platform: x86: dell-smo8800: Dell Latitude freefall driver (ACPI SMO8800/SMO8810)
authorPali Rohár <pali.rohar@gmail.com>
Thu, 22 May 2014 11:15:48 +0000 (13:15 +0200)
committerMatthew Garrett <matthew.garrett@nebula.com>
Tue, 10 Jun 2014 23:11:10 +0000 (19:11 -0400)
This acpi driver provide supports for freefall sensors SMO8800/SMO8810 which
can be found on Dell Latitude laptops. Driver register /dev/freefall misc
device which has same interface as driver hp_accel freefall driver. So any
existing applications for HP freefall sensor /dev/freefall will work for with
this new driver for Dell Latitude laptops too.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Cc: Sonal Santan <sonal.santan@gmail.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
drivers/platform/x86/Kconfig
drivers/platform/x86/Makefile
drivers/platform/x86/dell-smo8800.c [new file with mode: 0644]

index 60d33834f28fda2b48d411fcb952a68d103be39d..172f26ce59ac9d2dbf5966a04490065a08ddbaa0 100644 (file)
@@ -127,6 +127,16 @@ config DELL_WMI_AIO
          To compile this driver as a module, choose M here: the module will
          be called dell-wmi-aio.
 
+config DELL_SMO8800
+       tristate "Dell Latitude freefall driver (ACPI SMO8800/SMO8810)"
+       depends on ACPI
+       ---help---
+         Say Y here if you want to support SMO8800/SMO8810 freefall device
+         on Dell Latitude laptops.
+
+         To compile this driver as a module, choose M here: the module will
+         be called dell-smo8800.
+
 
 config FUJITSU_LAPTOP
        tristate "Fujitsu Laptop Extras"
index 1a2eafc9d48efa5d8d4fc19c6aec4862e8547eb4..c4ca428fd3db2651706171df439b24b52588e5c0 100644 (file)
@@ -13,6 +13,7 @@ obj-$(CONFIG_COMPAL_LAPTOP)   += compal-laptop.o
 obj-$(CONFIG_DELL_LAPTOP)      += dell-laptop.o
 obj-$(CONFIG_DELL_WMI)         += dell-wmi.o
 obj-$(CONFIG_DELL_WMI_AIO)     += dell-wmi-aio.o
+obj-$(CONFIG_DELL_SMO8800)     += dell-smo8800.o
 obj-$(CONFIG_ACER_WMI)         += acer-wmi.o
 obj-$(CONFIG_ACERHDF)          += acerhdf.o
 obj-$(CONFIG_HP_ACCEL)         += hp_accel.o
diff --git a/drivers/platform/x86/dell-smo8800.c b/drivers/platform/x86/dell-smo8800.c
new file mode 100644 (file)
index 0000000..a653716
--- /dev/null
@@ -0,0 +1,233 @@
+/*
+ *  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");