1 /* 2 * drivers/usb/otg/nop-usb-xceiv.c 3 * 4 * NOP USB transceiver for all USB transceiver which are either built-in 5 * into USB IP or which are mostly autonomous. 6 * 7 * Copyright (C) 2009 Texas Instruments Inc 8 * Author: Ajay Kumar Gupta <ajay.gupta@ti.com> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 23 * 24 * Current status: 25 * This provides a "nop" transceiver for PHYs which are 26 * autonomous such as isp1504, isp1707, etc. 27 */ 28 29 #include <linux/module.h> 30 #include <linux/platform_device.h> 31 #include <linux/dma-mapping.h> 32 #include <linux/usb/otg.h> 33 #include <linux/usb/usb_phy_generic.h> 34 #include <linux/slab.h> 35 #include <linux/clk.h> 36 #include <linux/regulator/consumer.h> 37 #include <linux/of.h> 38 #include <linux/of_gpio.h> 39 #include <linux/gpio.h> 40 #include <linux/delay.h> 41 42 #include "phy-generic.h" 43 44 struct platform_device *usb_phy_generic_register(void) 45 { 46 return platform_device_register_simple("usb_phy_generic", 47 PLATFORM_DEVID_AUTO, NULL, 0); 48 } 49 EXPORT_SYMBOL_GPL(usb_phy_generic_register); 50 51 void usb_phy_generic_unregister(struct platform_device *pdev) 52 { 53 platform_device_unregister(pdev); 54 } 55 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister); 56 57 static int nop_set_suspend(struct usb_phy *x, int suspend) 58 { 59 return 0; 60 } 61 62 static void nop_reset_set(struct usb_phy_generic *nop, int asserted) 63 { 64 int value; 65 66 if (!gpio_is_valid(nop->gpio_reset)) 67 return; 68 69 value = asserted; 70 if (nop->reset_active_low) 71 value = !value; 72 73 gpio_set_value_cansleep(nop->gpio_reset, value); 74 75 if (!asserted) 76 usleep_range(10000, 20000); 77 } 78 79 int usb_gen_phy_init(struct usb_phy *phy) 80 { 81 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 82 83 if (!IS_ERR(nop->vcc)) { 84 if (regulator_enable(nop->vcc)) 85 dev_err(phy->dev, "Failed to enable power\n"); 86 } 87 88 if (!IS_ERR(nop->clk)) 89 clk_prepare_enable(nop->clk); 90 91 /* De-assert RESET */ 92 nop_reset_set(nop, 0); 93 94 return 0; 95 } 96 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 97 98 void usb_gen_phy_shutdown(struct usb_phy *phy) 99 { 100 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 101 102 /* Assert RESET */ 103 nop_reset_set(nop, 1); 104 105 if (!IS_ERR(nop->clk)) 106 clk_disable_unprepare(nop->clk); 107 108 if (!IS_ERR(nop->vcc)) { 109 if (regulator_disable(nop->vcc)) 110 dev_err(phy->dev, "Failed to disable power\n"); 111 } 112 } 113 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 114 115 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 116 { 117 if (!otg) 118 return -ENODEV; 119 120 if (!gadget) { 121 otg->gadget = NULL; 122 return -ENODEV; 123 } 124 125 otg->gadget = gadget; 126 otg->phy->state = OTG_STATE_B_IDLE; 127 return 0; 128 } 129 130 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 131 { 132 if (!otg) 133 return -ENODEV; 134 135 if (!host) { 136 otg->host = NULL; 137 return -ENODEV; 138 } 139 140 otg->host = host; 141 return 0; 142 } 143 144 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 145 struct usb_phy_generic_platform_data *pdata) 146 { 147 enum usb_phy_type type = USB_PHY_TYPE_USB2; 148 int err; 149 150 u32 clk_rate = 0; 151 bool needs_vcc = false; 152 153 nop->reset_active_low = true; /* default behaviour */ 154 155 if (dev->of_node) { 156 struct device_node *node = dev->of_node; 157 enum of_gpio_flags flags = 0; 158 159 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 160 clk_rate = 0; 161 162 needs_vcc = of_property_read_bool(node, "vcc-supply"); 163 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios", 164 0, &flags); 165 if (nop->gpio_reset == -EPROBE_DEFER) 166 return -EPROBE_DEFER; 167 168 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW; 169 170 } else if (pdata) { 171 type = pdata->type; 172 clk_rate = pdata->clk_rate; 173 needs_vcc = pdata->needs_vcc; 174 nop->gpio_reset = pdata->gpio_reset; 175 } else { 176 nop->gpio_reset = -1; 177 } 178 179 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 180 GFP_KERNEL); 181 if (!nop->phy.otg) 182 return -ENOMEM; 183 184 nop->clk = devm_clk_get(dev, "main_clk"); 185 if (IS_ERR(nop->clk)) { 186 dev_dbg(dev, "Can't get phy clock: %ld\n", 187 PTR_ERR(nop->clk)); 188 } 189 190 if (!IS_ERR(nop->clk) && clk_rate) { 191 err = clk_set_rate(nop->clk, clk_rate); 192 if (err) { 193 dev_err(dev, "Error setting clock rate\n"); 194 return err; 195 } 196 } 197 198 nop->vcc = devm_regulator_get(dev, "vcc"); 199 if (IS_ERR(nop->vcc)) { 200 dev_dbg(dev, "Error getting vcc regulator: %ld\n", 201 PTR_ERR(nop->vcc)); 202 if (needs_vcc) 203 return -EPROBE_DEFER; 204 } 205 206 if (gpio_is_valid(nop->gpio_reset)) { 207 unsigned long gpio_flags; 208 209 /* Assert RESET */ 210 if (nop->reset_active_low) 211 gpio_flags = GPIOF_OUT_INIT_LOW; 212 else 213 gpio_flags = GPIOF_OUT_INIT_HIGH; 214 215 err = devm_gpio_request_one(dev, nop->gpio_reset, 216 gpio_flags, dev_name(dev)); 217 if (err) { 218 dev_err(dev, "Error requesting RESET GPIO %d\n", 219 nop->gpio_reset); 220 return err; 221 } 222 } 223 224 nop->dev = dev; 225 nop->phy.dev = nop->dev; 226 nop->phy.label = "nop-xceiv"; 227 nop->phy.set_suspend = nop_set_suspend; 228 nop->phy.state = OTG_STATE_UNDEFINED; 229 nop->phy.type = type; 230 231 nop->phy.otg->phy = &nop->phy; 232 nop->phy.otg->set_host = nop_set_host; 233 nop->phy.otg->set_peripheral = nop_set_peripheral; 234 235 return 0; 236 } 237 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 238 239 static int usb_phy_generic_probe(struct platform_device *pdev) 240 { 241 struct device *dev = &pdev->dev; 242 struct usb_phy_generic *nop; 243 int err; 244 245 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 246 if (!nop) 247 return -ENOMEM; 248 249 err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev)); 250 if (err) 251 return err; 252 253 nop->phy.init = usb_gen_phy_init; 254 nop->phy.shutdown = usb_gen_phy_shutdown; 255 256 err = usb_add_phy_dev(&nop->phy); 257 if (err) { 258 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 259 err); 260 return err; 261 } 262 263 platform_set_drvdata(pdev, nop); 264 265 return 0; 266 } 267 268 static int usb_phy_generic_remove(struct platform_device *pdev) 269 { 270 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 271 272 usb_remove_phy(&nop->phy); 273 274 return 0; 275 } 276 277 static const struct of_device_id nop_xceiv_dt_ids[] = { 278 { .compatible = "usb-nop-xceiv" }, 279 { } 280 }; 281 282 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 283 284 static struct platform_driver usb_phy_generic_driver = { 285 .probe = usb_phy_generic_probe, 286 .remove = usb_phy_generic_remove, 287 .driver = { 288 .name = "usb_phy_generic", 289 .owner = THIS_MODULE, 290 .of_match_table = nop_xceiv_dt_ids, 291 }, 292 }; 293 294 static int __init usb_phy_generic_init(void) 295 { 296 return platform_driver_register(&usb_phy_generic_driver); 297 } 298 subsys_initcall(usb_phy_generic_init); 299 300 static void __exit usb_phy_generic_exit(void) 301 { 302 platform_driver_unregister(&usb_phy_generic_driver); 303 } 304 module_exit(usb_phy_generic_exit); 305 306 MODULE_ALIAS("platform:usb_phy_generic"); 307 MODULE_AUTHOR("Texas Instruments Inc"); 308 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 309 MODULE_LICENSE("GPL"); 310