drivers/usb/host/ehci-st.c

   1 /*
   2  * ST EHCI driver
   3  *
   4  * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
   5  *
   6  * Author: Peter Griffin <peter.griffin@linaro.org>
   7  *
   8  * Derived from ehci-platform.c
   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 version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/err.h>
  18 #include <linux/kernel.h>
  19 #include <linux/hrtimer.h>
  20 #include <linux/io.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/phy/phy.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/reset.h>
  26 #include <linux/usb.h>
  27 #include <linux/usb/hcd.h>
  28 #include <linux/usb/ehci_pdriver.h>
  29
  30 #include "ehci.h"
  31
  32 #define USB_MAX_CLKS 3
  33
  34 struct st_ehci_platform_priv {
  35         struct clk *clks[USB_MAX_CLKS];
  36         struct clk *clk48;
  37         struct reset_control *rst;
  38         struct reset_control *pwr;
  39         struct phy *phy;
  40 };
  41
  42 #define DRIVER_DESC "EHCI STMicroelectronics driver"
  43
  44 #define hcd_to_ehci_priv(h) \
  45         ((struct st_ehci_platform_priv *)hcd_to_ehci(h)->priv)
  46
  47 static const char hcd_name[] = "ehci-st";
  48
  49 #define EHCI_CAPS_SIZE 0x10
  50 #define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
  51
  52 static int st_ehci_platform_reset(struct usb_hcd *hcd)
  53 {
  54         struct platform_device *pdev = to_platform_device(hcd->self.controller);
  55         struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
  56         struct ehci_hcd *ehci = hcd_to_ehci(hcd);
  57         u32 threshold;
  58
  59         /* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
  60         threshold = 128 | (128 << 16);
  61         writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
  62
  63         ehci->caps = hcd->regs + pdata->caps_offset;
  64         return ehci_setup(hcd);
  65 }
  66
  67 static int st_ehci_platform_power_on(struct platform_device *dev)
  68 {
  69         struct usb_hcd *hcd = platform_get_drvdata(dev);
  70         struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
  71         int clk, ret;
  72
  73         ret = reset_control_deassert(priv->pwr);
  74         if (ret)
  75                 return ret;
  76
  77         ret = reset_control_deassert(priv->rst);
  78         if (ret)
  79                 goto err_assert_power;
  80
  81         /* some SoCs don't have a dedicated 48Mhz clock, but those that do
  82            need the rate to be explicitly set */
  83         if (priv->clk48) {
  84                 ret = clk_set_rate(priv->clk48, 48000000);
  85                 if (ret)
  86                         goto err_assert_reset;
  87         }
  88
  89         for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
  90                 ret = clk_prepare_enable(priv->clks[clk]);
  91                 if (ret)
  92                         goto err_disable_clks;
  93         }
  94
  95         ret = phy_init(priv->phy);
  96         if (ret)
  97                 goto err_disable_clks;
  98
  99         ret = phy_power_on(priv->phy);
 100         if (ret)
 101                 goto err_exit_phy;
 102
 103         return 0;
 104
 105 err_exit_phy:
 106         phy_exit(priv->phy);
 107 err_disable_clks:
 108         while (--clk >= 0)
 109                 clk_disable_unprepare(priv->clks[clk]);
 110 err_assert_reset:
 111         reset_control_assert(priv->rst);
 112 err_assert_power:
 113         reset_control_assert(priv->pwr);
 114
 115         return ret;
 116 }
 117
 118 static void st_ehci_platform_power_off(struct platform_device *dev)
 119 {
 120         struct usb_hcd *hcd = platform_get_drvdata(dev);
 121         struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
 122         int clk;
 123
 124         reset_control_assert(priv->pwr);
 125
 126         reset_control_assert(priv->rst);
 127
 128         phy_power_off(priv->phy);
 129
 130         phy_exit(priv->phy);
 131
 132         for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
