[people/ms/u-boot.git] / drivers / tpm / tpm_tis_i2c.c

/*
 * Copyright (C) 2011 Infineon Technologies
 *
 * Authors:
 * Peter Huewe <huewe.external@infineon.com>
 *
 * Description:
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org
 *
 * This device driver implements the TPM interface as defined in
 * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
 * Infineon I2C Protocol Stack Specification v0.20.
 *
 * It is based on the Linux kernel driver tpm.c from Leendert van
 * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
 *
 * Version: 2.1.1
 *
 * 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, version 2 of the
 * License.
 *
 * 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 <common.h>
#include <fdtdec.h>
#include <compiler.h>
#include <i2c.h>
#include <tpm.h>
#include <asm-generic/errno.h>
#include <linux/types.h>
#include <linux/unaligned/be_byteshift.h>

#include "tpm_private.h"

DECLARE_GLOBAL_DATA_PTR;

/* Address of the TPM on the I2C bus */
#define TPM_I2C_ADDR		0x20

/* Max buffer size supported by our tpm */
#define TPM_DEV_BUFSIZE		1260

/* Max number of iterations after i2c NAK */
#define MAX_COUNT		3

/*
 * Max number of iterations after i2c NAK for 'long' commands
 *
 * We need this especially for sending TPM_READY, since the cleanup after the
 * transtion to the ready state may take some time, but it is unpredictable
 * how long it will take.
 */
#define MAX_COUNT_LONG		50

#define SLEEP_DURATION		60	/* in usec */
#define SLEEP_DURATION_LONG	210	/* in usec */

#define TPM_HEADER_SIZE		10

/*
 * Expected value for DIDVID register
 *
 * The only device the system knows about at this moment is Infineon slb9635.
 */
#define TPM_TIS_I2C_DID_VID	0x000b15d1L

enum tis_access {
	TPM_ACCESS_VALID		= 0x80,
	TPM_ACCESS_ACTIVE_LOCALITY	= 0x20,
	TPM_ACCESS_REQUEST_PENDING	= 0x04,
	TPM_ACCESS_REQUEST_USE		= 0x02,
};

enum tis_status {
	TPM_STS_VALID			= 0x80,
	TPM_STS_COMMAND_READY		= 0x40,
	TPM_STS_GO			= 0x20,
	TPM_STS_DATA_AVAIL		= 0x10,
	TPM_STS_DATA_EXPECT		= 0x08,
};

enum tis_defaults {
	TIS_SHORT_TIMEOUT		= 750,	/* ms */
	TIS_LONG_TIMEOUT		= 2000,	/* ms */
};

/* expected value for DIDVID register */
#define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L

enum i2c_chip_type {
	SLB9635,
	SLB9645,
	UNKNOWN,
};

static const char * const chip_name[] = {
	[SLB9635] = "slb9635tt",
	[SLB9645] = "slb9645tt",
	[UNKNOWN] = "unknown/fallback to slb9635",
};

#define	TPM_ACCESS(l)			(0x0000 | ((l) << 4))
#define	TPM_STS(l)			(0x0001 | ((l) << 4))
#define	TPM_DATA_FIFO(l)		(0x0005 | ((l) << 4))
#define	TPM_DID_VID(l)			(0x0006 | ((l) << 4))

/* Structure to store I2C TPM specific stuff */
struct tpm_dev {
	uint addr;
	u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)];  /* Max buffer size + addr */
	enum i2c_chip_type chip_type;
};

static struct tpm_dev tpm_dev = {
	.addr = TPM_I2C_ADDR
};

static struct tpm_dev tpm_dev;

/*
 * iic_tpm_read() - read from TPM register
 * @addr: register address to read from
 * @buffer: provided by caller
 * @len: number of bytes to read
 *
 * Read len bytes from TPM register and put them into
 * buffer (little-endian format, i.e. first byte is put into buffer[0]).
 *
 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 * values have to be swapped.
 *
 * Return -EIO on error, 0 on success.
 */
static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
{
	int rc;
	int count;
	uint32_t addrbuf = addr;

	if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
		/* slb9635 protocol should work in both cases */
		for (count = 0; count < MAX_COUNT; count++) {
			rc = i2c_write(tpm_dev.addr, 0, 0,
				       (uchar *)&addrbuf, 1);
			if (rc == 0)
				break;  /* Success, break to skip sleep */
			udelay(SLEEP_DURATION);
		}
		if (rc)
			return -rc;

		/* After the TPM has successfully received the register address
		 * it needs some time, thus we're sleeping here again, before
		 * retrieving the data
		 */
		for (count = 0; count < MAX_COUNT; count++) {
			udelay(SLEEP_DURATION);
			rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
			if (rc == 0)
				break;  /* success, break to skip sleep */
		}
	} else {
		/*
		 * Use a combined read for newer chips.
		 * Unfortunately the smbus functions are not suitable due to
		 * the 32 byte limit of the smbus.
		 * Retries should usually not be needed, but are kept just to
		 * be safe on the safe side.
		 */
		for (count = 0; count < MAX_COUNT; count++) {
			rc = i2c_read(tpm_dev.addr, addr, 1, buffer, len);
			if (rc == 0)
				break;  /* break here to skip sleep */
			udelay(SLEEP_DURATION);
		}
	}

