drivers/usb/gadget/fsl_mxc_udc.c

   1 /*
   2  * Copyright (C) 2009
   3  * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
   4  *
   5  * Description:
   6  * Helper routines for i.MX3x SoCs from Freescale, needed by the fsl_usb2_udc.c
   7  * driver to function correctly on these systems.
   8  *
   9  * This program is free software; you can redistribute  it and/or modify it
  10  * under  the terms of  the GNU General  Public License as published by the
  11  * Free Software Foundation;  either version 2 of the  License, or (at your
  12  * option) any later version.
  13  */
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16 #include <linux/err.h>
  17 #include <linux/fsl_devices.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/io.h>
  20
  21 static struct clk *mxc_ahb_clk;
  22 static struct clk *mxc_per_clk;
  23 static struct clk *mxc_ipg_clk;
  24
  25 /* workaround ENGcm09152 for i.MX35 */
  26 #define MX35_USBPHYCTRL_OFFSET          0x600
  27 #define USBPHYCTRL_OTGBASE_OFFSET       0x8
  28 #define USBPHYCTRL_EVDO                 (1 << 23)
  29
  30 int fsl_udc_clk_init(struct platform_device *pdev)
  31 {
  32         struct fsl_usb2_platform_data *pdata;
  33         unsigned long freq;
  34         int ret;
  35
  36         pdata = pdev->dev.platform_data;
  37
  38         mxc_ipg_clk = devm_clk_get(&pdev->dev, "ipg");
  39         if (IS_ERR(mxc_ipg_clk)) {
  40                 dev_err(&pdev->dev, "clk_get(\"ipg\") failed\n");
  41                 return PTR_ERR(mxc_ipg_clk);
  42         }
  43
  44         mxc_ahb_clk = devm_clk_get(&pdev->dev, "ahb");
  45         if (IS_ERR(mxc_ahb_clk)) {
  46                 dev_err(&pdev->dev, "clk_get(\"ahb\") failed\n");
  47                 return PTR_ERR(mxc_ahb_clk);
  48         }
  49
  50         mxc_per_clk = devm_clk_get(&pdev->dev, "per");
  51         if (IS_ERR(mxc_per_clk)) {
  52                 dev_err(&pdev->dev, "clk_get(\"per\") failed\n");
  53                 return PTR_ERR(mxc_per_clk);
  54         }
  55
  56         clk_prepare_enable(mxc_ipg_clk);
  57         clk_prepare_enable(mxc_ahb_clk);
  58         clk_prepare_enable(mxc_per_clk);
  59
  60         /* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
  61         if (!strcmp(pdev->id_entry->name, "imx-udc-mx27")) {
  62                 freq = clk_get_rate(mxc_per_clk);
  63                 if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
  64                     (freq < 59999000 || freq > 60001000)) {
  65                         dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
  66                         ret = -EINVAL;
  67                         goto eclkrate;
  68                 }
  69         }
  70
  71         return 0;
  72
  73 eclkrate:
  74         clk_disable_unprepare(mxc_ipg_clk);
  75         clk_disable_unprepare(mxc_ahb_clk);
  76         clk_disable_unprepare(mxc_per_clk);
  77         mxc_per_clk = NULL;
  78         return ret;
  79 }
  80
  81 int fsl_udc_clk_finalize(struct platform_device *pdev)
  82 {
  83         struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
  84         int ret = 0;
  85
  86         /* workaround ENGcm09152 for i.MX35 */
  87         if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
  88                 unsigned int v;
  89                 struct resource *res = platform_get_resource
  90                         (pdev, IORESOURCE_MEM, 0);
  91                 void __iomem *phy_regs = ioremap(res->start +
  92                                                 MX35_USBPHYCTRL_OFFSET, 512);
  93                 if (!phy_regs) {
  94                         dev_err(&pdev->dev, "ioremap for phy address fails\n");
  95                         ret = -EINVAL;
  96                         goto ioremap_err;
  97                 }
  98
  99                 v = readl(phy_regs + USBPHYCTRL_OTGBASE_OFFSET);
 100                 writel(v | USBPHYCTRL_EVDO,
 101                         phy_regs + USBPHYCTRL_OTGBASE_OFFSET);
 102
 103                 iounmap(phy_regs);
 104         }
 105
 106
 107 ioremap_err:
 108         /* ULPI transceivers don't need usbpll */
 109         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
 110                 clk_disable_unprepare(mxc_per_clk);
 111                 mxc_per_clk = NULL;
 112         }
 113
 114         return ret;
 115 }
 116
 117 void fsl_udc_clk_release(void)
 118 {
 119         if (mxc_per_clk)
 120                 clk_disable_unprepare(mxc_per_clk);
 121         clk_disable_unprepare(mxc_ahb_clk);
 122         clk_disable_unprepare(mxc_ipg_clk);
 123 }