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/consumer.h> 11 #include <linux/delay.h> 12 #include <linux/slab.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 #include <linux/platform_data/usb3503.h> 16 #include <linux/regmap.h> 17 18 #define USB3503_VIDL 0x00 19 #define USB3503_VIDM 0x01 20 #define USB3503_PIDL 0x02 21 #define USB3503_PIDM 0x03 22 #define USB3503_DIDL 0x04 23 #define USB3503_DIDM 0x05 24 25 #define USB3503_CFG1 0x06 26 #define USB3503_SELF_BUS_PWR (1 << 7) 27 28 #define USB3503_CFG2 0x07 29 #define USB3503_CFG3 0x08 30 #define USB3503_NRD 0x09 31 32 #define USB3503_PDS 0x0a 33 34 #define USB3503_SP_ILOCK 0xe7 35 #define USB3503_SPILOCK_CONNECT (1 << 1) 36 #define USB3503_SPILOCK_CONFIG (1 << 0) 37 38 #define USB3503_CFGP 0xee 39 #define USB3503_CLKSUSP (1 << 7) 40 41 #define USB3503_RESET 0xff 42 43 struct usb3503 { 44 enum usb3503_mode mode; 45 struct regmap *regmap; 46 struct device *dev; 47 struct clk *clk; 48 u8 port_off_mask; 49 struct gpio_desc *intn; 50 struct gpio_desc *reset; 51 struct gpio_desc *connect; 52 bool secondary_ref_clk; 53 }; 54 55 static int usb3503_reset(struct usb3503 *hub, int state) 56 { 57 if (!state && hub->connect) 58 gpiod_set_value_cansleep(hub->connect, 0); 59 60 if (hub->reset) 61 gpiod_set_value_cansleep(hub->reset, !state); 62 63 /* Wait T_HUBINIT == 4ms for hub logic to stabilize */ 64 if (state) 65 usleep_range(4000, 10000); 66 67 return 0; 68 } 69 70 static int usb3503_connect(struct usb3503 *hub) 71 { 72 struct device *dev = hub->dev; 73 int err; 74 75 usb3503_reset(hub, 1); 76 77 if (hub->regmap) { 78 /* SP_ILOCK: set connect_n, config_n for config */ 79 err = regmap_write(hub->regmap, USB3503_SP_ILOCK, 80 (USB3503_SPILOCK_CONNECT 81 | USB3503_SPILOCK_CONFIG)); 82 if (err < 0) { 83 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 84 return err; 85 } 86 87 /* PDS : Set the ports which are disabled in self-powered mode. */ 88 if (hub->port_off_mask) { 89 err = regmap_update_bits(hub->regmap, USB3503_PDS, 90 hub->port_off_mask, 91 hub->port_off_mask); 92 if (err < 0) { 93 dev_err(dev, "PDS failed (%d)\n", err); 94 return err; 95 } 96 } 97 98 /* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */ 99 err = regmap_update_bits(hub->regmap, USB3503_CFG1, 100 USB3503_SELF_BUS_PWR, 101 USB3503_SELF_BUS_PWR); 102 if (err < 0) { 103 dev_err(dev, "CFG1 failed (%d)\n", err); 104 return err; 105 } 106 107 /* SP_LOCK: clear connect_n, config_n for hub connect */ 108 err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK, 109 (USB3503_SPILOCK_CONNECT 110 | USB3503_SPILOCK_CONFIG), 0); 111 if (err < 0) { 112 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 113 return err; 114 } 115 } 116 117 if (hub->connect) 118 gpiod_set_value_cansleep(hub->connect, 1); 119 120 hub->mode = USB3503_MODE_HUB; 121 dev_info(dev, "switched to HUB mode\n"); 122 123 return 0; 124 } 125 126 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode) 127 { 128 struct device *dev = hub->dev; 129 int err = 0; 130 131 switch (mode) { 132 case USB3503_MODE_HUB: 133 err = usb3503_connect(hub); 134 break; 135 136 case USB3503_MODE_STANDBY: 137 usb3503_reset(hub, 0); 138 dev_info(dev, "switched to STANDBY mode\n"); 139 break; 140 141 default: 142 dev_err(dev, "unknown mode is requested\n"); 143 err = -EINVAL; 144 break; 145 } 146 147 return err; 148 } 149 150 static const struct regmap_config usb3503_regmap_config = { 151 .reg_bits = 8, 152 .val_bits = 8, 153 154 .max_register = USB3503_RESET, 155 }; 156 157 static int usb3503_probe(struct usb3503 *hub) 158 { 159 struct device *dev = hub->dev; 160 