[linux-2.6-block.git] / Documentation / i2c / busses / i2c-ocores.rst

========================
Kernel driver i2c-ocores
========================

Supported adapters:
  * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
    https://opencores.org/project/i2c/overview

Author: Peter Korsgaard <peter@korsgaard.com>

Description
-----------

i2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
IP core by Richard Herveille.

Usage
-----

i2c-ocores uses the platform bus, so you need to provide a struct
platform_device with the base address and interrupt number. The
dev.platform_data of the device should also point to a struct
ocores_i2c_platform_data (see linux/platform_data/i2c-ocores.h) describing the
distance between registers and the input clock speed.
There is also a possibility to attach a list of i2c_board_info which
the i2c-ocores driver will add to the bus upon creation.

E.G. something like::

  static struct resource ocores_resources[] = {
	[0] = {
		.start	= MYI2C_BASEADDR,
		.end	= MYI2C_BASEADDR + 8,
		.flags	= IORESOURCE_MEM,
	},
	[1] = {
		.start	= MYI2C_IRQ,
		.end	= MYI2C_IRQ,
		.flags	= IORESOURCE_IRQ,
	},
  };

  /* optional board info */
  struct i2c_board_info ocores_i2c_board_info[] = {
	{
		I2C_BOARD_INFO("tsc2003", 0x48),
		.platform_data = &tsc2003_platform_data,
		.irq = TSC_IRQ
	},
	{
		I2C_BOARD_INFO("adv7180", 0x42 >> 1),
		.irq = ADV_IRQ
	}
  };

  static struct ocores_i2c_platform_data myi2c_data = {
	.regstep	= 2,		/* two bytes between registers */
	.clock_khz	= 50000,	/* input clock of 50MHz */
	.devices	= ocores_i2c_board_info, /* optional table of devices */
	.num_devices	= ARRAY_SIZE(ocores_i2c_board_info), /* table size */
  };

  static struct platform_device myi2c = {
	.name			= "ocores-i2c",
	.dev = {
		.platform_data	= &myi2c_data,
	},
	.num_resources		= ARRAY_SIZE(ocores_resources),
	.resource		= ocores_resources,
  };
Commit	Line	Data
ccf988b6	1	========================
18f98b1e	2	Kernel driver i2c-ocores
ccf988b6	3	========================
18f98b1e PK	4
	5	Supported adapters:
	6	* OpenCores.org I2C controller by Richard Herveille (see datasheet link)
a0ccb6b5	7	https://opencores.org/project/i2c/overview
18f98b1e	8
5d3a01a2	9	Author: Peter Korsgaard <peter@korsgaard.com>
18f98b1e PK	10
	11	Description
	12	-----------
	13
	14	i2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
	15	IP core by Richard Herveille.
	16
	17	Usage
	18	-----
	19
	20	i2c-ocores uses the platform bus, so you need to provide a struct
	21	platform_device with the base address and interrupt number. The
	22	dev.platform_data of the device should also point to a struct
985ecf00	23	ocores_i2c_platform_data (see linux/platform_data/i2c-ocores.h) describing the
18f98b1e	24	distance between registers and the input clock speed.
dd14be4c RR	25	There is also a possibility to attach a list of i2c_board_info which
dd14be4c RR	26	the i2c-ocores driver will add to the bus upon creation.
18f98b1e	27
ccf988b6	28	E.G. something like::
18f98b1e	29
ccf988b6	30	static struct resource ocores_resources[] = {
18f98b1e PK	31	[0] = {
	32	.start = MYI2C_BASEADDR,
	33	.end = MYI2C_BASEADDR + 8,
	34	.flags = IORESOURCE_MEM,
	35	},
	36	[1] = {
	37	.start = MYI2C_IRQ,
	38	.end = MYI2C_IRQ,
	39	.flags = IORESOURCE_IRQ,
	40	},
ccf988b6	41	};
18f98b1e	42
ccf988b6 MCC	43	/* optional board info */
ccf988b6 MCC	44	struct i2c_board_info ocores_i2c_board_info[] = {
dd14be4c RR	45	{
	46	I2C_BOARD_INFO("tsc2003", 0x48),
	47	.platform_data = &tsc2003_platform_data,
	48	.irq = TSC_IRQ
	49	},
	50	{
	51	I2C_BOARD_INFO("adv7180", 0x42 >> 1),
	52	.irq = ADV_IRQ
	53	}
ccf988b6	54	};
dd14be4c	55
ccf988b6	56	static struct ocores_i2c_platform_data myi2c_data = {
18f98b1e PK	57	.regstep = 2, /* two bytes between registers */
18f98b1e PK	58	.clock_khz = 50000, /* input clock of 50MHz */
dd14be4c RR	59	.devices = ocores_i2c_board_info, /* optional table of devices */
dd14be4c RR	60	.num_devices = ARRAY_SIZE(ocores_i2c_board_info), /* table size */
ccf988b6	61	};
18f98b1e	62
ccf988b6	63	static struct platform_device myi2c = {
18f98b1e PK	64	.name = "ocores-i2c",
	65	.dev = {
	66	.platform_data = &myi2c_data,
	67	},
	68	.num_resources = ARRAY_SIZE(ocores_resources),
	69	.resource = ocores_resources,
ccf988b6	70	};