1 /* 2 * Driver for SMSC USB3503 USB 2.0 hub controller driver 3 * 4 * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com) 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 21 #include <linux/clk.h> 22 #include <linux/i2c.h> 23 #include <linux/gpio.h> 24 #include <linux/delay.h> 25 #include <linux/slab.h> 26 #include <linux/module.h> 27 #include <linux/of_gpio.h> 28 #include <linux/platform_device.h> 29 #include <linux/platform_data/usb3503.h> 30 #include <linux/regmap.h> 31 32 #define USB3503_VIDL 0x00 33 #define USB3503_VIDM 0x01 34 #define USB3503_PIDL 0x02 35 #define USB3503_PIDM 0x03 36 #define USB3503_DIDL 0x04 37 #define USB3503_DIDM 0x05 38 39 #define USB3503_CFG1 0x06 40 #define USB3503_SELF_BUS_PWR (1 << 7) 41 42 #define USB3503_CFG2 0x07 43 #define USB3503_CFG3 0x08 44 #define USB3503_NRD 0x09 45 46 #define USB3503_PDS 0x0a 47 48 #define USB3503_SP_ILOCK 0xe7 49 #define USB3503_SPILOCK_CONNECT (1 << 1) 50 #define USB3503_SPILOCK_CONFIG (1 << 0) 51 52 #define USB3503_CFGP 0xee 53 #define USB3503_CLKSUSP (1 << 7) 54 55 #define USB3503_RESET 0xff 56 57 struct usb3503 { 58 enum usb3503_mode mode; 59 struct regmap *regmap; 60 struct device *dev; 61 struct clk *clk; 62 u8 port_off_mask; 63 int gpio_intn; 64 int gpio_reset; 65 int gpio_connect; 66 bool secondary_ref_clk; 67 }; 68 69 static int usb3503_reset(struct usb3503 *hub, int state) 70 { 71 if (!state && gpio_is_valid(hub->gpio_connect)) 72 gpio_set_value_cansleep(hub->gpio_connect, 0); 73 74 if (gpio_is_valid(hub->gpio_reset)) 75 gpio_set_value_cansleep(hub->gpio_reset, state); 76 77 /* Wait T_HUBINIT == 4ms for hub logic to stabilize */ 78 if (state) 79 usleep_range(4000, 10000); 80 81 return 0; 82 } 83 84 static int usb3503_connect(struct usb3503 *hub) 85 { 86 struct device *dev = hub->dev; 87 int err; 88 89 usb3503_reset(hub, 1); 90 91 if (hub->regmap) { 92 /* SP_ILOCK: set connect_n, config_n for config */ 93 err = regmap_write(hub->regmap, USB3503_SP_ILOCK, 94 (USB3503_SPILOCK_CONNECT 95 | USB3503_SPILOCK_CONFIG)); 96 if (err < 0) { 97 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 98 return err; 99 } 100 101 /* PDS : Set the ports which are disabled in self-powered mode. */ 102 if (hub->port_off_mask) { 103 err = regmap_update_bits(hub->regmap, USB3503_PDS, 104 hub->port_off_mask, 105 hub->port_off_mask); 106 if (err < 0) { 107 dev_err(dev, "PDS failed (%d)\n", err); 108 return err; 109 } 110 } 111 112 /* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */ 113 err = regmap_update_bits(hub->regmap, USB3503_CFG1, 114 USB3503_SELF_BUS_PWR, 115 USB3503_SELF_BUS_PWR); 116 if (err < 0) { 117 dev_err(dev, "CFG1 failed (%d)\n", err); 118 return err; 119 } 120 121 /* SP_LOCK: clear connect_n, config_n for hub connect */ 122 err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK, 123 (USB3503_SPILOCK_CONNECT 124 | USB3503_SPILOCK_CONFIG), 0); 125 if (err < 0) { 126 dev_err(dev, "SP_ILOCK failed (%d)\n", err); 127 return err; 128 } 129 } 130 131 if (gpio_is_valid(hub->gpio_connect)) 132 gpio_set_value_cansleep(hub->gpio_connect, 1); 133 134 hub->mode = USB3503_MODE_HUB; 135 dev_info(dev, "switched to HUB mode\n"); 136 137 return 0; 138 } 139 140 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode) 141 { 142 struct device *dev = hub->dev; 143 int err = 0; 144 145 switch (mode) { 146 case USB3503_MODE_HUB: 147 err = usb3503_connect(hub); 148 break; 149 150 case USB3503_MODE_STANDBY: 151 usb3503_reset(hub, 0); 152 dev_info(dev, "switched