/*
 * 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
 *
 * 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 <malloc.h>
#include "tpm.h"

/* global structure for tpm chip data */
struct tpm_chip g_chip;

enum tpm_duration {
	TPM_SHORT = 0,
	TPM_MEDIUM = 1,
	TPM_LONG = 2,
	TPM_UNDEFINED,
};

#define TPM_MAX_ORDINAL 243
#define TPM_MAX_PROTECTED_ORDINAL 12
#define TPM_PROTECTED_ORDINAL_MASK 0xFF

/*
 * Array with one entry per ordinal defining the maximum amount
 * of time the chip could take to return the result.  The ordinal
 * designation of short, medium or long is defined in a table in
 * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
 * values of the SHORT, MEDIUM, and LONG durations are retrieved
 * from the chip during initialization with a call to tpm_get_timeouts.
 */
static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
	TPM_UNDEFINED,		/* 0 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 5 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 10 */
	TPM_SHORT,
};

static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
	TPM_UNDEFINED,		/* 0 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 5 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 10 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_LONG,
	TPM_MEDIUM,		/* 15 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_SHORT,		/* 20 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,		/* 25 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 30 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 35 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 40 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 45 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_LONG,
	TPM_MEDIUM,		/* 50 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 55 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 60 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 65 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 70 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 75 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 80 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 85 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 90 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 95 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 100 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 105 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 110 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 115 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 120 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 125 */
	TPM_SHORT,
	TPM_LONG,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 130 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_UNDEFINED,		/* 135 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 140 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 145 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 150 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 155 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 160 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 165 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 170 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 175 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 180 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,		/* 185 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 190 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 195 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 200 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 205 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 210 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_UNDEFINED,		/* 215 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 220 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 225 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 230 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 235 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 240 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
};

/*
 * Returns max number of milliseconds to wait
 */
unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
{
	int duration_idx = TPM_UNDEFINED;
	int duration = 0;

	if (ordinal < TPM_MAX_ORDINAL)
		duration_idx = tpm_ordinal_duration[ordinal];
	else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
		 TPM_MAX_PROTECTED_ORDINAL)
		duration_idx =
		    tpm_protected_ordinal_duration[ordinal &
						   TPM_PROTECTED_ORDINAL_MASK];

	if (duration_idx != TPM_UNDEFINED)
		duration = chip->vendor.duration[duration_idx];
	if (duration <= 0)
		return 2 * 60 * HZ; /*two minutes timeout*/
	else
		return duration;
}

#define TPM_CMD_COUNT_BYTE 2
#define TPM_CMD_ORDINAL_BYTE 6

ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
{
	ssize_t rc;
	u32 count, ordinal;
	unsigned long start, stop;

	struct tpm_chip *chip = &g_chip;

	/* switch endianess: big->little */
	count = get_unaligned_be32(buf + TPM_CMD_COUNT_BYTE);
	ordinal = get_unaligned_be32(buf + TPM_CMD_ORDINAL_BYTE);

	if (count == 0) {
		dev_err(chip->dev, "no data\n");
		return -ENODATA;
	}
	if (count > bufsiz) {
		dev_err(chip->dev,
			"invalid count value %x %zx\n", count, bufsiz);
		return -E2BIG;
	}

	rc = chip->vendor.send(chip, (u8 *)buf, count);
	if (rc < 0) {
		dev_err(chip->dev, "tpm_transmit: tpm_send: error %zd\n", rc);
		goto out;
	}

	if (chip->vendor.irq)
		goto out_recv;

	start = get_timer(0);
	stop = tpm_calc_ordinal_duration(chip, ordinal);
	do {
		dbg_printf("waiting for status...\n");
		u8 status = chip->vendor.status(chip);
		if ((status & chip->vendor.req_complete_mask) ==
		    chip->vendor.req_complete_val) {
			dbg_printf("...got it;\n");
			goto out_recv;
		}

		if ((status == chip->vendor.req_canceled)) {
			dev_err(chip->dev, "Operation Canceled\n");
			rc = -ECANCELED;
			goto out;
		}
		msleep(TPM_TIMEOUT);
	} while (get_timer(start) < stop);

	chip->vendor.cancel(chip);
	dev_err(chip->dev, "Operation Timed out\n");
	rc = -ETIME;
	goto out;

out_recv:

	dbg_printf("out_recv: reading response...\n");
	rc = chip->vendor.recv(chip, (u8 *)buf, TPM_BUFSIZE);
	if (rc < 0)
		dev_err(chip->dev, "tpm_transmit: tpm_recv: error %zd\n", rc);
out:
	return rc;
}

#define TPM_ERROR_SIZE 10

enum tpm_capabilities {
	TPM_CAP_PROP = cpu_to_be32(5),
};

enum tpm_sub_capabilities {
	TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
	TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
};

struct tpm_chip *tpm_register_hardware(const struct tpm_vendor_specific *entry)
{
	struct tpm_chip *chip;

	/* Driver specific per-device data */
	chip = &g_chip;
	memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
	chip->is_open = 1;

	return chip;
}

int tpm_open(uint32_t dev_addr)
{
	int rc;
	if (g_chip.is_open)
		return -EBUSY;
	rc = tpm_vendor_init(dev_addr);
	if (rc < 0)
		g_chip.is_open = 0;
	return rc;
}

void tpm_close(void)
{
	if (g_chip.is_open) {
		tpm_vendor_cleanup(&g_chip);
		g_chip.is_open = 0;
	}
}