	/* Take care of 'guard time' */
	udelay(SLEEP_DURATION);
	if (rc)
		return -rc;

	return 0;
}

static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
		unsigned int sleep_time, u8 max_count)
{
	int rc = 0;
	int count;

	/* Prepare send buffer */
	tpm_dev.buf[0] = addr;
	memcpy(&(tpm_dev.buf[1]), buffer, len);

	for (count = 0; count < max_count; count++) {
		rc = i2c_write(tpm_dev.addr, 0, 0, tpm_dev.buf, len + 1);
		if (rc == 0)
			break;  /* Success, break to skip sleep */
		udelay(sleep_time);
	}

	/* take care of 'guard time' */
	udelay(SLEEP_DURATION);
	if (rc)
		return -rc;

	return 0;
}

/*
 * iic_tpm_write() - write to TPM register
 * @addr: register address to write to
 * @buffer: containing data to be written
 * @len: number of bytes to write
 *
 * Write len bytes from provided buffer to TPM register (little
 * endian format, i.e. buffer[0] is written as first byte).
 *
 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
 * values have to be swapped.
 *
 * NOTE: use this function instead of the iic_tpm_write_generic function.
 *
 * Return -EIO on error, 0 on success
 */
static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
{
	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
			MAX_COUNT);
}

/*
 * This function is needed especially for the cleanup situation after
 * sending TPM_READY
 */
static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
{
	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
			MAX_COUNT_LONG);
}

static int check_locality(struct tpm_chip *chip, int loc)
{
	const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
	u8 buf;
	int rc;

	rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
	if (rc < 0)
		return rc;

	if ((buf & mask) == mask) {
		chip->vendor.locality = loc;
		return loc;
	}

	return -1;
}

static void release_locality(struct tpm_chip *chip, int loc, int force)
{
	const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
	u8 buf;

	if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
		return;

	if (force || (buf & mask) == mask) {
		buf = TPM_ACCESS_ACTIVE_LOCALITY;
		iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
	}
}

static int request_locality(struct tpm_chip *chip, int loc)
{
	unsigned long start, stop;
	u8 buf = TPM_ACCESS_REQUEST_USE;

	if (check_locality(chip, loc) >= 0)
		return loc;  /* We already have the locality */

	iic_tpm_write(TPM_ACCESS(loc), &buf, 1);

	/* Wait for burstcount */
	start = get_timer(0);
	stop = chip->vendor.timeout_a;
	do {
		if (check_locality(chip, loc) >= 0)
			return loc;
		udelay(TPM_TIMEOUT * 1000);
	} while (get_timer(start) < stop);

	return -1;
}

static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
{
	/* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
	u8 buf;

	if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
		return 0;
	else
		return buf;
}

static void tpm_tis_i2c_ready(struct tpm_chip *chip)
{
	/* This causes the current command to be aborted */
	u8 buf = TPM_STS_COMMAND_READY;

	iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
}

static ssize_t get_burstcount(struct tpm_chip *chip)
{
	unsigned long start, stop;
	ssize_t burstcnt;
	u8 addr, buf[3];

	/* Wait for burstcount */
	/* XXX: Which timeout value? Spec has 2 answers (c & d) */
	start = get_timer(0);
	stop = chip->vendor.timeout_d;
	do {
		/* Note: STS is little endian */
		addr = TPM_STS(chip->vendor.locality) + 1;
		if (iic_tpm_read(addr, buf, 3) < 0)
			burstcnt = 0;
		else
			burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];

		if (burstcnt)
			return burstcnt;
		udelay(TPM_TIMEOUT * 1000);
	} while (get_timer(start) < stop);

	return -EBUSY;
}

static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
		int *status)
{
	unsigned long start, stop;

	/* Check current status */
	*status = tpm_tis_i2c_status(chip);
	if ((*status & mask) == mask)
		return 0;

	start = get_timer(0);
	stop = timeout;
	do {
		udelay(TPM_TIMEOUT * 1000);
		*status = tpm_tis_i2c_status(chip);
		if ((*status & mask) == mask)
			return 0;
	} while (get_timer(start) < stop);

	return -ETIME;
}

static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
{
	size_t size = 0;
	ssize_t burstcnt;
	int rc;

	while (size < count) {
		burstcnt = get_burstcount(chip);

		/* burstcount < 0 -> tpm is busy */
		if (burstcnt < 0)
			return burstcnt;

