xref: /openbmc/u-boot/arch/x86/cpu/broadwell/lpc.c (revision 8f695232)
1 /*
2  * Copyright (c) 2016 Google, Inc
3  *
4  * From coreboot broadwell support
5  *
6  * SPDX-License-Identifier:	GPL-2.0
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <pch.h>
12 #include <asm/intel_regs.h>
13 #include <asm/io.h>
14 #include <asm/lpc_common.h>
15 #include <asm/arch/pch.h>
16 #include <asm/arch/spi.h>
17 
18 static void set_spi_speed(void)
19 {
20 	u32 fdod;
21 	u8 ssfc;
22 
23 	/* Observe SPI Descriptor Component Section 0 */
24 	writel(0x1000, SPI_REG(SPIBAR_FDOC));
25 
26 	/* Extract the Write/Erase SPI Frequency from descriptor */
27 	fdod = readl(SPI_REG(SPIBAR_FDOD));
28 	fdod >>= 24;
29 	fdod &= 7;
30 
31 	/* Set Software Sequence frequency to match */
32 	ssfc = readb(SPI_REG(SPIBAR_SSFC + 2));
33 	ssfc &= ~7;
34 	ssfc |= fdod;
35 	writeb(ssfc, SPI_REG(SPIBAR_SSFC + 2));
36 }
37 
38 static int broadwell_lpc_early_init(struct udevice *dev)
39 {
40 	set_spi_speed();
41 
42 	return 0;
43 }
44 
45 static int lpc_init_extra(struct udevice *dev)
46 {
47 	return 0;
48 }
49 
50 static int broadwell_lpc_probe(struct udevice *dev)
51 {
52 	int ret;
53 
54 	if (!(gd->flags & GD_FLG_RELOC)) {
55 		ret = lpc_common_early_init(dev);
56 		if (ret) {
57 			debug("%s: lpc_early_init() failed\n", __func__);
58 			return ret;
59 		}
60 
61 		return broadwell_lpc_early_init(dev);
62 	}
63 
64 	return lpc_init_extra(dev);
65 }
66 
67 static const struct udevice_id broadwell_lpc_ids[] = {
68 	{ .compatible = "intel,broadwell-lpc" },
69 	{ }
70 };
71 
72 U_BOOT_DRIVER(broadwell_lpc_drv) = {
73 	.name		= "lpc",
74 	.id		= UCLASS_LPC,
75 	.of_match	= broadwell_lpc_ids,
76 	.probe		= broadwell_lpc_probe,
77 };
78