linux/drivers/usb/musb/am35x.c

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/*
* Texas Instruments AM35x "glue layer"
*
* Copyright (c) 2010, by Texas Instruments
*
* Based on the DA8xx "glue layer" code.
* Copyright (c) 2008-2009, MontaVista Software, Inc. <source@mvista.com>
*
* This file is part of the Inventra Controller Driver for Linux.
*
* The Inventra Controller Driver for Linux is free software; you
* can redistribute it and/or modify it under the terms of the GNU
* General Public License version 2 as published by the Free Software
* Foundation.
*
* The Inventra Controller Driver for Linux 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 The Inventra Controller Driver for Linux ; if not,
* write to the Free Software Foundation, Inc., 59 Temple Place,
* Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <plat/control.h>
#include <plat/usb.h>
#include "musb_core.h"
/*
* AM35x specific definitions
*/
/* USB 2.0 OTG module registers */
#define USB_REVISION_REG 0x00
#define USB_CTRL_REG 0x04
#define USB_STAT_REG 0x08
#define USB_EMULATION_REG 0x0c
/* 0x10 Reserved */
#define USB_AUTOREQ_REG 0x14
#define USB_SRP_FIX_TIME_REG 0x18
#define USB_TEARDOWN_REG 0x1c
#define EP_INTR_SRC_REG 0x20
#define EP_INTR_SRC_SET_REG 0x24
#define EP_INTR_SRC_CLEAR_REG 0x28
#define EP_INTR_MASK_REG 0x2c
#define EP_INTR_MASK_SET_REG 0x30
#define EP_INTR_MASK_CLEAR_REG 0x34
#define EP_INTR_SRC_MASKED_REG 0x38
#define CORE_INTR_SRC_REG 0x40
#define CORE_INTR_SRC_SET_REG 0x44
#define CORE_INTR_SRC_CLEAR_REG 0x48
#define CORE_INTR_MASK_REG 0x4c
#define CORE_INTR_MASK_SET_REG 0x50
#define CORE_INTR_MASK_CLEAR_REG 0x54
#define CORE_INTR_SRC_MASKED_REG 0x58
/* 0x5c Reserved */
#define USB_END_OF_INTR_REG 0x60
/* Control register bits */
#define AM35X_SOFT_RESET_MASK 1
/* USB interrupt register bits */
#define AM35X_INTR_USB_SHIFT 16
#define AM35X_INTR_USB_MASK (0x1ff << AM35X_INTR_USB_SHIFT)
#define AM35X_INTR_DRVVBUS 0x100
#define AM35X_INTR_RX_SHIFT 16
#define AM35X_INTR_TX_SHIFT 0
#define AM35X_TX_EP_MASK 0xffff /* EP0 + 15 Tx EPs */
#define AM35X_RX_EP_MASK 0xfffe /* 15 Rx EPs */
#define AM35X_TX_INTR_MASK (AM35X_TX_EP_MASK << AM35X_INTR_TX_SHIFT)
#define AM35X_RX_INTR_MASK (AM35X_RX_EP_MASK << AM35X_INTR_RX_SHIFT)
#define USB_MENTOR_CORE_OFFSET 0x400
static inline void phy_on(void)
{
unsigned long timeout = jiffies + msecs_to_jiffies(100);
u32 devconf2;
/*
* Start the on-chip PHY and its PLL.
*/
devconf2 = omap_ctrl_readl(AM35XX_CONTROL_DEVCONF2);
devconf2 &= ~(CONF2_RESET | CONF2_PHYPWRDN | CONF2_OTGPWRDN);
devconf2 |= CONF2_PHY_PLLON;
omap_ctrl_writel(devconf2, AM35XX_CONTROL_DEVCONF2);
DBG(1, "Waiting for PHY clock good...\n");
while (!(omap_ctrl_readl(AM35XX_CONTROL_DEVCONF2)
& CONF2_PHYCLKGD)) {
cpu_relax();
if (time_after(jiffies, timeout)) {
DBG(1, "musb PHY clock good timed out\n");
break;
}
}
}
static inline void phy_off(void)
{
u32 devconf2;
/*
* Power down the on-chip PHY.
