android_kernel_xiaomi_sm8350/drivers/input/serio/sa1111ps2.c
Ben Nizette e4bd3e591c Input: sa1111ps2 - use disable_irq_nosync() in irq handlers
disable_irq() waits for all running handlers to complete before
returning.  As such, if it's used to disable an interrupt from
that interrupt's handler it will deadlock.  This replaces the
dangerous instances with the _nosync() variant which doesn't have
this problem.

Signed-off-by: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-04-17 20:41:54 -07:00

357 lines
7.6 KiB
C

/*
* linux/drivers/input/serio/sa1111ps2.c
*
* Copyright (C) 2002 Russell King
*
* 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/hardware/sa1111.h>
struct ps2if {
struct serio *io;
struct sa1111_dev *dev;
void __iomem *base;
unsigned int open;
spinlock_t lock;
unsigned int head;
unsigned int tail;
unsigned char buf[4];
};
/*
* Read all bytes waiting in the PS2 port. There should be
* at the most one, but we loop for safety. If there was a
* framing error, we have to manually clear the status.
*/
static irqreturn_t ps2_rxint(int irq, void *dev_id)
{
struct ps2if *ps2if = dev_id;
unsigned int scancode, flag, status;
status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
while (status & PS2STAT_RXF) {
if (status & PS2STAT_STP)
sa1111_writel(PS2STAT_STP, ps2if->base + SA1111_PS2STAT);
flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
(status & PS2STAT_RXP ? 0 : SERIO_PARITY);
scancode = sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff;
if (hweight8(scancode) & 1)
flag ^= SERIO_PARITY;
serio_interrupt(ps2if->io, scancode, flag);
status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
}
return IRQ_HANDLED;
}
/*
* Completion of ps2 write
*/
static irqreturn_t ps2_txint(int irq, void *dev_id)
{
struct ps2if *ps2if = dev_id;
unsigned int status;
spin_lock(&ps2if->lock);
status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
if (ps2if->head == ps2if->tail) {
disable_irq_nosync(irq);
/* done */
} else if (status & PS2STAT_TXE) {
sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + SA1111_PS2DATA);
ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
}
spin_unlock(&ps2if->lock);
return IRQ_HANDLED;
}
/*
* Write a byte to the PS2 port. We have to wait for the
* port to indicate that the transmitter is empty.
*/
static int ps2_write(struct serio *io, unsigned char val)
{
struct ps2if *ps2if = io->port_data;
unsigned long flags;
unsigned int head;
spin_lock_irqsave(&ps2if->lock, flags);
/*
* If the TX register is empty, we can go straight out.
*/
if (sa1111_readl(ps2if->base + SA1111_PS2STAT) & PS2STAT_TXE) {
sa1111_writel(val, ps2if->base + SA1111_PS2DATA);
} else {
if (ps2if->head == ps2if->tail)
enable_irq(ps2if->dev->irq[1]);
head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
if (head != ps2if->tail) {
ps2if->buf[ps2if->head] = val;
ps2if->head = head;
}
}
spin_unlock_irqrestore(&ps2if->lock, flags);
return 0;
}
static int ps2_open(struct serio *io)
{
struct ps2if *ps2if = io->port_data;
int ret;
sa1111_enable_device(ps2if->dev);
ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
SA1111_DRIVER_NAME(ps2if->dev), ps2if);
if (ret) {
printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
ps2if->dev->irq[0], ret);
return ret;
}
ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
SA1111_DRIVER_NAME(ps2if->dev), ps2if);
if (ret) {
printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
ps2if->dev->irq[1], ret);
free_irq(ps2if->dev->irq[0], ps2if);
return ret;
}
ps2if->open = 1;
enable_irq_wake(ps2if->dev->irq[0]);
sa1111_writel(PS2CR_ENA, ps2if->base + SA1111_PS2CR);
return 0;
}
static void ps2_close(struct serio *io)
{
struct ps2if *ps2if = io->port_data;