to STANDBY mode\n"); 153 break; 154 155 default: 156 dev_err(dev, "unknown mode is requested\n"); 157 err = -EINVAL; 158 break; 159 } 160 161 return err; 162 } 163 164 static const struct regmap_config usb3503_regmap_config = { 165 .reg_bits = 8, 166 .val_bits = 8, 167 168 .max_register = USB3503_RESET, 169 }; 170 171 static int usb3503_probe(struct usb3503 *hub) 172 { 173 struct device *dev = hub->dev; 174 struct usb3503_platform_data *pdata = dev_get_platdata(dev); 175 struct device_node *np = dev->of_node; 176 int err; 177 u32 mode = USB3503_MODE_HUB; 178 const u32 *property; 179 int len; 180 181 if (pdata) { 182 hub->port_off_mask = pdata->port_off_mask; 183 hub->gpio_intn = pdata->gpio_intn; 184 hub->gpio_connect = pdata->gpio_connect; 185 hub->gpio_reset = pdata->gpio_reset; 186 hub->mode = pdata->initial_mode; 187 } else if (np) { 188 struct clk *clk; 189 u32 rate = 0; 190 hub->port_off_mask = 0; 191 192 if (!of_property_read_u32(np, "refclk-frequency", &rate)) { 193 switch (rate) { 194 case 38400000: 195 case 26000000: 196 case 19200000: 197 case 12000000: 198 hub->secondary_ref_clk = 0; 199 break; 200 case 24000000: 201 case 27000000: 202 case 25000000: 203 case 50000000: 204 hub->secondary_ref_clk = 1; 205 break; 206 default: 207 dev_err(dev, 208 "unsupported reference clock rate (%d)\n", 209 (int) rate); 210 return -EINVAL; 211 } 212 } 213 214 clk = devm_clk_get(dev, "refclk"); 215 if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) { 216 dev_err(dev, "unable to request refclk (%ld)\n", 217 PTR_ERR(clk)); 218 return PTR_ERR(clk); 219 } 220 221 if (!IS_ERR(clk)) { 222 hub->clk = clk; 223 224 if (rate != 0) { 225 err = clk_set_rate(hub->clk, rate); 226 if (err) { 227 dev_err(dev, 228 "unable to set reference clock rate to %d\n", 229 (int) rate); 230 return err; 231 } 232 } 233 234 err = clk_prepare_enable(hub->clk); 235 if (err) { 236 dev_err(dev, 237 "unable to enable reference clock\n"); 238 return err; 239 } 240 } 241 242 property = of_get_property(np, "disabled-ports", &len); 243 if (property && (len / sizeof(u32)) > 0) { 244 int i; 245 for (i = 0; i < len / sizeof(u32); i++) { 246 u32 port = be32_to_cpu(property[i]); 247 if ((1 <= port) && (port <= 3)) 248 hub->port_off_mask |= (1 << port); 249 } 250 } 251 252 hub->gpio_intn = of_get_named_gpio(np, "intn-gpios", 0); 253 if (hub->gpio_intn == -EPROBE_DEFER) 254 return -EPROBE_DEFER; 255 hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0); 256 if (hub->gpio_connect == -EPROBE_DEFER) 257 return -EPROBE_DEFER; 258 hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0); 259 if (hub->gpio_reset == -EPROBE_DEFER) 260 return -EPROBE_DEFER; 261 of_property_read_u32(np, "initial-mode", &mode); 262 hub->mode = mode; 263 } 264 265 if (hub->port_off_mask && !hub->regmap) 266 dev_err(dev, "Ports disabled with no control interface\n"); 267 268 if (gpio_is_valid(hub->gpio_intn)) { 269 int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW : 270 GPIOF_OUT_INIT_HIGH; 271 err = devm_gpio_request_one(dev, hub->gpio_intn, val, 272 "usb3503 intn"); 273 if (err) { 274 dev_err(dev, 275 "unable to request GPIO %d as interrupt pin (%d)\n", 276 hub->gpio_intn, err); 277 return err; 278 } 279 } 280 281 if (gpio_is_valid(hub->gpio_connect)) { 282 err = devm_gpio_request_one(dev, hub->gpio_connect, 283 GPIOF_OUT_INIT_LOW, "usb3503 connect"); 284 if (err) { 285 dev_err(dev, 286 "unable to request GPIO %d as connect pin (%d)\n", 287 hub->gpio_connect, err); 288 