*/
devconf2 = omap_ctrl_readl(AM35XX_CONTROL_DEVCONF2);
devconf2 &= ~CONF2_PHY_PLLON;
devconf2 |= CONF2_PHYPWRDN | CONF2_OTGPWRDN;
omap_ctrl_writel(devconf2, AM35XX_CONTROL_DEVCONF2);
}
/*
* am35x_musb_enable - enable interrupts
*/
static void am35x_musb_enable(struct musb *musb)
{
void __iomem *reg_base = musb->ctrl_base;
u32 epmask;
/* Workaround: setup IRQs through both register sets. */
epmask = ((musb->epmask & AM35X_TX_EP_MASK) << AM35X_INTR_TX_SHIFT) |
((musb->epmask & AM35X_RX_EP_MASK) << AM35X_INTR_RX_SHIFT);
musb_writel(reg_base, EP_INTR_MASK_SET_REG, epmask);
musb_writel(reg_base, CORE_INTR_MASK_SET_REG, AM35X_INTR_USB_MASK);
/* Force the DRVVBUS IRQ so we can start polling for ID change. */
if (is_otg_enabled(musb))
musb_writel(reg_base, CORE_INTR_SRC_SET_REG,
AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT);
}
/*
* am35x_musb_disable - disable HDRC and flush interrupts
*/
static void am35x_musb_disable(struct musb *musb)
{
void __iomem *reg_base = musb->ctrl_base;
musb_writel(reg_base, CORE_INTR_MASK_CLEAR_REG, AM35X_INTR_USB_MASK);
musb_writel(reg_base, EP_INTR_MASK_CLEAR_REG,
AM35X_TX_INTR_MASK | AM35X_RX_INTR_MASK);
musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
}
#ifdef CONFIG_USB_MUSB_HDRC_HCD
#define portstate(stmt) stmt
#else
#define portstate(stmt)
#endif
static void am35x_musb_set_vbus(struct musb *musb, int is_on)
{
WARN_ON(is_on && is_peripheral_active(musb));
}
#define POLL_SECONDS 2
static struct timer_list otg_workaround;
static void otg_timer(unsigned long _musb)
{
struct musb *musb = (void *)_musb;
void __iomem *mregs = musb->mregs;
u8 devctl;
unsigned long flags;
/*
* We poll because AM35x's won't expose several OTG-critical
* status change events (from the transceiver) otherwise.
*/
devctl = musb_readb(mregs, MUSB_DEVCTL);
DBG(7, "Poll devctl %02x (%s)\n", devctl, otg_state_string(musb));
spin_lock_irqsave(&musb->lock, flags);
switch (musb->xceiv->state) {
case OTG_STATE_A_WAIT_BCON:
devctl &= ~MUSB_DEVCTL_SESSION;
musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
if (devctl & MUSB_DEVCTL_BDEVICE) {
musb->xceiv->state = OTG_STATE_B_IDLE;
MUSB_DEV_MODE(musb);
} else {
musb->xceiv->state = OTG_STATE_A_IDLE;
MUSB_HST_MODE(musb);
}
break;
case OTG_STATE_A_WAIT_VFALL:
musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
musb_writel(musb->ctrl_base, CORE_INTR_SRC_SET_REG,
MUSB_INTR_VBUSERROR << AM35X_INTR_USB_SHIFT);
break;
case OTG_STATE_B_IDLE:
if (!is_peripheral_enabled(musb))
break;
devctl = musb_readb(mregs, MUSB_DEVCTL);
if (devctl & MUSB_DEVCTL_BDEVICE)
mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
else
musb->xceiv->state = OTG_STATE_A_IDLE;
break;
default:
break;
}
spin_unlock_irqrestore(&musb->lock, flags);
}
static void am35x_musb_try_idle(struct musb *musb, unsigned long timeout)
{
static unsigned long last_timer;
if (!is_otg_enabled(musb))
return;
if (timeout == 0)
timeout = jiffies + msecs_to_jiffies(3);
/* Never idle if active, or when VBUS timeout is not set as host */
if (musb->is_active || (musb->a_wait_bcon == 0 &&
musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
DBG(4, "%s active, deleting timer\n", otg_state_string(musb));
del_timer(&otg_workaround);
last_timer = jiffies;
return;
}
if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
DBG(4, "Longer idle timer already pending, ignoring...\n");
return;
}
last_timer = timeout;
DBG(4, "%s inactive, starting idle timer for %u ms\n",
otg_state_string(musb), jiffies_to_msecs(timeout - jiffies));
mod_timer(&otg_workaround, timeout);
}
static irqreturn_t am35x_musb_interrupt(int irq, void *hci)
{
struct musb *musb = hci;
void __iomem *reg_base = musb->ctrl_base;
unsigned long flags;
irqreturn_t ret = IRQ_NONE;
u32 epintr, usbintr, lvl_intr;
spin_lock_irqsave(&musb->lock, flags);
/* Get endpoint interrupts */
epintr = musb_readl(reg_base, EP_INTR_SRC_MASKED_REG);
if (epintr) {
musb_writel(reg_base, EP_INTR_SRC_CLEAR_REG, epintr);
musb->int_rx =
(epintr & AM35X_RX_INTR_MASK) >> AM35X_INTR_RX_SHIFT;
musb->int_tx =
(epintr & AM35X_TX_INTR_MASK) >> AM35X_INTR_TX_SHIFT;
}
/* Get usb core interrupts */
usbintr = musb_readl(reg_base, CORE_INTR_SRC_MASKED_REG);
if (!usbintr && !epintr)
goto eoi;
if (usbintr) {
musb_writel(reg_base, CORE_INTR_SRC_CLEAR_REG, usbintr);
musb->int_usb =
(usbintr & AM35X_INTR_USB_MASK) >> AM35X_INTR_USB_SHIFT;
}
/*
* DRVVBUS IRQs are the only proxy we have (a very poor one!) for
* AM35x's missing ID change IRQ. We need an ID change IRQ to
* switch appropriately between halves of the OTG state machine.
