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, *uclk;
  34 static int clocked;
  35
  36 /*-------------------------------------------------------------------------*/
  37
  38 static void atmel_start_clock(void)
  39 {
  40         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
  41                 clk_set_rate(uclk, 48000000);
  42                 clk_prepare_enable(uclk);
  43         }
  44         clk_prepare_enable(iclk);
  45         clk_prepare_enable(fclk);
  46         clocked = 1;
  47 }
  48
  49 static void atmel_stop_clock(void)
  50 {
  51         clk_disable_unprepare(fclk);
  52         clk_disable_unprepare(iclk);
  53         if (IS_ENABLED(CONFIG_COMMON_CLK))
  54                 clk_disable_unprepare(uclk);
  55         clocked = 0;
  56 }
  57
  58 static void atmel_start_ehci(struct platform_device *pdev)
  59 {
  60         dev_dbg(&pdev->dev, "start\n");
  61         atmel_start_clock();
  62 }
  63
  64 static void atmel_stop_ehci(struct platform_device *pdev)
  65 {
  66         dev_dbg(&pdev->dev, "stop\n");
  67         atmel_stop_clock();
  68 }
  69
  70 /*-------------------------------------------------------------------------*/
  71
  72 static int ehci_atmel_drv_probe(struct platform_device *pdev)
  73 {
  74         struct usb_hcd *hcd;
  75         const struct hc_driver *driver = &ehci_atmel_hc_driver;
  76         struct resource *res;
  77         struct ehci_hcd *ehci;
  78         int irq;
  79         int retval;
  80
  81         if (usb_disabled())
  82                 return -ENODEV;
  83
  84         pr_debug("Initializing Atmel-SoC USB Host Controller\n");
  85
  86         irq = platform_get_irq(pdev, 0);
  87         if (irq <= 0) {
  88                 dev_err(&pdev->dev,
  89                         "Found HC with no IRQ. Check %s setup!\n",
  90                         dev_name(&pdev->dev));
  91                 retval = -ENODEV;
  92                 goto fail_create_hcd;
  93         }
  94
  95         /* Right now device-tree probed devices don't get dma_mask set.
  96          * Since shared usb code relies on it, set it here for now.
  97          * Once we have dma capability bindings this can go away.
  98          */
  99         retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 100         if (retval)
 101                 goto fail_create_hcd;
 102
 103         hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
 104         if (!hcd) {
 105                 retval = -ENOMEM;
 106                 goto fail_create_hcd;
 107         }
 108
 109         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 110         if (!res) {
 111                 dev_err(&pdev->dev,
 112                         "Found HC with no register addr. Check %s setup!\n",
 113                         dev_name(&pdev->dev));
 114                 retval = -ENODEV;
 115                 goto fail_request_resource;
 116         }
 117         hcd->rsrc_start = res->start;
 118         hcd->rsrc_len = resource_size(res);
 119
 120         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 121         if (IS_ERR(hcd->regs)) {
 122                 retval = PTR_ERR(hcd->regs);
 123                 goto fail_request_resource;
 124         }
 125
 126         iclk = devm_clk_get(&pdev->dev, "ehci_clk");
 127         if (IS_ERR(iclk)) {
 128                 dev_err(&pdev->dev, "Error getting interface clock\n");
 129                 retval = -ENOENT;
 130                 goto fail_request_resource;
 131         }
 132         fclk = devm_clk_get(&pdev->dev, "uhpck");
 133         if (IS_ERR(fclk)) {
 134                 dev_err(&pdev->dev, "Error getting function clock\n");
 135                 retval = -ENOENT;
 136                 goto fail_request_resource;
 137         }
 138         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
 139                 uclk = devm_clk_get(&pdev->dev, "usb_clk");
 140                 if (IS_ERR(uclk)) {
 141                         dev_err(&pdev->dev, "failed to get uclk\n");
 142                         retval = PTR_ERR(uclk);
 143                         goto fail_request_resource;
 144                 }
 145         }
 146
 147         ehci = hcd_to_ehci(hcd);
 148         /* registers start at offset 0x0 */
 149         ehci->caps = hcd->regs;
 150
 151         atmel_start_ehci(pdev);
 152
 153         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 154         if (retval)
 155                 goto fail_add_hcd;
 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         fclk = iclk = NULL;
 179
 180         return 0;
 181 }
 182
 183 #ifdef CONFIG_OF
 184 static const struct of_device_id atmel_ehci_dt_ids[] = {
 185         { .compatible = "atmel,at91sam9g45-ehci" },
 186         { /* sentinel */ }
 187 };
 188
 189 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
 190 #endif
 191
 192 static struct platform_driver ehci_atmel_driver = {
 193         .probe          = ehci_atmel_drv_probe,
 194         .remove         = ehci_atmel_drv_remove,
 195         .shutdown       = usb_hcd_platform_shutdown,
 196         .driver         = {
 197                 .name   = "atmel-ehci",
 198                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
 199         },
 200 };
 201
 202 static int __init ehci_atmel_init(void)
 203 {
 204         if (usb_disabled())
 205                 return -ENODEV;
 206
 207         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 208         ehci_init_driver(&ehci_atmel_hc_driver, NULL);
 209         return platform_driver_register(&ehci_atmel_driver);
 210 }
 211 module_init(ehci_atmel_init);
 212
 213 static void __exit ehci_atmel_cleanup(void)
 214 {
 215         platform_driver_unregister(&ehci_atmel_driver);
 216 }
 217 module_exit(ehci_atmel_cleanup);
 218
 219 MODULE_DESCRIPTION(DRIVER_DESC);
 220 MODULE_ALIAS("platform:atmel-ehci");
 221 MODULE_AUTHOR("Nicolas Ferre");
 222 MODULE_LICENSE("GPL");