 133                 if (priv->clks[clk])
 134                         clk_disable_unprepare(priv->clks[clk]);
 135
 136 }
 137
 138 static struct hc_driver __read_mostly ehci_platform_hc_driver;
 139
 140 static const struct ehci_driver_overrides platform_overrides __initconst = {
 141         .reset =                st_ehci_platform_reset,
 142         .extra_priv_size =      sizeof(struct st_ehci_platform_priv),
 143 };
 144
 145 static struct usb_ehci_pdata ehci_platform_defaults = {
 146         .power_on =             st_ehci_platform_power_on,
 147         .power_suspend =        st_ehci_platform_power_off,
 148         .power_off =            st_ehci_platform_power_off,
 149 };
 150
 151 static int st_ehci_platform_probe(struct platform_device *dev)
 152 {
 153         struct usb_hcd *hcd;
 154         struct resource *res_mem;
 155         struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
 156         struct st_ehci_platform_priv *priv;
 157         struct ehci_hcd *ehci;
 158         int err, irq, clk = 0;
 159
 160         if (usb_disabled())
 161                 return -ENODEV;
 162
 163         irq = platform_get_irq(dev, 0);
 164         if (irq < 0) {
 165                 dev_err(&dev->dev, "no irq provided");
 166                 return irq;
 167         }
 168         res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
 169         if (!res_mem) {
 170                 dev_err(&dev->dev, "no memory resource provided");
 171                 return -ENXIO;
 172         }
 173
 174         hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
 175                              dev_name(&dev->dev));
 176         if (!hcd)
 177                 return -ENOMEM;
 178
 179         platform_set_drvdata(dev, hcd);
 180         dev->dev.platform_data = pdata;
 181         priv = hcd_to_ehci_priv(hcd);
 182         ehci = hcd_to_ehci(hcd);
 183
 184         priv->phy = devm_phy_get(&dev->dev, "usb");
 185         if (IS_ERR(priv->phy)) {
 186                 err = PTR_ERR(priv->phy);
 187                 goto err_put_hcd;
 188         }
 189
 190         for (clk = 0; clk < USB_MAX_CLKS; clk++) {
 191                 priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
 192                 if (IS_ERR(priv->clks[clk])) {
 193                         err = PTR_ERR(priv->clks[clk]);
 194                         if (err == -EPROBE_DEFER)
 195                                 goto err_put_clks;
 196                         priv->clks[clk] = NULL;
 197                         break;
 198                 }
 199         }
 200
 201         /* some SoCs don't have a dedicated 48Mhz clock, but those that
 202            do need the rate to be explicitly set */
 203         priv->clk48 = devm_clk_get(&dev->dev, "clk48");
 204         if (IS_ERR(priv->clk48)) {
 205                 dev_info(&dev->dev, "48MHz clk not found\n");
 206                 priv->clk48 = NULL;
 207         }
 208
 209         priv->pwr =
 210                 devm_reset_control_get_optional_shared(&dev->dev, "power");
 211         if (IS_ERR(priv->pwr)) {
 212                 err = PTR_ERR(priv->pwr);
 213                 if (err == -EPROBE_DEFER)
 214                         goto err_put_clks;
 215                 priv->pwr = NULL;
 216         }
 217
 218         priv->rst =
 219                 devm_reset_control_get_optional_shared(&dev->dev, "softreset");
 220         if (IS_ERR(priv->rst)) {
 221                 err = PTR_ERR(priv->rst);
 222                 if (err == -EPROBE_DEFER)
 223                         goto err_put_clks;
 224                 priv->rst = NULL;
 225         }
 226
 227         if (pdata->power_on) {
 228                 err = pdata->power_on(dev);
 229                 if (err < 0)
 230                         goto err_put_clks;
 231         }
 232
 233         hcd->rsrc_start = res_mem->start;
 234         hcd->rsrc_len = resource_size(res_mem);
 235
 236         hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
 237         if (IS_ERR(hcd->regs)) {
 238                 err = PTR_ERR(hcd->regs);