		/* Limit received data to max left */
		if (burstcnt > (count - size))
			burstcnt = count - size;

		rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
				&(buf[size]), burstcnt);
		if (rc == 0)
			size += burstcnt;
	}

	return size;
}

static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
	int size = 0;
	int expected, status;

	if (count < TPM_HEADER_SIZE) {
		size = -EIO;
		goto out;
	}

	/* Read first 10 bytes, including tag, paramsize, and result */
	size = recv_data(chip, buf, TPM_HEADER_SIZE);
	if (size < TPM_HEADER_SIZE) {
		error("Unable to read header\n");
		goto out;
	}

	expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
	if ((size_t)expected > count) {
		size = -EIO;
		goto out;
	}

	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
			expected - TPM_HEADER_SIZE);
	if (size < expected) {
		error("Unable to read remainder of result\n");
		size = -ETIME;
		goto out;
	}

	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
	if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
		error("Error left over data\n");
		size = -EIO;
		goto out;
	}

out:
	tpm_tis_i2c_ready(chip);
	/*
	 * The TPM needs some time to clean up here,
	 * so we sleep rather than keeping the bus busy
	 */
	udelay(2000);
	release_locality(chip, chip->vendor.locality, 0);

	return size;
}

static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
{
	int rc, status;
	ssize_t burstcnt;
	size_t count = 0;
	int retry = 0;
	u8 sts = TPM_STS_GO;

	if (len > TPM_DEV_BUFSIZE)
		return -E2BIG;  /* Command is too long for our tpm, sorry */

	if (request_locality(chip, 0) < 0)
		return -EBUSY;

	status = tpm_tis_i2c_status(chip);
	if ((status & TPM_STS_COMMAND_READY) == 0) {
		tpm_tis_i2c_ready(chip);
		if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
				  chip->vendor.timeout_b, &status) < 0) {
			rc = -ETIME;
			goto out_err;
		}
	}

	burstcnt = get_burstcount(chip);

	/* burstcount < 0 -> tpm is busy */
	if (burstcnt < 0)
		return burstcnt;

	while (count < len - 1) {
		if (burstcnt > len - 1 - count)
			burstcnt = len - 1 - count;

#ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
		if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION)
			burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION;
#endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */

		rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
				&(buf[count]), burstcnt);
		if (rc == 0)
			count += burstcnt;
		else {
			retry++;
			wait_for_stat(chip, TPM_STS_VALID,
				      chip->vendor.timeout_c, &status);

			if ((status & TPM_STS_DATA_EXPECT) == 0) {
				rc = -EIO;
				goto out_err;
			}
		}
	}

	/* Write last byte */
	iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
	if ((status & TPM_STS_DATA_EXPECT) != 0) {
		rc = -EIO;
		goto out_err;
	}

	/* Go and do it */
	iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);

	return len;

out_err:
	tpm_tis_i2c_ready(chip);
	/*
	 * The TPM needs some time to clean up here,
	 * so we sleep rather than keeping the bus busy
	 */
	udelay(2000);
	release_locality(chip, chip->vendor.locality, 0);

	return rc;
}

static struct tpm_vendor_specific tpm_tis_i2c = {
	.status = tpm_tis_i2c_status,
	.recv = tpm_tis_i2c_recv,
	.send = tpm_tis_i2c_send,
	.cancel = tpm_tis_i2c_ready,
	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
	.req_canceled = TPM_STS_COMMAND_READY,
};


static enum i2c_chip_type tpm_vendor_chip_type(void)
{
#ifdef CONFIG_OF_CONTROL
	const void *blob = gd->fdt_blob;

	if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
		return SLB9645;

	if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
		return SLB9635;
#endif
	return UNKNOWN;
}

/* Initialisation of i2c tpm */
int tpm_vendor_init(uint32_t dev_addr)
{
	u32 vendor;
	u32 expected_did_vid;
	uint old_addr;
	int rc = 0;
	struct tpm_chip *chip;

	old_addr = tpm_dev.addr;
	if (dev_addr != 0)
		tpm_dev.addr = dev_addr;

	tpm_dev.chip_type = tpm_vendor_chip_type();

	chip = tpm_register_hardware(&tpm_tis_i2c);
	if (chip < 0) {
		rc = -ENODEV;
		goto out_err;
	}

	/* Disable interrupts (not supported) */
	chip->vendor.irq = 0;

	/* Default timeouts */
	chip->vendor.timeout_a = TIS_SHORT_TIMEOUT;
	chip->vendor.timeout_b = TIS_LONG_TIMEOUT;
	chip->vendor.timeout_c = TIS_SHORT_TIMEOUT;
	chip->vendor.timeout_d = TIS_SHORT_TIMEOUT;

	if (request_locality(chip, 0) < 0) {
		rc = -ENODEV;
		goto out_err;
	}

	/* Read four bytes from DID_VID register */
	if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
		rc = -EIO;
		goto out_release;
	}

	if (tpm_dev.chip_type == SLB9635) {
		vendor = be32_to_cpu(vendor);
		expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
	} else {
		/* device id and byte order has changed for newer i2c tpms */
		expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
	}

	if (tpm_dev.chip_type != UNKNOWN && vendor != expected_did_vid) {
		error("Vendor id did not match! ID was %08x\n", vendor);
		rc = -ENODEV;
		goto out_release;
	}

	debug("1.2 TPM (chip type %s device-id 0x%X)\n",
	      chip_name[tpm_dev.chip_type], vendor >> 16);

