/*
* xHCI host controller driver
*
* Copyright (C) 2008 Intel Corp.
*
* Author: Sarah Sharp
* Some code borrowed from the Linux EHCI driver.
*
* This program 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.
*
* 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 <linux/irq.h>
#include <linux/module.h>
#include "xhci.h"
#define DRIVER_AUTHOR "Sarah Sharp"
#define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"
/* TODO: copied from ehci-hcd.c - can this be refactored? */
/*
* handshake - spin reading hc until handshake completes or fails
* @ptr: address of hc register to be read
* @mask: bits to look at in result of read
* @done: value of those bits when handshake succeeds
* @usec: timeout in microseconds
*
* Returns negative errno, or zero on success
*
* Success happens when the "mask" bits have the specified value (hardware
* handshake done). There are two failure modes: "usec" have passed (major
* hardware flakeout), or the register reads as all-ones (hardware removed).
*/
static int handshake(struct xhci_hcd *xhci, void __iomem *ptr,
u32 mask, u32 done, int usec)
{
u32 result;
do {
result = xhci_readl(xhci, ptr);
if (result == ~(u32)0) /* card removed */
return -ENODEV;
result &= mask;
if (result == done)
return 0;
udelay(1);
usec--;
} while (usec > 0);
return -ETIMEDOUT;
}
/*
* Force HC into halt state.
*
* Disable any IRQs and clear the run/stop bit.
* HC will complete any current and actively pipelined transactions, and
* should halt within 16 microframes of the run/stop bit being cleared.
* Read HC Halted bit in the status register to see when the HC is finished.
* XXX: shouldn't we set HC_STATE_HALT here somewhere?
*/
int xhci_halt(struct xhci_hcd *xhci)
{
u32 halted;
u32 cmd;
u32 mask;
xhci_dbg(xhci, "// Halt the HC\n");
/* Disable all interrupts from the host controller */
mask = ~(XHCI_IRQS);
halted = xhci_readl(xhci, &xhci->op_regs->status) & STS_HALT;
if (!halted)
mask &= ~CMD_RUN;
cmd = xhci_readl(xhci, &xhci->op_regs->command);
cmd &= mask;
xhci_writel(xhci, cmd, &xhci->op_regs->command);
return handshake(xhci, &xhci->op_regs->status,
STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
}
/*
* Reset a halted HC, and set the internal HC state to HC_STATE_HALT.
*
* This resets pipelines, timers, counters, state machines, etc.
* Transactions will be terminated immediately, and operational registers
* will be set to their defaults.
*/
int xhci_reset(struct xhci_hcd *xhci)
{
u32 command;
u32 state;
state = xhci_readl(xhci, &xhci->op_regs->status);
BUG_ON((state & STS_HALT) == 0);
xhci_dbg(xhci, "// Reset the HC\n");
command = xhci_readl(xhci, &xhci->op_regs->command);
command |= CMD_RESET;
xhci_writel(xhci, command, &xhci->op_regs->command);
/* XXX: Why does EHCI set this here? Shouldn't other code do this? */
xhci_to_hcd(xhci)->state = HC_STATE_HALT;
return handshake(xhci, &xhci->op_regs->command, CMD_RESET, 0, 250 * 1000);
}
/*
* Stop the HC from processing the endpoint queues.
*/
static void xhci_quiesce(struct xhci_hcd *xhci)
{
/*
* Queues are per endpoint, so we need to disable an endpoint or slot.
*
* To disable a slot, we need to insert a disable slot command on the
* command ring and ring the doorbell. This will also free any internal
* resources associated with the slot (which might not be what we want).
*
* A Release Endpoint command sounds better - doesn't free internal HC
* memory, but removes the endpoints from the schedule and releases the
* bandwidth, disables the doorbells, and clears the endpoint enable
* flag. Usually used prior to a set interface command.
*
* TODO: Implement after command ring code is done.
