asus-laptop: Pegatron Lucid accelerometer

Support the built-in accelerometer on the Lucid tablets as a standard
3-axis input device.

Signed-off-by: Andy Ross <andy.ross@windriver.com>
Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 4e5623e4fa0bba0d834cd8a8ad510b42c4fa0d12..0d4146ca011f47070b46cbf9415aa29aed995b47 100644 (file)
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -69,10 +69,11 @@ config ASUS_LAPTOP
          This is a driver for Asus laptops, Lenovo SL and the Pegatron
          Lucid tablet. It may also support some MEDION, JVC or VICTOR
          laptops. It makes all the extra buttons generate standard
-         ACPI events and input events. It also adds support for video
-         output switching, LCD backlight control, Bluetooth and Wlan
-         control, and most importantly, allows you to blink those
-         fancy LEDs.
+         ACPI events and input events, and on the Lucid the built-in
+         accelerometer appears as an input device.  It also adds
+         support for video output switching, LCD backlight control,
+         Bluetooth and Wlan control, and most importantly, allows you
+         to blink those fancy LEDs.
 
          For more information see <http://acpi4asus.sf.net>.
 

diff --git a/drivers/platform/x86/asus-laptop.c b/drivers/platform/x86/asus-laptop.c
index 8327d06b6e8adfe0d50ef7e379379bc9b68d9ff0..613762d825f9ffa71c5aee03ba05f3d80f6e6d5f 100644 (file)
--- a/drivers/platform/x86/asus-laptop.c
+++ b/drivers/platform/x86/asus-laptop.c
@@ -193,6 +193,14 @@ MODULE_PARM_DESC(als_status, "Set the ALS status on boot "
 #define PEGA_READ_ALS_H        0x02
 #define PEGA_READ_ALS_L        0x03
 
+#define PEGA_ACCEL_NAME "pega_accel"
+#define PEGA_ACCEL_DESC "Pegatron Lucid Tablet Accelerometer"
+#define METHOD_XLRX "XLRX"
+#define METHOD_XLRY "XLRY"
+#define METHOD_XLRZ "XLRZ"
+#define PEGA_ACC_CLAMP 512 /* 1G accel is reported as ~256, so clamp to 2G */
+#define PEGA_ACC_RETRIES 3
+
 /*
  * Define a specific led structure to keep the main structure clean
  */
@@ -218,6 +226,7 @@ struct asus_laptop {
 
        struct input_dev *inputdev;
        struct key_entry *keymap;
+       struct input_polled_dev *pega_accel_poll;
 
        struct asus_led mled;
        struct asus_led tled;
@@ -230,6 +239,10 @@ struct asus_laptop {
        int wireless_status;
        bool have_rsts;
        bool is_pega_lucid;
+       bool pega_acc_live;
+       int pega_acc_x;
+       int pega_acc_y;
+       int pega_acc_z;
 
        struct rfkill *gps_rfkill;
 
@@ -358,6 +371,113 @@ static int asus_pega_lucid_set(struct asus_laptop *asus, int unit, bool enable)
        return write_acpi_int(asus->handle, method, unit);
 }
 
