xref: /openbmc/u-boot/arch/x86/cpu/broadwell/me.c (revision d66ff4ba)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016 Google, Inc
4  *
5  * Based on code from coreboot src/soc/intel/broadwell/me_status.c
6  */
7 
8 #include <common.h>
9 #include <errno.h>
10 #include <asm/arch/me.h>
11 
12 static inline void me_read_dword_ptr(struct udevice *dev, void *ptr, int offset)
13 {
14 	u32 dword;
15 
16 	dm_pci_read_config32(dev, offset, &dword);
17 	memcpy(ptr, &dword, sizeof(dword));
18 }
19 
20 int intel_me_hsio_version(struct udevice *dev, uint16_t *versionp,
21 			  uint16_t *checksump)
22 {
23 	int count;
24 	u32 hsiover;
25 	struct me_hfs hfs;
26 
27 	/* Query for HSIO version, overloads H_GS and HFS */
28 	dm_pci_write_config32(dev, PCI_ME_H_GS,
29 			      ME_HSIO_MESSAGE | ME_HSIO_CMD_GETHSIOVER);
30 
31 	/* Must wait for ME acknowledgement */
32 	for (count = ME_RETRY; count > 0; --count) {
33 		me_read_dword_ptr(dev, &hfs, PCI_ME_HFS);
34 		if (hfs.bios_msg_ack)
35 			break;
36 		udelay(ME_DELAY);
37 	}
38 	if (!count) {
39 		debug("ERROR: ME failed to respond\n");
40 		return -ETIMEDOUT;
41 	}
42 
43 	/* HSIO version should be in HFS_5 */
44 	dm_pci_read_config32(dev, PCI_ME_HFS5, &hsiover);
45 	*versionp = hsiover >> 16;
46 	*checksump = hsiover & 0xffff;
47 
48 	debug("ME: HSIO Version            : %d (CRC 0x%04x)\n",
49 	      *versionp, *checksump);
50 
51 	/* Reset registers to normal behavior */
52 	dm_pci_write_config32(dev, PCI_ME_H_GS,
53 			      ME_HSIO_MESSAGE | ME_HSIO_CMD_GETHSIOVER);
54 
55 	return 0;
56 }
57