[J-u-boot.git] / drivers / tpm / tpm_tis_st33zp24_i2c.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver
 *
 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
 * Author(s): Christophe Ricard <[email protected]> for STMicroelectronics.
 *
 * Description: Device driver for ST33ZP24 I2C TPM TCG.
 *
 * This device driver implements the TPM interface as defined in
 * the TCG TPM Interface Spec version 1.21, revision 1.0 and the
 * STMicroelectronics Protocol Stack Specification version 1.2.0.
 */

#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
#include <log.h>
#include <tpm-v1.h>
#include <errno.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <asm/unaligned.h>

#include "tpm_tis.h"
#include "tpm_internal.h"

#define TPM_ACCESS			0x0
#define TPM_STS				0x18
#define TPM_DATA_FIFO			0x24

#define LOCALITY0			0

#define TPM_DUMMY_BYTE			0xAA
#define TPM_ST33ZP24_I2C_SLAVE_ADDR	0x13

#define TPM_WRITE_DIRECTION             0x80

/*
 * st33zp24_i2c_write8_reg
 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
 * @param: tpm_register, the tpm tis register where the data should be written
 * @param: tpm_data, the tpm_data to write inside the tpm_register
 * @param: tpm_size, The length of the data
 * @return: Number of byte written successfully else an error code.
 */
static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register,
				   const u8 *tpm_data, size_t tpm_size)
{
	struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev);

	chip_priv->buf[0] = tpm_register;
	memcpy(chip_priv->buf + 1, tpm_data, tpm_size);

	return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1);
}

/*
* st33zp24_i2c_read8_reg
* Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
* @param: tpm_register, the tpm tis register where the data should be read
* @param: tpm_data, the TPM response
* @param: tpm_size, tpm TPM response size to read.
* @return: Number of byte read successfully else an error code.
*/
static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register,
				  u8 *tpm_data, size_t tpm_size)
{
	int status;
	u8 data;

	data = TPM_DUMMY_BYTE;
	status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1);
	if (status < 0)
		return status;

	return dm_i2c_read(dev, 0, tpm_data, tpm_size);
}

/*
 * st33zp24_i2c_write
 * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
 * @param: phy_id, the phy description
 * @param: tpm_register, the tpm tis register where the data should be written
 * @param: tpm_data, the tpm_data to write inside the tpm_register
 * @param: tpm_size, the length of the data
 * @return: number of byte written successfully: should be one if success.
 */
static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register,
			      const u8 *tpm_data, size_t tpm_size)
{
	return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION,
				       tpm_data, tpm_size);
}

/*
 * st33zp24_i2c_read
 * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
 * @param: phy_id, the phy description
 * @param: tpm_register, the tpm tis register where the data should be read
 * @param: tpm_data, the TPM response
 * @param: tpm_size, tpm TPM response size to read.
 * @return: number of byte read successfully: should be one if success.
 */
static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register,
			     u8 *tpm_data, size_t tpm_size)
{
	return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size);
}

/*
 * st33zp24_i2c_release_locality release the active locality
 * @param: chip, the tpm chip description.
 */
static void st33zp24_i2c_release_locality(struct udevice *dev)
{
	u8 data = TPM_ACCESS_ACTIVE_LOCALITY;

	st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
}

/*
 * st33zp24_i2c_check_locality if the locality is active
 * @param: chip, the tpm chip description
 * @return: the active locality or -EACCES.
 */
static int st33zp24_i2c_check_locality(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	u8 data;
	u8 status;

	status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1);
	if (!status && (data &
		(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
		(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
		return chip->locality;

	return -EACCES;
}

/*
 * st33zp24_i2c_request_locality request the TPM locality
 * @param: chip, the chip description
 * @return: the active locality or negative value.
 */
static int st33zp24_i2c_request_locality(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	unsigned long start, stop;
	long ret;
	u8 data;

	if (st33zp24_i2c_check_locality(dev) == chip->locality)
		return chip->locality;

	data = TPM_ACCESS_REQUEST_USE;
	ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
	if (ret < 0)
		return ret;