 239                 goto err_put_clks;
 240         }
 241
 242         err = usb_add_hcd(hcd, irq, IRQF_SHARED);
 243         if (err)
 244                 goto err_put_clks;
 245
 246         device_wakeup_enable(hcd->self.controller);
 247         platform_set_drvdata(dev, hcd);
 248
 249         return err;
 250
 251 err_put_clks:
 252         while (--clk >= 0)
 253                 clk_put(priv->clks[clk]);
 254 err_put_hcd:
 255         if (pdata == &ehci_platform_defaults)
 256                 dev->dev.platform_data = NULL;
 257
 258         usb_put_hcd(hcd);
 259
 260         return err;
 261 }
 262
 263 static int st_ehci_platform_remove(struct platform_device *dev)
 264 {
 265         struct usb_hcd *hcd = platform_get_drvdata(dev);
 266         struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
 267         struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
 268         int clk;
 269
 270         usb_remove_hcd(hcd);
 271
 272         if (pdata->power_off)
 273                 pdata->power_off(dev);
 274
 275         for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
 276                 clk_put(priv->clks[clk]);
 277
 278         usb_put_hcd(hcd);
 279
 280         if (pdata == &ehci_platform_defaults)
 281                 dev->dev.platform_data = NULL;
 282
 283         return 0;
 284 }
 285
 286 #ifdef CONFIG_PM_SLEEP
 287
 288 static int st_ehci_suspend(struct device *dev)
 289 {
 290         struct usb_hcd *hcd = dev_get_drvdata(dev);
 291         struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
 292         struct platform_device *pdev = to_platform_device(dev);
 293         bool do_wakeup = device_may_wakeup(dev);
 294         int ret;
 295
 296         ret = ehci_suspend(hcd, do_wakeup);
 297         if (ret)
 298                 return ret;
 299
 300         if (pdata->power_suspend)
 301                 pdata->power_suspend(pdev);
 302
 303         pinctrl_pm_select_sleep_state(dev);
 304
 305         return ret;
 306 }
 307
 308 static int st_ehci_resume(struct device *dev)
 309 {
 310         struct usb_hcd *hcd = dev_get_drvdata(dev);
 311         struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
 312         struct platform_device *pdev = to_platform_device(dev);
 313         int err;
 314
 315         pinctrl_pm_select_default_state(dev);
 316
 317         if (pdata->power_on) {
 318                 err = pdata->power_on(pdev);
 319                 if (err < 0)
 320                         return err;
 321         }
 322
 323         ehci_resume(hcd, false);
 324         return 0;
 325 }
 326
 327 static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
 328
 329 #endif /* CONFIG_PM_SLEEP */
 330
 331 static const struct of_device_id st_ehci_ids[] = {
 332         { .compatible = "st,st-ehci-300x", },
 333         { /* sentinel */ }
 334 };
 335 MODULE_DEVICE_TABLE(of, st_ehci_ids);
 336
 337 static struct platform_driver ehci_platform_driver = {
 338         .probe          = st_ehci_platform_probe,
 339         .remove         = st_ehci_platform_remove,
 340         .shutdown       = usb_hcd_platform_shutdown,
 341         .driver         = {
 342                 .name   = "st-ehci",
 343 #ifdef CONFIG_PM_SLEEP
 344                 .pm     = &st_ehci_pm_ops,
 345 #endif
 346                 .of_match_table = st_ehci_ids,
 347         }
 348 };
 349
 350 static int __init ehci_platform_init(void)
 351 {
 352         if (usb_disabled())
 353                 return -ENODEV;
 354
 355         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 356
 357         ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
 358         return platform_driver_register(&ehci_platform_driver);
 359 }
 360 module_init(ehci_platform_init);
 361
 362 static void __exit ehci_platform_cleanup(void)
 363 {
 364         platform_driver_unregister(&ehci_platform_driver);
 365 }
 366 module_exit(ehci_platform_cleanup);
 367
 368 MODULE_DESCRIPTION(DRIVER_DESC);
 369 MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
 370 MODULE_LICENSE("GPL");