	/*
	 * A timeout query to TPM can be placed here.
	 * Standard timeout values are used so far
	 */

	return 0;

out_release:
	release_locality(chip, 0, 1);

out_err:
	tpm_dev.addr = old_addr;
	return rc;
}

void tpm_vendor_cleanup(struct tpm_chip *chip)
{
	release_locality(chip, chip->vendor.locality, 1);
}
Commit	Line	Data
f6267998 RC	1	/*
	2	* Copyright (C) 2011 Infineon Technologies
	3	*
	4	* Authors:
	5	* Peter Huewe <huewe.external@infineon.com>
	6	*
	7	* Description:
	8	* Device driver for TCG/TCPA TPM (trusted platform module).
	9	* Specifications at www.trustedcomputinggroup.org
	10	*
	11	* This device driver implements the TPM interface as defined in
	12	* the TCG TPM Interface Spec version 1.2, revision 1.0 and the
	13	* Infineon I2C Protocol Stack Specification v0.20.
	14	*
	15	* It is based on the Linux kernel driver tpm.c from Leendert van
	16	* Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
	17	*
	18	* Version: 2.1.1
	19	*
	20	* See file CREDITS for list of people who contributed to this
	21	* project.
	22	*
	23	* This program is free software; you can redistribute it and/or
	24	* modify it under the terms of the GNU General Public License as
	25	* published by the Free Software Foundation, version 2 of the
	26	* License.
	27	*
	28	* This program is distributed in the hope that it will be useful,
	29	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	30	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	31	* GNU General Public License for more details.
	32	*
	33	* You should have received a copy of the GNU General Public License
	34	* along with this program; if not, write to the Free Software
	35	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	36	* MA 02111-1307 USA
	37	*/
	38
	39	#include <common.h>
ec34fa5e	40	#include <fdtdec.h>
1b393db5	41	#include <compiler.h>
f6267998	42	#include <i2c.h>
1b393db5 TWHT	43	#include <tpm.h>
1b393db5 TWHT	44	#include <asm-generic/errno.h>
f6267998	45	#include <linux/types.h>
1b393db5	46	#include <linux/unaligned/be_byteshift.h>
f6267998	47
1b393db5	48	#include "tpm_private.h"
f6267998	49
ec34fa5e VP	50	DECLARE_GLOBAL_DATA_PTR;
ec34fa5e VP	51
f6267998	52	/* Address of the TPM on the I2C bus */
1b393db5 TWHT	53	#define TPM_I2C_ADDR 0x20
	54
	55	/* Max buffer size supported by our tpm */
	56	#define TPM_DEV_BUFSIZE 1260
f6267998	57
1b393db5 TWHT	58	/* Max number of iterations after i2c NAK */
1b393db5 TWHT	59	#define MAX_COUNT 3
f6267998	60
1b393db5 TWHT	61	/*
	62	* Max number of iterations after i2c NAK for 'long' commands
	63	*
	64	* We need this especially for sending TPM_READY, since the cleanup after the
f6267998 RC	65	* transtion to the ready state may take some time, but it is unpredictable
	66	* how long it will take.
	67	*/
1b393db5 TWHT	68	#define MAX_COUNT_LONG 50
	69
	70	#define SLEEP_DURATION 60 /* in usec */
	71	#define SLEEP_DURATION_LONG 210 /* in usec */
	72
	73	#define TPM_HEADER_SIZE 10
	74
	75	/*
	76	* Expected value for DIDVID register
	77	*
	78	* The only device the system knows about at this moment is Infineon slb9635.
	79	*/
	80	#define TPM_TIS_I2C_DID_VID 0x000b15d1L
	81
	82	enum tis_access {
	83	TPM_ACCESS_VALID = 0x80,
	84	TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
	85	TPM_ACCESS_REQUEST_PENDING = 0x04,
	86	TPM_ACCESS_REQUEST_USE = 0x02,
	87	};
	88
	89	enum tis_status {
	90	TPM_STS_VALID = 0x80,
	91	TPM_STS_COMMAND_READY = 0x40,
	92	TPM_STS_GO = 0x20,
	93	TPM_STS_DATA_AVAIL = 0x10,
	94	TPM_STS_DATA_EXPECT = 0x08,
	95	};
f6267998	96
1b393db5 TWHT	97	enum tis_defaults {
	98	TIS_SHORT_TIMEOUT = 750, /* ms */
	99	TIS_LONG_TIMEOUT = 2000, /* ms */
	100	};
f6267998 RC	101
f6267998 RC	102	/* expected value for DIDVID register */
ec34fa5e VP	103	#define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
	104	#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
	105
	106	enum i2c_chip_type {
	107	SLB9635,
	108	SLB9645,
	109	UNKNOWN,
	110	};
	111
