xref: /openbmc/u-boot/drivers/pch/pch7.c (revision 274bced8)
1 /*
2  * Copyright (C) 2014 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <pch.h>
10 
11 #define GPIO_BASE	0x44
12 #define BIOS_CTRL	0xd8
13 
14 static int pch7_get_spi_base(struct udevice *dev, ulong *sbasep)
15 {
16 	u32 rcba;
17 
18 	dm_pci_read_config32(dev, PCH_RCBA, &rcba);
19 	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable */
20 	rcba = rcba & 0xffffc000;
21 	*sbasep = rcba + 0x3020;
22 
23 	return 0;
24 }
25 
26 static int pch7_set_spi_protect(struct udevice *dev, bool protect)
27 {
28 	uint8_t bios_cntl;
29 
30 	/* Adjust the BIOS write protect to dis/allow write commands */
31 	dm_pci_read_config8(dev, BIOS_CTRL, &bios_cntl);
32 	if (protect)
33 		bios_cntl &= ~BIOS_CTRL_BIOSWE;
34 	else
35 		bios_cntl |= BIOS_CTRL_BIOSWE;
36 	dm_pci_write_config8(dev, BIOS_CTRL, bios_cntl);
37 
38 	return 0;
39 }
40 
41 static int pch7_get_gpio_base(struct udevice *dev, u32 *gbasep)
42 {
43 	u32 base;
44 
45 	/*
46 	 * GPIO_BASE moved to its current offset with ICH6, but prior to
47 	 * that it was unused (or undocumented). Check that it looks
48 	 * okay: not all ones or zeros.
49 	 *
50 	 * Note we don't need check bit0 here, because the Tunnel Creek
51 	 * GPIO base address register bit0 is reserved (read returns 0),
52 	 * while on the Ivybridge the bit0 is used to indicate it is an
53 	 * I/O space.
54 	 */
55 	dm_pci_read_config32(dev, GPIO_BASE, &base);
56 	if (base == 0x00000000 || base == 0xffffffff) {
57 		debug("%s: unexpected BASE value\n", __func__);
58 		return -ENODEV;
59 	}
60 
61 	/*
62 	 * Okay, I guess we're looking at the right device. The actual
63 	 * GPIO registers are in the PCI device's I/O space, starting
64 	 * at the offset that we just read. Bit 0 indicates that it's
65 	 * an I/O address, not a memory address, so mask that off.
66 	 */
67 	*gbasep = base & 1 ? base & ~3 : base & ~15;
68 
69 	return 0;
70 }
71 
72 static const struct pch_ops pch7_ops = {
73 	.get_spi_base	= pch7_get_spi_base,
74 	.set_spi_protect = pch7_set_spi_protect,
75 	.get_gpio_base	= pch7_get_gpio_base,
76 };
77 
78 static const struct udevice_id pch7_ids[] = {
79 	{ .compatible = "intel,pch7" },
80 	{ }
81 };
82 
83 U_BOOT_DRIVER(pch7_drv) = {
84 	.name		= "intel-pch7",
85 	.id		= UCLASS_PCH,
86 	.of_match	= pch7_ids,
87 	.ops		= &pch7_ops,
88 };
89