drivers/usb/phy/omap-usb2.c

   1 /*
   2  * omap-usb2.c - USB PHY, talking to musb controller in OMAP.
   3  *
   4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * Author: Kishon Vijay Abraham I <kishon@ti.com>
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/slab.h>
  22 #include <linux/of.h>
  23 #include <linux/io.h>
  24 #include <linux/usb/omap_usb.h>
  25 #include <linux/usb/phy_companion.h>
  26 #include <linux/clk.h>
  27 #include <linux/err.h>
  28 #include <linux/pm_runtime.h>
  29 #include <linux/delay.h>
  30
  31 /**
  32  * omap_usb2_set_comparator - links the comparator present in the sytem with
  33  *      this phy
  34  * @comparator - the companion phy(comparator) for this phy
  35  *
  36  * The phy companion driver should call this API passing the phy_companion
  37  * filled with set_vbus and start_srp to be used by usb phy.
  38  *
  39  * For use by phy companion driver
  40  */
  41 int omap_usb2_set_comparator(struct phy_companion *comparator)
  42 {
  43         struct omap_usb *phy;
  44         struct usb_phy  *x = usb_get_phy(USB_PHY_TYPE_USB2);
  45
  46         if (IS_ERR(x))
  47                 return -ENODEV;
  48
  49         phy = phy_to_omapusb(x);
  50         phy->comparator = comparator;
  51         return 0;
  52 }
  53 EXPORT_SYMBOL_GPL(omap_usb2_set_comparator);
  54
  55 /**
  56  * omap_usb_phy_power - power on/off the phy using control module reg
  57  * @phy: struct omap_usb *
  58  * @on: 0 or 1, based on powering on or off the PHY
  59  *
  60  * XXX: Remove this function once control module driver gets merged
  61  */
  62 static void omap_usb_phy_power(struct omap_usb *phy, int on)
  63 {
  64         u32 val;
  65
  66         if (on) {
  67                 val = readl(phy->control_dev);
  68                 if (val & PHY_PD) {
  69                         writel(~PHY_PD, phy->control_dev);
  70                         /* XXX: add proper documentation for this delay */
  71                         mdelay(200);
  72                 }
  73         } else {
  74                 writel(PHY_PD, phy->control_dev);
  75         }
  76 }
  77
  78 static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
  79 {
  80         struct omap_usb *phy = phy_to_omapusb(otg->phy);
  81
  82         if (!phy->comparator)
  83                 return -ENODEV;
  84
  85         return phy->comparator->set_vbus(phy->comparator, enabled);
  86 }
  87
  88 static int omap_usb_start_srp(struct usb_otg *otg)
  89 {
  90         struct omap_usb *phy = phy_to_omapusb(otg->phy);
  91
  92         if (!phy->comparator)
  93                 return -ENODEV;
  94
  95         return phy->comparator->start_srp(phy->comparator);
  96 }
  97
  98 static int omap_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
  99 {
 100         struct usb_phy  *phy = otg->phy;
 101
 102         otg->host = host;
 103         if (!host)
 104                 phy->state = OTG_STATE_UNDEFINED;
 105
 106         return 0;
 107 }
 108
 109 static int omap_usb_set_peripheral(struct usb_otg *otg,
 110                 struct usb_gadget *gadget)
 111 {
 112         struct usb_phy  *phy = otg->phy;
 113
 114         otg->gadget = gadget;
 115         if (!gadget)
 116                 phy->state = OTG_STATE_UNDEFINED;
 117
 118         return 0;
 119 }
 120
 121 static int omap_usb2_suspend(struct usb_phy *x, int suspend)
 122 {
 123         u32 ret;
 124         struct omap_usb *phy = phy_to_omapusb(x);
 125
 126         if (suspend && !phy->is_suspended) {
 127                 omap_usb_phy_power(phy, 0);
 128                 pm_runtime_put_sync(phy->dev);
 129                 phy->is_suspended = 1;
 130         } else if (!suspend && phy->is_suspended) {
 131                 ret = pm_runtime_get_sync(phy->dev);
 132                 if (ret < 0) {
 133                         dev_err(phy->dev, "get_sync failed with err %d\n",
 134                                                                         ret);
 135                         return ret;
 136                 }
 137                 omap_usb_phy_power(phy, 1);
 138                 phy->is_suspended = 0;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int omap_usb2_probe(struct platform_device *pdev)
 145 {
