/*
* Copyright (C) 2005-2006 by Texas Instruments
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <mach/hardware.h>
#include <mach/memory.h>
#include <mach/gpio.h>
#include <asm/mach-types.h>
#include "musb_core.h"
#ifdef CONFIG_MACH_DAVINCI_EVM
#define GPIO_nVBUS_DRV 87
#endif
#include "davinci.h"
#include "cppi_dma.h"
/* REVISIT (PM) we should be able to keep the PHY in low power mode most
* of the time (24 MHZ oscillator and PLL off, etc) by setting POWER.D0
* and, when in host mode, autosuspending idle root ports... PHYPLLON
* (overriding SUSPENDM?) then likely needs to stay off.
*/
static inline void phy_on(void)
{
/* start the on-chip PHY and its PLL */
__raw_writel(USBPHY_SESNDEN | USBPHY_VBDTCTEN | USBPHY_PHYPLLON,
(void __force __iomem *) IO_ADDRESS(USBPHY_CTL_PADDR));
while ((__raw_readl((void __force __iomem *)
IO_ADDRESS(USBPHY_CTL_PADDR))
& USBPHY_PHYCLKGD) == 0)
cpu_relax();
}
static inline void phy_off(void)
{
/* powerdown the on-chip PHY and its oscillator */
__raw_writel(USBPHY_OSCPDWN | USBPHY_PHYPDWN, (void __force __iomem *)
IO_ADDRESS(USBPHY_CTL_PADDR));
}
static int dma_off = 1;
void musb_platform_enable(struct musb *musb)
{
u32 tmp, old, val;
/* workaround: setup irqs through both register sets */
tmp = (musb->epmask & DAVINCI_USB_TX_ENDPTS_MASK)
<< DAVINCI_USB_TXINT_SHIFT;
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
old = tmp;
tmp = (musb->epmask & (0xfffe & DAVINCI_USB_RX_ENDPTS_MASK))
<< DAVINCI_USB_RXINT_SHIFT;
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
tmp |= old;
val = ~MUSB_INTR_SOF;
tmp |= ((val & 0x01ff) << DAVINCI_USB_USBINT_SHIFT);
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
if (is_dma_capable() && !dma_off)
printk(KERN_WARNING "%s %s: dma not reactivated\n",
__FILE__, __func__);
else
dma_off = 0;
/* force a DRVVBUS irq so we can start polling for ID change */
if (is_otg_enabled(musb))
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_SET_REG,
DAVINCI_INTR_DRVVBUS << DAVINCI_USB_USBINT_SHIFT);
}
/*
* Disable the HDRC and flush interrupts
*/
void musb_platform_disable(struct musb *musb)
{
/* because we don't set CTRLR.UINT, "important" to:
* - not read/write INTRUSB/INTRUSBE
* - (except during initial setup, as workaround)
* - use INTSETR/INTCLRR instead
*/
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_CLR_REG,
DAVINCI_USB_USBINT_MASK
| DAVINCI_USB_TXINT_MASK
| DAVINCI_USB_RXINT_MASK);
musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
musb_writel(musb->ctrl_base, DAVINCI_USB_EOI_REG, 0);
if (is_dma_capable() && !dma_off)
WARNING("dma still active\n");
}
/* REVISIT it's not clear whether DaVinci can support full OTG. */
static int vbus_state = -1;
#ifdef CONFIG_USB_MUSB_HDRC_HCD
#define portstate(stmt) stmt
#else
#define portstate(stmt)
#endif
/* VBUS SWITCHING IS BOARD-SPECIFIC */
#ifdef CONFIG_MACH_DAVINCI_EVM
/* I2C operations are always synchronous, and require a task context.
* With unloaded systems, using the shared workqueue seems to suffice
* to satisfy the 100msec A_WAIT_VRISE timeout...