	112	static const char * const chip_name[] = {
	113	[SLB9635] = "slb9635tt",
	114	[SLB9645] = "slb9645tt",
	115	[UNKNOWN] = "unknown/fallback to slb9635",
	116	};
f6267998	117
1b393db5 TWHT	118	#define TPM_ACCESS(l) (0x0000 \| ((l) << 4))
	119	#define TPM_STS(l) (0x0001 \| ((l) << 4))
	120	#define TPM_DATA_FIFO(l) (0x0005 \| ((l) << 4))
	121	#define TPM_DID_VID(l) (0x0006 \| ((l) << 4))
	122
f6267998	123	/* Structure to store I2C TPM specific stuff */
1b393db5	124	struct tpm_dev {
f6267998	125	uint addr;
1b393db5	126	u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */
ec34fa5e	127	enum i2c_chip_type chip_type;
f6267998 RC	128	};
f6267998 RC	129
1b393db5	130	static struct tpm_dev tpm_dev = {
f6267998 RC	131	.addr = TPM_I2C_ADDR
	132	};
	133
1b393db5 TWHT	134	static struct tpm_dev tpm_dev;
1b393db5 TWHT	135
f6267998 RC	136	/*
	137	* iic_tpm_read() - read from TPM register
	138	* @addr: register address to read from
	139	* @buffer: provided by caller
	140	* @len: number of bytes to read
	141	*
	142	* Read len bytes from TPM register and put them into
	143	* buffer (little-endian format, i.e. first byte is put into buffer[0]).
	144	*
	145	* NOTE: TPM is big-endian for multi-byte values. Multi-byte
	146	* values have to be swapped.
	147	*
	148	* Return -EIO on error, 0 on success.
	149	*/
1b393db5	150	static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
f6267998 RC	151	{
	152	int rc;
	153	int count;
1b393db5	154	uint32_t addrbuf = addr;
f6267998	155
ec34fa5e VP	156	if ((tpm_dev.chip_type == SLB9635) \|\| (tpm_dev.chip_type == UNKNOWN)) {
	157	/* slb9635 protocol should work in both cases */
	158	for (count = 0; count < MAX_COUNT; count++) {
	159	rc = i2c_write(tpm_dev.addr, 0, 0,
1b393db5	160	(uchar *)&addrbuf, 1);
ec34fa5e	161	if (rc == 0)
1b393db5	162	break; /* Success, break to skip sleep */
ec34fa5e VP	163	udelay(SLEEP_DURATION);
ec34fa5e VP	164	}
ec34fa5e VP	165	if (rc)
	166	return -rc;
	167
	168	/* After the TPM has successfully received the register address
	169	* it needs some time, thus we're sleeping here again, before
	170	* retrieving the data
	171	*/
	172	for (count = 0; count < MAX_COUNT; count++) {
	173	udelay(SLEEP_DURATION);
	174	rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
	175	if (rc == 0)
	176	break; /* success, break to skip sleep */
	177	}
	178	} else {
1b393db5 TWHT	179	/*
	180	* Use a combined read for newer chips.
	181	* Unfortunately the smbus functions are not suitable due to
ec34fa5e	182	* the 32 byte limit of the smbus.
1b393db5	183	* Retries should usually not be needed, but are kept just to
ec34fa5e VP	184	* be safe on the safe side.
	185	*/
	186	for (count = 0; count < MAX_COUNT; count++) {
	187	rc = i2c_read(tpm_dev.addr, addr, 1, buffer, len);
	188	if (rc == 0)
	189	break; /* break here to skip sleep */
	190	udelay(SLEEP_DURATION);
	191	}
f6267998 RC	192	}
f6267998 RC	193
1b393db5	194	/* Take care of 'guard time' */
ec34fa5e	195	udelay(SLEEP_DURATION);
f6267998 RC	196	if (rc)
	197	return -rc;
	198
	199	return 0;
	200	}
	201
	202	static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
1b393db5	203	unsigned int sleep_time, u8 max_count)
f6267998 RC	204	{
	205	int rc = 0;
	206	int count;
	207
1b393db5	208	/* Prepare send buffer */
f6267998 RC	209	tpm_dev.buf[0] = addr;
	210	memcpy(&(tpm_dev.buf[1]), buffer, len);
	211
	212	for (count = 0; count < max_count; count++) {
	213	rc = i2c_write(tpm_dev.addr, 0, 0, tpm_dev.buf, len + 1);
	214	if (rc == 0)
1b393db5	215	break; /* Success, break to skip sleep */
f6267998 RC	216	udelay(sleep_time);
	217	}
	218
ec34fa5e VP	219	/* take care of 'guard time' */
ec34fa5e VP	220	udelay(SLEEP_DURATION);
f6267998 RC	221	if (rc)
	222	return -rc;
	223
	224	return 0;
	225	}
	226
	227	/*
	228	* iic_tpm_write() - write to TPM register
	229	* @addr: register address to write to
	230	* @buffer: containing data to be written
	231	* @len: number of bytes to write
	232	*
	233	* Write len bytes from provided buffer to TPM register (little
