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