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 *fclk;
  38         struct clk *uclk;
  39         bool clocked;
  40 };
  41
  42 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
  43
  44 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
  45         .extra_priv_size = sizeof(struct atmel_ehci_priv),
  46 };
  47
  48 /*-------------------------------------------------------------------------*/
  49
  50 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
  51 {
  52         if (atmel_ehci->clocked)
  53                 return;
  54         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
  55                 clk_set_rate(atmel_ehci->uclk, 48000000);
  56                 clk_prepare_enable(atmel_ehci->uclk);
  57         }
  58         clk_prepare_enable(atmel_ehci->iclk);
  59         clk_prepare_enable(atmel_ehci->fclk);
  60         atmel_ehci->clocked = true;
  61 }
  62
  63 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
  64 {
  65         if (!atmel_ehci->clocked)
  66                 return;
  67         clk_disable_unprepare(atmel_ehci->fclk);
  68         clk_disable_unprepare(atmel_ehci->iclk);
  69         if (IS_ENABLED(CONFIG_COMMON_CLK))
  70                 clk_disable_unprepare(atmel_ehci->uclk);
  71         atmel_ehci->clocked = false;
  72 }
  73
  74 static void atmel_start_ehci(struct platform_device *pdev)
  75 {
  76         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  77         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  78
  79         dev_dbg(&pdev->dev, "start\n");
  80         atmel_start_clock(atmel_ehci);
  81 }
  82
  83 static void atmel_stop_ehci(struct platform_device *pdev)
  84 {
  85         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  86         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  87
  88         dev_dbg(&pdev->dev, "stop\n");
  89         atmel_stop_clock(atmel_ehci);
  90 }
  91
  92 /*-------------------------------------------------------------------------*/
  93
  94 static int ehci_atmel_drv_probe(struct platform_device *pdev)
  95 {
  96         struct usb_hcd *hcd;
  97         const struct hc_driver *driver = &ehci_atmel_hc_driver;
  98         struct resource *res;
  99         struct ehci_hcd *ehci;
 100         struct atmel_ehci_priv *atmel_ehci;
 101         int irq;
 102         int retval;
 103
 104         if (usb_disabled())
 105                 return -ENODEV;
 106
 107         pr_debug("Initializing Atmel-SoC USB Host Controller\n");
 108
 109         irq = platform_get_irq(pdev, 0);
 110         if (irq <= 0) {
 111                 dev_err(&pdev->dev,
 112                         "Found HC with no IRQ. Check %s setup!\n",
 113                         dev_name(&pdev->dev));
 114                 retval = -ENODEV;
 115                 goto fail_create_hcd;
 116         }
 117
 118         /* Right now device-tree probed devices don't get dma_mask set.
 119          * Since shared usb code relies on it, set it here for now.
 120          * Once we have dma capability bindings this can go away.
 121          */
 122         retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 123         if (retval)
 124                 goto fail_create_hcd;
 125
 126         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
 127         if (!hcd) {
 128                 retval = -ENOMEM;
 129                 goto fail_create_hcd;
 130         }
 131         atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 132
 133         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 134         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 135         if (IS_ERR(hcd->regs)) {
 136                 retval = PTR_ERR(hcd->regs);
 137                 goto fail_request_resource;
 138         }
 139
 140         hcd->rsrc_start = res->start;
 141         hcd->rsrc_len = resource_size(res);
 142
 143         atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 144         if (IS_ERR(atmel_ehci->iclk)) {
 145                 dev_err(&pdev->dev, "Error getting interface clock\n");
 146                 retval = -ENOENT;
 147                 goto fail_request_resource;
 148         }
 149         atmel_ehci->fclk = devm_clk_get(&pdev->dev, "uhpck");
 150         if (IS_ERR(atmel_ehci->fclk)) {
 151                 dev_err(&pdev->dev, "Error getting function clock\n");
 152                 retval = -ENOENT;
 153                 goto fail_request_resource;
 154         }
 155         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
 156                 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
 157                 if (IS_ERR(atmel_ehci->uclk)) {
 158                         dev_err(&pdev->dev, "failed to get uclk\n");
 159                         retval = PTR_ERR(atmel_ehci->uclk);
 160                         goto fail_request_resource;
 161                 }
 162         }
 163
 164         ehci = hcd_to_ehci(hcd);
 165         /* registers start at offset 0x0 */
 166         ehci->caps = hcd->regs;
 167
 168         atmel_start_ehci(pdev);
 169
 170         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 171         if (retval)
 172                 goto fail_add_hcd;
 173         device_wakeup_enable(hcd->self.controller);
 174
 175         return retval;
 176
 177 fail_add_hcd:
 178         atmel_stop_ehci(pdev);
 179 fail_request_resource:
 180         usb_put_hcd(hcd);
 181 fail_create_hcd:
 182         dev_err(&pdev->dev, "init %s fail, %d\n",
 183                 dev_name(&pdev->dev), retval);
 184
 185         return retval;
 186 }
 187
 188 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 189 {
 190         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 191
 192         usb_remove_hcd(hcd);
 193         usb_put_hcd(hcd);
 194
 195         atmel_stop_ehci(pdev);
 196
 197         return 0;
 198 }
 199
 200 #ifdef CONFIG_PM
 201 static int ehci_atmel_drv_suspend(struct device *dev)
 202 {
 203         struct usb_hcd *hcd = dev_get_drvdata(dev);
 204         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 205         int ret;
 206
 207         ret = ehci_suspend(hcd, false);
 208         if (ret)
 209                 return ret;
 210
 211         atmel_stop_clock(atmel_ehci);
 212         return 0;
 213 }
 214
 215 static int ehci_atmel_drv_resume(struct device *dev)
 216 {
 217         struct usb_hcd *hcd = dev_get_drvdata(dev);
 218         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 219
 220         atmel_start_clock(atmel_ehci);
 221         return ehci_resume(hcd, false);
 222 }
 223 #endif
 224
 225 #ifdef CONFIG_OF
 226 static const struct of_device_id atmel_ehci_dt_ids[] = {
 227         { .compatible = "atmel,at91sam9g45-ehci" },
 228         { /* sentinel */ }
 229 };
 230
 231 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 232 #endif
 233
 234 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
 235                                         ehci_atmel_drv_resume);
 236
 237 static struct platform_driver ehci_atmel_driver = {
 238         .probe          = ehci_atmel_drv_probe,
 239         .remove         = ehci_atmel_drv_remove,
 240         .shutdown       = usb_hcd_platform_shutdown,
 241         .driver         = {
 242                 .name   = "atmel-ehci",
 243                 .pm     = &ehci_atmel_pm_ops,
 244                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 245         },
 246 };
 247
 248 static int __init ehci_atmel_init(void)
 249 {
 250         if (usb_disabled())
 251                 return -ENODEV;
 252
 253         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 254         ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
 255         return platform_driver_register(&ehci_atmel_driver);
 256 }
 257 module_init(ehci_atmel_init);
 258
 259 static void __exit ehci_atmel_cleanup(void)
 260 {
 261         platform_driver_unregister(&ehci_atmel_driver);
 262 }
 263 module_exit(ehci_atmel_cleanup);
 264
 265 MODULE_DESCRIPTION(DRIVER_DESC);
 266 MODULE_ALIAS("platform:atmel-ehci");
 267 MODULE_AUTHOR("Nicolas Ferre");
 268 MODULE_LICENSE("GPL");