	/* wait for locality activated */
	start = get_timer(0);
	stop = chip->timeout_a;
	do {
		if (st33zp24_i2c_check_locality(dev) >= 0)
			return chip->locality;
		udelay(TPM_TIMEOUT_MS * 1000);
	} while	 (get_timer(start) < stop);

	return -EACCES;
}

/*
 * st33zp24_i2c_status return the TPM_STS register
 * @param: chip, the tpm chip description
 * @return: the TPM_STS register value.
 */
static u8 st33zp24_i2c_status(struct udevice *dev)
{
	u8 data;

	st33zp24_i2c_read(dev, TPM_STS, &data, 1);

	return data;
}

/*
 * st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A
 * @param: chip, the chip description
 * return: the burstcount or -TPM_DRIVER_ERR in case of error.
 */
static int st33zp24_i2c_get_burstcount(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	unsigned long start, stop;
	int burstcnt, status;
	u8 tpm_reg, temp;

	/* wait for burstcount */
	start = get_timer(0);
	stop = chip->timeout_d;
	do {
		tpm_reg = TPM_STS + 1;
		status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
		if (status < 0)
			return -EBUSY;

		tpm_reg = TPM_STS + 2;
		burstcnt = temp;
		status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
		if (status < 0)
			return -EBUSY;

		burstcnt |= temp << 8;
		if (burstcnt)
			return burstcnt;
		udelay(TIS_SHORT_TIMEOUT_MS * 1000);
	} while (get_timer(start) < stop);

	return -EBUSY;
}

/*
 * st33zp24_i2c_cancel, cancel the current command execution or
 * set STS to COMMAND READY.
 * @param: chip, tpm_chip description.
 */
static void st33zp24_i2c_cancel(struct udevice *dev)
{
	u8 data;

	data = TPM_STS_COMMAND_READY;
	st33zp24_i2c_write(dev, TPM_STS, &data, 1);
}

/*
 * st33zp24_i2c_wait_for_stat wait for a TPM_STS value
 * @param: chip, the tpm chip description
 * @param: mask, the value mask to wait
 * @param: timeout, the timeout
 * @param: status,
 * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
 */
static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask,
				      unsigned long timeout, int *status)
{
	unsigned long start, stop;

	/* Check current status */
	*status = st33zp24_i2c_status(dev);
	if ((*status & mask) == mask)
		return 0;

	start = get_timer(0);
	stop = timeout;
	do {
		udelay(TPM_TIMEOUT_MS * 1000);
		*status = st33zp24_i2c_status(dev);
		if ((*status & mask) == mask)
			return 0;
	} while (get_timer(start) < stop);

	return -ETIME;
}

/*
 * st33zp24_i2c_recv_data receive data
 * @param: chip, the tpm chip description
 * @param: buf, the buffer where the data are received
 * @param: count, the number of data to receive
 * @return: the number of bytes read from TPM FIFO.
 */
static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	int size = 0, burstcnt, len, ret, status;

	while (size < count &&
	       st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
				chip->timeout_c, &status) == 0) {
		burstcnt = st33zp24_i2c_get_burstcount(dev);
		if (burstcnt < 0)
			return burstcnt;
		len = min_t(int, burstcnt, count - size);
		ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len);
		if (ret < 0)
			return ret;

		size += len;
	}

	return size;
}

/*
 * st33zp24_i2c_recv received TPM response through TPM phy.
 * @param: chip, tpm_chip description.
 * @param: buf,	the buffer to store data.
 * @param: count, the number of bytes that can received (sizeof buf).
 * @return: Returns zero in case of success else -EIO.
 */
static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	int size;
	unsigned int expected;

	if (!chip)
		return -ENODEV;

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

	size = st33zp24_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
	if (size < TPM_HEADER_SIZE) {
		debug("TPM error, unable to read header\n");
		goto out;
	}

	expected = get_unaligned_be32(buf + 2);
	if (expected > count || expected < TPM_HEADER_SIZE) {
		size = -EIO;
		goto out;
	}

	size += st33zp24_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
				   expected - TPM_HEADER_SIZE);
	if (size < expected) {
		debug("TPM error, unable to read remaining bytes of result\n");
		size = -EIO;
		goto out;
	}

out:
	st33zp24_i2c_cancel(dev);
	st33zp24_i2c_release_locality(dev);

	return size;
}

/*
 * st33zp24_i2c_send send TPM commands through TPM phy.
 * @param: chip, tpm_chip description.
 * @param: buf,	the buffer to send.
 * @param: len, the number of bytes to send.
 * @return: Returns zero in case of success else the negative error code.
 */
static int st33zp24_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	u32 i, size;
	int burstcnt, ret, status;
	u8 data, tpm_stat;