* Managing DEVCTL.SESSION per Mentor docs requires that we know its
* value but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set.
* Also, DRVVBUS pulses for SRP (but not at 5V) ...
*/
if (usbintr & (AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT)) {
int drvvbus = musb_readl(reg_base, USB_STAT_REG);
void __iomem *mregs = musb->mregs;
u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
int err;
err = is_host_enabled(musb) && (musb->int_usb &
MUSB_INTR_VBUSERROR);
if (err) {
/*
* The Mentor core doesn't debounce VBUS as needed
* to cope with device connect current spikes. This
* means it's not uncommon for bus-powered devices
* to get VBUS errors during enumeration.
*
* This is a workaround, but newer RTL from Mentor
* seems to allow a better one: "re"-starting sessions
* without waiting for VBUS to stop registering in
* devctl.
*/
musb->int_usb &= ~MUSB_INTR_VBUSERROR;
musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
WARNING("VBUS error workaround (delay coming)\n");
} else if (is_host_enabled(musb) && drvvbus) {
MUSB_HST_MODE(musb);
musb->xceiv->default_a = 1;
musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
portstate(musb->port1_status |= USB_PORT_STAT_POWER);
del_timer(&otg_workaround);
} else {
musb->is_active = 0;
MUSB_DEV_MODE(musb);
musb->xceiv->default_a = 0;
musb->xceiv->state = OTG_STATE_B_IDLE;
portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
}
/* NOTE: this must complete power-on within 100 ms. */
DBG(2, "VBUS %s (%s)%s, devctl %02x\n",
drvvbus ? "on" : "off",
otg_state_string(musb),
err ? " ERROR" : "",
devctl);
ret = IRQ_HANDLED;
}
if (musb->int_tx || musb->int_rx || musb->int_usb)
ret |= musb_interrupt(musb);
eoi:
/* EOI needs to be written for the IRQ to be re-asserted. */
if (ret == IRQ_HANDLED || epintr || usbintr) {
/* clear level interrupt */
lvl_intr = omap_ctrl_readl(AM35XX_CONTROL_LVL_INTR_CLEAR);
lvl_intr |= AM35XX_USBOTGSS_INT_CLR;
omap_ctrl_writel(lvl_intr, AM35XX_CONTROL_LVL_INTR_CLEAR);
/* write EOI */
musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
}
/* Poll for ID change */
if (is_otg_enabled(musb) && musb->xceiv->state == OTG_STATE_B_IDLE)
mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
spin_unlock_irqrestore(&musb->lock, flags);
return ret;
}
static int am35x_musb_set_mode(struct musb *musb, u8 musb_mode)
{
u32 devconf2 = omap_ctrl_readl(AM35XX_CONTROL_DEVCONF2);
devconf2 &= ~CONF2_OTGMODE;
switch (musb_mode) {
#ifdef CONFIG_USB_MUSB_HDRC_HCD
case MUSB_HOST: /* Force VBUS valid, ID = 0 */
devconf2 |= CONF2_FORCE_HOST;
break;
#endif
#ifdef CONFIG_USB_GADGET_MUSB_HDRC
case MUSB_PERIPHERAL: /* Force VBUS valid, ID = 1 */
devconf2 |= CONF2_FORCE_DEVICE;
break;
#endif
#ifdef CONFIG_USB_MUSB_OTG
case MUSB_OTG: /* Don't override the VBUS/ID comparators */
devconf2 |= CONF2_NO_OVERRIDE;
break;
#endif
default:
DBG(2, "Trying to set unsupported mode %u\n", musb_mode);
}
omap_ctrl_writel(devconf2, AM35XX_CONTROL_DEVCONF2);
return 0;
}
