leds: driver for National Semiconductor LP5521 chip

This patchset provides support for LP5521 and LP5523 LED driver chips from
National Semicondutor.  Both drivers supports programmable engines and
naturally LED class features.

Documentation is provided as a part of the patchset.  I created "leds"
subdirectory under Documentation.  Perhaps the rest of the leds*
documentation should be moved there.

Datasheets are freely available at National Semiconductor www pages.

This patch:

LP5521 chip is three channel led driver with programmable engines.  Driver
provides support for that chip for direct access via led class or via
programmable engines.
Signed-off-by: NSamu Onkalo <samu.p.onkalo@nokia.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/leds-lp5521.h

+/*
+ * LP5521 LED chip driver.
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __LINUX_LP5521_H
+#define __LINUX_LP5521_H
+
+/* See Documentation/leds/leds-lp5521.txt */
+
+struct lp5521_led_config {
+	u8		chan_nr;
+	u8		led_current; /* mA x10, 0 if led is not connected */
+	u8		max_current;
+};
+
+#define LP5521_CLOCK_AUTO	0
+#define LP5521_CLOCK_INT	1
+#define LP5521_CLOCK_EXT	2
+
+struct lp5521_platform_data {
+	struct lp5521_led_config *led_config;
+	u8	num_channels;
+	u8	clock_mode;
+	int	(*setup_resources)(void);
+	void	(*release_resources)(void);
+	void	(*enable)(bool state);
+};
+
+#endif /* __LINUX_LP5521_H */