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 if (err) { 283 dev_err(dev, 284 "unable to request GPIO %d as reset pin (%d)\n", 285 hub->gpio_reset, err); 286 return err; 287 } 288 } 289 290 usb3503_switch_mode(hub, hub->mode); 291 292 dev_info(dev, "%s: probed in %s mode\n", __func__, 293 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby"); 294 295 return 0; 296 } 297 298 static int usb3503_i2c_probe(struct i2c_client *i2c, 299 const struct i2c_device_id *id) 300 { 301 struct usb3503 *hub; 302 int err; 303 304 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL); 305 if (!hub) 306 return -ENOMEM; 307 308 i2c_set_clientdata(i2c, hub); 309 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config); 310 if (IS_ERR(hub->regmap)) { 311 err = PTR_ERR(hub->regmap); 312 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err); 313 return err; 314 } 315 hub->dev = &i2c->dev; 316 317 return usb3503_probe(hub); 318 } 319 320 static int usb3503_i2c_remove(struct i2c_client *i2c) 321 { 322 struct usb3503 *hub; 323 324 hub = i2c_get_clientdata(i2c); 325 if (hub->clk) 326 clk_disable_unprepare(hub->clk); 327 328 return 0; 329 } 330 331 static int usb3503_platform_probe(struct platform_device *pdev) 332 { 333 struct usb3503 *hub; 334 335 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL); 336 if (!hub) 337 return -ENOMEM; 338 hub->dev = &pdev->dev; 339 platform_set_drvdata(pdev, hub); 340 341 return usb3503_probe(hub); 342 } 343 344 static int usb3503_platform_remove(struct platform_device *pdev) 345 { 346 struct usb3503 *hub; 347 348 hub = platform_get_drvdata(pdev); 349 if (hub->clk) 350 clk_disable_unprepare(hub->clk); 351 352 return 0; 353 } 354 355 #ifdef CONFIG_PM_SLEEP 356 static int usb3503_i2c_suspend(struct device *dev) 357 { 358 struct i2c_client *client = to_i2c_client(dev); 359 struct usb3503 *hub = i2c_get_clientdata(client); 360 361 usb3503_switch_mode(hub, USB3503_MODE_STANDBY); 362 363 if (hub->clk) 364 clk_disable_unprepare(hub->clk); 365 366 return 0; 367 } 368 369 static int usb3503_i2c_resume(struct device *dev) 370 { 371 struct i2c_client *client = to_i2c_client(dev); 372 struct usb3503 *hub = i2c_get_clientdata(client); 373 374 if (hub->clk) 375 clk_prepare_enable(hub->clk); 376 377 usb3503_switch_mode(hub, hub->mode); 378 379 return 0; 380 } 381 #endif 382 383 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend, 384 usb3503_i2c_resume); 385 386 static const struct i2c_device_id usb3503_id[] = { 387 { USB3503_I2C_NAME, 0 }, 388 { } 389 }; 390 MODULE_DEVICE_TABLE(i2c, usb3503_id); 391 392 #ifdef CONFIG_OF 393 static const struct of_device_id usb3503_of_match[] = { 394 { .compatible = "smsc,usb3503", }, 395 { .compatible = "smsc,usb3503a", }, 396 {}, 397 }; 398 MODULE_DEVICE_TABLE(of, usb3503_of_match); 399 #endif 400 401 static struct i2c_driver usb3503_i2c_driver = { 402 .driver = { 403 .name = USB3503_I2C_NAME, 404 .pm = &usb3503_i2c_pm_ops, 405 .of_match_table = of_match_ptr(usb3503_of_match), 406 }, 407 .probe = usb3503_i2c_probe, 408 .remove = usb3503_i2c_remove, 409 .id_table = usb3503_id, 410 }; 411 412 static struct platform_driver usb3503_platform_driver = { 413 .driver = { 414 .name = USB3503_I2C_NAME, 415 .of_match_table = of_match_ptr(usb3503_of_match), 416 }, 417 .probe = usb3503_platform_probe, 418 .remove = usb3503_platform_remove, 419 }; 420 421 static int __init usb3503_init(void) 422 { 423 int err; 424 425 err = i2c_add_driver(&usb3503_i2c_driver); 426 if (err != 0) 427 pr_err("usb3503: Failed to register I2C driver: %d\n", err); 428 429 err = platform_driver_register(&usb3503_platform_driver); 430 if (err != 0) 431 pr_err("usb3503: Failed to register platform driver: %d\n", 432 err); 433 434 return 0; 435 } 436 module_init(usb3503_init); 437 438 static void __exit usb3503_exit(void) 439 { 440 platform_driver_unregister(&usb3503_platform_driver); 441 i2c_del_driver(&usb3503_i2c_driver); 442 } 443 module_exit(usb3503_exit); 444 445 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>"); 446 MODULE_DESCRIPTION("USB3503 USB HUB driver"); 447 MODULE_LICENSE("GPL"); 448