/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
 22static struct clk *mxc_ahb_clk;
 23static struct clk *mxc_usb_clk;
 24
 25/* workaround ENGcm09152 for i.MX35 */
 26#define USBPHYCTRL_OTGBASE_OFFSET	0x608
 27#define USBPHYCTRL_EVDO			(1 << 23)
 28
 29int 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	if (!cpu_is_mx35() && !cpu_is_mx25()) {
 38		mxc_ahb_clk = clk_get(&pdev->dev, "usb_ahb");
 39		if (IS_ERR(mxc_ahb_clk))
 40			return PTR_ERR(mxc_ahb_clk);
 41
 42		ret = clk_enable(mxc_ahb_clk);
 43		if (ret < 0) {
 44			dev_err(&pdev->dev, "clk_enable(\"usb_ahb\") failed\n");
 45			goto eenahb;
 46		}
 47	}
 48
 49	/* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
 50	mxc_usb_clk = clk_get(&pdev->dev, "usb");
 51	if (IS_ERR(mxc_usb_clk)) {
 52		dev_err(&pdev->dev, "clk_get(\"usb\") failed\n");
 53		ret = PTR_ERR(mxc_usb_clk);
 54		goto egusb;
 55	}
 56
 57	if (!cpu_is_mx51()) {
 58		freq = clk_get_rate(mxc_usb_clk);
 59		if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
 60		    (freq < 59999000 || freq > 60001000)) {
 61			dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
 62			ret = -EINVAL;
 63			goto eclkrate;
 64		}
 65	}
 66
 67	ret = clk_enable(mxc_usb_clk);
 68	if (ret < 0) {
 69		dev_err(&pdev->dev, "clk_enable(\"usb_clk\") failed\n");
 70		goto eenusb;
 71	}
 72
 73	return 0;
 74
 75eenusb:
 76eclkrate:
 77	clk_put(mxc_usb_clk);
 78	mxc_usb_clk = NULL;
 79egusb:
 80	if (!cpu_is_mx35())
 81		clk_disable(mxc_ahb_clk);
 82eenahb:
 83	if (!cpu_is_mx35())
 84		clk_put(mxc_ahb_clk);
 85	return ret;
 86}
 87
 88void fsl_udc_clk_finalize(struct platform_device *pdev)
 89{
 90	struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
 91#if defined(CONFIG_SOC_IMX35)
 92	if (cpu_is_mx35()) {
 93		unsigned int v;
 94
 95		/* workaround ENGcm09152 for i.MX35 */
 96		if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
 97			v = readl(MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
 98					USBPHYCTRL_OTGBASE_OFFSET));
 99			writel(v | USBPHYCTRL_EVDO,
100				MX35_IO_ADDRESS(MX35_USB_BASE_ADDR +
101					USBPHYCTRL_OTGBASE_OFFSET));
102		}
103	}
104#endif
105
106	/* ULPI transceivers don't need usbpll */
107	if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
108		clk_disable(mxc_usb_clk);
109		clk_put(mxc_usb_clk);
110		mxc_usb_clk = NULL;
111	}
112}
113
114void fsl_udc_clk_release(void)
115{
116	if (mxc_usb_clk) {
117		clk_disable(mxc_usb_clk);
118		clk_put(mxc_usb_clk);
119	}
120	if (!cpu_is_mx35()) {
121		clk_disable(mxc_ahb_clk);
122		clk_put(mxc_ahb_clk);
123	}
124}