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linux/drivers/usb/gadget/fsl_mxc_udc.c
Eric Bénard 69cb1ec4ce mxc_udc: add workaround for ENGcm09152 for i.MX35
this patch gives the possibility to workaround bug ENGcm09152
on i.MX35 when the hardware workaround is also implemented on
the board.
It covers the workaround described on page 25 of the following Errata :
http://cache.freescale.com/files/dsp/doc/errata/IMX35CE.pdf

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:22:17 -07:00

122 lines
2.9 KiB
C

/*
* Copyright (C) 2009
* Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
*
* Description:
* Helper routines for i.MX3x SoCs from Freescale, needed by the fsl_usb2_udc.c
* driver to function correctly on these systems.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/fsl_devices.h>
#include <linux/platform_device.h>
#include <mach/hardware.h>
static struct clk *mxc_ahb_clk;
static struct clk *mxc_usb_clk;
/* workaround ENGcm09152 for i.MX35 */
#define USBPHYCTRL_OTGBASE_OFFSET 0x608
#define USBPHYCTRL_EVDO (1 << 23)
int fsl_udc_clk_init(struct platform_device *pdev)
{
struct fsl_usb2_platform_data *pdata;
unsigned long freq;
int ret;
pdata = pdev->dev.platform_data;
if (!cpu_is_mx35() && !cpu_is_mx25()) {
mxc_ahb_clk = clk_get(&pdev->dev, "usb_ahb");
if (IS_ERR(mxc_ahb_clk))
return PTR_ERR(mxc_ahb_clk);
ret = clk_enable(mxc_ahb_clk);
if (ret < 0) {
dev_err(&pdev->dev, "clk_enable(\"usb_ahb\") failed\n");
goto eenahb;
}
}
/* make sure USB_CLK is running at 60 MHz +/- 1000 Hz */
mxc_usb_clk = clk_get(&pdev->dev, "usb");
if (IS_ERR(mxc_usb_clk)) {
dev_err(&pdev->dev, "clk_get(\"usb\") failed\n");
ret = PTR_ERR(mxc_usb_clk);
goto egusb;
}
if (!cpu_is_mx51()) {
freq = clk_get_rate(mxc_usb_clk);
if (pdata->phy_mode != FSL_USB2_PHY_ULPI &&
(freq < 59999000 || freq > 60001000)) {
dev_err(&pdev->dev, "USB_CLK=%lu, should be 60MHz\n", freq);
ret = -EINVAL;
goto eclkrate;
}
}
ret = clk_enable(mxc_usb_clk);
if (ret < 0) {
dev_err(&pdev->dev, "clk_enable(\"usb_clk\") failed\n");
goto eenusb;
}
return 0;
eenusb:
eclkrate:
clk_put(mxc_usb_clk);
mxc_usb_clk = NULL;
egusb:
if (!cpu_is_mx35())
clk_disable(mxc_ahb_clk);
eenahb:
if (!cpu_is_mx35())
clk_put(mxc_ahb_clk);
return ret;
}
void fsl_udc_clk_finalize(struct platform_device *pdev)
{
struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
#if defined(CONFIG_ARCH_MX35)
unsigned int v;
/* workaround ENGcm09152 for i.MX35 */
if (pdata->workaround & FLS_USB2_WORKAROUND_ENGCM09152) {
v = readl(MX35_IO_ADDRESS(MX35_OTG_BASE_ADDR +
USBPHYCTRL_OTGBASE_OFFSET));
writel(v | USBPHYCTRL_EVDO, MX35_IO_ADDRESS(MX35_OTG_BASE_ADDR +
USBPHYCTRL_OTGBASE_OFFSET));
}
#endif
/* ULPI transceivers don't need usbpll */
if (pdata->phy_mode == FSL_USB2_PHY_ULPI) {
clk_disable(mxc_usb_clk);
clk_put(mxc_usb_clk);
mxc_usb_clk = NULL;
}
}
void fsl_udc_clk_release(void)
{
if (mxc_usb_clk) {
clk_disable(mxc_usb_clk);
clk_put(mxc_usb_clk);
}
if (!cpu_is_mx35()) {
clk_disable(mxc_ahb_clk);
clk_put(mxc_ahb_clk);
}
}