*/
static void evm_deferred_drvvbus(struct work_struct *ignored)
{
gpio_set_value_cansleep(GPIO_nVBUS_DRV, vbus_state);
vbus_state = !vbus_state;
}
static DECLARE_WORK(evm_vbus_work, evm_deferred_drvvbus);
#endif /* EVM */
static void davinci_source_power(struct musb *musb, int is_on, int immediate)
{
if (is_on)
is_on = 1;
if (vbus_state == is_on)
return;
vbus_state = !is_on; /* 0/1 vs "-1 == unknown/init" */
#ifdef CONFIG_MACH_DAVINCI_EVM
if (machine_is_davinci_evm()) {
if (immediate)
gpio_set_value_cansleep(GPIO_nVBUS_DRV, vbus_state);
else
schedule_work(&evm_vbus_work);
}
#endif
if (immediate)
vbus_state = is_on;
}
static void davinci_set_vbus(struct musb *musb, int is_on)
{
WARN_ON(is_on && is_peripheral_active(musb));
davinci_source_power(musb, is_on, 0);
}
#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 DaVinci'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_VFALL:
/* Wait till VBUS falls below SessionEnd (~0.2V); the 1.3 RTL
* seems to mis-handle session "start" otherwise (or in our
* case "recover"), in routine "VBUS was valid by the time
* VBUSERR got reported during enumeration" cases.
*/
if (devctl & MUSB_DEVCTL_VBUS) {
mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
break;
}
musb->xceiv.state = OTG_STATE_A_WAIT_VRISE;
musb_writel(musb->ctrl_base, DAVINCI_USB_INT_SET_REG,
MUSB_INTR_VBUSERROR << DAVINCI_USB_USBINT_SHIFT);
break;
case OTG_STATE_B_IDLE:
if (!is_peripheral_enabled(musb))
break;
/* There's no ID-changed IRQ, so we have no good way to tell
* when to switch to the A-Default state machine (by setting
* the DEVCTL.SESSION flag).
*
* Workaround: whenever we're in B_IDLE, try setting the
* session flag every few seconds. If it works, ID was
* grounded and we're now in the A-Default state machine.
*
* NOTE setting the session flag is _supposed_ to trigger
* SRP, but clearly it doesn't.
*/
musb_writeb(mregs, MUSB_DEVCTL,
devctl | MUSB_DEVCTL_SESSION);
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 irqreturn_t davinci_interrupt(int irq, void *__hci)
{
unsigned long flags;
irqreturn_t retval = IRQ_NONE;
struct musb *musb = __hci;
void __iomem *tibase = musb->ctrl_base;
u32 tmp;
spin_lock_irqsave(&musb->lock, flags);
/* NOTE: DaVinci shadows the Mentor IRQs. Don't manage them through
* the Mentor registers (except for setup), use the TI ones and EOI.
*
* Docs describe irq "vector" registers asociated with the CPPI and
* USB EOI registers. These hold a bitmask corresponding to the
* current IRQ, not an irq handler address. Would using those bits
* resolve some of the races observed in this dispatch code??
*/
/* CPPI interrupts share the same IRQ line, but have their own
* mask, state, "vector", and EOI registers.
*/
if (is_cppi_enabled()) {
u32 cppi_tx = musb_readl(tibase, DAVINCI_TXCPPI_MASKED_REG);
u32 cppi_rx = musb_readl(tibase, DAVINCI_RXCPPI_MASKED_REG);
if (cppi_tx || cppi_rx) {
DBG(4, "CPPI IRQ t%x r%x\n", cppi_tx, cppi_rx);
cppi_completion(musb, cppi_rx, cppi_tx);
retval = IRQ_HANDLED;
}
}
/* ack and handle non-CPPI interrupts */
tmp = musb_readl(tibase, DAVINCI_USB_INT_SRC_MASKED_REG);
musb_writel(tibase, DAVINCI_USB_INT_SRC_CLR_REG, tmp);
DBG(4, "IRQ %08x\n", tmp);
musb->int_rx = (tmp & DAVINCI_USB_RXINT_MASK)
>> DAVINCI_USB_RXINT_SHIFT;
musb->int_tx = (tmp & DAVINCI_USB_TXINT_MASK)
>> DAVINCI_USB_TXINT_SHIFT;
musb->int_usb = (tmp & DAVINCI_USB_USBINT_MASK)
>> DAVINCI_USB_USBINT_SHIFT;
/* DRVVBUS irqs are the only proxy we have (a very poor one!) for
* DaVinci'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 we know its
* value, but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set.
