xref: /linux/drivers/char/tpm/tpm_atmel.h (revision df6d3916f3b7b7e2067567a256dd4f0c1ea854a2)
1 /*
2  * Copyright (C) 2005 IBM Corporation
3  *
4  * Authors:
5  * Kylene Hall <kjhall@us.ibm.com>
6  *
7  * Maintained by: <tpmdd_devel@lists.sourceforge.net>
8  *
9  * Device driver for TCG/TCPA TPM (trusted platform module).
10  * Specifications at www.trustedcomputinggroup.org
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation, version 2 of the
15  * License.
16  *
17  * These difference are required on power because the device must be
18  * discovered through the device tree and iomap must be used to get
19  * around the need for holes in the io_page_mask.  This does not happen
20  * automatically because the tpm is not a normal pci device and lives
21  * under the root node.
22  *
23  */
24 
25 #ifdef CONFIG_PPC64
26 #define atmel_getb(chip, offset) readb(chip->vendor->iobase + offset);
27 #define atmel_putb(val, chip, offset) writeb(val, chip->vendor->iobase + offset)
28 #define atmel_request_region request_mem_region
29 #define atmel_release_region release_mem_region
30 
31 static inline void atmel_put_base_addr(void __iomem *iobase)
32 {
33 	iounmap(iobase);
34 }
35 
36 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
37 {
38 	struct device_node *dn;
39 	unsigned long address, size;
40 	const unsigned int *reg;
41 	int reglen;
42 	int naddrc;
43 	int nsizec;
44 
45 	dn = of_find_node_by_name(NULL, "tpm");
46 
47 	if (!dn)
48 		return NULL;
49 
50 	if (!of_device_is_compatible(dn, "AT97SC3201")) {
51 		of_node_put(dn);
52 		return NULL;
53 	}
54 
55 	reg = of_get_property(dn, "reg", &reglen);
56 	naddrc = of_n_addr_cells(dn);
57 	nsizec = of_n_size_cells(dn);
58 
59 	of_node_put(dn);
60 
61 
62 	if (naddrc == 2)
63 		address = ((unsigned long) reg[0] << 32) | reg[1];
64 	else
65 		address = reg[0];
66 
67 	if (nsizec == 2)
68 		size =
69 		    ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
70 	else
71 		size = reg[naddrc];
72 
73 	*base = address;
74 	*region_size = size;
75 	return ioremap(*base, *region_size);
76 }
77 #else
78 #define atmel_getb(chip, offset) inb(chip->vendor->base + offset)
79 #define atmel_putb(val, chip, offset) outb(val, chip->vendor->base + offset)
80 #define atmel_request_region request_region
81 #define atmel_release_region release_region
82 /* Atmel definitions */
83 enum tpm_atmel_addr {
84 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
85 	TPM_ATMEL_BASE_ADDR_HI = 0x09
86 };
87 
88 /* Verify this is a 1.1 Atmel TPM */
89 static int atmel_verify_tpm11(void)
90 {
91 
92 	/* verify that it is an Atmel part */
93 	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
94 	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
95 	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
96 	    tpm_read_index(TPM_ADDR, 7) != 'L')
97 		return 1;
98 
99 	/* query chip for its version number */
100 	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
101 	    tpm_read_index(TPM_ADDR, 0x01) != 1)
102 		return 1;
103 
104 	/* This is an atmel supported part */
105 	return 0;
106 }
107 
108 static inline void atmel_put_base_addr(void __iomem *iobase)
109 {
110 }
111 
112 /* Determine where to talk to device */
113 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
114 {
115 	int lo, hi;
116 
117 	if (atmel_verify_tpm11() != 0)
118 		return NULL;
119 
120 	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
121 	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
122 
123 	*base = (hi << 8) | lo;
124 	*region_size = 2;
125 
126 	return ioport_map(*base, *region_size);
127 }
128 #endif
129