 146         struct omap_usb                 *phy;
 147         struct usb_otg                  *otg;
 148         struct resource                 *res;
 149
 150         phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
 151         if (!phy) {
 152                 dev_err(&pdev->dev, "unable to allocate memory for USB2 PHY\n");
 153                 return -ENOMEM;
 154         }
 155
 156         otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
 157         if (!otg) {
 158                 dev_err(&pdev->dev, "unable to allocate memory for USB OTG\n");
 159                 return -ENOMEM;
 160         }
 161
 162         phy->dev                = &pdev->dev;
 163
 164         phy->phy.dev            = phy->dev;
 165         phy->phy.label          = "omap-usb2";
 166         phy->phy.set_suspend    = omap_usb2_suspend;
 167         phy->phy.otg            = otg;
 168
 169         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 170
 171         phy->control_dev = devm_request_and_ioremap(&pdev->dev, res);
 172         if (phy->control_dev == NULL) {
 173                 dev_err(&pdev->dev, "Failed to obtain io memory\n");
 174                 return -ENXIO;
 175         }
 176
 177         phy->is_suspended       = 1;
 178         omap_usb_phy_power(phy, 0);
 179
 180         otg->set_host           = omap_usb_set_host;
 181         otg->set_peripheral     = omap_usb_set_peripheral;
 182         otg->set_vbus           = omap_usb_set_vbus;
 183         otg->start_srp          = omap_usb_start_srp;
 184         otg->phy                = &phy->phy;
 185
 186         phy->wkupclk = devm_clk_get(phy->dev, "usb_phy_cm_clk32k");
 187         if (IS_ERR(phy->wkupclk)) {
 188                 dev_err(&pdev->dev, "unable to get usb_phy_cm_clk32k\n");
 189                 return PTR_ERR(phy->wkupclk);
 190         }
 191         clk_prepare(phy->wkupclk);
 192
 193         usb_add_phy(&phy->phy, USB_PHY_TYPE_USB2);
 194
 195         platform_set_drvdata(pdev, phy);
 196
 197         pm_runtime_enable(phy->dev);
 198
 199         return 0;
 200 }
 201
 202 static int omap_usb2_remove(struct platform_device *pdev)
 203 {
 204         struct omap_usb *phy = platform_get_drvdata(pdev);
 205
 206         clk_unprepare(phy->wkupclk);
 207         usb_remove_phy(&phy->phy);
 208
 209         return 0;
 210 }
 211
 212 #ifdef CONFIG_PM_RUNTIME
 213
 214 static int omap_usb2_runtime_suspend(struct device *dev)
 215 {
 216         struct platform_device  *pdev = to_platform_device(dev);
 217         struct omap_usb *phy = platform_get_drvdata(pdev);
 218
 219         clk_disable(phy->wkupclk);
 220
 221         return 0;
 222 }
 223
 224 static int omap_usb2_runtime_resume(struct device *dev)
 225 {
 226         u32 ret = 0;
 227         struct platform_device  *pdev = to_platform_device(dev);
 228         struct omap_usb *phy = platform_get_drvdata(pdev);
 229
 230         ret = clk_enable(phy->wkupclk);
 231         if (ret < 0)
 232                 dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
 233
 234         return ret;
 235 }
 236
 237 static const struct dev_pm_ops omap_usb2_pm_ops = {
 238         SET_RUNTIME_PM_OPS(omap_usb2_runtime_suspend, omap_usb2_runtime_resume,
 239                 NULL)
 240 };
 241
 242 #define DEV_PM_OPS     (&omap_usb2_pm_ops)
 243 #else
 244 #define DEV_PM_OPS     NULL
 245 #endif
 246
 247 #ifdef CONFIG_OF
 248 static const struct of_device_id omap_usb2_id_table[] = {
 249         { .compatible = "ti,omap-usb2" },
 250         {}
 251 };
 252 MODULE_DEVICE_TABLE(of, omap_usb2_id_table);
 253 #endif
 254
 255 static struct platform_driver omap_usb2_driver = {
 256         .probe          = omap_usb2_probe,
 257         .remove         = omap_usb2_remove,
 258         .driver         = {
 259                 .name   = "omap-usb2",
 260                 .owner  = THIS_MODULE,
 261                 .pm     = DEV_PM_OPS,
 262                 .of_match_table = of_match_ptr(omap_usb2_id_table),
 263         },
 264 };
 265
 266 module_platform_driver(omap_usb2_driver);
 267
 268 MODULE_ALIAS("platform: omap_usb2");
 269 MODULE_AUTHOR("Texas Instruments Inc.");
 270 MODULE_DESCRIPTION("OMAP USB2 phy driver");
 271 MODULE_LICENSE("GPL v2");