); 227 if (err) { 228 dev_err(dev, 229 "unable to set reference clock rate to %d\n", 230 (int) rate); 231 return err; 232 } 233 } 234 235 err = clk_prepare_enable(hub->clk); 236 if (err) { 237 dev_err(dev, 238 "unable to enable reference clock\n"); 239 return err; 240 } 241 } 242 243 property = of_get_property(np, "disabled-ports", &len); 244 if (property && (len / sizeof(u32)) > 0) { 245 int i; 246 for (i = 0; i < len / sizeof(u32); i++) { 247 u32 port = be32_to_cpu(property[i]); 248 if ((1 <= port) && (port <= 3)) 249 hub->port_off_mask |= (1 << port); 250 } 251 } 252 253 hub->gpio_intn = of_get_named_gpio(np, "intn-gpios", 0); 254 if (hub->gpio_intn == -EPROBE_DEFER) 255 return -EPROBE_DEFER; 256 hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0); 257 if (hub->gpio_connect == -EPROBE_DEFER) 258 return -EPROBE_DEFER; 259 hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0); 260 if (hub->gpio_reset == -EPROBE_DEFER) 261 return -EPROBE_DEFER; 262 of_property_read_u32(np, "initial-mode", &mode); 263 hub->mode = mode; 264 } 265 266 if (hub->port_off_mask && !hub->regmap) 267 dev_err(dev, "Ports disabled with no control interface\n"); 268 269 if (gpio_is_valid(hub->gpio_intn)) { 270 int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW : 271 GPIOF_OUT_INIT_HIGH; 272 err = devm_gpio_request_one(dev, hub->gpio_intn, val, 273 "usb3503 intn"); 274 if (err) { 275 dev_err(dev, 276 "unable to request GPIO %d as interrupt pin (%d)\n", 277 hub->gpio_intn, err); 278 return err; 279 } 280 } 281 282 if (gpio_is_valid(hub->gpio_connect)) { 283 err = devm_gpio_request_one(dev, hub->gpio_connect, 284 GPIOF_OUT_INIT_LOW, "usb3503 connect"); 285 if (err) { 286 dev_err(dev, 287 "unable to request GPIO %d as connect pin (%d)\n", 288 hub->gpio_connect, err); 289 return err; 290 } 291 } 292 293 if (gpio_is_valid(hub->gpio_reset)) { 294 err = devm_gpio_request_one(dev, hub->gpio_reset, 295 GPIOF_OUT_INIT_LOW, "usb3503 reset"); 296 if (err) { 297 dev_err(dev, 298 "unable to request GPIO %d as reset pin (%d)\n", 299 hub->gpio_reset, err); 300 return err; 301 } 302 } 303 304 usb3503_switch_mode(hub, hub->mode); 305 306 dev_info(dev, "%s: probed in %s mode\n", __func__, 307 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby"); 308 309 return 0; 310 } 311 312 static int usb3503_i2c_probe(struct i2c_client *i2c, 313 const struct i2c_device_id *id) 314 { 315 struct usb3503 *hub; 316 int err; 317 318 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL); 319 if (!hub) 320 return -ENOMEM; 321 322 i2c_set_clientdata(i2c, hub); 323 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config); 324 if (IS_ERR(hub->regmap)) { 325 err = PTR_ERR(hub->regmap); 326 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err); 327 return err; 328 } 329 hub->dev = &i2c->dev; 330 331 return usb3503_probe(hub); 332 } 333 334 static int usb3503_i2c_remove(struct i2c_client *i2c) 335 { 336 struct usb3503 *hub; 337 338 hub = i2c_get_clientdata(i2c); 339 if (hub->clk) 340 clk_disable_unprepare(hub->clk); 341 342 return 0; 343 } 344 345 static int usb3503_platform_probe(struct platform_device *pdev) 346 { 347 struct usb3503 *hub; 348 349 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL); 350 if (!hub) 351 return -ENOMEM; 352 hub->dev = &pdev->dev; 353 platform_set_drvdata(pdev, hub); 354 355 return usb3503_probe(hub); 356 } 357 358 static int usb3503_platform_remove(struct platform_device *pdev) 359 { 360 struct usb3503 *hub; 361 362 hub = platform_get_drvdata(pdev); 363 if (hub->clk) 364 clk_disable_unprepare(hub->clk); 365 366 return 0; 367 } 368 369 #ifdef CONFIG_PM_SLEEP 370 static int usb3503_i2c_suspend(struct device *dev) 371 { 372 struct i2c_client *client = to_i2c_client(dev); 373 struct usb3503 *hub = i2c_get_clientdata(client); 374 375 usb3503_switch_mode(hub, USB3503_MODE_STANDBY); 376 377 if (hub->clk) 378 clk_disable_unprepare(hub->clk); 379 380 return 0; 381 } 382 383 static int usb3503_i2c_resume(struct device *dev) 384 { 385 struct i2c_client *client = to_i2c_client(dev); 386 struct usb3503 *hub = i2c_get_clientdata(client); 387 388 if (hub->clk) 389 clk_prepare_enable(hub->clk); 390 391 usb3503_switch_mode(hub, hub->mode); 392 393 return 0; 394 } 395 #endif 396 397 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend, 398 usb3503_i2c_resume); 399 400 static const struct i2c_device_id usb3503_id[] = { 401 { USB3503_I2C_NAME, 0 }, 402 { } 403 }; 404 MODULE_DEVICE_TABLE(i2c, usb3503_id); 405 406 #ifdef CONFIG_OF 407 static const struct of_device_id usb3503_of_match[] = { 408 { .compatible = "smsc,usb3503", }, 409 { .compatible = "smsc,usb3503a", }, 410 {}, 411 }; 412 MODULE_DEVICE_TABLE(of, usb3503_of_match); 413 #endif 414 415 static struct i2c_driver usb3503_i2c_driver = { 416 .driver = { 417 .name = USB3503_I2C_NAME, 418 .pm = &usb3503_i2c_pm_ops, 419 .of_match_table = of_match_ptr(usb3503_of_match), 420 }, 421 .probe = usb3503_i2c_probe, 422 .remove = usb3503_i2c_remove, 423 .id_table = usb3503_id, 424 }; 425 426 static struct platform_driver usb3503_platform_driver = { 427 .driver = { 428 .name = USB3503_I2C_NAME, 429 .of_match_table = of_match_ptr(usb3503_of_match), 430 }, 431 .probe = usb3503_platform_probe, 432 .remove = usb3503_platform_remove, 433 }; 434 435 static int __init usb3503_init(void) 436 { 437 int err; 438 439 err = i2c_add_driver(&usb3503_i2c_driver); 440 if (err != 0) 441 pr_err("usb3503: Failed to register I2C driver: %d\n", err); 442 443 err = platform_driver_register(&usb3503_platform_driver); 444 if (err != 0) 445 pr_err("usb3503: Failed to register platform driver: %d\n", 446 err); 447 448 return 0; 449 } 450 module_init(usb3503_init); 451 452 static void __exit usb3503_exit(void) 453 { 454 platform_driver_unregister(&usb3503_platform_driver); 455 i2c_del_driver(&usb3503_i2c_driver); 456 } 457 module_exit(usb3503_exit); 458 459 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>"); 460 MODULE_DESCRIPTION("USB3503 USB HUB driver"); 461 MODULE_LICENSE("GPL"); 462