xref: /openbmc/linux/drivers/char/tpm/tpm_atmel.h (revision 87c2ce3b)
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(struct tpm_vendor_specific
32 					 *vendor)
33 {
34 	iounmap(vendor->iobase);
35 }
36 
37 static void __iomem * atmel_get_base_addr(struct tpm_vendor_specific *vendor)
38 {
39 	struct device_node *dn;
40 	unsigned long address, size;
41 	unsigned int *reg;
42 	int reglen;
43 	int naddrc;
44 	int nsizec;
45 
46 	dn = of_find_node_by_name(NULL, "tpm");
47 
48 	if (!dn)
49 		return NULL;
50 
51 	if (!device_is_compatible(dn, "AT97SC3201")) {
52 		of_node_put(dn);
53 		return NULL;
54 	}
55 
56 	reg = (unsigned int *) get_property(dn, "reg", &reglen);
57 	naddrc = prom_n_addr_cells(dn);
58 	nsizec = prom_n_size_cells(dn);
59 
60 	of_node_put(dn);
61 
62 
63 	if (naddrc == 2)
64 		address = ((unsigned long) reg[0] << 32) | reg[1];
65 	else
66 		address = reg[0];
67 
68 	if (nsizec == 2)
69 		size =
70 		    ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
71 	else
72 		size = reg[naddrc];
73 
74 	vendor->base = address;
75 	vendor->region_size = size;
76 	return ioremap(vendor->base, vendor->region_size);
77 }
78 #else
79 #define atmel_getb(chip, offset) inb(chip->vendor->base + offset)
80 #define atmel_putb(val, chip, offset) outb(val, chip->vendor->base + offset)
81 #define atmel_request_region request_region
82 #define atmel_release_region release_region
83 /* Atmel definitions */
84 enum tpm_atmel_addr {
85 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
86 	TPM_ATMEL_BASE_ADDR_HI = 0x09
87 };
88 
89 /* Verify this is a 1.1 Atmel TPM */
90 static int atmel_verify_tpm11(void)
91 {
92 
93 	/* verify that it is an Atmel part */
94 	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
95 	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
96 	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
97 	    tpm_read_index(TPM_ADDR, 7) != 'L')
98 		return 1;
99 
100 	/* query chip for its version number */
101 	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
102 	    tpm_read_index(TPM_ADDR, 0x01) != 1)
103 		return 1;
104 
105 	/* This is an atmel supported part */
106 	return 0;
107 }
108 
109 static inline void atmel_put_base_addr(struct tpm_vendor_specific
110 					 *vendor)
111 {
112 }
113 
114 /* Determine where to talk to device */
115 static void __iomem * atmel_get_base_addr(struct tpm_vendor_specific
116 					 *vendor)
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 	vendor->base = (hi << 8) | lo;
127 	vendor->region_size = 2;
128 
129 	return ioport_map(vendor->base, vendor->region_size);
130 }
131 #endif
132