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@xxxxxxxxx>
Cc: Sonal Santan <sonal.santan@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 10 ++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/dell-smo8800.c | 253 +++++++++++++++++++++++++++++++++++
3 files changed, 264 insertions(+)
create mode 100644 drivers/platform/x86/dell-smo8800.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 27df2c5..f0c2e45 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -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"
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 1a2eafc..c4ca428 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -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
index 0000000..4aabb74
--- /dev/null
+++ b/drivers/platform/x86/dell-smo8800.c
@@ -0,0 +1,253 @@
+/*
+ * dell-smo8800.c - Dell Latitude ACPI SMO8800/SMO8810 freefall sensor driver
+ *
+ * Copyright (C) 2012 Sonal Santan <sonal.santan@xxxxxxxxx>
+ * Copyright (C) 2014 Pali Rohár <pali.rohar@xxxxxxxxx>
+ *
+ * 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"
+#define pr_fmt(fmt) DRIVER_NAME ": " fmt
+
+#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 count; /* 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->count);
+ 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);
+
+ DECLARE_WAITQUEUE(wait, current);
+ u32 data;
+ unsigned char byte_data;
+ ssize_t retval = 1;
+
+ if (count < 1)
+ return -EINVAL;
+
+ add_wait_queue(&smo8800->misc_wait, &wait);
+ while (true) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ data = atomic_xchg(&smo8800->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(&smo8800->misc_wait, &wait);
+
+ 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->count, 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;
+
+ if (!device)
+ return -EINVAL;
+
+ 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;
+ }
+
+ atomic_set(&smo8800->count, 0);
+ 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_info(&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_info(&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");
--
1.7.9.5
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