	234	* endian format, i.e. buffer[0] is written as first byte).
	235	*
	236	* NOTE: TPM is big-endian for multi-byte values. Multi-byte
	237	* values have to be swapped.
	238	*
	239	* NOTE: use this function instead of the iic_tpm_write_generic function.
	240	*
	241	* Return -EIO on error, 0 on success
	242	*/
	243	static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
	244	{
	245	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
	246	MAX_COUNT);
	247	}
	248
	249	/*
	250	* This function is needed especially for the cleanup situation after
	251	* sending TPM_READY
1b393db5	252	*/
f6267998 RC	253	static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
	254	{
	255	return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
	256	MAX_COUNT_LONG);
	257	}
	258
f6267998 RC	259	static int check_locality(struct tpm_chip *chip, int loc)
f6267998 RC	260	{
1b393db5	261	const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY \| TPM_ACCESS_VALID;
f6267998 RC	262	u8 buf;
	263	int rc;
	264
	265	rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
	266	if (rc < 0)
	267	return rc;
	268
1b393db5	269	if ((buf & mask) == mask) {
f6267998 RC	270	chip->vendor.locality = loc;
	271	return loc;
	272	}
	273
	274	return -1;
	275	}
	276
	277	static void release_locality(struct tpm_chip *chip, int loc, int force)
	278	{
1b393db5	279	const u8 mask = TPM_ACCESS_REQUEST_PENDING \| TPM_ACCESS_VALID;
f6267998	280	u8 buf;
1b393db5	281
f6267998 RC	282	if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
	283	return;
	284
1b393db5	285	if (force \|\| (buf & mask) == mask) {
f6267998 RC	286	buf = TPM_ACCESS_ACTIVE_LOCALITY;
	287	iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
	288	}
	289	}
	290
	291	static int request_locality(struct tpm_chip *chip, int loc)
	292	{
	293	unsigned long start, stop;
	294	u8 buf = TPM_ACCESS_REQUEST_USE;
	295
	296	if (check_locality(chip, loc) >= 0)
1b393db5	297	return loc; /* We already have the locality */
f6267998 RC	298
	299	iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
	300
1b393db5	301	/* Wait for burstcount */
f6267998 RC	302	start = get_timer(0);
	303	stop = chip->vendor.timeout_a;
	304	do {
	305	if (check_locality(chip, loc) >= 0)
	306	return loc;
1b393db5	307	udelay(TPM_TIMEOUT * 1000);
f6267998 RC	308	} while (get_timer(start) < stop);
	309
	310	return -1;
	311	}
	312
	313	static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
	314	{
1b393db5	315	/* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
f6267998	316	u8 buf;
1b393db5	317
f6267998 RC	318	if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
	319	return 0;
	320	else
	321	return buf;
	322	}
	323
	324	static void tpm_tis_i2c_ready(struct tpm_chip *chip)
	325	{
1b393db5	326	/* This causes the current command to be aborted */
f6267998	327	u8 buf = TPM_STS_COMMAND_READY;
1b393db5	328
f6267998 RC	329	iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
	330	}
	331
	332	static ssize_t get_burstcount(struct tpm_chip *chip)
	333	{
	334	unsigned long start, stop;
	335	ssize_t burstcnt;
1b393db5	336	u8 addr, buf[3];
f6267998	337
1b393db5 TWHT	338	/* Wait for burstcount */
1b393db5 TWHT	339	/* XXX: Which timeout value? Spec has 2 answers (c & d) */
f6267998 RC	340	start = get_timer(0);
	341	stop = chip->vendor.timeout_d;
	342	do {
	343	/* Note: STS is little endian */
1b393db5 TWHT	344	addr = TPM_STS(chip->vendor.locality) + 1;
1b393db5 TWHT	345	if (iic_tpm_read(addr, buf, 3) < 0)
f6267998 RC	346	burstcnt = 0;
	347	else
	348	burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
	349
	350	if (burstcnt)
	351	return burstcnt;
1b393db5	352	udelay(TPM_TIMEOUT * 1000);
f6267998 RC	353	} while (get_timer(start) < stop);
	354
	355	return -EBUSY;
	356	}
	357
	358	static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
1b393db5	359	int *status)
f6267998 RC	360	{
	361	unsigned long start, stop;
	362
1b393db5	363	/* Check current status */
