u-boot/drivers/usb/musb/am35x.c
Ajay Kumar Gupta 5689f4b5b4 musb: am35x: Workaround for fifo read issue
AM35x supports only 32bit read operations so we need to have
workaround for 8bit and 16bit read operations.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
2010-08-12 16:40:00 +02:00

150 lines
3.6 KiB
C

/*
* am35x.c - TI's AM35x platform specific usb wrapper functions.
*
* Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
*
* Based on drivers/usb/musb/da8xx.c
*
* Copyright (c) 2010 Texas Instruments Incorporated
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <common.h>
#include "am35x.h"
/* MUSB platform configuration */
struct musb_config musb_cfg = {
.regs = (struct musb_regs *)AM35X_USB_OTG_CORE_BASE,
.timeout = AM35X_USB_OTG_TIMEOUT,
.musb_speed = 0,
};
/*
* Enable the USB phy
*/
static u8 phy_on(void)
{
u32 devconf2;
u32 timeout;
devconf2 = readl(&am35x_scm_general_regs->devconf2);
devconf2 &= ~(DEVCONF2_RESET | DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN |
DEVCONF2_OTGMODE | DEVCONF2_REFFREQ |
DEVCONF2_PHY_GPIOMODE);
devconf2 |= DEVCONF2_SESENDEN | DEVCONF2_VBDTCTEN | DEVCONF2_PHY_PLLON |
DEVCONF2_REFFREQ_13MHZ | DEVCONF2_DATPOL;
writel(devconf2, &am35x_scm_general_regs->devconf2);
/* wait until the USB phy is turned on */
timeout = musb_cfg.timeout;
while (timeout--)
if (readl(&am35x_scm_general_regs->devconf2) & DEVCONF2_PHYCKGD)
return 1;
/* USB phy was not turned on */
return 0;
}
/*
* Disable the USB phy
*/
static void phy_off(void)
{
u32 devconf2;
/*
* Power down the on-chip PHY.
*/
devconf2 = readl(&am35x_scm_general_regs->devconf2);
devconf2 &= ~DEVCONF2_PHY_PLLON;
devconf2 |= DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN;
writel(devconf2, &am35x_scm_general_regs->devconf2);
}
/*
* This function performs platform specific initialization for usb0.
*/
int musb_platform_init(void)
{
u32 revision;
u32 sw_reset;
/* global usb reset */
sw_reset = readl(&am35x_scm_general_regs->ip_sw_reset);
sw_reset |= (1 << 0);
writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
sw_reset &= ~(1 << 0);
writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
/* reset the controller */
writel(0x1, &am35x_usb_regs->control);
udelay(5000);
/* start the on-chip usb phy and its pll */
if (phy_on() == 0)
return -1;
/* Returns zero if e.g. not clocked */
revision = readl(&am35x_usb_regs->revision);
if (revision == 0)
return -1;
return 0;
}
/*
* This function performs platform specific deinitialization for usb0.
*/
void musb_platform_deinit(void)
{
/* Turn off the phy */
phy_off();
}
/*
* This function reads data from endpoint fifo for AM35x
* which supports only 32bit read operation.
*
* ep - endpoint number
* length - number of bytes to read from FIFO
* fifo_data - pointer to data buffer into which data is read
*/
__attribute__((weak))
void read_fifo(u8 ep, u32 length, void *fifo_data)
{
u8 *data = (u8 *)fifo_data;
u32 val;
int i;
/* select the endpoint index */
writeb(ep, &musbr->index);
if (length > 4) {
for (i = 0; i < (length >> 2); i++) {
val = readl(&musbr->fifox[ep]);
memcpy(data, &val, 4);
data += 4;
}
length %= 4;
}
if (length > 0) {
val = readl(&musbr->fifox[ep]);
memcpy(data, &val, length);
}
}