*/
BUG_ON(!HC_IS_RUNNING(xhci_to_hcd(xhci)->state));
xhci_dbg(xhci, "Finished quiescing -- code not written yet\n");
}
#if 0
/* Set up MSI-X table for entry 0 (may claim other entries later) */
static int xhci_setup_msix(struct xhci_hcd *xhci)
{
int ret;
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
xhci->msix_count = 0;
/* XXX: did I do this right? ixgbe does kcalloc for more than one */
xhci->msix_entries = kmalloc(sizeof(struct msix_entry), GFP_KERNEL);
if (!xhci->msix_entries) {
xhci_err(xhci, "Failed to allocate MSI-X entries\n");
return -ENOMEM;
}
xhci->msix_entries[0].entry = 0;
ret = pci_enable_msix(pdev, xhci->msix_entries, xhci->msix_count);
if (ret) {
xhci_err(xhci, "Failed to enable MSI-X\n");
goto free_entries;
}
/*
* Pass the xhci pointer value as the request_irq "cookie".
* If more irqs are added, this will need to be unique for each one.
*/
ret = request_irq(xhci->msix_entries[0].vector, &xhci_irq, 0,
"xHCI", xhci_to_hcd(xhci));
if (ret) {
xhci_err(xhci, "Failed to allocate MSI-X interrupt\n");
goto disable_msix;
}
xhci_dbg(xhci, "Finished setting up MSI-X\n");
return 0;
disable_msix:
pci_disable_msix(pdev);
free_entries:
kfree(xhci->msix_entries);
xhci->msix_entries = NULL;
return ret;
}
/* XXX: code duplication; can xhci_setup_msix call this? */
/* Free any IRQs and disable MSI-X */
static void xhci_cleanup_msix(struct xhci_hcd *xhci)
{
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
if (!xhci->msix_entries)
return;
free_irq(xhci->msix_entries[0].vector, xhci);
pci_disable_msix(pdev);
kfree(xhci->msix_entries);
xhci->msix_entries = NULL;
xhci_dbg(xhci, "Finished cleaning up MSI-X\n");
}
#endif
/*
* Initialize memory for HCD and xHC (one-time init).
*
* Program the PAGESIZE register, initialize the device context array, create
* device contexts (?), set up a command ring segment (or two?), create event
* ring (one for now).
*/
int xhci_init(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
int retval = 0;
xhci_dbg(xhci, "xhci_init\n");
spin_lock_init(&xhci->lock);
retval = xhci_mem_init(xhci, GFP_KERNEL);
xhci_dbg(xhci, "Finished xhci_init\n");
return retval;
}
/*
* Start the HC after it was halted.
*
* This function is called by the USB core when the HC driver is added.
* Its opposite is xhci_stop().
*
* xhci_init() must be called once before this function can be called.
* Reset the HC, enable device slot contexts, program DCBAAP, and
* set command ring pointer and event ring pointer.
*
* Setup MSI-X vectors and enable interrupts.
