drivers/usb/host/ehci-atmel.c

   1 /*
   2  * Driver for EHCI UHP on Atmel chips
   3  *
   4  *  Copyright (C) 2009 Atmel Corporation,
   5  *                     Nicolas Ferre <nicolas.ferre@atmel.com>
   6  *
   7  *  Based on various ehci-*.c drivers
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file COPYING in the main directory of this archive for
  11  * more details.
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/dma-mapping.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/hcd.h>
  24
  25 #include "ehci.h"
  26
  27 #define DRIVER_DESC "EHCI Atmel driver"
  28
  29 static const char hcd_name[] = "ehci-atmel";
  30
  31 /* interface and function clocks */
  32 #define hcd_to_atmel_ehci_priv(h) \
  33         ((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)
  34
  35 struct atmel_ehci_priv {
  36         struct clk *iclk;
  37         struct clk *uclk;
  38         bool clocked;
  39 };
  40
  41 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
  42
  43 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
  44         .extra_priv_size = sizeof(struct atmel_ehci_priv),
  45 };
  46
  47 /*-------------------------------------------------------------------------*/
  48
  49 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
  50 {
  51         if (atmel_ehci->clocked)
  52                 return;
  53
  54         clk_prepare_enable(atmel_ehci->uclk);
  55         clk_prepare_enable(atmel_ehci->iclk);
  56         atmel_ehci->clocked = true;
  57 }
  58
  59 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
  60 {
  61         if (!atmel_ehci->clocked)
  62                 return;
  63
  64         clk_disable_unprepare(atmel_ehci->iclk);
  65         clk_disable_unprepare(atmel_ehci->uclk);
  66         atmel_ehci->clocked = false;
  67 }
  68
  69 static void atmel_start_ehci(struct platform_device *pdev)
  70 {
  71         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  72         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  73
  74         dev_dbg(&pdev->dev, "start\n");
  75         atmel_start_clock(atmel_ehci);
  76 }
  77
  78 static void atmel_stop_ehci(struct platform_device *pdev)
  79 {
  80         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  81         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  82
  83         dev_dbg(&pdev->dev, "stop\n");
  84         atmel_stop_clock(atmel_ehci);
  85 }
  86
  87 /*-------------------------------------------------------------------------*/
  88
  89 static int ehci_atmel_drv_probe(struct platform_device *pdev)
  90 {
  91         struct usb_hcd *hcd;
  92         const struct hc_driver *driver = &ehci_atmel_hc_driver;
  93         struct resource *res;
  94         struct ehci_hcd *ehci;
  95         struct atmel_ehci_priv *atmel_ehci;
  96         int irq;
  97         int retval;
  98
  99         if (usb_disabled())
 100                 return -ENODEV;
 101
 102         pr_debug("Initializing Atmel-SoC USB Host Controller\n");
 103
 104         irq = platform_get_irq(pdev, 0);
 105         if (irq <= 0) {
 106                 dev_err(&pdev->dev,
 107                         "Found HC with no IRQ. Check %s setup!\n",
 108                         dev_name(&pdev->dev));
 109                 retval = -ENODEV;
 110                 goto fail_create_hcd;
 111         }
 112
 113         /* Right now device-tree probed devices don't get dma_mask set.
 114          * Since shared usb code relies on it, set it here for now.
 115          * Once we have dma capability bindings this can go away.
 116          */
 117         retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 118         if (retval)
 119                 goto fail_create_hcd;
 120
 121         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
 122         if (!hcd) {
 123                 retval = -ENOMEM;
 124                 goto fail_create_hcd;
 125         }
 126         atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 127
 128         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 129         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 130         if (IS_ERR(hcd->regs)) {
 131                 retval = PTR_ERR(hcd->regs);
 132                 goto fail_request_resource;
 133         }
 134
 135         hcd->rsrc_start = res->start;
 136         hcd->rsrc_len = resource_size(res);
 137
 138         atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 139         if (IS_ERR(atmel_ehci->iclk)) {
 140                 dev_err(&pdev->dev, "Error getting interface clock\n");
 141                 retval = -ENOENT;
 142                 goto fail_request_resource;
 143         }
 144
 145         atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
 146         if (IS_ERR(atmel_ehci->uclk)) {
 147                 dev_err(&pdev->dev, "failed to get uclk\n");
 148                 retval = PTR_ERR(atmel_ehci->uclk);
 149                 goto fail_request_resource;
 150         }
 151
 152         ehci = hcd_to_ehci(hcd);
 153         /* registers start at offset 0x0 */
 154         ehci->caps = hcd->regs;
 155
 156         atmel_start_ehci(pdev);
 157
 158         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 159         if (retval)
 160                 goto fail_add_hcd;
 161         device_wakeup_enable(hcd->self.controller);
 162
 163         return retval;
 164
 165 fail_add_hcd:
 166         atmel_stop_ehci(pdev);
 167 fail_request_resource:
 168         usb_put_hcd(hcd);
 169 fail_create_hcd:
 170         dev_err(&pdev->dev, "init %s fail, %d\n",
 171                 dev_name(&pdev->dev), retval);
 172
 173         return retval;
 174 }
 175
 176 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 177 {
 178         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 179
 180         usb_remove_hcd(hcd);
 181         usb_put_hcd(hcd);
 182
 183         atmel_stop_ehci(pdev);
 184
 185         return 0;
 186 }
 187
 188 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
 189 {
 190         struct usb_hcd *hcd = dev_get_drvdata(dev);
 191         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 192         int ret;
 193
 194         ret = ehci_suspend(hcd, false);
 195         if (ret)
 196                 return ret;
 197
 198         atmel_stop_clock(atmel_ehci);
 199         return 0;
 200 }
 201
 202 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
 203 {
 204         struct usb_hcd *hcd = dev_get_drvdata(dev);
 205         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 206
 207         atmel_start_clock(atmel_ehci);
 208         return ehci_resume(hcd, false);
 209 }
 210
 211 #ifdef CONFIG_OF
 212 static const struct of_device_id atmel_ehci_dt_ids[] = {
 213         { .compatible = "atmel,at91sam9g45-ehci" },
 214         { /* sentinel */ }
 215 };
 216
 217 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 218 #endif
 219
 220 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
 221                                         ehci_atmel_drv_resume);
 222
 223 static struct platform_driver ehci_atmel_driver = {
 224         .probe          = ehci_atmel_drv_probe,
 225         .remove         = ehci_atmel_drv_remove,
 226         .shutdown       = usb_hcd_platform_shutdown,
 227         .driver         = {
 228                 .name   = "atmel-ehci",
 229                 .pm     = &ehci_atmel_pm_ops,
 230                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 231         },
 232 };
 233
 234 static int __init ehci_atmel_init(void)
 235 {
 236         if (usb_disabled())
 237                 return -ENODEV;
 238
 239         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 240         ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
 241         return platform_driver_register(&ehci_atmel_driver);
 242 }
 243 module_init(ehci_atmel_init);
 244
 245 static void __exit ehci_atmel_cleanup(void)
 246 {
 247         platform_driver_unregister(&ehci_atmel_driver);
 248 }
 249 module_exit(ehci_atmel_cleanup);
 250
 251 MODULE_DESCRIPTION(DRIVER_DESC);
 252 MODULE_ALIAS("platform:atmel-ehci");
 253 MODULE_AUTHOR("Nicolas Ferre");
 254 MODULE_LICENSE("GPL");