drivers/char/tpm/tpm_atmel.h

   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 static inline int tpm_read_index(int base, int index)
 100 {
 101         outb(index, base);
 102         return inb(base+1) & 0xFF;
 103 }
 104
 105 /* Verify this is a 1.1 Atmel TPM */
 106 static int atmel_verify_tpm11(void)
 107 {
 108
 109         /* verify that it is an Atmel part */
 110         if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
 111             tpm_read_index(TPM_ADDR, 5) != 'T' ||
 112             tpm_read_index(TPM_ADDR, 6) != 'M' ||
 113             tpm_read_index(TPM_ADDR, 7) != 'L')
 114                 return 1;
 115
 116         /* query chip for its version number */
 117         if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
 118             tpm_read_index(TPM_ADDR, 0x01) != 1)
 119                 return 1;
 120
 121         /* This is an atmel supported part */
 122         return 0;
 123 }
 124
 125 static inline void atmel_put_base_addr(void __iomem *iobase)
 126 {
 127 }
 128
 129 /* Determine where to talk to device */
 130 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
 131 {
 132         int lo, hi;
 133
 134         if (atmel_verify_tpm11() != 0)
 135                 return NULL;
 136
 137         lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
 138         hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
 139
 140         *base = (hi << 8) | lo;
 141         *region_size = 2;
 142
 143         return ioport_map(*base, *region_size);
 144 }
 145 #endif