[U-Boot] [PATCH] tpm: Remove the LPC TPM driver

Marek Vasut marex at denx.de
Sun Sep 30 19:36:49 CEST 2012


The driver is not used anywhere. It is a dead code and it seems to
be falling apart slowly due to bitrot. Remove this driver.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Vadim Bendebury <vbendeb at chromium.org>
Cc: Tom Rini <trini at ti.com>
---
 Makefile                      |    1 -
 README                        |   10 -
 drivers/tpm/Makefile          |   43 ----
 drivers/tpm/generic_lpc_tpm.c |  495 -----------------------------------------
 include/tpm.h                 |   71 ------
 5 files changed, 620 deletions(-)
 delete mode 100644 drivers/tpm/Makefile
 delete mode 100644 drivers/tpm/generic_lpc_tpm.c
 delete mode 100644 include/tpm.h

diff --git a/Makefile b/Makefile
index a40d4cc..1325be0 100644
--- a/Makefile
+++ b/Makefile
@@ -293,7 +293,6 @@ LIBS-y += arch/powerpc/cpu/mpc8xxx/lib8xxx.o
 endif
 LIBS-y += drivers/rtc/librtc.o
 LIBS-y += drivers/serial/libserial.o
-LIBS-$(CONFIG_GENERIC_LPC_TPM) += drivers/tpm/libtpm.o
 LIBS-y += drivers/twserial/libtws.o
 LIBS-y += drivers/usb/eth/libusb_eth.o
 LIBS-y += drivers/usb/gadget/libusb_gadget.o
diff --git a/README b/README
index a745d0b..c4ad6d8 100644
--- a/README
+++ b/README
@@ -1149,16 +1149,6 @@ The following options need to be configured:
 			CONFIG_SH_ETHER_CACHE_WRITEBACK
 			If this option is set, the driver enables cache flush.
 
-- TPM Support:
-		CONFIG_GENERIC_LPC_TPM
-		Support for generic parallel port TPM devices. Only one device
-		per system is supported at this time.
-
-			CONFIG_TPM_TIS_BASE_ADDRESS
-			Base address where the generic TPM device is mapped
-			to. Contemporary x86 systems usually map it at
-			0xfed40000.
-
 - USB Support:
 		At the moment only the UHCI host controller is
 		supported (PIP405, MIP405, MPC5200); define
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
deleted file mode 100644
index be11c8b..0000000
--- a/drivers/tpm/Makefile
+++ /dev/null
@@ -1,43 +0,0 @@
-# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
-#
-# See file CREDITS for list of people who contributed to this
-# project.
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License as
-# published by the Free Software Foundation; either version 2 of
-# the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-# MA 02111-1307 USA
-#
-
-include $(TOPDIR)/config.mk
-
-LIB := $(obj)libtpm.o
-
-COBJS-$(CONFIG_GENERIC_LPC_TPM) = generic_lpc_tpm.o
-
-COBJS	:= $(COBJS-y)
-SRCS	:= $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-
-all:	$(LIB)
-
-$(LIB): $(obj).depend $(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
diff --git a/drivers/tpm/generic_lpc_tpm.c b/drivers/tpm/generic_lpc_tpm.c
deleted file mode 100644
index 6c494eb..0000000
--- a/drivers/tpm/generic_lpc_tpm.c
+++ /dev/null
@@ -1,495 +0,0 @@
-/*
- * Copyright (c) 2011 The Chromium OS Authors.
- *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- */
-
-/*
- * The code in this file is based on the article "Writing a TPM Device Driver"
- * published on http://ptgmedia.pearsoncmg.com.
- *
- * One principal difference is that in the simplest config the other than 0
- * TPM localities do not get mapped by some devices (for instance, by Infineon
- * slb9635), so this driver provides access to locality 0 only.
- */
-
-#include <common.h>
-#include <asm/io.h>
-#include <tpm.h>
-
-#define PREFIX "lpc_tpm: "
-
-struct tpm_locality {
-	u32 access;
-	u8 padding0[4];
-	u32 int_enable;
-	u8 vector;
-	u8 padding1[3];
-	u32 int_status;
-	u32 int_capability;
-	u32 tpm_status;
-	u8 padding2[8];
-	u8 data;
-	u8 padding3[3803];
-	u32 did_vid;
-	u8 rid;
-	u8 padding4[251];
-};
-
-/*
- * This pointer refers to the TPM chip, 5 of its localities are mapped as an
- * array.