sa1111_writel(0, ps2if->base + SA1111_PS2CR);
disable_irq_wake(ps2if->dev->irq[0]);
ps2if->open = 0;
free_irq(ps2if->dev->irq[1], ps2if);
free_irq(ps2if->dev->irq[0], ps2if);
sa1111_disable_device(ps2if->dev);
}
/*
* Clear the input buffer.
*/
static void __devinit ps2_clear_input(struct ps2if *ps2if)
{
int maxread = 100;
while (maxread--) {
if ((sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff) == 0xff)
break;
}
}
static inline unsigned int
ps2_test_one(struct ps2if *ps2if, unsigned int mask)
{
unsigned int val;
sa1111_writel(PS2CR_ENA | mask, ps2if->base + SA1111_PS2CR);
udelay(2);
val = sa1111_readl(ps2if->base + SA1111_PS2STAT);
return val & (PS2STAT_KBC | PS2STAT_KBD);
}
/*
* Test the keyboard interface. We basically check to make sure that
* we can drive each line to the keyboard independently of each other.
*/
static int __init ps2_test(struct ps2if *ps2if)
{
unsigned int stat;
int ret = 0;
stat = ps2_test_one(ps2if, PS2CR_FKC);
if (stat != PS2STAT_KBD) {
printk("PS/2 interface test failed[1]: %02x\n", stat);
ret = -ENODEV;
}
stat = ps2_test_one(ps2if, 0);
if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
printk("PS/2 interface test failed[2]: %02x\n", stat);
ret = -ENODEV;
}
stat = ps2_test_one(ps2if, PS2CR_FKD);
if (stat != PS2STAT_KBC) {
printk("PS/2 interface test failed[3]: %02x\n", stat);
ret = -ENODEV;
}
sa1111_writel(0, ps2if->base + SA1111_PS2CR);
return ret;
}
/*
* Add one device to this driver.
*/
static int __devinit ps2_probe(struct sa1111_dev *dev)
{
struct ps2if *ps2if;
struct serio *serio;
int ret;
ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
if (!ps2if || !serio) {
ret = -ENOMEM;
goto free;
}
serio->id.type = SERIO_8042;
serio->write = ps2_write;
serio->open = ps2_open;
serio->close = ps2_close;
strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
serio->port_data = ps2if;
serio->dev.parent = &dev->dev;
ps2if->io = serio;
ps2if->dev = dev;
sa1111_set_drvdata(dev, ps2if);
spin_lock_init(&ps2if->lock);
/*
* Request the physical region for this PS2 port.
*/
if (!request_mem_region(dev->res.start,
dev->res.end - dev->res.start + 1,
SA1111_DRIVER_NAME(dev))) {
ret = -EBUSY;
goto free;
}
/*
* Our parent device has already mapped the region.
*/
ps2if->base = dev->mapbase;
sa1111_enable_device(ps2if->dev);
/* Incoming clock is 8MHz */
sa1111_writel(0, ps2if->base + SA1111_PS2CLKDIV);
sa1111_writel(127, ps2if->base + SA1111_PS2PRECNT);
/*
* Flush any pending input.
*/
ps2_clear_input(ps2if);
/*
* Test the keyboard interface.
*/
ret = ps2_test(ps2if);
if (ret)
goto out;
/*
* Flush any pending input.
*/
ps2_clear_input(ps2if);
sa1111_disable_device(ps2if->dev);
serio_register_port(ps2if->io);
return 0;
out:
sa1111_disable_device(ps2if->dev);
release_mem_region(dev->res.start,
dev->res.end - dev->res.start + 1);
free:
sa1111_set_drvdata(dev, NULL);
kfree(ps2if);
kfree(serio);
return ret;
}
/*
* Remove one device from this driver.
*/
static int ps2_remove(struct sa1111_dev *dev)
{
struct ps2if *ps2if = sa1111_get_drvdata(dev);
serio_unregister_port(ps2if->io);
release_mem_region(dev->res.start,
dev->res.end - dev->res.start + 1);
sa1111_set_drvdata(dev, NULL);
kfree(ps2if);
return 0;
}
/*
* Our device driver structure
*/
static struct sa1111_driver ps2_driver = {
.drv = {
.name = "sa1111-ps2",
},
.devid = SA1111_DEVID_PS2,
.probe = ps2_probe,
.remove = ps2_remove,
};
static int __init ps2_init(void)
{
return sa1111_driver_register(&ps2_driver);
}
static void __exit ps2_exit(void)
{
sa1111_driver_unregister(&ps2_driver);
}
module_init(ps2_init);
module_exit(ps2_exit);
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("SA1111 PS2 controller driver");
MODULE_LICENSE("GPL");