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
  20 #include <mach/hardware.h>
  21
  22 static struct clk *mxc_ahb_clk;
  23 static struct clk *mxc_usb_clk;
  24
  25 int fsl_udc_clk_init(struct platform_device *pdev)
  26 {
  27         struct fsl_usb2_platform_data *pdata;
  28         unsigned long freq;
  29         int ret;
  30
  31         pdata = pdev->dev.platform_data;
  32
  33         if (!cpu_is_mx35() && !cpu_is_mx25()) {
  34                 mxc_ahb_clk = clk_get(&pdev->dev, "usb_ahb");
  35                 if (IS_ERR(mxc_ahb_clk))
  36                         return PTR_ERR(mxc_ahb_clk);
  37
  38                 ret = clk_enable(mxc_ahb_clk);
  39                 if (ret < 0) {
  40                         dev_err(&pdev->dev, "clk_enable(\"usb_ahb\") failed\n");
  41                         goto eenahb;
  42                 }
  43         }
  44
  45         /* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
  46         mxc_usb_clk = clk_get(&pdev->dev, "usb");
  47         if (IS_ERR(mxc_usb_clk)) {
  48                 dev_err(&pdev->dev, "clk_get(\"usb\") failed\n");
  49                 ret = PTR_ERR(mxc_usb_clk);
  50                 goto egusb;
  51         }
  52
  53         if (!cpu_is_mx51()) {
  54                 freq = clk_get_rate(mxc_usb_clk);
  55                 if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
  56                     (freq < 59999000 || freq > 60001000)) {
  57                         dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
  58                         ret = -EINVAL;
  59                         goto eclkrate;
  60                 }
  61         }
  62
  63         ret = clk_enable(mxc_usb_clk);
  64         if (ret < 0) {
  65                 dev_err(&pdev->dev, "clk_enable(\"usb_clk\") failed\n");
  66                 goto eenusb;
  67         }
  68
  69         return 0;
  70
  71 eenusb:
  72 eclkrate:
  73         clk_put(mxc_usb_clk);
  74         mxc_usb_clk = NULL;
  75 egusb:
  76         if (!cpu_is_mx35())
  77                 clk_disable(mxc_ahb_clk);
  78 eenahb:
  79         if (!cpu_is_mx35())
  80                 clk_put(mxc_ahb_clk);
  81         return ret;
  82 }
  83
  84 void fsl_udc_clk_finalize(struct platform_device *pdev)
  85 {
  86         struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
  87
  88         /* ULPI transceivers don't need usbpll */
  89         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
  90                 clk_disable(mxc_usb_clk);
  91                 clk_put(mxc_usb_clk);
  92                 mxc_usb_clk = NULL;
  93         }
  94 }
  95
  96 void fsl_udc_clk_release(void)
  97 {
  98         if (mxc_usb_clk) {
  99                 clk_disable(mxc_usb_clk);
 100                 clk_put(mxc_usb_clk);
 101         }
 102         if (!cpu_is_mx35()) {
 103                 clk_disable(mxc_ahb_clk);
 104                 clk_put(mxc_ahb_clk);
 105         }
 106 }