1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *	nv_tco:	TCO timer driver for nVidia chipsets.
4  *
5  *	(c) Copyright 2005 Google Inc., All Rights Reserved.
6  *
7  *	Supported Chipsets:
8  *		- MCP51/MCP55
9  *
10  *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
11  *	Reserved.
12  *				https://www.kernelconcepts.de
13  *
14  *	Neither kernel concepts nor Nils Faerber admit liability nor provide
15  *	warranty for any of this software. This material is provided
16  *	"AS-IS" and at no charge.
17  *
18  *	(c) Copyright 2000	kernel concepts <nils@kernelconcepts.de>
19  *				developed for
20  *                              Jentro AG, Haar/Munich (Germany)
21  *
22  *	TCO timer driver for NV chipsets
23  *	based on softdog.c by Alan Cox <alan@redhat.com>
24  */
25 
26 /*
27  * Some address definitions for the TCO
28  */
29 
30 #define TCO_RLD(base)	((base) + 0x00)	/* TCO Timer Reload and Current Value */
31 #define TCO_TMR(base)	((base) + 0x01)	/* TCO Timer Initial Value	*/
32 
33 #define TCO_STS(base)	((base) + 0x04)	/* TCO Status Register		*/
34 /*
35  * TCO Boot Status bit: set on TCO reset, reset by software or standby
36  * power-good (survives reboots), unfortunately this bit is never
37  * set.
38  */
39 #  define TCO_STS_BOOT_STS	(1 << 9)
40 /*
41  * first and 2nd timeout status bits, these also survive a warm boot,
42  * and they work, so we use them.
43  */
44 #  define TCO_STS_TCO_INT_STS	(1 << 1)
45 #  define TCO_STS_TCO2TO_STS	(1 << 10)
46 #  define TCO_STS_RESET		(TCO_STS_BOOT_STS | TCO_STS_TCO2TO_STS | \
47 				 TCO_STS_TCO_INT_STS)
48 
49 #define TCO_CNT(base)	((base) + 0x08)	/* TCO Control Register	*/
50 #  define TCO_CNT_TCOHALT	(1 << 12)
51 
52 #define MCP51_SMBUS_SETUP_B 0xe8
53 #  define MCP51_SMBUS_SETUP_B_TCO_REBOOT (1 << 25)
54 
55 /*
56  * The SMI_EN register is at the base io address + 0x04,
57  * while TCOBASE is + 0x40.
58  */
59 #define MCP51_SMI_EN(base)	((base) - 0x40 + 0x04)
60 #  define MCP51_SMI_EN_TCO	((1 << 4) | (1 << 5))
61