	if (!chip)
		return -ENODEV;
	if (len < TPM_HEADER_SIZE)
		return -EIO;

	ret = st33zp24_i2c_request_locality(dev);
	if (ret < 0)
		return ret;

	tpm_stat = st33zp24_i2c_status(dev);
	if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
		st33zp24_i2c_cancel(dev);
		if (st33zp24_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
					       chip->timeout_b, &status) < 0) {
			ret = -ETIME;
			goto out_err;
		}
	}

	for (i = 0; i < len - 1;) {
		burstcnt = st33zp24_i2c_get_burstcount(dev);
		if (burstcnt < 0)
			return burstcnt;

		size = min_t(int, len - i - 1, burstcnt);
		ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size);
		if (ret < 0)
			goto out_err;

		i += size;
	}

	tpm_stat = st33zp24_i2c_status(dev);
	if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
		ret = -EIO;
		goto out_err;
	}

	ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
	if (ret < 0)
		goto out_err;

	tpm_stat = st33zp24_i2c_status(dev);
	if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
		ret = -EIO;
		goto out_err;
	}

	data = TPM_STS_GO;
	ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1);
	if (ret < 0)
		goto out_err;

	return len;

out_err:
	st33zp24_i2c_cancel(dev);
	st33zp24_i2c_release_locality(dev);

	return ret;
}

static int st33zp24_i2c_cleanup(struct udevice *dev)
{
	st33zp24_i2c_cancel(dev);
	/*
	 * The TPM needs some time to clean up here,
	 * so we sleep rather than keeping the bus busy
	 */
	mdelay(2);
	st33zp24_i2c_release_locality(dev);

	return 0;
}

static int st33zp24_i2c_init(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);

	chip->is_open = 1;

	/* Default timeouts - these could move to the device tree */
	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;

	chip->locality = LOCALITY0;

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

	return 0;
}

static int st33zp24_i2c_open(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);
	int rc;

	debug("%s: start\n", __func__);
	if (chip->is_open)
		return -EBUSY;

	rc = st33zp24_i2c_init(dev);
	if (rc < 0)
		chip->is_open = 0;

	return rc;
}

static int st33zp24_i2c_close(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);

	if (chip->is_open) {
		st33zp24_i2c_release_locality(dev);
		chip->is_open = 0;
		chip->vend_dev = 0;
	}

	return 0;
}

static int st33zp24_i2c_get_desc(struct udevice *dev, char *buf, int size)
{
	struct tpm_chip *chip = dev_get_priv(dev);

	if (size < 50)
		return -ENOSPC;

	return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
			chip->is_open ? "open" : "closed",
			dev->name,
			chip->vend_dev >> 16);
}

static const struct tpm_ops st33zp24_i2c_tpm_ops = {
	.open = st33zp24_i2c_open,
	.close = st33zp24_i2c_close,
	.recv = st33zp24_i2c_recv,
	.send = st33zp24_i2c_send,
	.cleanup = st33zp24_i2c_cleanup,
	.get_desc = st33zp24_i2c_get_desc,
};

static int st33zp24_i2c_probe(struct udevice *dev)
{
	struct tpm_chip *chip = dev_get_priv(dev);

	/* Default timeouts */
	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;

	chip->locality = LOCALITY0;

	i2c_set_chip_offset_len(dev, 0);

	debug("ST33ZP24 I2C TPM from STMicroelectronics found\n");

	return 0;
}

static int st33zp24_i2c_remove(struct udevice *dev)
{
	st33zp24_i2c_release_locality(dev);

	return 0;
}

static const struct udevice_id st33zp24_i2c_ids[] = {
	{ .compatible = "st,st33zp24-i2c" },
	{ }
};

