bcm2079x-i2c.txt


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Kernel driver for the Broadcom bcm2079x contactless
communication controller

General
-------

The bcm2079x is an integrated Controller for contactless communication.

Host Interfaces: I2C, SPI and UART, this driver supports I2C.

The Driver
----------

The bcm2079x-i2c driver can be found under drivers/misc/bcm2079x-i2c.c and its
header file include/linux/platform_data/bcm2079x.h.

The userspace application uses /dev/bcm2079x-i2c device to communicate with the
Controller using NCI command messages. In a typical scenario application
will open /dev/bcm2079x-i2c; power up and wake up the Controller chip using
ioctl(). write to the Controller using write(). poll() the device to check if
data is available. Use read() to read the data from the Controller.

The driver waits for bcm2079x Controller's interrupt which occurs if there are
data to be read.  Then, poll() will indicate the fact to the userspace.  read()
will return full NCI or HCI packet to the userspace application. Unsolicited
read() will receive garbage data.

Userspace application may use ioctl() to allow the Controller to enter snooze or
sleep mode.

Userspace application may use ioctl() to set the client address the driver uses
to communicate with the Controller.  This allows userspace application to change
the device address of the Controller.

Platform Data
-------------

The following platform data should be set when configuring board.

struct bcm2079x_platform_data {
	unsigned int irq_gpio;
	unsigned int en_gpio;
	unsigned int wake_gpio;
};