xref: /linux/drivers/char/tpm/tpm_atmel.h (revision 4a7126a25b4dfd07d61c699f724118275acc0c25)
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 struct tpm_atmel_priv {
26 	int region_size;
27 	int have_region;
28 	unsigned long base;
29 	void __iomem *iobase;
30 };
31 
32 #ifdef CONFIG_PPC64
33 
34 #include <asm/prom.h>
35 
36 #define atmel_getb(priv, offset) readb(priv->iobase + offset)
37 #define atmel_putb(val, priv, offset) writeb(val, priv->iobase + offset)
38 #define atmel_request_region request_mem_region
39 #define atmel_release_region release_mem_region
40 
41 static inline void atmel_put_base_addr(void __iomem *iobase)
42 {
43 	iounmap(iobase);
44 }
45 
46 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
47 {
48 	struct device_node *dn;
49 	unsigned long address, size;
50 	const unsigned int *reg;
51 	int reglen;
52 	int naddrc;
53 	int nsizec;
54 
55 	dn = of_find_node_by_name(NULL, "tpm");
56 
57 	if (!dn)
58 		return NULL;
59 
60 	if (!of_device_is_compatible(dn, "AT97SC3201")) {
61 		of_node_put(dn);
62 		return NULL;
63 	}
64 
65 	reg = of_get_property(dn, "reg", &reglen);
66 	naddrc = of_n_addr_cells(dn);
67 	nsizec = of_n_size_cells(dn);
68 
69 	of_node_put(dn);
70 
71 
72 	if (naddrc == 2)
73 		address = ((unsigned long) reg[0] << 32) | reg[1];
74 	else
75 		address = reg[0];
76 
77 	if (nsizec == 2)
78 		size =
79 		    ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
80 	else
81 		size = reg[naddrc];
82 
83 	*base = address;
84 	*region_size = size;
85 	return ioremap(*base, *region_size);
86 }
87 #else
88 #define atmel_getb(chip, offset) inb(atmel_get_priv(chip)->base + offset)
89 #define atmel_putb(val, chip, offset) \
90 	outb(val, atmel_get_priv(chip)->base + offset)
91 #define atmel_request_region request_region
92 #define atmel_release_region release_region
93 /* Atmel definitions */
94 enum tpm_atmel_addr {
95 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
96 	TPM_ATMEL_BASE_ADDR_HI = 0x09
97 };
98 
99 /* Verify this is a 1.1 Atmel TPM */
100 static int atmel_verify_tpm11(void)
101 {
102 
103 	/* verify that it is an Atmel part */
104 	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
105 	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
106 	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
107 	    tpm_read_index(TPM_ADDR, 7) != 'L')
108 		return 1;
109 
110 	/* query chip for its version number */
111 	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
112 	    tpm_read_index(TPM_ADDR, 0x01) != 1)
113 		return 1;
114 
115 	/* This is an atmel supported part */
116 	return 0;
117 }
118 
119 static inline void atmel_put_base_addr(void __iomem *iobase)
120 {
121 }
122 
123 /* Determine where to talk to device */
124 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
125 {
126 	int lo, hi;
127 
128 	if (atmel_verify_tpm11() != 0)
129 		return NULL;
130 
131 	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
132 	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
133 
134 	*base = (hi << 8) | lo;
135 	*region_size = 2;
136 
137 	return ioport_map(*base, *region_size);
138 }
139 #endif
140