aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/i2c/busses/i2c-ocores
blob: cfcebb10d14edb0e70af97d2b4ec0df4378eed05 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Kernel driver i2c-ocores

Supported adapters:
  * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
    Datasheet: http://www.opencores.org/projects.cgi/web/i2c/overview

Author: Peter Korsgaard <jacmet@sunsite.dk>

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/i2c-ocores.h) describing the
distance between registers and the input clock speed.

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,
	},
};

static struct ocores_i2c_platform_data myi2c_data = {
	.regstep	= 2,		/* two bytes between registers */
	.clock_khz	= 50000,	/* input clock of 50MHz */
};

static struct platform_device myi2c = {
	.name			= "ocores-i2c",
	.dev = {
		.platform_data	= &myi2c_data,
	},
	.num_resources		= ARRAY_SIZE(ocores_resources),
	.resource		= ocores_resources,
};