* Also, DRVVBUS pulses for SRP (but not at 5V) ...
*/
if (tmp & (DAVINCI_INTR_DRVVBUS << DAVINCI_USB_USBINT_SHIFT)) {
int drvvbus = musb_readl(tibase, DAVINCI_USB_STAT_REG);
void __iomem *mregs = musb->mregs;
u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
int err = musb->int_usb & MUSB_INTR_VBUSERROR;
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 (on EVM, a **long** time) 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->is_active = 1;
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 poweron within 100 msec */
davinci_source_power(musb, drvvbus, 0);
DBG(2, "VBUS %s (%s)%s, devctl %02x\n",
drvvbus ? "on" : "off",
otg_state_string(musb),
err ? " ERROR" : "",
devctl);
retval = IRQ_HANDLED;
}
if (musb->int_tx || musb->int_rx || musb->int_usb)
retval |= musb_interrupt(musb);
/* irq stays asserted until EOI is written */
musb_writel(tibase, DAVINCI_USB_EOI_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);
/* REVISIT we sometimes get unhandled IRQs
* (e.g. ep0). not clear why...
*/
if (retval != IRQ_HANDLED)
DBG(5, "unhandled? %08x\n", tmp);
return IRQ_HANDLED;
}
int musb_platform_set_mode(struct musb *musb, u8 mode)
{
/* EVM can't do this (right?) */
return -EIO;
}
int __init musb_platform_init(struct musb *musb)
{
void __iomem *tibase = musb->ctrl_base;
u32 revision;
musb->mregs += DAVINCI_BASE_OFFSET;
clk_enable(musb->clock);
/* returns zero if e.g. not clocked */
revision = musb_readl(tibase, DAVINCI_USB_VERSION_REG);
if (revision == 0)
return -ENODEV;
if (is_host_enabled(musb))
setup_timer(&otg_workaround, otg_timer, (unsigned long) musb);
musb->board_set_vbus = davinci_set_vbus;
davinci_source_power(musb, 0, 1);
/* reset the controller */
musb_writel(tibase, DAVINCI_USB_CTRL_REG, 0x1);
/* start the on-chip PHY and its PLL */
phy_on();
msleep(5);
/* NOTE: irqs are in mixed mode, not bypass to pure-musb */
pr_debug("DaVinci OTG revision %08x phy %03x control %02x\n",
revision, __raw_readl((void __force __iomem *)
IO_ADDRESS(USBPHY_CTL_PADDR)),
musb_readb(tibase, DAVINCI_USB_CTRL_REG));
musb->isr = davinci_interrupt;
return 0;
}
int musb_platform_exit(struct musb *musb)
{
if (is_host_enabled(musb))
del_timer_sync(&otg_workaround);
davinci_source_power(musb, 0 /*off*/, 1);
/* delay, to avoid problems with module reload */
if (is_host_enabled(musb) && musb->xceiv.default_a) {
int maxdelay = 30;
u8 devctl, warn = 0;
/* if there's no peripheral connected, this can take a
* long time to fall, especially on EVM with huge C133.
*/
do {
devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
if (!(devctl & MUSB_DEVCTL_VBUS))
break;
if ((devctl & MUSB_DEVCTL_VBUS) != warn) {
warn = devctl & MUSB_DEVCTL_VBUS;
DBG(1, "VBUS %d\n",
warn >> MUSB_DEVCTL_VBUS_SHIFT);
}
msleep(1000);
maxdelay--;
} while (maxdelay > 0);
/* in OTG mode, another host might be connected */
if (devctl & MUSB_DEVCTL_VBUS)
DBG(1, "VBUS off timeout (devctl %02x)\n", devctl);
}
phy_off();
clk_disable(musb->clock);
return 0;
}
