tsc210x cleanup

[linux-2.6-omap-h63xx.git] / drivers / input / touchscreen / tsc210x_ts.c

diff --git a/drivers/input/touchscreen/tsc210x_ts.c b/drivers/input/touchscreen/tsc210x_ts.c
index 09c693757d27d70e937a6b28db3349219be08172..ae2c77f43ba4f25ffd0df42f44e24b92c1223c2e 100644 (file)
--- a/drivers/input/touchscreen/tsc210x_ts.c
+++ b/drivers/input/touchscreen/tsc210x_ts.c
@@ -1,7 +1,5 @@
 /*
- * input/touchscreen/tsc210x_ts.c
- *
- * Touchscreen input device driver for the TSC 2101/2102 chips.
+ * tsc210x_ts.c - touchscreen input device for TI TSC210x chips
  *
  * Copyright (c) 2006-2007 Andrzej Zaborowski  <balrog@zabor.org>
  *
@@ -29,8 +27,23 @@
 
 #include <linux/spi/tsc210x.h>
 
-static void tsc210x_touch(struct input_dev *dev, int touching)
+
+/*
+ * The sensor ADC on tsc210x chips is most often used with the smart
+ * touchscreen controller.   Those controllers can be made to improve
+ * sample quality directly by multi-sampling and by taking the mean or
+ * median of various numbers of samples.  They also take X, Y, and
+ * pressure measurements automatically, so this driver has relatively
+ * little to do.
+ *
+ * There are a few chips in this family that don't have quite the same
+ * touchscreen interface, e.g. no "median" mode.
+ */
+
+static void tsc210x_touch(void *context, int touching)
 {
+       struct input_dev *dev = context;
+
        if (!touching) {
                input_report_abs(dev, ABS_X, 0);
                input_report_abs(dev, ABS_Y, 0);
@@ -41,8 +54,9 @@ static void tsc210x_touch(struct input_dev *dev, int touching)
        input_report_key(dev, BTN_TOUCH, touching);
 }
 
-static void tsc210x_coords(struct input_dev *dev, int x, int y, int z1, int z2)
+static void tsc210x_coords(void *context, int x, int y, int z1, int z2)
 {
+       struct input_dev *dev = context;
        int p;
 
        /* Calculate the touch resistance a la equation #1 */
@@ -66,17 +80,15 @@ static int tsc210x_ts_probe(struct platform_device *pdev)
        if (!dev)
                return -ENOMEM;
 
-       status = tsc210x_touch_cb(pdev->dev.parent,
-                       (tsc210x_touch_t) tsc210x_touch, dev);
+       status = tsc210x_touch_cb(pdev->dev.parent, tsc210x_touch, dev);
        if (status) {
                input_free_device(dev);
                return status;
        }
 
-       status = tsc210x_coords_cb(pdev->dev.parent,
-                       (tsc210x_coords_t) tsc210x_coords, dev);
+       status = tsc210x_coords_cb(pdev->dev.parent, tsc210x_coords, dev);
        if (status) {
-               tsc210x_touch_cb(pdev->dev.parent, 0, 0);
+               tsc210x_touch_cb(pdev->dev.parent, NULL, NULL);
                input_free_device(dev);
                return status;
        }
@@ -94,8 +106,8 @@ static int tsc210x_ts_probe(struct platform_device *pdev)
 
        status = input_register_device(dev);
        if (status) {
-               tsc210x_coords_cb(pdev->dev.parent, 0, 0);
-               tsc210x_touch_cb(pdev->dev.parent, 0, 0);
+               tsc210x_coords_cb(pdev->dev.parent, NULL, NULL);
+               tsc210x_touch_cb(pdev->dev.parent, NULL, NULL);
                input_free_device(dev);
                return status;
        }
@@ -105,14 +117,13 @@ static int tsc210x_ts_probe(struct platform_device *pdev)
        return 0;
 }
 
-static int tsc210x_ts_remove(struct platform_device *pdev)
+static int __exit tsc210x_ts_remove(struct platform_device *pdev)
 {
-       struct input_dev *dev = (struct input_dev *)
-               platform_get_drvdata(pdev);
+       struct input_dev *dev = platform_get_drvdata(pdev);
 
-       tsc210x_touch_cb(pdev->dev.parent, 0, 0);
-       tsc210x_coords_cb(pdev->dev.parent, 0, 0);
-       platform_set_drvdata(pdev, 0);
+       tsc210x_touch_cb(pdev->dev.parent, NULL, NULL);
+       tsc210x_coords_cb(pdev->dev.parent, NULL, NULL);
+       platform_set_drvdata(pdev, NULL);
        input_unregister_device(dev);
        input_free_device(dev);
 
@@ -120,8 +131,8 @@ static int tsc210x_ts_remove(struct platform_device *pdev)
 }
 
 static struct platform_driver tsc210x_ts_driver = {
-       .probe          = tsc210x_ts_probe,
-       .remove         = tsc210x_ts_remove,
+       .probe          = tsc210x_ts_probe,
+       .remove         = __exit_p(tsc210x_ts_remove),
        /* Nothing to do on suspend/resume */
        .driver         = {
                .name   = "tsc210x-ts",
@@ -131,21 +142,17 @@ static struct platform_driver tsc210x_ts_driver = {
 
 static int __init tsc210x_ts_init(void)
 {
-       int ret;
-
-       ret = platform_driver_register(&tsc210x_ts_driver);
-       if (ret)
-               return -ENODEV;
-
-       return 0;
+       /* can't use driver_probe() here since the parent device
+        * gets registered "late"
+        */
+       return platform_driver_register(&tsc210x_ts_driver);
 }
+module_init(tsc210x_ts_init);
 
 static void __exit tsc210x_ts_exit(void)
 {
        platform_driver_unregister(&tsc210x_ts_driver);
 }
-
-module_init(tsc210x_ts_init);
 module_exit(tsc210x_ts_exit);
 
 MODULE_AUTHOR("Andrzej Zaborowski");