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 USBPHYCTRL_OTGBASE_OFFSET       0x608
  27 #define USBPHYCTRL_EVDO                 (1 << 23)
  28
  29 int fsl_udc_clk_init(struct platform_device *pdev)
  30 {
  31         struct fsl_usb2_platform_data *pdata;
  32         unsigned long freq;
  33         int ret;
  34
  35         pdata = pdev->dev.platform_data;
  36
  37         mxc_ipg_clk = devm_clk_get(&pdev->dev, "ipg");
  38         if (IS_ERR(mxc_ipg_clk)) {
  39                 dev_err(&pdev->dev, "clk_get(\"ipg\") failed\n");
  40                 return PTR_ERR(mxc_ipg_clk);
  41         }
  42
  43         mxc_ahb_clk = devm_clk_get(&pdev->dev, "ahb");
  44         if (IS_ERR(mxc_ahb_clk)) {
  45                 dev_err(&pdev->dev, "clk_get(\"ahb\") failed\n");
  46                 return PTR_ERR(mxc_ahb_clk);
  47         }
  48
  49         mxc_per_clk = devm_clk_get(&pdev->dev, "per");
  50         if (IS_ERR(mxc_per_clk)) {
  51                 dev_err(&pdev->dev, "clk_get(\"per\") failed\n");
  52                 return PTR_ERR(mxc_per_clk);
  53         }
  54
  55         clk_prepare_enable(mxc_ipg_clk);
  56         clk_prepare_enable(mxc_ahb_clk);
  57         clk_prepare_enable(mxc_per_clk);
  58
  59         /* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
  60         if (!strcmp(pdev->id_entry->name, "imx-udc-mx27")) {
  61                 freq = clk_get_rate(mxc_per_clk);
  62                 if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
  63                     (freq < 59999000 || freq > 60001000)) {
  64                         dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
  65                         ret = -EINVAL;
  66                         goto eclkrate;
  67                 }
  68         }
  69
  70         return 0;
  71
  72 eclkrate:
  73         clk_disable_unprepare(mxc_ipg_clk);
  74         clk_disable_unprepare(mxc_ahb_clk);
  75         clk_disable_unprepare(mxc_per_clk);
  76         mxc_per_clk = NULL;
  77         return ret;
  78 }
  79
  80 void fsl_udc_clk_finalize(struct platform_device *pdev)
  81 {
  82         struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
  83         unsigned int v;
  84
  85         /* workaround ENGcm09152 for i.MX35 */
  86         if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
  87                 v = readl(MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
  88                                 USBPHYCTRL_OTGBASE_OFFSET));
  89                 writel(v | USBPHYCTRL_EVDO,
  90                         MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
  91                                 USBPHYCTRL_OTGBASE_OFFSET));
  92         }
  93
  94         /* ULPI transceivers don't need usbpll */
  95         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
  96                 clk_disable_unprepare(mxc_per_clk);
  97                 mxc_per_clk = NULL;
  98         }
  99 }
 100
 101 void fsl_udc_clk_release(void)
 102 {
 103         if (mxc_per_clk)
 104                 clk_disable_unprepare(mxc_per_clk);
 105         clk_disable_unprepare(mxc_ahb_clk);
 106         clk_disable_unprepare(mxc_ipg_clk);
 107 }