leds: add driver for LM3530 ALS

Simple backlight driver for National Semiconductor LM3530.  Presently only
manual mode is supported, PWM and ALS support to be added.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/led-lm3530.h b/include/linux/led-lm3530.h
new file mode 100644
index 0000000..bb69d20
--- /dev/null
+++ b/include/linux/led-lm3530.h
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2011 ST-Ericsson SA.
+ * Copyright (C) 2009 Motorola, Inc.
+ *
+ * License Terms: GNU General Public License v2
+ *
+ * Simple driver for National Semiconductor LM35330 Backlight driver chip
+ *
+ * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
+ * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
+ */
+
+#ifndef _LINUX_LED_LM3530_H__
+#define _LINUX_LED_LM3530_H__
+
+#define LM3530_FS_CURR_5mA		(0) /* Full Scale Current */
+#define LM3530_FS_CURR_8mA		(1)
+#define LM3530_FS_CURR_12mA		(2)
+#define LM3530_FS_CURR_15mA		(3)
+#define LM3530_FS_CURR_19mA		(4)
+#define LM3530_FS_CURR_22mA		(5)
+#define LM3530_FS_CURR_26mA		(6)
+#define LM3530_FS_CURR_29mA		(7)
+
+#define LM3530_ALS_AVRG_TIME_32ms	(0) /* ALS Averaging Time */
+#define LM3530_ALS_AVRG_TIME_64ms	(1)
+#define LM3530_ALS_AVRG_TIME_128ms	(2)
+#define LM3530_ALS_AVRG_TIME_256ms	(3)
+#define LM3530_ALS_AVRG_TIME_512ms	(4)
+#define LM3530_ALS_AVRG_TIME_1024ms	(5)
+#define LM3530_ALS_AVRG_TIME_2048ms	(6)
+#define LM3530_ALS_AVRG_TIME_4096ms	(7)
+
+#define LM3530_RAMP_TIME_1ms		(0) /* Brigtness Ramp Time */
+#define LM3530_RAMP_TIME_130ms		(1) /* Max to 0 and vice versa */
+#define LM3530_RAMP_TIME_260ms		(2)
+#define LM3530_RAMP_TIME_520ms		(3)
+#define LM3530_RAMP_TIME_1s		(4)
+#define LM3530_RAMP_TIME_2s		(5)
+#define LM3530_RAMP_TIME_4s		(6)
+#define LM3530_RAMP_TIME_8s		(7)
+
+/* ALS Resistor Select */
+#define LM3530_ALS_IMPD_Z		(0x00) /* ALS Impedence */
+#define LM3530_ALS_IMPD_13_53kOhm	(0x01)
+#define LM3530_ALS_IMPD_9_01kOhm	(0x02)
+#define LM3530_ALS_IMPD_5_41kOhm	(0x03)
+#define LM3530_ALS_IMPD_2_27kOhm	(0x04)
+#define LM3530_ALS_IMPD_1_94kOhm	(0x05)
+#define LM3530_ALS_IMPD_1_81kOhm	(0x06)
+#define LM3530_ALS_IMPD_1_6kOhm		(0x07)
+#define LM3530_ALS_IMPD_1_138kOhm	(0x08)
+#define LM3530_ALS_IMPD_1_05kOhm	(0x09)
+#define LM3530_ALS_IMPD_1_011kOhm	(0x0A)
+#define LM3530_ALS_IMPD_941Ohm		(0x0B)
+#define LM3530_ALS_IMPD_759Ohm		(0x0C)
+#define LM3530_ALS_IMPD_719Ohm		(0x0D)
+#define LM3530_ALS_IMPD_700Ohm		(0x0E)
+#define LM3530_ALS_IMPD_667Ohm		(0x0F)
+
+enum lm3530_mode {
+	LM3530_BL_MODE_MANUAL = 0,	/* "man" */
+	LM3530_BL_MODE_ALS,		/* "als" */
+	LM3530_BL_MODE_PWM,		/* "pwm" */
+};
+
+/* ALS input select */
+enum lm3530_als_mode {
+	LM3530_INPUT_AVRG = 0,	/* ALS1 and ALS2 input average */
+	LM3530_INPUT_ALS1,	/* ALS1 Input */
+	LM3530_INPUT_ALS2,	/* ALS2 Input */
+	LM3530_INPUT_CEIL,	/* Max of ALS1 and ALS2 */
+};
+
+/**
+ * struct lm3530_platform_data
+ * @mode: mode of operation i.e. Manual, ALS or PWM
+ * @als_input_mode: select source of ALS input - ALS1/2 or average
+ * @max_current: full scale LED current
+ * @pwm_pol_hi: PWM input polarity - active high/active low
+ * @als_avrg_time: ALS input averaging time
+ * @brt_ramp_law: brightness mapping mode - exponential/linear
+ * @brt_ramp_fall: rate of fall of led current
+ * @brt_ramp_rise: rate of rise of led current
+ * @als1_resistor_sel: internal resistance from ALS1 input to ground
+ * @als2_resistor_sel: internal resistance from ALS2 input to ground
+ * @brt_val: brightness value (0-255)
+ */
+struct lm3530_platform_data {
+	enum lm3530_mode mode;
+	enum lm3530_als_mode als_input_mode;
+
+	u8 max_current;
+	bool pwm_pol_hi;
+	u8 als_avrg_time;
+
+	bool brt_ramp_law;
+	u8 brt_ramp_fall;
+	u8 brt_ramp_rise;
+
+	u8 als1_resistor_sel;
+	u8 als2_resistor_sel;
+
+	u8 brt_val;
+};
+
+#endif	/* _LINUX_LED_LM3530_H__ */