xref: /linux/drivers/char/tpm/tpm_atmel.h (revision 23d06ff700f546a6a1d63c85ade095dbd75b7ab5)
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 };
29 
30 #ifdef CONFIG_PPC64
31 
32 #include <asm/prom.h>
33 
34 #define atmel_getb(chip, offset) readb(chip->vendor->iobase + offset);
35 #define atmel_putb(val, chip, offset) writeb(val, chip->vendor->iobase + offset)
36 #define atmel_request_region request_mem_region
37 #define atmel_release_region release_mem_region
38 
39 static inline void atmel_put_base_addr(void __iomem *iobase)
40 {
41 	iounmap(iobase);
42 }
43 
44 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
45 {
46 	struct device_node *dn;
47 	unsigned long address, size;
48 	const unsigned int *reg;
49 	int reglen;
50 	int naddrc;
51 	int nsizec;
52 
53 	dn = of_find_node_by_name(NULL, "tpm");
54 
55 	if (!dn)
56 		return NULL;
57 
58 	if (!of_device_is_compatible(dn, "AT97SC3201")) {
59 		of_node_put(dn);
60 		return NULL;
61 	}
62 
63 	reg = of_get_property(dn, "reg", &reglen);
64 	naddrc = of_n_addr_cells(dn);
65 	nsizec = of_n_size_cells(dn);
66 
67 	of_node_put(dn);
68 
69 
70 	if (naddrc == 2)
71 		address = ((unsigned long) reg[0] << 32) | reg[1];
72 	else
73 		address = reg[0];
74 
75 	if (nsizec == 2)
76 		size =
77 		    ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
78 	else
79 		size = reg[naddrc];
80 
81 	*base = address;
82 	*region_size = size;
83 	return ioremap(*base, *region_size);
84 }
85 #else
86 #define atmel_getb(chip, offset) inb(chip->vendor->base + offset)
87 #define atmel_putb(val, chip, offset) outb(val, chip->vendor->base + offset)
88 #define atmel_request_region request_region
89 #define atmel_release_region release_region
90 /* Atmel definitions */
91 enum tpm_atmel_addr {
92 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
93 	TPM_ATMEL_BASE_ADDR_HI = 0x09
94 };
95 
96 /* Verify this is a 1.1 Atmel TPM */
97 static int atmel_verify_tpm11(void)
98 {
99 
100 	/* verify that it is an Atmel part */
101 	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
102 	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
103 	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
104 	    tpm_read_index(TPM_ADDR, 7) != 'L')
105 		return 1;
106 
107 	/* query chip for its version number */
108 	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
109 	    tpm_read_index(TPM_ADDR, 0x01) != 1)
110 		return 1;
111 
112 	/* This is an atmel supported part */
113 	return 0;
114 }
115 
116 static inline void atmel_put_base_addr(void __iomem *iobase)
117 {
118 }
119 
120 /* Determine where to talk to device */
121 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
122 {
123 	int lo, hi;
124 
125 	if (atmel_verify_tpm11() != 0)
126 		return NULL;
127 
128 	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
129 	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
130 
131 	*base = (hi << 8) | lo;
132 	*region_size = 2;
133 
134 	return ioport_map(*base, *region_size);
135 }
136 #endif
137