static int am35x_musb_init(struct musb *musb)
{
void __iomem *reg_base = musb->ctrl_base;
u32 rev, lvl_intr, sw_reset;
int status;
musb->mregs += USB_MENTOR_CORE_OFFSET;
clk_enable(musb->clock);
DBG(2, "musb->clock=%lud\n", clk_get_rate(musb->clock));
musb->phy_clock = clk_get(musb->controller, "fck");
if (IS_ERR(musb->phy_clock)) {
status = PTR_ERR(musb->phy_clock);
goto exit0;
}
clk_enable(musb->phy_clock);
DBG(2, "musb->phy_clock=%lud\n", clk_get_rate(musb->phy_clock));
/* Returns zero if e.g. not clocked */
rev = musb_readl(reg_base, USB_REVISION_REG);
if (!rev) {
status = -ENODEV;
goto exit1;
}
usb_nop_xceiv_register();
musb->xceiv = otg_get_transceiver();
if (!musb->xceiv) {
status = -ENODEV;
goto exit1;
}
if (is_host_enabled(musb))
setup_timer(&otg_workaround, otg_timer, (unsigned long) musb);
musb->board_set_vbus = am35x_musb_set_vbus;
/* Global reset */
sw_reset = omap_ctrl_readl(AM35XX_CONTROL_IP_SW_RESET);
sw_reset |= AM35XX_USBOTGSS_SW_RST;
omap_ctrl_writel(sw_reset, AM35XX_CONTROL_IP_SW_RESET);
sw_reset &= ~AM35XX_USBOTGSS_SW_RST;
omap_ctrl_writel(sw_reset, AM35XX_CONTROL_IP_SW_RESET);
/* Reset the controller */
musb_writel(reg_base, USB_CTRL_REG, AM35X_SOFT_RESET_MASK);
/* Start the on-chip PHY and its PLL. */
phy_on();
msleep(5);
musb->isr = am35x_musb_interrupt;
/* clear level interrupt */
lvl_intr = omap_ctrl_readl(AM35XX_CONTROL_LVL_INTR_CLEAR);
lvl_intr |= AM35XX_USBOTGSS_INT_CLR;
omap_ctrl_writel(lvl_intr, AM35XX_CONTROL_LVL_INTR_CLEAR);
return 0;
exit1:
clk_disable(musb->phy_clock);
clk_put(musb->phy_clock);
exit0:
clk_disable(musb->clock);
return status;
}
static int am35x_musb_exit(struct musb *musb)
{
if (is_host_enabled(musb))
del_timer_sync(&otg_workaround);
phy_off();
otg_put_transceiver(musb->xceiv);
usb_nop_xceiv_unregister();
clk_disable(musb->clock);
clk_disable(musb->phy_clock);
clk_put(musb->phy_clock);
return 0;
}
#ifdef CONFIG_PM
void musb_platform_save_context(struct musb *musb,
struct musb_context_registers *musb_context)
{
phy_off();
}
void musb_platform_restore_context(struct musb *musb,
struct musb_context_registers *musb_context)
{
phy_on();
}
#endif
/* AM35x supports only 32bit read operation */
void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
{
void __iomem *fifo = hw_ep->fifo;
u32 val;
int i;
/* Read for 32bit-aligned destination address */
if (likely((0x03 & (unsigned long) dst) == 0) && len >= 4) {
readsl(fifo, dst, len >> 2);
dst += len & ~0x03;
len &= 0x03;
}
/*
* Now read the remaining 1 to 3 byte or complete length if
* unaligned address.
*/
if (len > 4) {
for (i = 0; i < (len >> 2); i++) {
*(u32 *) dst = musb_readl(fifo, 0);
dst += 4;
}
len &= 0x03;
}
if (len > 0) {
val = musb_readl(fifo, 0);
memcpy(dst, &val, len);
}
}
const struct musb_platform_ops musb_ops = {
.init = am35x_musb_init,
.exit = am35x_musb_exit,
.enable = am35x_musb_enable,
.disable = am35x_musb_disable,
.set_mode = am35x_musb_set_mode,
.try_idle = am35x_musb_try_idle,
.set_vbus = am35x_musb_set_vbus,
};