xref: /linux/drivers/char/tpm/tpm_atmel.h (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 
27 #include <asm/prom.h>
28 
29 #define atmel_getb(chip, offset) readb(chip->vendor->iobase + offset);
30 #define atmel_putb(val, chip, offset) writeb(val, chip->vendor->iobase + offset)
31 #define atmel_request_region request_mem_region
32 #define atmel_release_region release_mem_region
33 
34 static inline void atmel_put_base_addr(void __iomem *iobase)
35 {
36 	iounmap(iobase);
37 }
38 
39 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
40 {
41 	struct device_node *dn;
42 	unsigned long address, size;
43 	const unsigned int *reg;
44 	int reglen;
45 	int naddrc;
46 	int nsizec;
47 
48 	dn = of_find_node_by_name(NULL, "tpm");
49 
50 	if (!dn)
51 		return NULL;
52 
53 	if (!of_device_is_compatible(dn, "AT97SC3201")) {
54 		of_node_put(dn);
55 		return NULL;
56 	}
57 
58 	reg = of_get_property(dn, "reg", &reglen);
59 	naddrc = of_n_addr_cells(dn);
60 	nsizec = of_n_size_cells(dn);
61 
62 	of_node_put(dn);
63 
64 
65 	if (naddrc == 2)
66 		address = ((unsigned long) reg[0] << 32) | reg[1];
67 	else
68 		address = reg[0];
69 
70 	if (nsizec == 2)
71 		size =
72 		    ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
73 	else
74 		size = reg[naddrc];
75 
76 	*base = address;
77 	*region_size = size;
78 	return ioremap(*base, *region_size);
79 }
80 #else
81 #define atmel_getb(chip, offset) inb(chip->vendor->base + offset)
82 #define atmel_putb(val, chip, offset) outb(val, chip->vendor->base + offset)
83 #define atmel_request_region request_region
84 #define atmel_release_region release_region
85 /* Atmel definitions */
86 enum tpm_atmel_addr {
87 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
88 	TPM_ATMEL_BASE_ADDR_HI = 0x09
89 };
90 
91 /* Verify this is a 1.1 Atmel TPM */
92 static int atmel_verify_tpm11(void)
93 {
94 
95 	/* verify that it is an Atmel part */
96 	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
97 	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
98 	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
99 	    tpm_read_index(TPM_ADDR, 7) != 'L')
100 		return 1;
101 
102 	/* query chip for its version number */
103 	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
104 	    tpm_read_index(TPM_ADDR, 0x01) != 1)
105 		return 1;
106 
107 	/* This is an atmel supported part */
108 	return 0;
109 }
110 
111 static inline void atmel_put_base_addr(void __iomem *iobase)
112 {
113 }
114 
115 /* Determine where to talk to device */
116 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
117 {
118 	int lo, hi;
119 
120 	if (atmel_verify_tpm11() != 0)
121 		return NULL;
122 
123 	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
124 	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
125 
126 	*base = (hi << 8) | lo;
127 	*region_size = 2;
128 
129 	return ioport_map(*base, *region_size);
130 }
131 #endif
132