+static int pega_acc_axis(struct asus_laptop *asus, int curr, char *method)
+{
+       int i, delta;
+       unsigned long long val;
+       for (i = 0; i < PEGA_ACC_RETRIES; i++) {
+               acpi_evaluate_integer(asus->handle, method, NULL, &val);
+
+               /* The output is noisy.  From reading the ASL
+                * dissassembly, timeout errors are returned with 1's
+                * in the high word, and the lack of locking around
+                * thei hi/lo byte reads means that a transition
+                * between (for example) -1 and 0 could be read as
+                * 0xff00 or 0x00ff. */
+               delta = abs(curr - (short)val);
+               if (delta < 128 && !(val & ~0xffff))
+                       break;
+       }
+       return clamp_val((short)val, -PEGA_ACC_CLAMP, PEGA_ACC_CLAMP);
+}
+
+static void pega_accel_poll(struct input_polled_dev *ipd)
+{
+       struct device *parent = ipd->input->dev.parent;
+       struct asus_laptop *asus = dev_get_drvdata(parent);
+
+       /* In some cases, the very first call to poll causes a
+        * recursive fault under the polldev worker.  This is
+        * apparently related to very early userspace access to the
+        * device, and perhaps a firmware bug. Fake the first report. */
+       if (!asus->pega_acc_live) {
+               asus->pega_acc_live = true;
+               input_report_abs(ipd->input, ABS_X, 0);
+               input_report_abs(ipd->input, ABS_Y, 0);
+               input_report_abs(ipd->input, ABS_Z, 0);
+               input_sync(ipd->input);
+               return;
+       }
+
+       asus->pega_acc_x = pega_acc_axis(asus, asus->pega_acc_x, METHOD_XLRX);
+       asus->pega_acc_y = pega_acc_axis(asus, asus->pega_acc_y, METHOD_XLRY);
+       asus->pega_acc_z = pega_acc_axis(asus, asus->pega_acc_z, METHOD_XLRZ);
+
+       /* Note transform, convert to "right/up/out" in the native
+        * landscape orientation (i.e. the vector is the direction of
+        * "real up" in the device's cartiesian coordinates). */
+       input_report_abs(ipd->input, ABS_X, -asus->pega_acc_x);
+       input_report_abs(ipd->input, ABS_Y, -asus->pega_acc_y);
+       input_report_abs(ipd->input, ABS_Z,  asus->pega_acc_z);
+       input_sync(ipd->input);
+}
+
+static void pega_accel_exit(struct asus_laptop *asus)
+{
+       if (asus->pega_accel_poll) {
+               input_unregister_polled_device(asus->pega_accel_poll);
+               input_free_polled_device(asus->pega_accel_poll);
+       }
+       asus->pega_accel_poll = NULL;
+}
+
+static int pega_accel_init(struct asus_laptop *asus)
+{
+       int err;
+       struct input_polled_dev *ipd;
+
+       if (!asus->is_pega_lucid)
+               return -ENODEV;
+
+       if (acpi_check_handle(asus->handle, METHOD_XLRX, NULL) ||
+           acpi_check_handle(asus->handle, METHOD_XLRY, NULL) ||
+           acpi_check_handle(asus->handle, METHOD_XLRZ, NULL))
+               return -ENODEV;
+
+       ipd = input_allocate_polled_device();
+       if (!ipd)
+               return -ENOMEM;
+
+       ipd->poll = pega_accel_poll;
+       ipd->poll_interval = 125;
+       ipd->poll_interval_min = 50;
+       ipd->poll_interval_max = 2000;
+
+       ipd->input->name = PEGA_ACCEL_DESC;
+       ipd->input->phys = PEGA_ACCEL_NAME "/input0";
+       ipd->input->dev.parent = &asus->platform_device->dev;
+       ipd->input->id.bustype = BUS_HOST;
+
+       set_bit(EV_ABS, ipd->input->evbit);
+       input_set_abs_params(ipd->input, ABS_X,
+                            -PEGA_ACC_CLAMP, PEGA_ACC_CLAMP, 0, 0);
+       input_set_abs_params(ipd->input, ABS_Y,
+                            -PEGA_ACC_CLAMP, PEGA_ACC_CLAMP, 0, 0);
+       input_set_abs_params(ipd->input, ABS_Z,
+                            -PEGA_ACC_CLAMP, PEGA_ACC_CLAMP, 0, 0);
+
+       err = input_register_polled_device(ipd);
+       if (err)
+               goto exit;
+
+       asus->pega_accel_poll = ipd;
+       return 0;
+
+exit:
+       input_free_polled_device(ipd);
+       return err;
+}
+
 /* Generic LED function */
 static int asus_led_set(struct asus_laptop *asus, const char *method,
                         int value)
@@ -1348,7 +1468,7 @@ static struct platform_driver platform_driver = {
        .driver = {
                .name = ASUS_LAPTOP_FILE,
                .owner = THIS_MODULE,
-       }
+       },
 };
 
 /*
@@ -1558,9 +1678,15 @@ static int __devinit asus_acpi_add(struct acpi_device *device)
        if (result)
                goto fail_rfkill;
 
+       result = pega_accel_init(asus);
+       if (result && result != -ENODEV)
+               goto fail_pega_accel;
+
        asus_device_present = true;
        return 0;
 
+fail_pega_accel:
+       asus_rfkill_exit(asus);
 fail_rfkill:
        asus_led_exit(asus);
 fail_led:
@@ -1584,6 +1710,7 @@ static int asus_acpi_remove(struct acpi_device *device, int type)
        asus_rfkill_exit(asus);
        asus_led_exit(asus);
        asus_input_exit(asus);
+       pega_accel_exit(asus);
        asus_platform_exit(asus);
 
        kfree(asus->name);