struct usb3503_platform_data *pdata = dev_get_platdata(dev); 161 struct device_node *np = dev->of_node; 162 int err; 163 u32 mode = USB3503_MODE_HUB; 164 const u32 *property; 165 enum gpiod_flags flags; 166 int len; 167 168 if (pdata) { 169 hub->port_off_mask = pdata->port_off_mask; 170 hub->mode = pdata->initial_mode; 171 } else if (np) { 172 u32 rate = 0; 173 hub->port_off_mask = 0; 174 175 if (!of_property_read_u32(np, "refclk-frequency", &rate)) { 176 switch (rate) { 177 case 38400000: 178 case 26000000: 179 case 19200000: 180 case 12000000: 181 hub->secondary_ref_clk = 0; 182 break; 183 case 24000000: 184 case 27000000: 185 case 25000000: 186 case 50000000: 187 hub->secondary_ref_clk = 1; 188 break; 189 default: 190 dev_err(dev, 191 "unsupported reference clock rate (%d)\n", 192 (int) rate); 193 return -EINVAL; 194 } 195 } 196 197 hub->clk = devm_clk_get_optional(dev, "refclk"); 198 if (IS_ERR(hub->clk)) { 199 dev_err(dev, "unable to request refclk (%ld)\n", 200 PTR_ERR(hub->clk)); 201 return PTR_ERR(hub->clk); 202 } 203 204 if (rate != 0) { 205 err = clk_set_rate(hub->clk, rate); 206 if (err) { 207 dev_err(dev, 208 "unable to set reference clock rate to %d\n", 209 (int)rate); 210 return err; 211 } 212 } 213 214 err = clk_prepare_enable(hub->clk); 215 if (err) { 216 dev_err(dev, "unable to enable reference clock\n"); 217 return err; 218 } 219 220 property = of_get_property(np, "disabled-ports", &len); 221 if (property && (len / sizeof(u32)) > 0) { 222 int i; 223 for (i = 0; i < len / sizeof(u32); i++) { 224 u32 port = be32_to_cpu(property[i]); 225 if ((1 <= port) && (port <= 3)) 226 hub->port_off_mask |= (1 << port); 227 } 228 } 229 230 of_property_read_u32(np, "initial-mode", &mode); 231 hub->mode = mode; 232 } 233 234 if (hub->secondary_ref_clk) 235 flags = GPIOD_OUT_LOW; 236 else 237 flags = GPIOD_OUT_HIGH; 238 hub->intn = devm_gpiod_get_optional(dev, "intn", flags); 239 if (IS_ERR(hub->intn)) 240 return PTR_ERR(hub->intn); 241 if (hub->intn) 242 gpiod_set_consumer_name(hub->intn, "usb3503 intn"); 243 244 hub->connect = devm_gpiod_get_optional(dev, "connect", GPIOD_OUT_LOW); 245 if (IS_ERR(hub->connect)) 246 return PTR_ERR(hub->connect); 247 if (hub->connect) 248 gpiod_set_consumer_name(hub->connect, "usb3503 connect"); 249 250 hub->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); 251 if (IS_ERR(hub->reset)) 252 return PTR_ERR(hub->reset); 253 if (hub->reset) { 254 /* Datasheet defines a hardware reset to be at least 100us */ 255 usleep_range(100, 10000); 256 gpiod_set_consumer_name(hub->reset, "usb3503 reset"); 257 } 258 259 if (hub->port_off_mask && !hub->regmap) 260 dev_err(dev, "Ports disabled with no control interface\n"); 261 262 usb3503_switch_mode(hub, hub->mode); 263 264 dev_info(dev, "%s: probed in %s mode\n", __func__, 265 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby"); 266 267 return 0; 268 } 269 270 static int usb3503_i2c_probe(struct i2c_client *i2c, 271 const struct i2c_device_id *id) 272 { 273 struct usb3503 *hub; 274 int err; 275 276 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL); 277 if (!hub) 278 return -ENOMEM; 279 280 i2c_set_clientdata(i2c, hub); 281 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config); 282 if (IS_ERR(hub->regmap)) { 283 err = PTR_ERR(hub->regmap); 284 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err); 285 return err; 286 } 287 hub->dev = &i2c->dev; 288 289 return usb3503_probe(hub); 290 } 291 292 static int usb3503_i2c_remove(struct i2c_client *i2c) 293 { 294 struct usb3503 *hub; 295 296 hub = i2c_get_clientdata(i2c); 297 clk_disable_unprepare(hub->clk); 