xref: /OK3568_Linux_fs/kernel/Documentation/i2c/busses/i2c-ocores.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun========================
2*4882a593SmuzhiyunKernel driver i2c-ocores
3*4882a593Smuzhiyun========================
4*4882a593Smuzhiyun
5*4882a593SmuzhiyunSupported adapters:
6*4882a593Smuzhiyun  * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
7*4882a593Smuzhiyun    https://opencores.org/project/i2c/overview
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunAuthor: Peter Korsgaard <peter@korsgaard.com>
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunDescription
12*4882a593Smuzhiyun-----------
13*4882a593Smuzhiyun
14*4882a593Smuzhiyuni2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
15*4882a593SmuzhiyunIP core by Richard Herveille.
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunUsage
18*4882a593Smuzhiyun-----
19*4882a593Smuzhiyun
20*4882a593Smuzhiyuni2c-ocores uses the platform bus, so you need to provide a struct
21*4882a593Smuzhiyunplatform_device with the base address and interrupt number. The
22*4882a593Smuzhiyundev.platform_data of the device should also point to a struct
23*4882a593Smuzhiyunocores_i2c_platform_data (see linux/platform_data/i2c-ocores.h) describing the
24*4882a593Smuzhiyundistance between registers and the input clock speed.
25*4882a593SmuzhiyunThere is also a possibility to attach a list of i2c_board_info which
26*4882a593Smuzhiyunthe i2c-ocores driver will add to the bus upon creation.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunE.G. something like::
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun  static struct resource ocores_resources[] = {
31*4882a593Smuzhiyun	[0] = {
32*4882a593Smuzhiyun		.start	= MYI2C_BASEADDR,
33*4882a593Smuzhiyun		.end	= MYI2C_BASEADDR + 8,
34*4882a593Smuzhiyun		.flags	= IORESOURCE_MEM,
35*4882a593Smuzhiyun	},
36*4882a593Smuzhiyun	[1] = {
37*4882a593Smuzhiyun		.start	= MYI2C_IRQ,
38*4882a593Smuzhiyun		.end	= MYI2C_IRQ,
39*4882a593Smuzhiyun		.flags	= IORESOURCE_IRQ,
40*4882a593Smuzhiyun	},
41*4882a593Smuzhiyun  };
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun  /* optional board info */
44*4882a593Smuzhiyun  struct i2c_board_info ocores_i2c_board_info[] = {
45*4882a593Smuzhiyun	{
46*4882a593Smuzhiyun		I2C_BOARD_INFO("tsc2003", 0x48),
47*4882a593Smuzhiyun		.platform_data = &tsc2003_platform_data,
48*4882a593Smuzhiyun		.irq = TSC_IRQ
49*4882a593Smuzhiyun	},
50*4882a593Smuzhiyun	{
51*4882a593Smuzhiyun		I2C_BOARD_INFO("adv7180", 0x42 >> 1),
52*4882a593Smuzhiyun		.irq = ADV_IRQ
53*4882a593Smuzhiyun	}
54*4882a593Smuzhiyun  };
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun  static struct ocores_i2c_platform_data myi2c_data = {
57*4882a593Smuzhiyun	.regstep	= 2,		/* two bytes between registers */
58*4882a593Smuzhiyun	.clock_khz	= 50000,	/* input clock of 50MHz */
59*4882a593Smuzhiyun	.devices	= ocores_i2c_board_info, /* optional table of devices */
60*4882a593Smuzhiyun	.num_devices	= ARRAY_SIZE(ocores_i2c_board_info), /* table size */
61*4882a593Smuzhiyun  };
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun  static struct platform_device myi2c = {
64*4882a593Smuzhiyun	.name			= "ocores-i2c",
65*4882a593Smuzhiyun	.dev = {
66*4882a593Smuzhiyun		.platform_data	= &myi2c_data,
67*4882a593Smuzhiyun	},
68*4882a593Smuzhiyun	.num_resources		= ARRAY_SIZE(ocores_resources),
69*4882a593Smuzhiyun	.resource		= ocores_resources,
70*4882a593Smuzhiyun  };
71