Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/Documentation/leds/leds-lp3944.rst b/Documentation/leds/leds-lp3944.rst
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+====================
+Kernel driver lp3944
+====================
+
+  * National Semiconductor LP3944 Fun-light Chip
+
+    Prefix: 'lp3944'
+
+    Addresses scanned: None (see the Notes section below)
+
+    Datasheet:
+
+	Publicly available at the National Semiconductor website
+	http://www.national.com/pf/LP/LP3944.html
+
+Authors:
+	Antonio Ospite <ospite@studenti.unina.it>
+
+
+Description
+-----------
+The LP3944 is a helper chip that can drive up to 8 leds, with two programmable
+DIM modes; it could even be used as a gpio expander but this driver assumes it
+is used as a led controller.
+
+The DIM modes are used to set _blink_ patterns for leds, the pattern is
+specified supplying two parameters:
+
+  - period:
+	from 0s to 1.6s
+  - duty cycle:
+	percentage of the period the led is on, from 0 to 100
+
+Setting a led in DIM0 or DIM1 mode makes it blink according to the pattern.
+See the datasheet for details.
+
+LP3944 can be found on Motorola A910 smartphone, where it drives the rgb
+leds, the camera flash light and the lcds power.
+
+
+Notes
+-----
+The chip is used mainly in embedded contexts, so this driver expects it is
+registered using the i2c_board_info mechanism.
+
+To register the chip at address 0x60 on adapter 0, set the platform data
+according to include/linux/leds-lp3944.h, set the i2c board info::
+
+	static struct i2c_board_info a910_i2c_board_info[] __initdata = {
+		{
+			I2C_BOARD_INFO("lp3944", 0x60),
+			.platform_data = &a910_lp3944_leds,
+		},
+	};
+
+and register it in the platform init function::
+
+	i2c_register_board_info(0, a910_i2c_board_info,
+			ARRAY_SIZE(a910_i2c_board_info));