drivers/char/tpm/tpm_atmel.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2005 IBM Corporation
   4  *
   5  * Authors:
   6  * Kylene Hall <kjhall@us.ibm.com>
   7  *
   8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
   9  *
  10  * Device driver for TCG/TCPA TPM (trusted platform module).
  11  * Specifications at www.trustedcomputinggroup.org
  12  *
  13  * These difference are required on power because the device must be
  14  * discovered through the device tree and iomap must be used to get
  15  * around the need for holes in the io_page_mask.  This does not happen
  16  * automatically because the tpm is not a normal pci device and lives
  17  * under the root node.
  18  */
  19
  20 struct tpm_atmel_priv {
  21         int region_size;
  22         int have_region;
  23         unsigned long base;
  24         void __iomem *iobase;
  25 };
  26
  27 #ifdef CONFIG_PPC64
  28
  29 #include <asm/prom.h>
  30
  31 #define atmel_getb(priv, offset) readb(priv->iobase + offset)
  32 #define atmel_putb(val, priv, offset) writeb(val, priv->iobase + offset)
  33 #define atmel_request_region request_mem_region
  34 #define atmel_release_region release_mem_region
  35
  36 static inline void atmel_put_base_addr(void __iomem *iobase)
  37 {
  38         iounmap(iobase);
  39 }
  40
  41 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
  42 {
  43         struct device_node *dn;
  44         unsigned long address, size;
  45         const unsigned int *reg;
  46         int reglen;
  47         int naddrc;
  48         int nsizec;
  49
  50         dn = of_find_node_by_name(NULL, "tpm");
  51
  52         if (!dn)
  53                 return NULL;
  54
  55         if (!of_device_is_compatible(dn, "AT97SC3201")) {
  56                 of_node_put(dn);
  57                 return NULL;
  58         }
  59
  60         reg = of_get_property(dn, "reg", &reglen);
  61         naddrc = of_n_addr_cells(dn);
  62         nsizec = of_n_size_cells(dn);
  63
  64         of_node_put(dn);
  65
  66
  67         if (naddrc == 2)
  68                 address = ((unsigned long) reg[0] << 32) | reg[1];
  69         else
  70                 address = reg[0];
  71
  72         if (nsizec == 2)
  73                 size =
  74                     ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
  75         else
  76                 size = reg[naddrc];
  77
  78         *base = address;
  79         *region_size = size;
  80         return ioremap(*base, *region_size);
  81 }
  82 #else
  83 #define atmel_getb(chip, offset) inb(atmel_get_priv(chip)->base + offset)
  84 #define atmel_putb(val, chip, offset) \
  85         outb(val, atmel_get_priv(chip)->base + offset)
  86 #define atmel_request_region request_region
  87 #define atmel_release_region release_region
  88 /* Atmel definitions */
  89 enum tpm_atmel_addr {
  90         TPM_ATMEL_BASE_ADDR_LO = 0x08,
  91         TPM_ATMEL_BASE_ADDR_HI = 0x09
  92 };
  93
  94 static inline int tpm_read_index(int base, int index)
  95 {
  96         outb(index, base);
  97         return inb(base+1) & 0xFF;
  98 }
  99
 100 /* Verify this is a 1.1 Atmel TPM */
 101 static int atmel_verify_tpm11(void)
 102 {
 103
 104         /* verify that it is an Atmel part */
 105         if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
 106             tpm_read_index(TPM_ADDR, 5) != 'T' ||
 107             tpm_read_index(TPM_ADDR, 6) != 'M' ||
 108             tpm_read_index(TPM_ADDR, 7) != 'L')
 109                 return 1;
 110
 111         /* query chip for its version number */
 112         if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
 113             tpm_read_index(TPM_ADDR, 0x01) != 1)
 114                 return 1;
 115
 116         /* This is an atmel supported part */
 117         return 0;
 118 }
 119
 120 static inline void atmel_put_base_addr(void __iomem *iobase)
 121 {
 122 }
 123
 124 /* Determine where to talk to device */
 125 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
 126 {
 127         int lo, hi;
 128
 129         if (atmel_verify_tpm11() != 0)
 130                 return NULL;
 131
 132         lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
 133         hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
 134
 135         *base = (hi << 8) | lo;
 136         *region_size = 2;
 137
 138         return ioport_map(*base, *region_size);
 139 }
 140 #endif