*/
int xhci_run(struct usb_hcd *hcd)
{
u32 temp;
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
xhci_dbg(xhci, "xhci_run\n");
#if 0 /* FIXME: MSI not setup yet */
/* Do this at the very last minute */
ret = xhci_setup_msix(xhci);
if (!ret)
return ret;
return -ENOSYS;
#endif
xhci_dbg(xhci, "// Set the interrupt modulation register\n");
temp = xhci_readl(xhci, &xhci->ir_set->irq_control);
temp &= 0xffff;
temp |= (u32) 160;
xhci_writel(xhci, temp, &xhci->ir_set->irq_control);
/* Set the HCD state before we enable the irqs */
hcd->state = HC_STATE_RUNNING;
temp = xhci_readl(xhci, &xhci->op_regs->command);
temp |= (CMD_EIE);
xhci_dbg(xhci, "// Enable interrupts, cmd = 0x%x.\n",
temp);
xhci_writel(xhci, temp, &xhci->op_regs->command);
temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
xhci_dbg(xhci, "// Enabling event ring interrupter 0x%x"
" by writing 0x%x to irq_pending\n",
(unsigned int) xhci->ir_set,
(unsigned int) ER_IRQ_ENABLE(temp));
xhci_writel(xhci, ER_IRQ_ENABLE(temp),
&xhci->ir_set->irq_pending);
xhci_print_ir_set(xhci, xhci->ir_set, 0);
xhci_dbg(xhci, "Command ring memory map follows:\n");
xhci_debug_ring(xhci, xhci->cmd_ring);
xhci_dbg(xhci, "ERST memory map follows:\n");
xhci_dbg_erst(xhci, &xhci->erst);
temp = xhci_readl(xhci, &xhci->op_regs->command);
temp |= (CMD_RUN);
xhci_dbg(xhci, "// Turn on HC, cmd = 0x%x.\n",
temp);
xhci_writel(xhci, temp, &xhci->op_regs->command);
/* Flush PCI posted writes */
temp = xhci_readl(xhci, &xhci->op_regs->command);
xhci_dbg(xhci, "// @%x = 0x%x\n",
(unsigned int) &xhci->op_regs->command, temp);
xhci_dbg(xhci, "Finished xhci_run\n");
return 0;
}
/*
* Stop xHCI driver.
*
* This function is called by the USB core when the HC driver is removed.
* Its opposite is xhci_run().
*
* Disable device contexts, disable IRQs, and quiesce the HC.
* Reset the HC, finish any completed transactions, and cleanup memory.
*/
void xhci_stop(struct usb_hcd *hcd)
{
u32 temp;
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
spin_lock_irq(&xhci->lock);
if (HC_IS_RUNNING(hcd->state))
xhci_quiesce(xhci);
xhci_halt(xhci);
xhci_reset(xhci);
spin_unlock_irq(&xhci->lock);
#if 0 /* No MSI yet */
xhci_cleanup_msix(xhci);
#endif
xhci_dbg(xhci, "// Disabling event ring interrupts\n");
temp = xhci_readl(xhci, &xhci->op_regs->status);
xhci_writel(xhci, temp & ~STS_EINT, &xhci->op_regs->status);
temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
xhci_writel(xhci, ER_IRQ_DISABLE(temp),
&xhci->ir_set->irq_pending);
xhci_print_ir_set(xhci, xhci->ir_set, 0);
xhci_dbg(xhci, "cleaning up memory\n");
xhci_mem_cleanup(xhci);
xhci_dbg(xhci, "xhci_stop completed - status = %x\n",
xhci_readl(xhci, &xhci->op_regs->status));
}
/*
* Shutdown HC (not bus-specific)
*
* This is called when the machine is rebooting or halting. We assume that the
* machine will be powered off, and the HC's internal state will be reset.
* Don't bother to free memory.
*/
void xhci_shutdown(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
spin_lock_irq(&xhci->lock);
xhci_halt(xhci);
spin_unlock_irq(&xhci->lock);
#if 0
xhci_cleanup_msix(xhci);
#endif
xhci_dbg(xhci, "xhci_shutdown completed - status = %x\n",
xhci_readl(xhci, &xhci->op_regs->status));
}
int xhci_get_frame(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
/* EHCI mods by the periodic size. Why? */
return xhci_readl(xhci, &xhci->run_regs->microframe_index) >> 3;
}
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_LICENSE("GPL");
static int __init xhci_hcd_init(void)
{
#ifdef CONFIG_PCI
int retval = 0;
retval = xhci_register_pci();
if (retval < 0) {
printk(KERN_DEBUG "Problem registering PCI driver.");
return retval;
}
#endif
return 0;
}
module_init(xhci_hcd_init);
static void __exit xhci_hcd_cleanup(void)
{
#ifdef CONFIG_PCI
xhci_unregister_pci();
#endif
}
module_exit(xhci_hcd_cleanup);