U_BOOT_DRIVER(st33zp24_i2c) = {
	.name   = "st33zp24-i2c",
	.id     = UCLASS_TPM,
	.of_match = of_match_ptr(st33zp24_i2c_ids),
	.probe  = st33zp24_i2c_probe,
	.remove = st33zp24_i2c_remove,
	.ops = &st33zp24_i2c_tpm_ops,
	.priv_auto	= sizeof(struct tpm_chip),
};
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
3aa74088 CR	2	/*
	3	* STMicroelectronics TPM ST33ZP24 I2C UBOOT driver
	4	*
05cd1194 PC	5	* Copyright (C) 2016, STMicroelectronics - All Rights Reserved
05cd1194 PC	6	* Author(s): Christophe Ricard <[email protected]> for STMicroelectronics.
3aa74088 CR	7	*
	8	* Description: Device driver for ST33ZP24 I2C TPM TCG.
	9	*
	10	* This device driver implements the TPM interface as defined in
	11	* the TCG TPM Interface Spec version 1.21, revision 1.0 and the
	12	* STMicroelectronics Protocol Stack Specification version 1.2.0.
3aa74088 CR	13	*/
	14
	15	#include <common.h>
	16	#include <dm.h>
	17	#include <fdtdec.h>
	18	#include <i2c.h>
f7ae49fc	19	#include <log.h>
d677bfe2	20	#include <tpm-v1.h>
3aa74088	21	#include <errno.h>
c05ed00a	22	#include <linux/delay.h>
3aa74088 CR	23	#include <linux/types.h>
	24	#include <asm/unaligned.h>
	25
	26	#include "tpm_tis.h"
	27	#include "tpm_internal.h"
	28
	29	#define TPM_ACCESS 0x0
	30	#define TPM_STS 0x18
	31	#define TPM_DATA_FIFO 0x24
	32
	33	#define LOCALITY0 0
	34
	35	#define TPM_DUMMY_BYTE 0xAA
	36	#define TPM_ST33ZP24_I2C_SLAVE_ADDR 0x13
	37
	38	#define TPM_WRITE_DIRECTION 0x80
	39
	40	/*
	41	* st33zp24_i2c_write8_reg
	42	* Send byte to the TIS register according to the ST33ZP24 I2C protocol.
	43	* @param: tpm_register, the tpm tis register where the data should be written
	44	* @param: tpm_data, the tpm_data to write inside the tpm_register
	45	* @param: tpm_size, The length of the data
	46	* @return: Number of byte written successfully else an error code.
	47	*/
	48	static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register,
	49	const u8 *tpm_data, size_t tpm_size)
	50	{
	51	struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev);
	52
	53	chip_priv->buf[0] = tpm_register;
	54	memcpy(chip_priv->buf + 1, tpm_data, tpm_size);
	55
	56	return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1);
	57	}
	58
	59	/*
	60	* st33zp24_i2c_read8_reg
	61	* Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
	62	* @param: tpm_register, the tpm tis register where the data should be read
	63	* @param: tpm_data, the TPM response
	64	* @param: tpm_size, tpm TPM response size to read.
	65	* @return: Number of byte read successfully else an error code.
	66	*/
	67	static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register,
	68	u8 *tpm_data, size_t tpm_size)
	69	{
	70	int status;
	71	u8 data;
	72
	73	data = TPM_DUMMY_BYTE;
	74	status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1);
	75	if (status < 0)
	76	return status;
	77
	78	return dm_i2c_read(dev, 0, tpm_data, tpm_size);
	79	}
	80
	81	/*
	82	* st33zp24_i2c_write
	83	* Send byte to the TIS register according to the ST33ZP24 I2C protocol.
	84	* @param: phy_id, the phy description
	85	* @param: tpm_register, the tpm tis register where the data should be written
	86	* @param: tpm_data, the tpm_data to write inside the tpm_register
87	* @param: tpm_size, the length of the data
88	* @return: number of byte written successfully: should be one if success.
89	*/
90	static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register,
91	const u8 *tpm_data, size_t tpm_size)
92	{
93	return st33zp24_i2c_write8_reg(dev, tpm_register \| TPM_WRITE_DIRECTION,
94	tpm_data, tpm_size);
95	}
96
97	/*
98	* st33zp24_i2c_read
99	* Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
100	* @param: phy_id, the phy description
101	* @param: tpm_register, the tpm tis register where the data should be read
102	* @param: tpm_data, the TPM response
103	* @param: tpm_size, tpm TPM response size to read.
104	* @return: number of byte read successfully: should be one if success.
105	*/
106	static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register,
107	u8 *tpm_data, size_t tpm_size)
108	{
109	return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size);
110	}
111
112	/*
113	* st33zp24_i2c_release_locality release the active locality
