Add filter_chain object

Filter chains should be completely opaque to the drivers that use it.
We fix this with this patch.

~ Make the "filter chain" a new object.
~ We can build with CONFIG_TOUCHSCREEN_FILTER=n with no problems in
  a cleaner way.
~ Update s3c2410_ts.c to use the filter_chain object.
~ Cleanups.

Signed-off-by: Nelson Castillo <arhuaco@freaks-unidos.net>

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ts_filter_chain.h b/drivers/input/touchscreen/ts_filter_chain.h
new file mode 100644
index 00000000000..806bffe6c99
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_chain.h
@@ -0,0 +1,58 @@
+#ifndef __TS_FILTER_CHAIN_H__
+#define __TS_FILTER_CHAIN_H__
+
+/*
+ * Touchscreen filter chains.
+ *
+ * (c) 2008,2009 Andy Green <andy@openmoko.com>
+ */
+
+#include "ts_filter.h"
+
+#include <linux/err.h>
+
+struct ts_filter_chain_configuration {
+	/* API to use. */
+	const struct ts_filter_api *api;
+	/* Generic filter configuration. Different for each filter. */
+	const struct ts_filter_configuration *config;
+};
+
+struct ts_filter_chain;
+
+#ifdef CONFIG_TOUCHSCREEN_FILTER
+
+/*
+ * Create a filter chain. It will allocate an array of
+ * null-terminated pointers to filters. On error it will return
+ * an error you can check with IS_ERR.
+ */
+extern struct ts_filter_chain *ts_filter_chain_create(
+	struct platform_device *pdev,
+	const struct ts_filter_chain_configuration conf[],
+	int count_coords);
+
+/* Destroy the chain. */
+extern void ts_filter_chain_destroy(struct ts_filter_chain *c);
+
+/* Clear the filter chain. */
+extern void ts_filter_chain_clear(struct ts_filter_chain *c);
+
+/*
+ * Try to get one point. Returns 0 if no points are available.
+ * coords will be used as temporal space, thus you supply a point
+ * using coords but you shouldn't rely on its value on return unless
+ * it returns a nonzero value that is not -1.
+ * If one of the filters find an error then this function will
+ * return -1.
+ */
+int ts_filter_chain_feed(struct ts_filter_chain *c, int *coords);
+
+#else /* !CONFIG_TOUCHSCREEN_FILTER */
+#define ts_filter_chain_create(pdev, config, count_coords) (NULL)
+#define ts_filter_chain_destroy(c) do { } while (0)
+#define ts_filter_chain_clear(c) do { } while (0)
+#define ts_filter_chain_feed(c, coords) (1)
+#endif
+
+#endif