LXR linux/drivers/char/tpm/tpm

   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
  20struct 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
  36static inline void atmel_put_base_addr(void __iomem *iobase)
  37{
  38        iounmap(iobase);
  39}
  40
  41static 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 */
  89enum tpm_atmel_addr {
  90        TPM_ATMEL_BASE_ADDR_LO = 0x08,
  91        TPM_ATMEL_BASE_ADDR_HI = 0x09
  92};
  93
  94static 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 */
 101static 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
 120static inline void atmel_put_base_addr(void __iomem *iobase)
 121{
 122}
 123
 124/* Determine where to talk to device */
 125static 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
 141