xref: /openbmc/u-boot/arch/x86/cpu/broadwell/lpc.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016 Google, Inc
4  *
5  * From coreboot broadwell support
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <pch.h>
11 #include <asm/intel_regs.h>
12 #include <asm/io.h>
13 #include <asm/lpc_common.h>
14 #include <asm/arch/pch.h>
15 #include <asm/arch/spi.h>
16 
17 static void set_spi_speed(void)
18 {
19 	u32 fdod;
20 	u8 ssfc;
21 
22 	/* Observe SPI Descriptor Component Section 0 */
23 	writel(0x1000, SPI_REG(SPIBAR_FDOC));
24 
25 	/* Extract the Write/Erase SPI Frequency from descriptor */
26 	fdod = readl(SPI_REG(SPIBAR_FDOD));
27 	fdod >>= 24;
28 	fdod &= 7;
29 
30 	/* Set Software Sequence frequency to match */
31 	ssfc = readb(SPI_REG(SPIBAR_SSFC + 2));
32 	ssfc &= ~7;
33 	ssfc |= fdod;
34 	writeb(ssfc, SPI_REG(SPIBAR_SSFC + 2));
35 }
36 
37 static int broadwell_lpc_early_init(struct udevice *dev)
38 {
39 	set_spi_speed();
40 
41 	return 0;
42 }
43 
44 static int lpc_init_extra(struct udevice *dev)
45 {
46 	return 0;
47 }
48 
49 static int broadwell_lpc_probe(struct udevice *dev)
50 {
51 	int ret;
52 
53 	if (!(gd->flags & GD_FLG_RELOC)) {
54 		ret = lpc_common_early_init(dev);
55 		if (ret) {
56 			debug("%s: lpc_early_init() failed\n", __func__);
57 			return ret;
58 		}
59 
60 		return broadwell_lpc_early_init(dev);
61 	}
62 
63 	return lpc_init_extra(dev);
64 }
65 
66 static const struct udevice_id broadwell_lpc_ids[] = {
67 	{ .compatible = "intel,broadwell-lpc" },
68 	{ }
69 };
70 
71 U_BOOT_DRIVER(broadwell_lpc_drv) = {
72 	.name		= "lpc",
73 	.id		= UCLASS_LPC,
74 	.of_match	= broadwell_lpc_ids,
75 	.probe		= broadwell_lpc_probe,
76 };
77