xref: /openbmc/u-boot/drivers/i2c/intel_i2c.c (revision d08957e6)
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 };
76