- */
-#define TPM_TOTAL_LOCALITIES	5
-static struct tpm_locality *lpc_tpm_dev =
-	(struct tpm_locality *)CONFIG_TPM_TIS_BASE_ADDRESS;
-
-/* Some registers' bit field definitions */
-#define TIS_STS_VALID                  (1 << 7) /* 0x80 */
-#define TIS_STS_COMMAND_READY          (1 << 6) /* 0x40 */
-#define TIS_STS_TPM_GO                 (1 << 5) /* 0x20 */
-#define TIS_STS_DATA_AVAILABLE         (1 << 4) /* 0x10 */
-#define TIS_STS_EXPECT                 (1 << 3) /* 0x08 */
-#define TIS_STS_RESPONSE_RETRY         (1 << 1) /* 0x02 */
-
-#define TIS_ACCESS_TPM_REG_VALID_STS   (1 << 7) /* 0x80 */
-#define TIS_ACCESS_ACTIVE_LOCALITY     (1 << 5) /* 0x20 */
-#define TIS_ACCESS_BEEN_SEIZED         (1 << 4) /* 0x10 */
-#define TIS_ACCESS_SEIZE               (1 << 3) /* 0x08 */
-#define TIS_ACCESS_PENDING_REQUEST     (1 << 2) /* 0x04 */
-#define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
-#define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */
-
-#define TIS_STS_BURST_COUNT_MASK       (0xffff)
-#define TIS_STS_BURST_COUNT_SHIFT      (8)
-
-/*
- * Error value returned if a tpm register does not enter the expected state
- * after continuous polling. No actual TPM register reading ever returns -1,
- * so this value is a safe error indication to be mixed with possible status
- * register values.
- */
-#define TPM_TIMEOUT_ERR			(-1)
-
-/* Error value returned on various TPM driver errors. */
-#define TPM_DRIVER_ERR		(1)
-
- /* 1 second is plenty for anything TPM does. */
-#define MAX_DELAY_US	(1000 * 1000)
-
-/* Retrieve burst count value out of the status register contents. */
-static u16 burst_count(u32 status)
-{
-	return (status >> TIS_STS_BURST_COUNT_SHIFT) & TIS_STS_BURST_COUNT_MASK;
-}
-
-/*
- * Structures defined below allow creating descriptions of TPM vendor/device
- * ID information for run time discovery. The only device the system knows
- * about at this time is Infineon slb9635.
- */
-struct device_name {
-	u16 dev_id;
-	const char * const dev_name;
-};
-
-struct vendor_name {
-	u16 vendor_id;
-	const char *vendor_name;
-	const struct device_name *dev_names;
-};
-
-static const struct device_name infineon_devices[] = {
-	{0xb, "SLB9635 TT 1.2"},
-	{0}
-};
-
-static const struct vendor_name vendor_names[] = {
-	{0x15d1, "Infineon", infineon_devices},
-};
-
-/*
- * Cached vendor/device ID pair to indicate that the device has been already
- * discovered.
- */
-static u32 vendor_dev_id;
-
-/* TPM access wrappers to support tracing */
-static u8 tpm_read_byte(const u8 *ptr)
-{
-	u8  ret = readb(ptr);
-	debug(PREFIX "Read reg 0x%4.4x returns 0x%2.2x\n",
-	      (u32)ptr - (u32)lpc_tpm_dev, ret);
-	return ret;
-}
-
-static u32 tpm_read_word(const u32 *ptr)
-{
-	u32  ret = readl(ptr);
-	debug(PREFIX "Read reg 0x%4.4x returns 0x%8.8x\n",
-	      (u32)ptr - (u32)lpc_tpm_dev, ret);
-	return ret;
-}
-
-static void tpm_write_byte(u8 value, u8 *ptr)
-{
-	debug(PREFIX "Write reg 0x%4.4x with 0x%2.2x\n",
-	      (u32)ptr - (u32)lpc_tpm_dev, value);
-	writeb(value, ptr);
-}
-
-static void tpm_write_word(u32 value, u32 *ptr)
-{
-	debug(PREFIX "Write reg 0x%4.4x with 0x%8.8x\n",
-	      (u32)ptr - (u32)lpc_tpm_dev, value);
-	writel(value, ptr);
-}
-
-/*
- * tis_wait_reg()
- *
- * Wait for at least a second for a register to change its state to match the
- * expected state. Normally the transition happens within microseconds.
