drivers/usb/gadget/udc/fsl_mxc_udc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2009
   4  * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
   5  *
   6  * Description:
   7  * Helper routines for i.MX3x SoCs from Freescale, needed by the fsl_usb2_udc.c
   8  * driver to function correctly on these systems.
   9  */
  10 #include <linux/clk.h>
  11 #include <linux/delay.h>
  12 #include <linux/err.h>
  13 #include <linux/fsl_devices.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/io.h>
  17
  18 #include "fsl_usb2_udc.h"
  19
  20 static struct clk *mxc_ahb_clk;
  21 static struct clk *mxc_per_clk;
  22 static struct clk *mxc_ipg_clk;
  23
  24 /* workaround ENGcm09152 for i.MX35 */
  25 #define MX35_USBPHYCTRL_OFFSET          0x600
  26 #define USBPHYCTRL_OTGBASE_OFFSET       0x8
  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 = dev_get_platdata(&pdev->dev);
  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 int fsl_udc_clk_finalize(struct platform_device *pdev)
  81 {
  82         struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);
  83         int ret = 0;
  84
  85         /* workaround ENGcm09152 for i.MX35 */
  86         if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
  87                 unsigned int v;
  88                 struct resource *res = platform_get_resource
  89                         (pdev, IORESOURCE_MEM, 0);
  90                 void __iomem *phy_regs = ioremap(res->start +
  91                                                 MX35_USBPHYCTRL_OFFSET, 512);
  92                 if (!phy_regs) {
  93                         dev_err(&pdev->dev, "ioremap for phy address fails\n");
  94                         ret = -EINVAL;
  95                         goto ioremap_err;
  96                 }
  97
  98                 v = readl(phy_regs + USBPHYCTRL_OTGBASE_OFFSET);
  99                 writel(v | USBPHYCTRL_EVDO,
 100                         phy_regs + USBPHYCTRL_OTGBASE_OFFSET);
 101
 102                 iounmap(phy_regs);
 103         }
 104
 105
 106 ioremap_err:
 107         /* ULPI transceivers don't need usbpll */
 108         if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
 109                 clk_disable_unprepare(mxc_per_clk);
 110                 mxc_per_clk = NULL;
 111         }
 112
 113         return ret;
 114 }
 115
 116 void fsl_udc_clk_release(void)
 117 {
 118         if (mxc_per_clk)
 119                 clk_disable_unprepare(mxc_per_clk);
 120         clk_disable_unprepare(mxc_ahb_clk);
 121         clk_disable_unprepare(mxc_ipg_clk);
 122 }