drivers/usb/gadget/fsl_mx3_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
  20 static struct clk *mxc_ahb_clk;
  21 static struct clk *mxc_usb_clk;
  22
  23 int fsl_udc_clk_init(struct platform_device *pdev)
  24 {
  25         struct fsl_usb2_platform_data *pdata;
  26         unsigned long freq;
  27         int ret;
  28
  29         pdata = pdev->dev.platform_data;
  30
  31         mxc_ahb_clk = clk_get(&pdev->dev, "usb_ahb");
  32         if (IS_ERR(mxc_ahb_clk))
  33                 return PTR_ERR(mxc_ahb_clk);
  34
  35         ret = clk_enable(mxc_ahb_clk);
  36         if (ret < 0) {
  37                 dev_err(&pdev->dev, "clk_enable(\"usb_ahb\") failed\n");
  38                 goto eenahb;
  39         }
  40
  41         /* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
  42         mxc_usb_clk = clk_get(&pdev->dev, "usb");
  43         if (IS_ERR(mxc_usb_clk)) {
  44                 dev_err(&pdev->dev, "clk_get(\"usb\") failed\n");
  45                 ret = PTR_ERR(mxc_usb_clk);
  46                 goto egusb;
  47         }
  48
  49         freq = clk_get_rate(mxc_usb_clk);
  50         if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
  51             (freq < 59999000 || freq > 60001000)) {
  52                 dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
  53                 goto eclkrate;
  54         }
  55
  56         ret = clk_enable(mxc_usb_clk);
  57         if (ret < 0) {
  58                 dev_err(&pdev->dev, "clk_enable(\"usb_clk\") failed\n");
  59                 goto eenusb;
  60         }
  61
  62         return 0;
  63
  64 eenusb:
  65 eclkrate:
  66         clk_put(mxc_usb_clk);
  67         mxc_usb_clk = NULL;
  68 egusb:
  69         clk_disable(mxc_ahb_clk);
  70 eenahb:
  71         clk_put(mxc_ahb_clk);
  72         return ret;
  73 }
  74
  75 void fsl_udc_clk_finalize(struct platform_device *pdev)
  76 {
  77         struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
  78
  79         /* ULPI transceivers don't need usbpll */
  80         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
  81                 clk_disable(mxc_usb_clk);
  82                 clk_put(mxc_usb_clk);
  83                 mxc_usb_clk = NULL;
  84         }
  85 }
  86
  87 void fsl_udc_clk_release(void)
  88 {
  89         if (mxc_usb_clk) {
  90                 clk_disable(mxc_usb_clk);
  91                 clk_put(mxc_usb_clk);
  92         }
  93         clk_disable(mxc_ahb_clk);
  94         clk_put(mxc_ahb_clk);
  95 }