- *
- * @reg - pointer to the TPM register
- * @mask - bitmask for the bitfield(s) to watch
- * @expected - value the field(s) are supposed to be set to
- *
- * Returns the register contents in case the expected value was found in the
- * appropriate register bits, or TPM_TIMEOUT_ERR on timeout.
- */
-static u32 tis_wait_reg(u32 *reg, u8 mask, u8 expected)
-{
-	u32 time_us = MAX_DELAY_US;
-
-	while (time_us > 0) {
-		u32 value = tpm_read_word(reg);
-		if ((value & mask) == expected)
-			return value;
-		udelay(1); /* 1 us */
-		time_us--;
-	}
-	return TPM_TIMEOUT_ERR;
-}
-
-/*
- * Probe the TPM device and try determining its manufacturer/device name.
- *
- * Returns 0 on success (the device is found or was found during an earlier
- * invocation) or TPM_DRIVER_ERR if the device is not found.
- */
-int tis_init(void)
-{
-	u32 didvid = tpm_read_word(&lpc_tpm_dev[0].did_vid);
-	int i;
-	const char *device_name = "unknown";
-	const char *vendor_name = device_name;
-	u16 vid, did;
-
-	if (vendor_dev_id)
-		return 0;  /* Already probed. */
-
-	if (!didvid || (didvid == 0xffffffff)) {
-		printf("%s: No TPM device found\n", __func__);
-		return TPM_DRIVER_ERR;
-	}
-
-	vendor_dev_id = didvid;
-
-	vid = didvid & 0xffff;
-	did = (didvid >> 16) & 0xffff;
-	for (i = 0; i < ARRAY_SIZE(vendor_names); i++) {
-		int j = 0;
-		u16 known_did;
-
-		if (vid == vendor_names[i].vendor_id)
-			vendor_name = vendor_names[i].vendor_name;
-
-		while ((known_did = vendor_names[i].dev_names[j].dev_id) != 0) {
-			if (known_did == did) {
-				device_name =
-					vendor_names[i].dev_names[j].dev_name;
-				break;
-			}
-			j++;
-		}
-		break;
-	}
-
-	printf("Found TPM %s by %s\n", device_name, vendor_name);
-	return 0;
-}
-
-/*
- * tis_senddata()
- *
- * send the passed in data to the TPM device.
- *
- * @data - address of the data to send, byte by byte
- * @len - length of the data to send
- *
- * Returns 0 on success, TPM_DRIVER_ERR on error (in case the device does
- * not accept the entire command).
- */
-static u32 tis_senddata(const u8 * const data, u32 len)
-{
-	u32 offset = 0;
-	u16 burst = 0;
-	u32 max_cycles = 0;
-	u8 locality = 0;
-	u32 value;
-
-	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
-			     TIS_STS_COMMAND_READY, TIS_STS_COMMAND_READY);
-	if (value == TPM_TIMEOUT_ERR) {
-		printf("%s:%d - failed to get 'command_ready' status\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
-	}
-	burst = burst_count(value);
-
-	while (1) {
-		unsigned count;
-
-		/* Wait till the device is ready to accept more data. */
-		while (!burst) {
-			if (max_cycles++ == MAX_DELAY_US) {
-				printf("%s:%d failed to feed %d bytes of %d\n",
-				       __FILE__, __LINE__, len - offset, len);
-				return TPM_DRIVER_ERR;
-			}
-			udelay(1);
-			burst = burst_count(tpm_read_word(&lpc_tpm_dev
-						     [locality].tpm_status));
-		}
-
-		max_cycles = 0;
-
-		/*
-		 * Calculate number of bytes the TPM is ready to accept in one
-		 * shot.
