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   };