xref: /openbmc/u-boot/arch/x86/cpu/broadwell/me.c (revision c7c47ca2)
1 /*
2  * Copyright (c) 2016 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0
5  *
6  * Based on code from coreboot src/soc/intel/broadwell/me_status.c
7  */
8 
9 #include <common.h>
10 #include <errno.h>
11 #include <asm/arch/me.h>
12 
13 static inline void me_read_dword_ptr(struct udevice *dev, void *ptr, int offset)
14 {
15 	u32 dword;
16 
17 	dm_pci_read_config32(dev, offset, &dword);
18 	memcpy(ptr, &dword, sizeof(dword));
19 }
20 
21 int intel_me_hsio_version(struct udevice *dev, uint16_t *versionp,
22 			  uint16_t *checksump)
23 {
24 	int count;
25 	u32 hsiover;
26 	struct me_hfs hfs;
27 
28 	/* Query for HSIO version, overloads H_GS and HFS */
29 	dm_pci_write_config32(dev, PCI_ME_H_GS,
30 			      ME_HSIO_MESSAGE | ME_HSIO_CMD_GETHSIOVER);
31 
32 	/* Must wait for ME acknowledgement */
33 	for (count = ME_RETRY; count > 0; --count) {
34 		me_read_dword_ptr(dev, &hfs, PCI_ME_HFS);
35 		if (hfs.bios_msg_ack)
36 			break;
37 		udelay(ME_DELAY);
38 	}
39 	if (!count) {
40 		debug("ERROR: ME failed to respond\n");
41 		return -ETIMEDOUT;
42 	}
43 
44 	/* HSIO version should be in HFS_5 */
45 	dm_pci_read_config32(dev, PCI_ME_HFS5, &hsiover);
46 	*versionp = hsiover >> 16;
47 	*checksump = hsiover & 0xffff;
48 
49 	debug("ME: HSIO Version            : %d (CRC 0x%04x)\n",
50 	      *versionp, *checksump);
51 
52 	/* Reset registers to normal behavior */
53 	dm_pci_write_config32(dev, PCI_ME_H_GS,
54 			      ME_HSIO_MESSAGE | ME_HSIO_CMD_GETHSIOVER);
55 
56 	return 0;
57 }
58