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 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         retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
  94         if (retval)
  95                 goto fail_create_hcd;
  96
  97         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
  98         if (!hcd) {
  99                 retval = -ENOMEM;
 100                 goto fail_create_hcd;
 101         }
 102
 103         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 104         if (!res) {
 105                 dev_err(&pdev->dev,
 106                         "Found HC with no register addr. Check %s setup!\n",
 107                         dev_name(&pdev->dev));
 108                 retval = -ENODEV;
 109                 goto fail_request_resource;
 110         }
 111         hcd->rsrc_start = res->start;
 112         hcd->rsrc_len = resource_size(res);
 113
 114         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 115         if (IS_ERR(hcd->regs)) {
 116                 retval = PTR_ERR(hcd->regs);
 117                 goto fail_request_resource;
 118         }
 119
 120         iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 121         if (IS_ERR(iclk)) {
 122                 dev_err(&pdev->dev, "Error getting interface clock\n");
 123                 retval = -ENOENT;
 124                 goto fail_request_resource;
 125         }
 126         fclk = devm_clk_get(&pdev->dev, "uhpck");
 127         if (IS_ERR(fclk)) {
 128                 dev_err(&pdev->dev, "Error getting function clock\n");
 129                 retval = -ENOENT;
 130                 goto fail_request_resource;
 131         }
 132
 133         ehci = hcd_to_ehci(hcd);
 134         /* registers start at offset 0x0 */
 135         ehci->caps = hcd->regs;
 136
 137         atmel_start_ehci(pdev);
 138
 139         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 140         if (retval)
 141                 goto fail_add_hcd;
 142
 143         return retval;
 144
 145 fail_add_hcd:
 146         atmel_stop_ehci(pdev);
 147 fail_request_resource:
 148         usb_put_hcd(hcd);
 149 fail_create_hcd:
 150         dev_err(&pdev->dev, "init %s fail, %d\n",
 151                 dev_name(&pdev->dev), retval);
 152
 153         return retval;
 154 }
 155
 156 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 157 {
 158         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 159
 160         usb_remove_hcd(hcd);
 161         usb_put_hcd(hcd);
 162
 163         atmel_stop_ehci(pdev);
 164         fclk = iclk = NULL;
 165
 166         return 0;
 167 }
 168
 169 #ifdef CONFIG_OF
 170 static const struct of_device_id atmel_ehci_dt_ids[] = {
 171         { .compatible = "atmel,at91sam9g45-ehci" },
 172         { /* sentinel */ }
 173 };
 174
 175 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 176 #endif
 177
 178 static struct platform_driver ehci_atmel_driver = {
 179         .probe          = ehci_atmel_drv_probe,
 180         .remove         = ehci_atmel_drv_remove,
 181         .shutdown       = usb_hcd_platform_shutdown,
 182         .driver         = {
 183                 .name   = "atmel-ehci",
 184                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 185         },
 186 };
 187
 188 static int __init ehci_atmel_init(void)
 189 {
 190         if (usb_disabled())
 191                 return -ENODEV;
 192
 193         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 194         ehci_init_driver(&ehci_atmel_hc_driver, NULL);
 195         return platform_driver_register(&ehci_atmel_driver);
 196 }
 197 module_init(ehci_atmel_init);
 198
 199 static void __exit ehci_atmel_cleanup(void)
 200 {
 201         platform_driver_unregister(&ehci_atmel_driver);
 202 }
 203 module_exit(ehci_atmel_cleanup);
 204
 205 MODULE_DESCRIPTION(DRIVER_DESC);
 206 MODULE_ALIAS("platform:atmel-ehci");
 207 MODULE_AUTHOR("Nicolas Ferre");
 208 MODULE_LICENSE("GPL");