3 files changed, 187 insertions, 17 deletions

diff --git a/drivers/hwmon/hp_accel.c b/drivers/hwmon/hp_accel.c
index abf4dfc8ec22..dcefe1d2adbd 100644
--- a/drivers/hwmon/hp_accel.c
+++ b/drivers/hwmon/hp_accel.c
@@ -213,6 +213,30 @@ static struct delayed_led_classdev hpled_led = {
         .set_brightness = hpled_set,
 };
 
+static acpi_status
+lis3lv02d_get_resource(struct acpi_resource *resource, void *context)
+{
+        if (resource->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
+                struct acpi_resource_extended_irq *irq;
+                u32 *device_irq = context;
+
+                irq = &resource->data.extended_irq;
+                *device_irq = irq->interrupts[0];
+        }
+
+        return AE_OK;
+}
+
+static void lis3lv02d_enum_resources(struct acpi_device *device)
+{
+        acpi_status status;
+
+        status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+                                        lis3lv02d_get_resource, &adev.irq);
+        if (ACPI_FAILURE(status))
+                printk(KERN_DEBUG DRIVER_NAME ": Error getting resources\n");
+}
+
 static int lis3lv02d_add(struct acpi_device *device)
 {
         u8 val;
@@ -247,6 +271,9 @@ static int lis3lv02d_add(struct acpi_device *device)
         if (ret)
                 return ret;
 
+        /* obtain IRQ number of our device from ACPI */
+        lis3lv02d_enum_resources(adev.device);
+
         ret = lis3lv02d_init_device(&adev);
         if (ret) {
                 flush_work(&hpled_led.work);
diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index 219d2d0d5a62..3afa3afc77f3 100644
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2007-2008 Yan Burman
  *  Copyright (C) 2008 Eric Piel
- *  Copyright (C) 2008 Pavel Machek
+ *  Copyright (C) 2008-2009 Pavel Machek
  *
  *  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
@@ -35,6 +35,7 @@
 #include <linux/poll.h>
 #include <linux/freezer.h>
 #include <linux/uaccess.h>
+#include <linux/miscdevice.h>
 #include <acpi/acpi_drivers.h>
 #include <asm/atomic.h>
 #include "lis3lv02d.h"
@@ -55,7 +56,10 @@
 /* Maximum value our axis may get for the input device (signed 12 bits) */
 #define MDPS_MAX_VAL 2048
 
-struct acpi_lis3lv02d adev;
+struct acpi_lis3lv02d adev = {
+        .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(adev.misc_wait),
+};
+
 EXPORT_SYMBOL_GPL(adev);
 
 static int lis3lv02d_add_fs(struct acpi_device *device);
@@ -110,26 +114,13 @@ static void lis3lv02d_get_xyz(acpi_handle handle, int *x, int *y, int *z)
 void lis3lv02d_poweroff(acpi_handle handle)
 {
         adev.is_on = 0;
-        /* disable X,Y,Z axis and power down */
-        adev.write(handle, CTRL_REG1, 0x00);
 }
 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 
 void lis3lv02d_poweron(acpi_handle handle)
 {
-        u8 val;
-
         adev.is_on = 1;
         adev.init(handle);
-        adev.write(handle, FF_WU_CFG, 0);
-        /*
-         * BDU: LSB and MSB values are not updated until both have been read.
-         *      So the value read will always be correct.
-         * IEN: Interrupt for free-fall and DD, not for data-ready.
-         */
-        adev.read(handle, CTRL_REG2, &val);
-        val |= CTRL2_BDU | CTRL2_IEN;
-        adev.write(handle, CTRL_REG2, val);
 }
 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 
@@ -162,6 +153,140 @@ static void lis3lv02d_decrease_use(struct acpi_lis3lv02d *dev)
         mutex_unlock(&dev->lock);
 }
 
