drivers/i2c/intel_i2c.c

   1 /*
   2  * Copyright (c) 2015 Google, Inc
   3  * Written by Simon Glass <sjg@chromium.org>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <i2c.h>
  11 #include <asm/io.h>
  12 #include <asm/arch/pch.h>
  13
  14 int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
  15 {
  16         return -ENOSYS;
  17 }
  18
  19 int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr, uint chip_flags)
  20 {
  21         return -ENOSYS;
  22 }
  23
  24 int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
  25 {
  26         return 0;
  27 }
  28
  29 static int intel_i2c_probe(struct udevice *dev)
  30 {
  31         /*
  32          * So far this is just setup code for ivybridge SMbus. When we have
  33          * a full I2C driver this may need to be moved, generalised or made
  34          * dependant on a particular compatible string.
  35          *
  36          * Set SMBus I/O base
  37          */
  38         dm_pci_write_config32(dev, SMB_BASE,
  39                               SMBUS_IO_BASE | PCI_BASE_ADDRESS_SPACE_IO);
  40
  41         /* Set SMBus enable. */
  42         dm_pci_write_config8(dev, HOSTC, HST_EN);
  43
  44         /* Set SMBus I/O space enable. */
  45         dm_pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_IO);
  46
  47         /* Disable interrupt generation. */
  48         outb(0, SMBUS_IO_BASE + SMBHSTCTL);
  49
  50         /* Clear any lingering errors, so transactions can run. */
  51         outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
  52         debug("SMBus controller enabled\n");
  53
  54         return 0;
  55 }
  56
  57 static const struct dm_i2c_ops intel_i2c_ops = {
  58         .xfer           = intel_i2c_xfer,
  59         .probe_chip     = intel_i2c_probe_chip,
  60         .set_bus_speed  = intel_i2c_set_bus_speed,
  61 };
  62
  63 static const struct udevice_id intel_i2c_ids[] = {
  64         { .compatible = "intel,ich-i2c" },
  65         { }
  66 };
  67
  68 U_BOOT_DRIVER(intel_i2c) = {
  69         .name   = "i2c_intel",
  70         .id     = UCLASS_I2C,
  71         .of_match = intel_i2c_ids,
  72         .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
  73         .ops    = &intel_i2c_ops,
  74         .probe  = intel_i2c_probe,
  75 };