return err; 289 } 290 } 291 292 if (gpio_is_valid(hub->gpio_reset)) { 293 err = devm_gpio_request_one(dev, hub->gpio_reset, 294 GPIOF_OUT_INIT_LOW, "usb3503 reset"); 295 if (err) { 296 dev_err(dev, 297 "unable to request GPIO %d as reset pin (%d)\n", 298 hub->gpio_reset, err); 299 return err; 300 } 301 } 302 303 usb3503_switch_mode(hub, hub->mode); 304 305 dev_info(dev, "%s: probed in %s mode\n", __func__, 306 (hub->mode == USB3503_MODE_HUB) ? "hub" : "standby"); 307 308 return 0; 309 } 310 311 static int usb3503_i2c_probe(struct i2c_client *i2c, 312 const struct i2c_device_id *id) 313 { 314 struct usb3503 *hub; 315 int err; 316 317 hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL); 318 if (!hub) 319 return -ENOMEM; 320 321 i2c_set_clientdata(i2c, hub); 322 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config); 323 if (IS_ERR(hub->regmap)) { 324 err = PTR_ERR(hub->regmap); 325 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err); 326 return err; 327 } 328 hub->dev = &i2c->dev; 329 330 return usb3503_probe(hub); 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; 341 342 return usb3503_probe(hub); 343 } 344 345 #ifdef CONFIG_PM_SLEEP 346 static int usb3503_i2c_suspend(struct device *dev) 347 { 348 struct i2c_client *client = to_i2c_client(dev); 349 struct usb3503 *hub = i2c_get_clientdata(client); 350 351 usb3503_switch_mode(hub, USB3503_MODE_STANDBY); 352 353 if (hub->clk) 354 clk_disable_unprepare(hub->clk); 355 356 return 0; 357 } 358 359 static int usb3503_i2c_resume(struct device *dev) 360 { 361 struct i2c_client *client = to_i2c_client(dev); 362 struct usb3503 *hub = i2c_get_clientdata(client); 363 364 if (hub->clk) 365 clk_prepare_enable(hub->clk); 366 367 usb3503_switch_mode(hub, hub->mode); 368 369 return 0; 370 } 371 #endif 372 373 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend, 374 usb3503_i2c_resume); 375 376 static const struct i2c_device_id usb3503_id[] = { 377 { USB3503_I2C_NAME, 0 }, 378 { } 379 }; 380 MODULE_DEVICE_TABLE(i2c, usb3503_id); 381 382 #ifdef CONFIG_OF 383 static const struct of_device_id usb3503_of_match[] = { 384 { .compatible = "smsc,usb3503", }, 385 { .compatible = "smsc,usb3503a", }, 386 {}, 387 }; 388 MODULE_DEVICE_TABLE(of, usb3503_of_match); 389 #endif 390 391 static struct i2c_driver usb3503_i2c_driver = { 392 .driver = { 393 .name = USB3503_I2C_NAME, 394 .pm = &usb3503_i2c_pm_ops, 395 .of_match_table = of_match_ptr(usb3503_of_match), 396 }, 397 .probe = usb3503_i2c_probe, 398 .id_table = usb3503_id, 399 }; 400 401 static struct platform_driver usb3503_platform_driver = { 402 .driver = { 403 .name = USB3503_I2C_NAME, 404 .of_match_table = of_match_ptr(usb3503_of_match), 405 }, 406 .probe = usb3503_platform_probe, 407 }; 408 409 static int __init usb3503_init(void) 410 { 411 int err; 412 413 err = i2c_add_driver(&usb3503_i2c_driver); 414 if (err != 0) 415 pr_err("usb3503: Failed to register I2C driver: %d\n", err); 416 417 err = platform_driver_register(&usb3503_platform_driver); 418 if (err != 0) 419 pr_err("usb3503: Failed to register platform driver: %d\n", 420 err); 421 422 return 0; 423 } 424 module_init(usb3503_init); 425 426 static void __exit usb3503_exit(void) 427 { 428 platform_driver_unregister(&usb3503_platform_driver); 429 i2c_del_driver(&usb3503_i2c_driver); 430 } 431 module_exit(usb3503_exit); 432 433 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>"); 434 MODULE_DESCRIPTION("USB3503 USB HUB driver"); 435 MODULE_LICENSE("GPL"); 436