drivers/usb/host/ehci-atmel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for EHCI UHP on Atmel chips
   4  *
   5  *  Copyright (C) 2009 Atmel Corporation,
   6  *                     Nicolas Ferre <nicolas.ferre@atmel.com>
   7  *
   8  *  Based on various ehci-*.c drivers
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/io.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/usb.h>
  20 #include <linux/usb/hcd.h>
  21
  22 #include "ehci.h"
  23
  24 #define DRIVER_DESC "EHCI Atmel driver"
  25
  26 static const char hcd_name[] = "ehci-atmel";
  27
  28 /* interface and function clocks */
  29 #define hcd_to_atmel_ehci_priv(h) \
  30         ((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)
  31
  32 struct atmel_ehci_priv {
  33         struct clk *iclk;
  34         struct clk *uclk;
  35         bool clocked;
  36 };
  37
  38 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
  39
  40 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
  41         .extra_priv_size = sizeof(struct atmel_ehci_priv),
  42 };
  43
  44 /*-------------------------------------------------------------------------*/
  45
  46 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
  47 {
  48         if (atmel_ehci->clocked)
  49                 return;
  50
  51         clk_prepare_enable(atmel_ehci->uclk);
  52         clk_prepare_enable(atmel_ehci->iclk);
  53         atmel_ehci->clocked = true;
  54 }
  55
  56 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
  57 {
  58         if (!atmel_ehci->clocked)
  59                 return;
  60
  61         clk_disable_unprepare(atmel_ehci->iclk);
  62         clk_disable_unprepare(atmel_ehci->uclk);
  63         atmel_ehci->clocked = false;
  64 }
  65
  66 static void atmel_start_ehci(struct platform_device *pdev)
  67 {
  68         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  69         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  70
  71         dev_dbg(&pdev->dev, "start\n");
  72         atmel_start_clock(atmel_ehci);
  73 }
  74
  75 static void atmel_stop_ehci(struct platform_device *pdev)
  76 {
  77         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  78         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
  79
  80         dev_dbg(&pdev->dev, "stop\n");
  81         atmel_stop_clock(atmel_ehci);
  82 }
  83
  84 /*-------------------------------------------------------------------------*/
  85
  86 static int ehci_atmel_drv_probe(struct platform_device *pdev)
  87 {
  88         struct usb_hcd *hcd;
  89         const struct hc_driver *driver = &ehci_atmel_hc_driver;
  90         struct resource *res;
  91         struct ehci_hcd *ehci;
  92         struct atmel_ehci_priv *atmel_ehci;
  93         int irq;
  94         int retval;
  95
  96         if (usb_disabled())
  97                 return -ENODEV;
  98
  99         pr_debug("Initializing Atmel-SoC USB Host Controller\n");
 100
 101         irq = platform_get_irq(pdev, 0);
 102         if (irq <= 0) {
 103                 retval = -ENODEV;
 104                 goto fail_create_hcd;
 105         }
 106
 107         /* Right now device-tree probed devices don't get dma_mask set.
 108          * Since shared usb code relies on it, set it here for now.
 109          * Once we have dma capability bindings this can go away.
 110          */
 111         retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 112         if (retval)
 113                 goto fail_create_hcd;
 114
 115         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
 116         if (!hcd) {
 117                 retval = -ENOMEM;
 118                 goto fail_create_hcd;
 119         }
 120         atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 121
 122         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 123         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 124         if (IS_ERR(hcd->regs)) {
 125                 retval = PTR_ERR(hcd->regs);
 126                 goto fail_request_resource;
 127         }
 128
 129         hcd->rsrc_start = res->start;
 130         hcd->rsrc_len = resource_size(res);
 131
 132         atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 133         if (IS_ERR(atmel_ehci->iclk)) {
 134                 dev_err(&pdev->dev, "Error getting interface clock\n");
 135                 retval = -ENOENT;
 136                 goto fail_request_resource;
 137         }
 138
 139         atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
 140         if (IS_ERR(atmel_ehci->uclk)) {
 141                 dev_err(&pdev->dev, "failed to get uclk\n");
 142                 retval = PTR_ERR(atmel_ehci->uclk);
 143                 goto fail_request_resource;
 144         }
 145
 146         ehci = hcd_to_ehci(hcd);
 147         /* registers start at offset 0x0 */
 148         ehci->caps = hcd->regs;
 149
 150         atmel_start_ehci(pdev);
 151
 152         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 153         if (retval)
 154                 goto fail_add_hcd;
 155         device_wakeup_enable(hcd->self.controller);
 156
 157         return retval;
 158
 159 fail_add_hcd:
 160         atmel_stop_ehci(pdev);
 161 fail_request_resource:
 162         usb_put_hcd(hcd);
 163 fail_create_hcd:
 164         dev_err(&pdev->dev, "init %s fail, %d\n",
 165                 dev_name(&pdev->dev), retval);
 166
 167         return retval;
 168 }
 169
 170 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 171 {
 172         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 173
 174         usb_remove_hcd(hcd);
 175         usb_put_hcd(hcd);
 176
 177         atmel_stop_ehci(pdev);
 178
 179         return 0;
 180 }
 181
 182 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
 183 {
 184         struct usb_hcd *hcd = dev_get_drvdata(dev);
 185         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 186         int ret;
 187
 188         ret = ehci_suspend(hcd, false);
 189         if (ret)
 190                 return ret;
 191
 192         atmel_stop_clock(atmel_ehci);
 193         return 0;
 194 }
 195
 196 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
 197 {
 198         struct usb_hcd *hcd = dev_get_drvdata(dev);
 199         struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
 200
 201         atmel_start_clock(atmel_ehci);
 202         ehci_resume(hcd, false);
 203         return 0;
 204 }
 205
 206 #ifdef CONFIG_OF
 207 static const struct of_device_id atmel_ehci_dt_ids[] = {
 208         { .compatible = "atmel,at91sam9g45-ehci" },
 209         { /* sentinel */ }
 210 };
 211
 212 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 213 #endif
 214
 215 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
 216                                         ehci_atmel_drv_resume);
 217
 218 static struct platform_driver ehci_atmel_driver = {
 219         .probe          = ehci_atmel_drv_probe,
 220         .remove         = ehci_atmel_drv_remove,
 221         .shutdown       = usb_hcd_platform_shutdown,
 222         .driver         = {
 223                 .name   = "atmel-ehci",
 224                 .pm     = &ehci_atmel_pm_ops,
 225                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 226         },
 227 };
 228
 229 static int __init ehci_atmel_init(void)
 230 {
 231         if (usb_disabled())
 232                 return -ENODEV;
 233
 234         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 235         ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
 236         return platform_driver_register(&ehci_atmel_driver);
 237 }
 238 module_init(ehci_atmel_init);
 239
 240 static void __exit ehci_atmel_cleanup(void)
 241 {
 242         platform_driver_unregister(&ehci_atmel_driver);
 243 }
 244 module_exit(ehci_atmel_cleanup);
 245
 246 MODULE_DESCRIPTION(DRIVER_DESC);
 247 MODULE_ALIAS("platform:atmel-ehci");
 248 MODULE_AUTHOR("Nicolas Ferre");
 249 MODULE_LICENSE("GPL");