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 : Disable For Self Powered Operation */ 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 : SELF_BUS_PWR -> Self-Powerd 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); 152 153 hub->mode = mode; 154 dev_info(dev, "switched to STANDBY mode\n"); 155 break; 156 157 default: 158 dev_err(dev, "unknown mode is requested\n"); 159 err = -EINVAL; 160 break; 161 } 162 163 return err; 164 } 165 166 static const struct regmap_config usb3503_regmap_config = { 167 .reg_bits = 8, 168 .val_bits = 8, 169 170 .max_register = USB3503_RESET, 171 }; 172 173 static int usb3503_probe(struct usb3503 *hub) 174 { 175 struct device *dev = hub->dev; 176 struct usb3503_platform_data *pdata = dev_get_platdata(dev); 177 struct device_node *np = dev->of_node; 178 int err; 179 u32 mode = USB3503_MODE_HUB; 180 const u32 *property; 181 int len; 182 183 if (pdata) { 184 hub->port_off_mask = pdata->port_off_mask; 185 hub->gpio_intn = pdata->gpio_intn; 186 hub->gpio_connect = pdata->gpio_connect; 187 hub->gpio_reset = pdata->gpio_reset; 188 hub->mode = pdata->initial_mode; 189 } else if (np) { 190 struct clk *clk; 191 hub->port_off_mask = 0; 192 193 clk = devm_clk_get(dev, "refclk"); 194 if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) { 195 dev_err(dev, "unable to request refclk (%d)\n", err); 196 return PTR_ERR(clk); 197 } 198 199 if (!IS_ERR(clk)) { 200 u32 rate = 0; 201 hub->clk = clk; 202 203 if (!of_property_read_u32(np, "refclk-frequency", 204 &rate)) { 205 206 switch (rate) { 207 case 38400000: 208 case 26000000: 209 case 19200000: 210 case 12000000: 211 hub->secondary_ref_clk = 0; 212 break; 213 case 24000000: 214 case 27000000: 215 case 25000000: 216 case 50000000: 217 hub->secondary_ref_clk = 1; 218 break; 219 default: 220 dev_err(dev, 221 "unsupported reference clock rate (%d)\n", 222 (int) rate); 223 return -EINVAL; 224 } 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 connect 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 dev_err(&i2c->dev, "private data alloc fail\n"); 320 return -ENOMEM; 321 } 322 323 i2c_set_clientdata(i2c, hub); 324 hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config); 325 if (IS_ERR(hub->regmap)) { 326 err = PTR_ERR(hub->regmap); 327 dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err); 328 return err; 329 } 330 hub->dev = &i2c->dev; 331 332 return usb3503_probe(hub); 333 } 334 335 static int usb3503_platform_probe(struct platform_device *pdev) 336 { 337 struct usb3503 *hub; 338 339 hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL); 340 if (!hub) { 341 dev_err(&pdev->dev, "private data alloc fail\n"); 342 return -ENOMEM; 343 } 344 hub->dev = &pdev->dev; 345 346 return usb3503_probe(hub); 347 } 348 349 static const struct i2c_device_id usb3503_id[] = { 350 { USB3503_I2C_NAME, 0 }, 351 { } 352 }; 353 MODULE_DEVICE_TABLE(i2c, usb3503_id); 354 355 #ifdef CONFIG_OF 356 static const struct of_device_id usb3503_of_match[] = { 357 { .compatible = "smsc,usb3503", }, 358 { .compatible = "smsc,usb3503a", }, 359 {}, 360 }; 361 MODULE_DEVICE_TABLE(of, usb3503_of_match); 362 #endif 363 364 static struct i2c_driver usb3503_i2c_driver = { 365 .driver = { 366 .name = USB3503_I2C_NAME, 367 .of_match_table = of_match_ptr(usb3503_of_match), 368 }, 369 .probe = usb3503_i2c_probe, 370 .id_table = usb3503_id, 371 }; 372 373 static struct platform_driver usb3503_platform_driver = { 374 .driver = { 375 .name = USB3503_I2C_NAME, 376 .of_match_table = of_match_ptr(usb3503_of_match), 377 .owner = THIS_MODULE, 378 }, 379 .probe = usb3503_platform_probe, 380 }; 381 382 static int __init usb3503_init(void) 383 { 384 int err; 385 386 err = i2c_register_driver(THIS_MODULE, &usb3503_i2c_driver); 387 if (err != 0) 388 pr_err("usb3503: Failed to register I2C driver: %d\n", err); 389 390 err = platform_driver_register(&usb3503_platform_driver); 391 if (err != 0) 392 pr_err("usb3503: Failed to register platform driver: %d\n", 393 err); 394 395 return 0; 396 } 397 module_init(usb3503_init); 398 399 static void __exit usb3503_exit(void) 400 { 401 platform_driver_unregister(&usb3503_platform_driver); 402 i2c_del_driver(&usb3503_i2c_driver); 403 } 404 module_exit(usb3503_exit); 405 406 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>"); 407 MODULE_DESCRIPTION("USB3503 USB HUB driver"); 408 MODULE_LICENSE("GPL"); 409