+static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
+{
+        /*
+         * Be careful: on some HP laptops the bios force DD when on battery and
+         * the lid is closed. This leads to interrupts as soon as a little move
+         * is done.
+         */
+        atomic_inc(&adev.count);
+
+        wake_up_interruptible(&adev.misc_wait);
+        kill_fasync(&adev.async_queue, SIGIO, POLL_IN);
+        return IRQ_HANDLED;
+}
+
+static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
+{
+        int ret;
+
+        if (test_and_set_bit(0, &adev.misc_opened))
+                return -EBUSY; /* already open */
+
+        atomic_set(&adev.count, 0);
+
+        /*
+         * The sensor can generate interrupts for free-fall and direction
+         * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
+         * the things simple and _fast_ we activate it only for free-fall, so
+         * no need to read register (very slow with ACPI). For the same reason,
+         * we forbid shared interrupts.
+         *
+         * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
+         * io-apic is not configurable (and generates a warning) but I keep it
+         * in case of support for other hardware.
+         */
+        ret = request_irq(adev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
+                          DRIVER_NAME, &adev);
+
+        if (ret) {
+                clear_bit(0, &adev.misc_opened);
+                printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", adev.irq);
+                return -EBUSY;
+        }
+        lis3lv02d_increase_use(&adev);
+        printk("lis3: registered interrupt %d\n", adev.irq);
+        return 0;
+}
+
+static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
+{
+        fasync_helper(-1, file, 0, &adev.async_queue);
+        lis3lv02d_decrease_use(&adev);
+        free_irq(adev.irq, &adev);
+        clear_bit(0, &adev.misc_opened); /* release the device */
+        return 0;
+}
+
+static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
+                                size_t count, loff_t *pos)
+{
+        DECLARE_WAITQUEUE(wait, current);
+        u32 data;
+        unsigned char byte_data;
+        ssize_t retval = 1;
+
+        if (count < 1)
+                return -EINVAL;
+
+        add_wait_queue(&adev.misc_wait, &wait);
+        while (true) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                data = atomic_xchg(&adev.count, 0);
+                if (data)
+                        break;
+
+                if (file->f_flags & O_NONBLOCK) {
+                        retval = -EAGAIN;
+                        goto out;
+                }
+
+                if (signal_pending(current)) {
+                        retval = -ERESTARTSYS;
+                        goto out;
+                }
+
+                schedule();
+        }
+
+        if (data < 255)
+                byte_data = data;
+        else
+                byte_data = 255;
+
+        /* make sure we are not going into copy_to_user() with
+         * TASK_INTERRUPTIBLE state */
+        set_current_state(TASK_RUNNING);
+        if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
+                retval = -EFAULT;
+
+out:
+        __set_current_state(TASK_RUNNING);
+        remove_wait_queue(&adev.misc_wait, &wait);
+
+        return retval;
+}
+
+static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
+{
+        poll_wait(file, &adev.misc_wait, wait);
+        if (atomic_read(&adev.count))
+                return POLLIN | POLLRDNORM;
+        return 0;
+}
+
+static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
+{
+        return fasync_helper(fd, file, on, &adev.async_queue);
+}
+
+static const struct file_operations lis3lv02d_misc_fops = {
+        .owner   = THIS_MODULE,
+        .llseek  = no_llseek,
+        .read    = lis3lv02d_misc_read,
+        .open    = lis3lv02d_misc_open,
+        .release = lis3lv02d_misc_release,
+        .poll    = lis3lv02d_misc_poll,
+        .fasync  = lis3lv02d_misc_fasync,
+};
+
+static struct miscdevice lis3lv02d_misc_device = {
+        .minor   = MISC_DYNAMIC_MINOR,
+        .name    = "freefall",
+        .fops    = &lis3lv02d_misc_fops,
+};
+
 /**
  * lis3lv02d_joystick_kthread - Kthread polling function
  * @data: unused - here to conform to threadfn prototype
@@ -203,7 +328,6 @@ static void lis3lv02d_joystick_close(struct input_dev *input)
         lis3lv02d_decrease_use(&adev);
 }
 
-
 static inline void lis3lv02d_calibrate_joystick(void)
 {
         lis3lv02d_get_xyz(adev.device->handle, &adev.xcalib, &adev.ycalib, &adev.zcalib);
@@ -250,6 +374,7 @@ void lis3lv02d_joystick_disable(void)
         if (!adev.idev)
                 return;
 
+        misc_deregister(&lis3lv02d_misc_device);
         input_unregister_device(adev.idev);
         adev.idev = NULL;
 }
@@ -268,6 +393,19 @@ int lis3lv02d_init_device(struct acpi_lis3lv02d *dev)
         if (lis3lv02d_joystick_enable())
                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 
+        printk("lis3_init_device: irq %d\n", dev->irq);
+
+        /* if we did not get an IRQ from ACPI - we have nothing more to do */
+        if (!dev->irq) {
+                printk(KERN_ERR DRIVER_NAME
+                        ": No IRQ in ACPI. Disabling /dev/freefall\n");
+                goto out;
+        }
+
+        printk("lis3: registering device\n");
+        if (misc_register(&lis3lv02d_misc_device))
+                printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
+out:
         lis3lv02d_decrease_use(dev);
         return 0;
 }
@@ -351,6 +489,6 @@ int lis3lv02d_remove_fs(void)
 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 
 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
-MODULE_AUTHOR("Yan Burman and Eric Piel");
+MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 MODULE_LICENSE("GPL");
 
diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index 223f1c0763bb..2e7597c42d80 100644
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -170,6 +170,11 @@ struct acpi_lis3lv02d {
         unsigned char           is_on;     /* whether the device is on or off */
         unsigned char           usage;     /* usage counter */
         struct axis_conversion  ac;        /* hw -> logical axis */
+
+        u32                     irq;       /* IRQ number */
+        struct fasync_struct    *async_queue; /* queue for the misc device */
+        wait_queue_head_t       misc_wait; /* Wait queue for the misc device */
+        unsigned long           misc_opened; /* bit0: whether the device is open */
 };
 
 int lis3lv02d_init_device(struct acpi_lis3lv02d *dev);