xref: /openbmc/u-boot/drivers/pch/pch7.c (revision ae485b54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2014 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <pch.h>
9 
10 #define GPIO_BASE	0x44
11 #define BIOS_CTRL	0xd8
12 
13 static int pch7_get_spi_base(struct udevice *dev, ulong *sbasep)
14 {
15 	u32 rcba;
16 
17 	dm_pci_read_config32(dev, PCH_RCBA, &rcba);
18 	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable */
19 	rcba = rcba & 0xffffc000;
20 	*sbasep = rcba + 0x3020;
21 
22 	return 0;
23 }
24 
25 static int pch7_set_spi_protect(struct udevice *dev, bool protect)
26 {
27 	uint8_t bios_cntl;
28 
29 	/* Adjust the BIOS write protect to dis/allow write commands */
30 	dm_pci_read_config8(dev, BIOS_CTRL, &bios_cntl);
31 	if (protect)
32 		bios_cntl &= ~BIOS_CTRL_BIOSWE;
33 	else
34 		bios_cntl |= BIOS_CTRL_BIOSWE;
35 	dm_pci_write_config8(dev, BIOS_CTRL, bios_cntl);
36 
37 	return 0;
38 }
39 
40 static int pch7_get_gpio_base(struct udevice *dev, u32 *gbasep)
41 {
42 	u32 base;
43 
44 	/*
45 	 * GPIO_BASE moved to its current offset with ICH6, but prior to
46 	 * that it was unused (or undocumented). Check that it looks
47 	 * okay: not all ones or zeros.
48 	 *
49 	 * Note we don't need check bit0 here, because the Tunnel Creek
50 	 * GPIO base address register bit0 is reserved (read returns 0),
51 	 * while on the Ivybridge the bit0 is used to indicate it is an
52 	 * I/O space.
53 	 */
54 	dm_pci_read_config32(dev, GPIO_BASE, &base);
55 	if (base == 0x00000000 || base == 0xffffffff) {
56 		debug("%s: unexpected BASE value\n", __func__);
57 		return -ENODEV;
58 	}
59 
60 	/*
61 	 * Okay, I guess we're looking at the right device. The actual
62 	 * GPIO registers are in the PCI device's I/O space, starting
63 	 * at the offset that we just read. Bit 0 indicates that it's
64 	 * an I/O address, not a memory address, so mask that off.
65 	 */
66 	*gbasep = base & 1 ? base & ~3 : base & ~15;
67 
68 	return 0;
69 }
70 
71 static const struct pch_ops pch7_ops = {
72 	.get_spi_base	= pch7_get_spi_base,
73 	.set_spi_protect = pch7_set_spi_protect,
74 	.get_gpio_base	= pch7_get_gpio_base,
75 };
76 
77 static const struct udevice_id pch7_ids[] = {
78 	{ .compatible = "intel,pch7" },
79 	{ }
80 };
81 
82 U_BOOT_DRIVER(pch7_drv) = {
83 	.name		= "intel-pch7",
84 	.id		= UCLASS_PCH,
85 	.of_match	= pch7_ids,
86 	.ops		= &pch7_ops,
87 };
88