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 <[email protected]>
   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 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
  31
  32 /* interface and function clocks */
  33 static struct clk *iclk, *fclk;
  34 static int clocked;
  35
  36 /*-------------------------------------------------------------------------*/
  37
  38 static void atmel_start_clock(void)
  39 {
  40         clk_prepare_enable(iclk);
  41         clk_prepare_enable(fclk);
  42         clocked = 1;
  43 }
  44
  45 static void atmel_stop_clock(void)
  46 {
  47         clk_disable_unprepare(fclk);
  48         clk_disable_unprepare(iclk);
  49         clocked = 0;
  50 }
  51
  52 static void atmel_start_ehci(struct platform_device *pdev)
  53 {
  54         dev_dbg(&pdev->dev, "start\n");
  55         atmel_start_clock();
  56 }
  57
  58 static void atmel_stop_ehci(struct platform_device *pdev)
  59 {
  60         dev_dbg(&pdev->dev, "stop\n");
  61         atmel_stop_clock();
  62 }
  63
  64 /*-------------------------------------------------------------------------*/
  65
  66 static int ehci_atmel_drv_probe(struct platform_device *pdev)
  67 {
  68         struct usb_hcd *hcd;
  69         const struct hc_driver *driver = &ehci_atmel_hc_driver;
  70         struct resource *res;
  71         struct ehci_hcd *ehci;
  72         int irq;
  73         int retval;
  74
  75         if (usb_disabled())
  76                 return -ENODEV;
  77
  78         pr_debug("Initializing Atmel-SoC USB Host Controller\n");
  79
  80         irq = platform_get_irq(pdev, 0);
  81         if (irq <= 0) {
  82                 dev_err(&pdev->dev,
  83                         "Found HC with no IRQ. Check %s setup!\n",
  84                         dev_name(&pdev->dev));
  85                 retval = -ENODEV;
  86                 goto fail_create_hcd;
  87         }
  88
  89         /* Right now device-tree probed devices don't get dma_mask set.
  90          * Since shared usb code relies on it, set it here for now.
  91          * Once we have dma capability bindings this can go away.
  92          */
  93         if (!pdev->dev.dma_mask)
  94                 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
  95         if (!pdev->dev.coherent_dma_mask)
  96                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
  97
  98         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
  99         if (!hcd) {
 100                 retval = -ENOMEM;
 101                 goto fail_create_hcd;
 102         }
 103
 104         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 105         if (!res) {
 106                 dev_err(&pdev->dev,
 107                         "Found HC with no register addr. Check %s setup!\n",
 108                         dev_name(&pdev->dev));
 109                 retval = -ENODEV;
 110                 goto fail_request_resource;
 111         }
 112         hcd->rsrc_start = res->start;
 113         hcd->rsrc_len = resource_size(res);
 114
 115         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 116         if (IS_ERR(hcd->regs)) {
 117                 retval = PTR_ERR(hcd->regs);
 118                 goto fail_request_resource;
 119         }
 120
 121         iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 122         if (IS_ERR(iclk)) {
 123                 dev_err(&pdev->dev, "Error getting interface clock\n");
 124                 retval = -ENOENT;
 125                 goto fail_request_resource;
 126         }
 127         fclk = devm_clk_get(&pdev->dev, "uhpck");
 128         if (IS_ERR(fclk)) {
 129                 dev_err(&pdev->dev, "Error getting function clock\n");
 130                 retval = -ENOENT;
 131                 goto fail_request_resource;
 132         }
 133
 134         ehci = hcd_to_ehci(hcd);
 135         /* registers start at offset 0x0 */
 136         ehci->caps = hcd->regs;
 137
 138         atmel_start_ehci(pdev);
 139
 140         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 141         if (retval)
 142                 goto fail_add_hcd;
 143
 144         return retval;
 145
 146 fail_add_hcd:
 147         atmel_stop_ehci(pdev);
 148 fail_request_resource:
 149         usb_put_hcd(hcd);
 150 fail_create_hcd:
 151         dev_err(&pdev->dev, "init %s fail, %d\n",
 152                 dev_name(&pdev->dev), retval);
 153
 154         return retval;
 155 }
 156
 157 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 158 {
 159         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 160
 161         usb_remove_hcd(hcd);
 162         usb_put_hcd(hcd);
 163
 164         atmel_stop_ehci(pdev);
 165         fclk = iclk = NULL;
 166
 167         return 0;
 168 }
 169
 170 #ifdef CONFIG_OF
 171 static const struct of_device_id atmel_ehci_dt_ids[] = {
 172         { .compatible = "atmel,at91sam9g45-ehci" },
 173         { /* sentinel */ }
 174 };
 175
 176 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 177 #endif
 178
 179 static struct platform_driver ehci_atmel_driver = {
 180         .probe          = ehci_atmel_drv_probe,
 181         .remove         = ehci_atmel_drv_remove,
 182         .shutdown       = usb_hcd_platform_shutdown,
 183         .driver         = {
 184                 .name   = "atmel-ehci",
 185                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 186         },
 187 };
 188
 189 static int __init ehci_atmel_init(void)
 190 {
 191         if (usb_disabled())
 192                 return -ENODEV;
 193
 194         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 195         ehci_init_driver(&ehci_atmel_hc_driver, NULL);
 196         return platform_driver_register(&ehci_atmel_driver);
 197 }
 198 module_init(ehci_atmel_init);
 199
 200 static void __exit ehci_atmel_cleanup(void)
 201 {
 202         platform_driver_unregister(&ehci_atmel_driver);
 203 }
 204 module_exit(ehci_atmel_cleanup);
 205
 206 MODULE_DESCRIPTION(DRIVER_DESC);
 207 MODULE_ALIAS("platform:atmel-ehci");
 208 MODULE_AUTHOR("Nicolas Ferre");
 209 MODULE_LICENSE("GPL");