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 #include <mach/hardware.h>
  22
  23 static struct clk *mxc_ahb_clk;
  24 static struct clk *mxc_per_clk;
  25 static struct clk *mxc_ipg_clk;
  26
  27 /* workaround ENGcm09152 for i.MX35 */
  28 #define USBPHYCTRL_OTGBASE_OFFSET       0x608
  29 #define USBPHYCTRL_EVDO                 (1 << 23)
  30
  31 int fsl_udc_clk_init(struct platform_device *pdev)
  32 {
  33         struct fsl_usb2_platform_data *pdata;
  34         unsigned long freq;
  35         int ret;
  36
  37         pdata = pdev->dev.platform_data;
  38
  39         mxc_ipg_clk = devm_clk_get(&pdev->dev, "ipg");
  40         if (IS_ERR(mxc_ipg_clk)) {
  41                 dev_err(&pdev->dev, "clk_get(\"ipg\") failed\n");
  42                 return PTR_ERR(mxc_ipg_clk);
  43         }
  44
  45         mxc_ahb_clk = devm_clk_get(&pdev->dev, "ahb");
  46         if (IS_ERR(mxc_ahb_clk)) {
  47                 dev_err(&pdev->dev, "clk_get(\"ahb\") failed\n");
  48                 return PTR_ERR(mxc_ahb_clk);
  49         }
  50
  51         mxc_per_clk = devm_clk_get(&pdev->dev, "per");
  52         if (IS_ERR(mxc_per_clk)) {
  53                 dev_err(&pdev->dev, "clk_get(\"per\") failed\n");
  54                 return PTR_ERR(mxc_per_clk);
  55         }
  56
  57         clk_prepare_enable(mxc_ipg_clk);
  58         clk_prepare_enable(mxc_ahb_clk);
  59         clk_prepare_enable(mxc_per_clk);
  60
  61         /* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
  62         if (!cpu_is_mx51()) {
  63                 freq = clk_get_rate(mxc_per_clk);
  64                 if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
  65                     (freq < 59999000 || freq > 60001000)) {
  66                         dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
  67                         ret = -EINVAL;
  68                         goto eclkrate;
  69                 }
  70         }
  71
  72         return 0;
  73
  74 eclkrate:
  75         clk_disable_unprepare(mxc_ipg_clk);
  76         clk_disable_unprepare(mxc_ahb_clk);
  77         clk_disable_unprepare(mxc_per_clk);
  78         mxc_per_clk = NULL;
  79         return ret;
  80 }
  81
  82 void fsl_udc_clk_finalize(struct platform_device *pdev)
  83 {
  84         struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
  85         if (cpu_is_mx35()) {
  86                 unsigned int v;
  87
  88                 /* workaround ENGcm09152 for i.MX35 */
  89                 if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
  90                         v = readl(MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
  91                                         USBPHYCTRL_OTGBASE_OFFSET));
  92                         writel(v | USBPHYCTRL_EVDO,
  93                                 MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
  94                                         USBPHYCTRL_OTGBASE_OFFSET));
  95                 }
  96         }
  97
  98         /* ULPI transceivers don't need usbpll */
  99         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
 100                 clk_disable_unprepare(mxc_per_clk);
 101                 mxc_per_clk = NULL;
 102         }
 103 }
 104
 105 void fsl_udc_clk_release(void)
 106 {
 107         if (mxc_per_clk)
 108                 clk_disable_unprepare(mxc_per_clk);
 109         clk_disable_unprepare(mxc_ahb_clk);
 110         clk_disable_unprepare(mxc_ipg_clk);
 111 }