-		 *
-		 * We want to send the last byte outside of the loop (hence
-		 * the -1 below) to make sure that the 'expected' status bit
-		 * changes to zero exactly after the last byte is fed into the
-		 * FIFO.
-		 */
-		count = min(burst, len - offset - 1);
-		while (count--)
-			tpm_write_byte(data[offset++],
-				  &lpc_tpm_dev[locality].data);
-
-		value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
-				     TIS_STS_VALID, TIS_STS_VALID);
-
-		if ((value == TPM_TIMEOUT_ERR) || !(value & TIS_STS_EXPECT)) {
-			printf("%s:%d TPM command feed overflow\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
-		}
-
-		burst = burst_count(value);
-		if ((offset == (len - 1)) && burst) {
-			/*
-			 * We need to be able to send the last byte to the
-			 * device, so burst size must be nonzero before we
-			 * break out.
-			 */
-			break;
-		}
-	}
-
-	/* Send the last byte. */
-	tpm_write_byte(data[offset++], &lpc_tpm_dev[locality].data);
-	/*
-	 * Verify that TPM does not expect any more data as part of this
-	 * command.
-	 */
-	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
-			     TIS_STS_VALID, TIS_STS_VALID);
-	if ((value == TPM_TIMEOUT_ERR) || (value & TIS_STS_EXPECT)) {
-		printf("%s:%d unexpected TPM status 0x%x\n",
-		       __FILE__, __LINE__, value);
-		return TPM_DRIVER_ERR;
-	}
-
-	/* OK, sitting pretty, let's start the command execution. */
-	tpm_write_word(TIS_STS_TPM_GO, &lpc_tpm_dev[locality].tpm_status);
-	return 0;
-}
-
-/*
- * tis_readresponse()
- *
- * read the TPM device response after a command was issued.
- *
- * @buffer - address where to read the response, byte by byte.
- * @len - pointer to the size of buffer
- *
- * On success stores the number of received bytes to len and returns 0. On
- * errors (misformatted TPM data or synchronization problems) returns
- * TPM_DRIVER_ERR.
- */
-static u32 tis_readresponse(u8 *buffer, u32 *len)
-{
-	u16 burst;
-	u32 value;
-	u32 offset = 0;
-	u8 locality = 0;
-	const u32 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
-	u32 expected_count = *len;
-	int max_cycles = 0;
-
-	/* Wait for the TPM to process the command. */
-	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
-			      has_data, has_data);
-	if (value == TPM_TIMEOUT_ERR) {
-		printf("%s:%d failed processing command\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
-	}
-
-	do {
-		while ((burst = burst_count(value)) == 0) {
-			if (max_cycles++ == MAX_DELAY_US) {
-				printf("%s:%d TPM stuck on read\n",
-				       __FILE__, __LINE__);
-				return TPM_DRIVER_ERR;
-			}
-			udelay(1);
-			value = tpm_read_word(&lpc_tpm_dev
-					      [locality].tpm_status);
-		}
-
-		max_cycles = 0;
-
-		while (burst-- && (offset < expected_count)) {
-			buffer[offset++] = tpm_read_byte(&lpc_tpm_dev
-							 [locality].data);
-
-			if (offset == 6) {
-				/*
-				 * We got the first six bytes of the reply,
-				 * let's figure out how many bytes to expect
-				 * total - it is stored as a 4 byte number in
-				 * network order, starting with offset 2 into
-				 * the body of the reply.
-				 */
-				u32 real_length;
-				memcpy(&real_length,
-				       buffer + 2,
-				       sizeof(real_length));
-				expected_count = be32_to_cpu(real_length);
-
-				if ((expected_count < offset) ||
-				    (expected_count > *len)) {
-					printf("%s:%d bad response size %d\n",
-					       __FILE__, __LINE__,
-					       expected_count);
-					return TPM_DRIVER_ERR;
-				}
-			}
-		}
-
-		/* Wait for the next portion. */
-		value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
-				     TIS_STS_VALID, TIS_STS_VALID);
-		if (value == TPM_TIMEOUT_ERR) {
-			printf("%s:%d failed to read response\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
-		}
-
-		if (offset == expected_count)
-			break;	/* We got all we needed. */
-
-	} while ((value & has_data) == has_data);
-
-	/*
-	 * Make sure we indeed read all there was. The TIS_STS_VALID bit is
-	 * known to be set.
