This patch adds the accelerometer axis data to the IIO subsystem.

Currently reporting the X, Y and Z values, as no other data can be
queried given the fact that the accelerometer chip itself is hidden
behind the Toshiba proprietary interface.

Signed-off-by: Azael Avalos <coproscef...@gmail.com>
---
All:
 This is my first attempt with the IIO subsysem, I'll be looking
 forward for your valuable input on this.

Darren:
 There's a warning about more than 80 columns on this patch, once
 I get feedback from the IIO guys I'll respin this with that issue
 corrected.

 drivers/platform/x86/toshiba_acpi.c | 130 ++++++++++++++++++++++++++++++++++--
 1 file changed, 126 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/toshiba_acpi.c 
b/drivers/platform/x86/toshiba_acpi.c
index 01e12d2..85014a3 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -53,6 +53,7 @@
 #include <linux/uaccess.h>
 #include <linux/miscdevice.h>
 #include <linux/rfkill.h>
+#include <linux/iio/iio.h>
 #include <linux/toshiba.h>
 #include <acpi/video.h>
 
@@ -134,6 +135,7 @@ MODULE_LICENSE("GPL");
 
 /* Field definitions */
 #define HCI_ACCEL_MASK                 0x7fff
+#define HCI_ACCEL_DIRECTION_MASK       0x8000
 #define HCI_HOTKEY_DISABLE             0x0b
 #define HCI_HOTKEY_ENABLE              0x09
 #define HCI_HOTKEY_SPECIAL_FUNCTIONS   0x10
@@ -178,6 +180,7 @@ struct toshiba_acpi_dev {
        struct led_classdev eco_led;
        struct miscdevice miscdev;
        struct rfkill *wwan_rfk;
+       struct iio_dev *indio_dev;
 
        int force_fan;
        int last_key_event;
@@ -1962,8 +1965,8 @@ static ssize_t position_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
 {
        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
-       u32 xyval, zval, tmp;
-       u16 x, y, z;
+       u32 xyval, zval;
+       int x, y, z;
        int ret;
 
        xyval = zval = 0;
@@ -1971,10 +1974,14 @@ static ssize_t position_show(struct device *dev,
        if (ret < 0)
                return ret;
 
+       /* Accelerometer values */
        x = xyval & HCI_ACCEL_MASK;
-       tmp = xyval >> HCI_MISC_SHIFT;
-       y = tmp & HCI_ACCEL_MASK;
+       y = (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_MASK;
        z = zval & HCI_ACCEL_MASK;
+       /* Movement direction */
+       x *= xyval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
+       y *= (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
+       z *= zval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
 
        return sprintf(buf, "%d %d %d\n", x, y, z);
 }
@@ -2420,6 +2427,94 @@ static void toshiba_acpi_kbd_bl_work(struct work_struct 
*work)
 }
 
 /*
+ * IIO device
+ */
+
+enum toshiba_accel_chan {
+       AXIS_X,
+       AXIS_Y,
+       AXIS_Z
+};
+
+static int toshiba_accel_get_axis(enum toshiba_accel_chan chan)
+{
+       u32 xyval, zval;
+       int x, y, z;
+       int ret;
+
+       xyval = zval = 0;
+       ret = toshiba_accelerometer_get(toshiba_acpi, &xyval, &zval);
+       if (ret < 0)
+               return ret;
+
+       /* Accelerometer values */
+       x = xyval & HCI_ACCEL_MASK;
+       y = (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_MASK;
+       z = zval & HCI_ACCEL_MASK;
+       /* Movement direction */
+       x *= xyval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
+       y *= (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
+       z *= zval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
+
+       switch (chan) {
+       case AXIS_X:
+               ret = x;
+               break;
+       case AXIS_Y:
+               ret = y;
+               break;
+       case AXIS_Z:
+               ret = z;
+               break;
+       }
+
+       return ret;
+}
+
+static int toshiba_accel_read_raw(struct iio_dev *indio_dev,
+                                 struct iio_chan_spec const *chan,
+                                 int *val, int *val2, long mask)
+{
+       int ret;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               if (iio_buffer_enabled(indio_dev))
+                       return -EBUSY;
+
+               ret = toshiba_accel_get_axis(chan->scan_index);
+               if (ret == -EIO || ret == -ENODEV)
+                       return ret;
+
+               *val = ret;
+
+               return IIO_VAL_INT;
+       }
+
+       return -EINVAL;
+}
+
+#define TOSHIBA_ACCEL_CHANNEL(axis, chan) { \
+       .type = IIO_ACCEL, \
+       .modified = 1, \
+       .channel2 = IIO_MOD_##axis, \
+       .output = 1, \
+       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+       .scan_index = chan, \
+}
+
+static const struct iio_chan_spec toshiba_accel_channels[] = {
+       TOSHIBA_ACCEL_CHANNEL(X, AXIS_X),
+       TOSHIBA_ACCEL_CHANNEL(Y, AXIS_Y),
+       TOSHIBA_ACCEL_CHANNEL(Z, AXIS_Z),
+};
+
+static const struct iio_info toshiba_accel_info = {
+       .driver_module = THIS_MODULE,
+       .read_raw = &toshiba_accel_read_raw,
+};
+
+/*
  * Misc device
  */
 static int toshiba_acpi_smm_bridge(SMMRegisters *regs)
@@ -2903,6 +2998,11 @@ static int toshiba_acpi_remove(struct acpi_device 
*acpi_dev)
        misc_deregister(&dev->miscdev);
 
        remove_toshiba_proc_entries(dev);
+
+       if (dev->accelerometer_supported) {
+               iio_device_unregister(dev->indio_dev);
+               iio_device_free(dev->indio_dev);
+       }
 
        if (dev->sysfs_created)
                sysfs_remove_group(&dev->acpi_dev->dev.kobj,
@@ -3051,6 +3151,28 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
        dev->touchpad_supported = !ret;
 
        toshiba_accelerometer_available(dev);
+       if (dev->accelerometer_supported) {
+               dev->indio_dev = iio_device_alloc(sizeof(*dev));
+               if (!dev->indio_dev)
+                       return -ENOMEM;
+
+               pr_info("Registering Toshiba accelerometer iio device\n");
+
+               dev->indio_dev->info = &toshiba_accel_info;
+               dev->indio_dev->name = "Toshiba accelerometer";
+               dev->indio_dev->dev.parent = &acpi_dev->dev;
+               dev->indio_dev->modes = INDIO_DIRECT_MODE;
+               dev->indio_dev->channels = toshiba_accel_channels;
+               dev->indio_dev->num_channels = 
ARRAY_SIZE(toshiba_accel_channels);
+
+               ret = iio_device_register(dev->indio_dev);
+               if (ret < 0) {
+                       pr_err("Unable to register iio device\n");
+                       iio_device_free(dev->indio_dev);
+               }
+
+               iio_device_set_drvdata(dev->indio_dev, dev);
+       }
 
        toshiba_usb_sleep_charge_available(dev);
 
-- 
2.8.3

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