char/tpm/tpm_atmel.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2005 IBM Corporation
0004  *
0005  * Authors:
0006  * Kylene Hall <kjhall@us.ibm.com>
0007  *
0008  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
0009  *
0010  * Device driver for TCG/TCPA TPM (trusted platform module).
0011  * Specifications at www.trustedcomputinggroup.org
0012  *
0013  * These difference are required on power because the device must be
0014  * discovered through the device tree and iomap must be used to get
0015  * around the need for holes in the io_page_mask.  This does not happen
0016  * automatically because the tpm is not a normal pci device and lives
0017  * under the root node.
0018  */
0019
0020 struct tpm_atmel_priv {
0021     int region_size;
0022     int have_region;
0023     unsigned long base;
0024     void __iomem *iobase;
0025 };
0026
0027 #ifdef CONFIG_PPC64
0028
0029 #include <asm/prom.h>
0030
0031 #define atmel_getb(priv, offset) readb(priv->iobase + offset)
0032 #define atmel_putb(val, priv, offset) writeb(val, priv->iobase + offset)
0033 #define atmel_request_region request_mem_region
0034 #define atmel_release_region release_mem_region
0035
0036 static inline void atmel_put_base_addr(void __iomem *iobase)
0037 {
0038     iounmap(iobase);
0039 }
0040
0041 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
0042 {
0043     struct device_node *dn;
0044     unsigned long address, size;
0045     const unsigned int *reg;
0046     int reglen;
0047     int naddrc;
0048     int nsizec;
0049
0050     dn = of_find_node_by_name(NULL, "tpm");
0051
0052     if (!dn)
0053         return NULL;
0054
0055     if (!of_device_is_compatible(dn, "AT97SC3201")) {
0056         of_node_put(dn);
0057         return NULL;
0058     }
0059
0060     reg = of_get_property(dn, "reg", &reglen);
0061     naddrc = of_n_addr_cells(dn);
0062     nsizec = of_n_size_cells(dn);
0063
0064     of_node_put(dn);
0065
0066
0067     if (naddrc == 2)
0068         address = ((unsigned long) reg[0] << 32) | reg[1];
0069     else
0070         address = reg[0];
0071
0072     if (nsizec == 2)
0073         size =
0074             ((unsigned long) reg[naddrc] << 32) | reg[naddrc + 1];
0075     else
0076         size = reg[naddrc];
0077
0078     *base = address;
0079     *region_size = size;
0080     return ioremap(*base, *region_size);
0081 }
0082 #else
0083 #define atmel_getb(chip, offset) inb(atmel_get_priv(chip)->base + offset)
0084 #define atmel_putb(val, chip, offset) \
0085     outb(val, atmel_get_priv(chip)->base + offset)
0086 #define atmel_request_region request_region
0087 #define atmel_release_region release_region
0088 /* Atmel definitions */
0089 enum tpm_atmel_addr {
0090     TPM_ATMEL_BASE_ADDR_LO = 0x08,
0091     TPM_ATMEL_BASE_ADDR_HI = 0x09
0092 };
0093
0094 static inline int tpm_read_index(int base, int index)
0095 {
0096     outb(index, base);
0097     return inb(base+1) & 0xFF;
0098 }
0099
0100 /* Verify this is a 1.1 Atmel TPM */
0101 static int atmel_verify_tpm11(void)
0102 {
0103
0104     /* verify that it is an Atmel part */
0105     if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
0106         tpm_read_index(TPM_ADDR, 5) != 'T' ||
0107         tpm_read_index(TPM_ADDR, 6) != 'M' ||
0108         tpm_read_index(TPM_ADDR, 7) != 'L')
0109         return 1;
0110
0111     /* query chip for its version number */
0112     if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
0113         tpm_read_index(TPM_ADDR, 0x01) != 1)
0114         return 1;
0115
0116     /* This is an atmel supported part */
0117     return 0;
0118 }
0119
0120 static inline void atmel_put_base_addr(void __iomem *iobase)
0121 {
0122 }
0123
0124 /* Determine where to talk to device */
0125 static void __iomem * atmel_get_base_addr(unsigned long *base, int *region_size)
0126 {
0127     int lo, hi;
0128
0129     if (atmel_verify_tpm11() != 0)
0130         return NULL;
0131
0132     lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
0133     hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
0134
0135     *base = (hi << 8) | lo;
0136     *region_size = 2;
0137
0138     return ioport_map(*base, *region_size);
0139 }
0140 #endif