Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / input / touchscreen / of_touchscreen.c

diff --git a/kernel/drivers/input/touchscreen/of_touchscreen.c b/kernel/drivers/input/touchscreen/of_touchscreen.c
new file mode 100644 (file)
index 0000000..b82b520
--- /dev/null
+++ b/kernel/drivers/input/touchscreen/of_touchscreen.c
@@ -0,0 +1,87 @@
+/*
+ *  Generic DT helper functions for touchscreen devices
+ *
+ *  Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/of.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+
+static u32 of_get_optional_u32(struct device_node *np,
+                              const char *property)
+{
+       u32 val = 0;
+
+       of_property_read_u32(np, property, &val);
+
+       return val;
+}
+
+static void touchscreen_set_params(struct input_dev *dev,
+                                  unsigned long axis,
+                                  int max, int fuzz)
+{
+       struct input_absinfo *absinfo;
+
+       if (!test_bit(axis, dev->absbit)) {
+               /*
+                * Emit a warning only if the axis is not a multitouch
+                * axis, which might not be set by the driver.
+                */
+               if (!input_is_mt_axis(axis))
+                       dev_warn(&dev->dev,
+                                "DT specifies parameters but the axis is not set up\n");
+               return;
+       }
+
+       absinfo = &dev->absinfo[axis];
+       absinfo->maximum = max;
+       absinfo->fuzz = fuzz;
+}
+
+/**
+ * touchscreen_parse_of_params - parse common touchscreen DT properties
+ * @dev: device that should be parsed
+ *
+ * This function parses common DT properties for touchscreens and setups the
+ * input device accordingly. The function keeps previously setuped default
+ * values if no value is specified via DT.
+ */
+void touchscreen_parse_of_params(struct input_dev *dev)
+{
+       struct device_node *np = dev->dev.parent->of_node;
+       u32 maximum, fuzz;
+
+       input_alloc_absinfo(dev);
+       if (!dev->absinfo)
+               return;
+
+       maximum = of_get_optional_u32(np, "touchscreen-size-x");
+       fuzz = of_get_optional_u32(np, "touchscreen-fuzz-x");
+       if (maximum || fuzz) {
+               touchscreen_set_params(dev, ABS_X, maximum, fuzz);
+               touchscreen_set_params(dev, ABS_MT_POSITION_X, maximum, fuzz);
+       }
+
+       maximum = of_get_optional_u32(np, "touchscreen-size-y");
+       fuzz = of_get_optional_u32(np, "touchscreen-fuzz-y");
+       if (maximum || fuzz) {
+               touchscreen_set_params(dev, ABS_Y, maximum, fuzz);
+               touchscreen_set_params(dev, ABS_MT_POSITION_Y, maximum, fuzz);
+       }
+
+       maximum = of_get_optional_u32(np, "touchscreen-max-pressure");
+       fuzz = of_get_optional_u32(np, "touchscreen-fuzz-pressure");
+       if (maximum || fuzz) {
+               touchscreen_set_params(dev, ABS_PRESSURE, maximum, fuzz);
+               touchscreen_set_params(dev, ABS_MT_PRESSURE, maximum, fuzz);
+       }
+}
+EXPORT_SYMBOL(touchscreen_parse_of_params);