-	 */
-	if (value & TIS_STS_DATA_AVAILABLE) {
-		printf("%s:%d wrong receive status %x\n",
-		       __FILE__, __LINE__, value);
-		return TPM_DRIVER_ERR;
-	}
-
-	/* Tell the TPM that we are done. */
-	tpm_write_word(TIS_STS_COMMAND_READY, &lpc_tpm_dev
-		  [locality].tpm_status);
-	*len = offset;
-	return 0;
-}
-
-int tis_open(void)
-{
-	u8 locality = 0; /* we use locality zero for everything. */
-
-	if (tis_close())
-		return TPM_DRIVER_ERR;
-
-	/* now request access to locality. */
-	tpm_write_word(TIS_ACCESS_REQUEST_USE, &lpc_tpm_dev[locality].access);
-
-	/* did we get a lock? */
-	if (tis_wait_reg(&lpc_tpm_dev[locality].access,
-			 TIS_ACCESS_ACTIVE_LOCALITY,
-			 TIS_ACCESS_ACTIVE_LOCALITY) == TPM_TIMEOUT_ERR) {
-		printf("%s:%d - failed to lock locality %d\n",
-		       __FILE__, __LINE__, locality);
-		return TPM_DRIVER_ERR;
-	}
-
-	tpm_write_word(TIS_STS_COMMAND_READY,
-		       &lpc_tpm_dev[locality].tpm_status);
-	return 0;
-}
-
-int tis_close(void)
-{
-	u8 locality = 0;
-
-	if (tpm_read_word(&lpc_tpm_dev[locality].access) &
-	    TIS_ACCESS_ACTIVE_LOCALITY) {
-		tpm_write_word(TIS_ACCESS_ACTIVE_LOCALITY,
-			       &lpc_tpm_dev[locality].access);
-
-		if (tis_wait_reg(&lpc_tpm_dev[locality].access,
-				 TIS_ACCESS_ACTIVE_LOCALITY, 0) ==
-		    TPM_TIMEOUT_ERR) {
-			printf("%s:%d - failed to release locality %d\n",
-			       __FILE__, __LINE__, locality);
-			return TPM_DRIVER_ERR;
-		}
-	}
-	return 0;
-}
-
-int tis_sendrecv(const u8 *sendbuf, size_t send_size,
-		 u8 *recvbuf, size_t *recv_len)
-{
-	if (tis_senddata(sendbuf, send_size)) {
-		printf("%s:%d failed sending data to TPM\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
-	}
-
-	return tis_readresponse(recvbuf, recv_len);
-}
diff --git a/include/tpm.h b/include/tpm.h
deleted file mode 100644
index 6b21e9c..0000000
--- a/include/tpm.h
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright (c) 2011 The Chromium OS Authors.
- *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- */
-
-#ifndef _INCLUDE_TPM_H_
-#define _INCLUDE_TPM_H_
-
-#include <common.h>
-
-/*
- * tis_init()
- *
- * Initialize the TPM device. Returns 0 on success or -1 on
- * failure (in case device probing did not succeed).
- */
-int tis_init(void);
-
-/*
- * tis_open()
- *
- * Requests access to locality 0 for the caller. After all commands have been
- * completed the caller is supposed to call tis_close().
- *
- * Returns 0 on success, -1 on failure.
- */
-int tis_open(void);
-
-/*
- * tis_close()
- *
- * terminate the currect session with the TPM by releasing the locked
- * locality. Returns 0 on success of -1 on failure (in case lock
- * removal did not succeed).
- */
-int tis_close(void);
-
-/*
- * tis_sendrecv()
- *
- * Send the requested data to the TPM and then try to get its response
- *
- * @sendbuf - buffer of the data to send
- * @send_size size of the data to send
- * @recvbuf - memory to save the response to
- * @recv_len - pointer to the size of the response buffer
- *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or -1 on failure.
- */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
-			size_t *recv_len);
-
-#endif /* _INCLUDE_TPM_H_ */
-- 
1.7.10.4



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