GNU Linux-libre 6.9-gnu
[releases.git] / Documentation / i2c / busses / i2c-ocores.rst
1 ========================
2 Kernel driver i2c-ocores
3 ========================
4
5 Supported adapters:
6   * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
7     https://opencores.org/project/i2c/overview
8
9 Author: Peter Korsgaard <peter@korsgaard.com>
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
23 ocores_i2c_platform_data (see linux/platform_data/i2c-ocores.h) describing the
24 distance between registers and the input clock speed.
25 There is also a possibility to attach a list of i2c_board_info which
26 the i2c-ocores driver will add to the bus upon creation.
27
28 E.G. something like::
29
30   static struct resource ocores_resources[] = {
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         },
41   };
42
43   /* optional board info */
44   struct i2c_board_info ocores_i2c_board_info[] = {
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         }
54   };
55
56   static struct ocores_i2c_platform_data myi2c_data = {
57         .regstep        = 2,            /* two bytes between registers */
58         .clock_khz      = 50000,        /* input clock of 50MHz */
59         .devices        = ocores_i2c_board_info, /* optional table of devices */
60         .num_devices    = ARRAY_SIZE(ocores_i2c_board_info), /* table size */
61   };
62
63   static struct platform_device myi2c = {
64         .name                   = "ocores-i2c",
65         .dev = {
66                 .platform_data  = &myi2c_data,
67         },
68         .num_resources          = ARRAY_SIZE(ocores_resources),
69         .resource               = ocores_resources,
70   };