--- /dev/null
+/*
+ * dell-smo8800.c - Dell Latitude ACPI SMO8800/SMO8810 freefall sensor driver
+ *
+ * Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
+ * Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * This is loosely based on lis3lv02d driver.
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#define DRIVER_NAME "smo8800"
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+#include <linux/miscdevice.h>
+
+struct smo8800_device {
+ u32 irq; /* acpi device irq */
+ atomic_t counter; /* count after last read */
+ struct miscdevice miscdev; /* for /dev/freefall */
+ unsigned long misc_opened; /* whether the device is open */
+ wait_queue_head_t misc_wait; /* Wait queue for the misc dev */
+ struct device *dev; /* acpi device */
+};
+
+static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
+{
+ struct smo8800_device *smo8800 = data;
+
+ atomic_inc(&smo8800->counter);
+ wake_up_interruptible(&smo8800->misc_wait);
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
+{
+ struct smo8800_device *smo8800 = data;
+
+ dev_info(smo8800->dev, "detected free fall\n");
+ return IRQ_HANDLED;
+}
+
+static acpi_status smo8800_get_resource(struct acpi_resource *resource,
+ void *context)
+{
+ struct acpi_resource_extended_irq *irq;
+
+ if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
+ return AE_OK;
+
+ irq = &resource->data.extended_irq;
+ if (!irq || !irq->interrupt_count)
+ return AE_OK;
+
+ *((u32 *)context) = irq->interrupts[0];
+ return AE_CTRL_TERMINATE;
+}
+
+static u32 smo8800_get_irq(struct acpi_device *device)
+{
+ u32 irq = 0;
+ acpi_status status;
+
+ status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+ smo8800_get_resource, &irq);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&device->dev, "acpi_walk_resources failed\n");
+ return 0;
+ }
+
+ return irq;
+}
+
+static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct smo8800_device *smo8800 = container_of(file->private_data,
+ struct smo8800_device, miscdev);
+
+ u32 data = 0;
+ unsigned char byte_data = 0;
+ ssize_t retval = 1;
+
+ if (count < 1)
+ return -EINVAL;
+
+ atomic_set(&smo8800->counter, 0);
+ retval = wait_event_interruptible(smo8800->misc_wait,
+ (data = atomic_xchg(&smo8800->counter, 0)));
+
+ if (retval)
+ return retval;
+
+ byte_data = 1;
+ retval = 1;
+
+ if (data < 255)
+ byte_data = data;
+ else
+ byte_data = 255;
+
+ if (put_user(byte_data, buf))
+ retval = -EFAULT;
+
+ return retval;
+}
+
+static int smo8800_misc_open(struct inode *inode, struct file *file)
+{
+ struct smo8800_device *smo8800 = container_of(file->private_data,
+ struct smo8800_device, miscdev);
+
+ if (test_and_set_bit(0, &smo8800->misc_opened))
+ return -EBUSY; /* already open */
+
+ atomic_set(&smo8800->counter, 0);
+ return 0;
+}
+
+static int smo8800_misc_release(struct inode *inode, struct file *file)
+{
+ struct smo8800_device *smo8800 = container_of(file->private_data,
+ struct smo8800_device, miscdev);
+
+ clear_bit(0, &smo8800->misc_opened); /* release the device */
+ return 0;
+}
+
+static const struct file_operations smo8800_misc_fops = {
+ .owner = THIS_MODULE,
+ .read = smo8800_misc_read,
+ .open = smo8800_misc_open,
+ .release = smo8800_misc_release,
+};
+
+static int smo8800_add(struct acpi_device *device)
+{
+ int err;
+ struct smo8800_device *smo8800;
+
+ smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);
+ if (!smo8800) {
+ dev_err(&device->dev, "failed to allocate device data\n");
+ return -ENOMEM;
+ }
+
+ smo8800->dev = &device->dev;
+ smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
+ smo8800->miscdev.name = "freefall";
+ smo8800->miscdev.fops = &smo8800_misc_fops;
+
+ init_waitqueue_head(&smo8800->misc_wait);
+
+ err = misc_register(&smo8800->miscdev);
+ if (err) {
+ dev_err(&device->dev, "failed to register misc dev: %d\n", err);
+ return err;
+ }
+
+ device->driver_data = smo8800;
+
+ smo8800->irq = smo8800_get_irq(device);
+ if (!smo8800->irq) {
+ dev_err(&device->dev, "failed to obtain IRQ\n");
+ err = -EINVAL;
+ goto error;
+ }
+
+ err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,
+ smo8800_interrupt_thread,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ DRIVER_NAME, smo8800);
+ if (err) {
+ dev_err(&device->dev,
+ "failed to request thread for IRQ %d: %d\n",
+ smo8800->irq, err);
+ goto error;
+ }
+
+ dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
+ smo8800->irq);
+ return 0;
+
+error:
+ misc_deregister(&smo8800->miscdev);
+ return err;
+}
+
+static int smo8800_remove(struct acpi_device *device)
+{
+ struct smo8800_device *smo8800 = device->driver_data;
+
+ free_irq(smo8800->irq, smo8800);
+ misc_deregister(&smo8800->miscdev);
+ dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
+ return 0;
+}
+
+static const struct acpi_device_id smo8800_ids[] = {
+ { "SMO8800", 0 },
+ { "SMO8810", 0 },
+ { "", 0 },
+};
+
+MODULE_DEVICE_TABLE(acpi, smo8800_ids);
+
+static struct acpi_driver smo8800_driver = {
+ .name = DRIVER_NAME,
+ .class = "Latitude",
+ .ids = smo8800_ids,
+ .ops = {
+ .add = smo8800_add,
+ .remove = smo8800_remove,
+ },
+ .owner = THIS_MODULE,
+};
+
+module_acpi_driver(smo8800_driver);
+
+MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO8800/SMO8810)");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sonal Santan, Pali Rohár");
projects / karo-tx-linux.git / commitdiff