298 299 return 0; 300 } 301 302 static int usb3503_platform_probe(struct platform_device *pdev) 303 { 304 struct usb3503 *hub; 305 306 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL); 307 if (!hub) 308 return -ENOMEM; 309 hub->dev = &pdev->dev; 310 platform_set_drvdata(pdev, hub); 311 312 return usb3503_probe(hub); 313 } 314 315 static int usb3503_platform_remove(struct platform_device *pdev) 316 { 317 struct usb3503 *hub; 318 319 hub = platform_get_drvdata(pdev); 320 clk_disable_unprepare(hub->clk); 321 322 return 0; 323 } 324 325 static int __maybe_unused usb3503_suspend(struct usb3503 *hub) 326 { 327 usb3503_switch_mode(hub, USB3503_MODE_STANDBY); 328 clk_disable_unprepare(hub->clk); 329 330 return 0; 331 } 332 333 static int __maybe_unused usb3503_resume(struct usb3503 *hub) 334 { 335 clk_prepare_enable(hub->clk); 336 usb3503_switch_mode(hub, hub->mode); 337 338 return 0; 339 } 340 341 static int __maybe_unused usb3503_i2c_suspend(struct device *dev) 342 { 343 struct i2c_client *client = to_i2c_client(dev); 344 345 return usb3503_suspend(i2c_get_clientdata(client)); 346 } 347 348 static int __maybe_unused usb3503_i2c_resume(struct device *dev) 349 { 350 struct i2c_client *client = to_i2c_client(dev); 351 352 return usb3503_resume(i2c_get_clientdata(client)); 353 } 354 355 static int __maybe_unused usb3503_platform_suspend(struct device *dev) 356 { 357 return usb3503_suspend(dev_get_drvdata(dev)); 358 } 359 360 static int __maybe_unused usb3503_platform_resume(struct device *dev) 361 { 362 return usb3503_resume(dev_get_drvdata(dev)); 363 } 364 365 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend, 366 usb3503_i2c_resume); 367 368 static SIMPLE_DEV_PM_OPS(usb3503_platform_pm_ops, usb3503_platform_suspend, 369 usb3503_platform_resume); 370 371 static const struct i2c_device_id usb3503_id[] = { 372 { USB3503_I2C_NAME, 0 }, 373 { } 374 }; 375 MODULE_DEVICE_TABLE(i2c, usb3503_id); 376 377 #ifdef CONFIG_OF 378 static const struct of_device_id usb3503_of_match[] = { 379 { .compatible = "smsc,usb3503", }, 380 { .compatible = "smsc,usb3503a", }, 381 {}, 382 }; 383 MODULE_DEVICE_TABLE(of, usb3503_of_match); 384 #endif 385 386 static struct i2c_driver usb3503_i2c_driver = { 387 .driver = { 388 .name = USB3503_I2C_NAME, 389 .pm = pm_ptr(&usb3503_i2c_pm_ops), 390 .of_match_table = of_match_ptr(usb3503_of_match), 391 }, 392 .probe = usb3503_i2c_probe, 393 .remove = usb3503_i2c_remove, 394 .id_table = usb3503_id, 395 }; 396 397 static struct platform_driver usb3503_platform_driver = { 398 .driver = { 399 .name = USB3503_I2C_NAME, 400 .of_match_table = of_match_ptr(usb3503_of_match), 401 .pm = pm_ptr(&usb3503_platform_pm_ops), 402 }, 403 .probe = usb3503_platform_probe, 404 .remove = usb3503_platform_remove, 405 }; 406 407 static int __init usb3503_init(void) 408 { 409 int err; 410 411 err = i2c_add_driver(&usb3503_i2c_driver); 412 if (err) { 413 pr_err("usb3503: Failed to register I2C driver: %d\n", err); 414 return err; 415 } 416 417 err = platform_driver_register(&usb3503_platform_driver); 418 if (err) { 419 pr_err("usb3503: Failed to register platform driver: %d\n", 420 err); 421 i2c_del_driver(&usb3503_i2c_driver); 422 return err; 423 } 424 425 return 0; 426 } 427 module_init(usb3503_init); 428 429 static void __exit usb3503_exit(void) 430 { 431 platform_driver_unregister(&usb3503_platform_driver); 432 i2c_del_driver(&usb3503_i2c_driver); 433 } 434 module_exit(usb3503_exit); 435 436 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>"); 437 MODULE_DESCRIPTION("USB3503 USB HUB driver"); 438 MODULE_LICENSE("GPL"); 439