f6267998 RC	364	*status = tpm_tis_i2c_status(chip);
	365	if ((*status & mask) == mask)
	366	return 0;
	367
	368	start = get_timer(0);
	369	stop = timeout;
	370	do {
1b393db5	371	udelay(TPM_TIMEOUT * 1000);
f6267998 RC	372	*status = tpm_tis_i2c_status(chip);
	373	if ((*status & mask) == mask)
	374	return 0;
f6267998 RC	375	} while (get_timer(start) < stop);
	376
	377	return -ETIME;
	378	}
	379
	380	static int recv_data(struct tpm_chip chip, u8 buf, size_t count)
	381	{
	382	size_t size = 0;
	383	ssize_t burstcnt;
	384	int rc;
	385
	386	while (size < count) {
	387	burstcnt = get_burstcount(chip);
	388
1b393db5	389	/* burstcount < 0 -> tpm is busy */
f6267998 RC	390	if (burstcnt < 0)
	391	return burstcnt;
	392
1b393db5	393	/* Limit received data to max left */
f6267998 RC	394	if (burstcnt > (count - size))
	395	burstcnt = count - size;
	396
	397	rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
1b393db5	398	&(buf[size]), burstcnt);
f6267998 RC	399	if (rc == 0)
	400	size += burstcnt;
	401	}
	402
	403	return size;
	404	}
	405
	406	static int tpm_tis_i2c_recv(struct tpm_chip chip, u8 buf, size_t count)
	407	{
	408	int size = 0;
	409	int expected, status;
	410
	411	if (count < TPM_HEADER_SIZE) {
	412	size = -EIO;
	413	goto out;
	414	}
	415
1b393db5	416	/* Read first 10 bytes, including tag, paramsize, and result */
f6267998 RC	417	size = recv_data(chip, buf, TPM_HEADER_SIZE);
f6267998 RC	418	if (size < TPM_HEADER_SIZE) {
1b393db5	419	error("Unable to read header\n");
f6267998 RC	420	goto out;
	421	}
	422
	423	expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
	424	if ((size_t)expected > count) {
	425	size = -EIO;
	426	goto out;
	427	}
	428
	429	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
1b393db5	430	expected - TPM_HEADER_SIZE);
f6267998	431	if (size < expected) {
1b393db5	432	error("Unable to read remainder of result\n");
f6267998 RC	433	size = -ETIME;
	434	goto out;
	435	}
	436
	437	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
1b393db5 TWHT	438	if (status & TPM_STS_DATA_AVAIL) { /* Retry? */
1b393db5 TWHT	439	error("Error left over data\n");
f6267998 RC	440	size = -EIO;
	441	goto out;
	442	}
	443
	444	out:
	445	tpm_tis_i2c_ready(chip);
1b393db5 TWHT	446	/*
1b393db5 TWHT	447	* The TPM needs some time to clean up here,
f6267998 RC	448	* so we sleep rather than keeping the bus busy
	449	*/
	450	udelay(2000);
	451	release_locality(chip, chip->vendor.locality, 0);
	452
	453	return size;
	454	}
	455
	456	static int tpm_tis_i2c_send(struct tpm_chip chip, u8 buf, size_t len)
	457	{
	458	int rc, status;
	459	ssize_t burstcnt;
	460	size_t count = 0;
1b393db5	461	int retry = 0;
f6267998 RC	462	u8 sts = TPM_STS_GO;
f6267998 RC	463
1b393db5 TWHT	464	if (len > TPM_DEV_BUFSIZE)
1b393db5 TWHT	465	return -E2BIG; /* Command is too long for our tpm, sorry */
f6267998 RC	466
	467	if (request_locality(chip, 0) < 0)
	468	return -EBUSY;
	469
	470	status = tpm_tis_i2c_status(chip);
	471	if ((status & TPM_STS_COMMAND_READY) == 0) {
	472	tpm_tis_i2c_ready(chip);
1b393db5 TWHT	473	if (wait_for_stat(chip, TPM_STS_COMMAND_READY,
1b393db5 TWHT	474	chip->vendor.timeout_b, &status) < 0) {
f6267998 RC	475	rc = -ETIME;
	476	goto out_err;
	477	}
	478	}
	479
1b393db5	480	burstcnt = get_burstcount(chip);
f6267998	481
1b393db5 TWHT	482	/* burstcount < 0 -> tpm is busy */
	483	if (burstcnt < 0)
	484	return burstcnt;
f6267998	485
1b393db5 TWHT	486	while (count < len - 1) {
	487	if (burstcnt > len - 1 - count)
	488	burstcnt = len - 1 - count;
f6267998	489
1b393db5 TWHT	490	#ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
	491	if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION)
	492	burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION;
	493	#endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
f6267998 RC	494
f6267998 RC	495	rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
1b393db5	496	&(buf[count]), burstcnt);
f6267998 RC	497	if (rc == 0)
