186 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			186 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
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|  * Use of this source code is governed by a BSD-style license that can be
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|  * found in the LICENSE file.
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|  */
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| 
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| #include <config.h>
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| #include <common.h>
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| #include <fdtdec.h>
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| #include <i2c.h>
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| #include "slb9635_i2c/tpm.h"
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| 
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| DECLARE_GLOBAL_DATA_PTR;
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| 
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| /* TPM configuration */
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| struct tpm {
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| 	int i2c_bus;
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| 	int slave_addr;
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| 	char inited;
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| 	int old_bus;
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| } tpm;
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| 
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| 
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| static int tpm_select(void)
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| {
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| 	int ret;
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| 
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| 	tpm.old_bus = i2c_get_bus_num();
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| 	if (tpm.old_bus != tpm.i2c_bus) {
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| 		ret = i2c_set_bus_num(tpm.i2c_bus);
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| 		if (ret) {
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| 			debug("%s: Fail to set i2c bus %d\n", __func__,
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| 			      tpm.i2c_bus);
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| 			return -1;
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| 		}
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| 	}
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| 	return 0;
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| }
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| 
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| static int tpm_deselect(void)
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| {
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| 	int ret;
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| 
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| 	if (tpm.old_bus != i2c_get_bus_num()) {
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| 		ret = i2c_set_bus_num(tpm.old_bus);
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| 		if (ret) {
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| 			debug("%s: Fail to restore i2c bus %d\n",
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| 			      __func__, tpm.old_bus);
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| 			return -1;
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| 		}
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| 	}
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| 	tpm.old_bus = -1;
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| 	return 0;
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| }
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| 
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| /**
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|  * Decode TPM configuration.
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|  *
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|  * @param dev	Returns a configuration of TPM device
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|  * @return 0 if ok, -1 on error
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|  */
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| static int tpm_decode_config(struct tpm *dev)
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| {
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| #ifdef CONFIG_OF_CONTROL
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| 	const void *blob = gd->fdt_blob;
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| 	int node, parent;
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| 	int i2c_bus;
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| 
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| 	node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
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| 	if (node < 0) {
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| 		node = fdtdec_next_compatible(blob, 0,
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| 					      COMPAT_INFINEON_SLB9645_TPM);
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| 	}
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| 	if (node < 0) {
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| 		debug("%s: Node not found\n", __func__);
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| 		return -1;
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| 	}
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| 	parent = fdt_parent_offset(blob, node);
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| 	if (parent < 0) {
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| 		debug("%s: Cannot find node parent\n", __func__);
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| 		return -1;
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| 	}
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| 	i2c_bus = i2c_get_bus_num_fdt(parent);
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| 	if (i2c_bus < 0)
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| 		return -1;
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| 	dev->i2c_bus = i2c_bus;
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| 	dev->slave_addr = fdtdec_get_addr(blob, node, "reg");
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| #else
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| 	dev->i2c_bus = CONFIG_INFINEON_TPM_I2C_BUS;
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| 	dev->slave_addr = CONFIG_INFINEON_TPM_I2C_ADDR;
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| #endif
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| 	return 0;
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| }
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| 
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| int tis_init(void)
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| {
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| 	if (tpm.inited)
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| 		return 0;
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| 
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| 	if (tpm_decode_config(&tpm))
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| 		return -1;
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| 
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| 	if (tpm_select())
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| 		return -1;
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| 
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| 	/*
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| 	 * Probe TPM twice; the first probing might fail because TPM is asleep,
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| 	 * and the probing can wake up TPM.
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| 	 */
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| 	if (i2c_probe(tpm.slave_addr) && i2c_probe(tpm.slave_addr)) {
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| 		debug("%s: fail to probe i2c addr 0x%x\n", __func__,
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| 		      tpm.slave_addr);
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| 		return -1;
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| 	}
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| 
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| 	tpm_deselect();
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| 
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| 	tpm.inited = 1;
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| 
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| 	return 0;
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| }
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| 
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| int tis_open(void)
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| {
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| 	int rc;
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| 
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| 	if (!tpm.inited)
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| 		return -1;
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| 
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| 	if (tpm_select())
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| 		return -1;
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| 
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| 	rc = tpm_open(tpm.slave_addr);
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| 
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| 	tpm_deselect();
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| 
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| 	return rc;
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| }
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| 
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| int tis_close(void)
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| {
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| 	if (!tpm.inited)
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| 		return -1;
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| 
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| 	if (tpm_select())
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| 		return -1;
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| 
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| 	tpm_close();
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| 
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| 	tpm_deselect();
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| 
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| 	return 0;
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| }
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| 
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| int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
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| 		uint8_t *recvbuf, size_t *rbuf_len)
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| {
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| 	int len;
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| 	uint8_t buf[4096];
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| 
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| 	if (!tpm.inited)
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| 		return -1;
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| 
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| 	if (sizeof(buf) < sbuf_size)
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| 		return -1;
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| 
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| 	memcpy(buf, sendbuf, sbuf_size);
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| 
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| 	if (tpm_select())
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| 		return -1;
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| 
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| 	len = tpm_transmit(buf, sbuf_size);
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| 
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| 	tpm_deselect();
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| 
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| 	if (len < 10) {
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| 		*rbuf_len = 0;
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| 		return -1;
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| 	}
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| 
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| 	memcpy(recvbuf, buf, len);
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| 	*rbuf_len = len;
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| 
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| 	return 0;
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| }
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