/*
* hdaps_readb_one - reads a byte from a single I/O port, placing the value in
* the given pointer. Returns zero on success or a negative error on failure.
* Can sleep.
*/
static int hdaps_readb_one(unsigned int port, u8 *val)
{
int ret;
down(&hdaps_sem);
/* do a sync refresh -- we need to be sure that we read fresh data */
ret = __device_refresh_sync();
if (ret)
goto out;
*val = inb(port);
__device_complete();
out:
up(&hdaps_sem);
return ret;
}
static int hdaps_readb_one(unsigned int port, u8 *val)
{
int ret;
mutex_lock(&hdaps_mtx);
ret = __device_refresh_sync();
if (ret)
goto out;
*val = inb(port);
__device_complete();
out:
mutex_unlock(&hdaps_mtx);
return ret;
}
/* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
int *x, int *y)
{
/* do a sync refresh -- we need to be sure that we read fresh data */
if (__device_refresh_sync())
return -EIO;
*y = inw(port2);
*x = inw(port1);
km_activity = inb(HDAPS_PORT_KMACT);
__device_complete();
/* if hdaps_invert is set, negate the two values */
if (hdaps_invert) {
*x = -*x;
*y = -*y;
}
return 0;
}
static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
int *x, int *y)
{
if (__device_refresh_sync())
return -EIO;
*y = inw(port2);
*x = inw(port1);
km_activity = inb(HDAPS_PORT_KMACT);
__device_complete();
if (hdaps_invert & HDAPS_X_AXIS)
*x = -*x;
if (hdaps_invert & HDAPS_Y_AXIS)
*y = -*y;
return 0;
}
/*
* hdaps_device_init - initialize the accelerometer. Returns zero on success
* and negative error code on failure. Can sleep.
*/
static int hdaps_device_init(void)
{
int total, ret = -ENXIO;
down(&hdaps_sem);
outb(0x13, 0x1610);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
/*
* Most ThinkPads return 0x01.
*
* Others--namely the R50p, T41p, and T42p--return 0x03. These laptops
* have "inverted" axises.
*
* The 0x02 value occurs when the chip has been previously initialized.
*/
if (__check_latch(0x1611, 0x03) &&
__check_latch(0x1611, 0x02) &&
__check_latch(0x1611, 0x01))
goto out;
printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
__get_latch(0x1611));
outb(0x17, 0x1610);
outb(0x81, 0x1611);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
if (__wait_latch(0x1611, 0x00))
goto out;
if (__wait_latch(0x1612, 0x60))
goto out;
if (__wait_latch(0x1613, 0x00))
goto out;
outb(0x14, 0x1610);
outb(0x01, 0x1611);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
outb(0x10, 0x1610);
outb(0xc8, 0x1611);
outb(0x00, 0x1612);
outb(0x02, 0x1613);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
if (__device_refresh_sync())
goto out;
if (__wait_latch(0x1611, 0x00))
goto out;
/* we have done our dance, now let's wait for the applause */
for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
int x, y;
/* a read of the device helps push it into action */
__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
if (!__wait_latch(0x1611, 0x02)) {
ret = 0;
break;
}
msleep(INIT_WAIT_MSECS);
}
out:
up(&hdaps_sem);
return ret;
}
static int hdaps_device_init(void)
{
int total, ret = -ENXIO;
mutex_lock(&hdaps_mtx);
outb(0x13, 0x1610);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
if (__check_latch(0x1611, 0x03) &&
__check_latch(0x1611, 0x02) &&
__check_latch(0x1611, 0x01))
goto out;
printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
__get_latch(0x1611));
outb(0x17, 0x1610);
outb(0x81, 0x1611);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
if (__wait_latch(0x1611, 0x00))
goto out;
if (__wait_latch(0x1612, 0x60))
goto out;
if (__wait_latch(0x1613, 0x00))
goto out;
outb(0x14, 0x1610);
outb(0x01, 0x1611);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
outb(0x10, 0x1610);
outb(0xc8, 0x1611);
outb(0x00, 0x1612);
outb(0x02, 0x1613);
outb(0x01, 0x161f);
if (__wait_latch(0x161f, 0x00))
goto out;
if (__device_refresh_sync())
goto out;
if (__wait_latch(0x1611, 0x00))
goto out;
for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
int x, y;
__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
if (!__wait_latch(0x1611, 0x02)) {
ret = 0;
break;
}
msleep(INIT_WAIT_MSECS);
}
out:
mutex_unlock(&hdaps_mtx);
return ret;
}