f6267998 RC	498	count += burstcnt;
1b393db5 TWHT	499	else {
	500	retry++;
	501	wait_for_stat(chip, TPM_STS_VALID,
	502	chip->vendor.timeout_c, &status);
	503
	504	if ((status & TPM_STS_DATA_EXPECT) == 0) {
	505	rc = -EIO;
	506	goto out_err;
	507	}
f6267998 RC	508	}
	509	}
	510
1b393db5	511	/* Write last byte */
f6267998 RC	512	iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
	513	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
	514	if ((status & TPM_STS_DATA_EXPECT) != 0) {
	515	rc = -EIO;
	516	goto out_err;
	517	}
	518
1b393db5	519	/* Go and do it */
f6267998 RC	520	iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
	521
	522	return len;
1b393db5	523
f6267998 RC	524	out_err:
f6267998 RC	525	tpm_tis_i2c_ready(chip);
1b393db5 TWHT	526	/*
1b393db5 TWHT	527	* The TPM needs some time to clean up here,
f6267998 RC	528	* so we sleep rather than keeping the bus busy
	529	*/
	530	udelay(2000);
	531	release_locality(chip, chip->vendor.locality, 0);
	532
	533	return rc;
	534	}
	535
	536	static struct tpm_vendor_specific tpm_tis_i2c = {
	537	.status = tpm_tis_i2c_status,
	538	.recv = tpm_tis_i2c_recv,
	539	.send = tpm_tis_i2c_send,
	540	.cancel = tpm_tis_i2c_ready,
	541	.req_complete_mask = TPM_STS_DATA_AVAIL \| TPM_STS_VALID,
	542	.req_complete_val = TPM_STS_DATA_AVAIL \| TPM_STS_VALID,
	543	.req_canceled = TPM_STS_COMMAND_READY,
	544	};
	545
1b393db5	546
ec34fa5e VP	547	static enum i2c_chip_type tpm_vendor_chip_type(void)
	548	{
	549	#ifdef CONFIG_OF_CONTROL
	550	const void *blob = gd->fdt_blob;
	551
	552	if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
	553	return SLB9645;
	554
	555	if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
	556	return SLB9635;
	557	#endif
	558	return UNKNOWN;
	559	}
	560
1b393db5	561	/* Initialisation of i2c tpm */
f6267998 RC	562	int tpm_vendor_init(uint32_t dev_addr)
	563	{
	564	u32 vendor;
ec34fa5e	565	u32 expected_did_vid;
f6267998 RC	566	uint old_addr;
	567	int rc = 0;
	568	struct tpm_chip *chip;
	569
	570	old_addr = tpm_dev.addr;
	571	if (dev_addr != 0)
	572	tpm_dev.addr = dev_addr;
	573
ec34fa5e VP	574	tpm_dev.chip_type = tpm_vendor_chip_type();
ec34fa5e VP	575
f6267998 RC	576	chip = tpm_register_hardware(&tpm_tis_i2c);
	577	if (chip < 0) {
	578	rc = -ENODEV;
	579	goto out_err;
	580	}
	581
	582	/* Disable interrupts (not supported) */
	583	chip->vendor.irq = 0;
	584
	585	/* Default timeouts */
	586	chip->vendor.timeout_a = TIS_SHORT_TIMEOUT;
	587	chip->vendor.timeout_b = TIS_LONG_TIMEOUT;
	588	chip->vendor.timeout_c = TIS_SHORT_TIMEOUT;
	589	chip->vendor.timeout_d = TIS_SHORT_TIMEOUT;
	590
1b393db5	591	if (request_locality(chip, 0) < 0) {
f6267998 RC	592	rc = -ENODEV;
	593	goto out_err;
	594	}
	595
1b393db5	596	/* Read four bytes from DID_VID register */
f6267998 RC	597	if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
	598	rc = -EIO;
	599	goto out_release;
	600	}
	601
ec34fa5e VP	602	if (tpm_dev.chip_type == SLB9635) {
	603	vendor = be32_to_cpu(vendor);
	604	expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
	605	} else {
	606	/* device id and byte order has changed for newer i2c tpms */
	607	expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
	608	}
f6267998	609
ec34fa5e	610	if (tpm_dev.chip_type != UNKNOWN && vendor != expected_did_vid) {
1b393db5	611	error("Vendor id did not match! ID was %08x\n", vendor);
f6267998 RC	612	rc = -ENODEV;
	613	goto out_release;
	614	}
	615
1b393db5 TWHT	616	debug("1.2 TPM (chip type %s device-id 0x%X)\n",
1b393db5 TWHT	617	chip_name[tpm_dev.chip_type], vendor >> 16);
f6267998 RC	618
	619	/*
	620	* A timeout query to TPM can be placed here.
	621	* Standard timeout values are used so far
	622	*/
	623
	624	return 0;
	625
	626	out_release:
	627	release_locality(chip, 0, 1);
	628
	629	out_err:
	630	tpm_dev.addr = old_addr;
	631	return rc;
	632	}
	633
	634	void tpm_vendor_cleanup(struct tpm_chip *chip)
	635	{
	636	release_locality(chip, chip->vendor.locality, 1);
	637	}