114	* @param: chip, the tpm chip description.
115	*/
116	static void st33zp24_i2c_release_locality(struct udevice *dev)
117	{
118	u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
119
120	st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
121	}
122
123	/*
124	* st33zp24_i2c_check_locality if the locality is active
125	* @param: chip, the tpm chip description
126	* @return: the active locality or -EACCES.
127	*/
128	static int st33zp24_i2c_check_locality(struct udevice *dev)
129	{
130	struct tpm_chip *chip = dev_get_priv(dev);
131	u8 data;
132	u8 status;
133
134	status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1);
135	if (!status && (data &
136	(TPM_ACCESS_ACTIVE_LOCALITY \| TPM_ACCESS_VALID)) ==
137	(TPM_ACCESS_ACTIVE_LOCALITY \| TPM_ACCESS_VALID))
138	return chip->locality;
139
140	return -EACCES;
141	}
142
143	/*
144	* st33zp24_i2c_request_locality request the TPM locality
145	* @param: chip, the chip description
146	* @return: the active locality or negative value.
147	*/
148	static int st33zp24_i2c_request_locality(struct udevice *dev)
149	{
150	struct tpm_chip *chip = dev_get_priv(dev);
151	unsigned long start, stop;
152	long ret;
153	u8 data;
154
155	if (st33zp24_i2c_check_locality(dev) == chip->locality)
156	return chip->locality;
157
158	data = TPM_ACCESS_REQUEST_USE;
159	ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
160	if (ret < 0)
161	return ret;
162
163	/* wait for locality activated */
164	start = get_timer(0);
165	stop = chip->timeout_a;
166	do {
167	if (st33zp24_i2c_check_locality(dev) >= 0)
168	return chip->locality;
169	udelay(TPM_TIMEOUT_MS * 1000);
170	} while (get_timer(start) < stop);
171
172	return -EACCES;
173	}
174
175	/*
176	* st33zp24_i2c_status return the TPM_STS register
177	* @param: chip, the tpm chip description
178	* @return: the TPM_STS register value.
179	*/
180	static u8 st33zp24_i2c_status(struct udevice *dev)
181	{
182	u8 data;
183
184	st33zp24_i2c_read(dev, TPM_STS, &data, 1);
185
186	return data;
187	}
188
189	/*
190	* st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A
191	* @param: chip, the chip description
192	* return: the burstcount or -TPM_DRIVER_ERR in case of error.
193	*/
194	static int st33zp24_i2c_get_burstcount(struct udevice *dev)
195	{
196	struct tpm_chip *chip = dev_get_priv(dev);
197	unsigned long start, stop;
198	int burstcnt, status;
199	u8 tpm_reg, temp;
200
201	/* wait for burstcount */
202	start = get_timer(0);
203	stop = chip->timeout_d;
204	do {
205	tpm_reg = TPM_STS + 1;
206	status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
207	if (status < 0)
208	return -EBUSY;
209
210	tpm_reg = TPM_STS + 2;
211	burstcnt = temp;
212	status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
213	if (status < 0)
214	return -EBUSY;
215
216	burstcnt \|= temp << 8;
217	if (burstcnt)
218	return burstcnt;
219	udelay(TIS_SHORT_TIMEOUT_MS * 1000);
220	} while (get_timer(start) < stop);
221
222	return -EBUSY;
223	}
224
225	/*
226	* st33zp24_i2c_cancel, cancel the current command execution or
227	* set STS to COMMAND READY.
228	* @param: chip, tpm_chip description.
229	*/
230	static void st33zp24_i2c_cancel(struct udevice *dev)
231	{
232	u8 data;
233
234	data = TPM_STS_COMMAND_READY;
235	st33zp24_i2c_write(dev, TPM_STS, &data, 1);
236	}
237
238	/*
239	* st33zp24_i2c_wait_for_stat wait for a TPM_STS value
240	* @param: chip, the tpm chip description
241	* @param: mask, the value mask to wait
242	* @param: timeout, the timeout
243	* @param: status,
244	* @return: the tpm status, 0 if success, -ETIME if timeout is reached.
245	*/
246	static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask,
247	unsigned long timeout, int *status)
248	{
249	unsigned long start, stop;
250
251	/* Check current status */
252	*status = st33zp24_i2c_status(dev);
253	if ((*status & mask) == mask)
254	return 0;
255
256	start = get_timer(0);
257	stop = timeout;
258	do {
259	udelay(TPM_TIMEOUT_MS * 1000);
260	*status = st33zp24_i2c_status(dev);
261	if ((*status & mask) == mask)
262	return 0;
263	} while (get_timer(start) < stop);
264
265	return -ETIME;
266	}
267
268	/*
269	* st33zp24_i2c_recv_data receive data
270	* @param: chip, the tpm chip description
271	* @param: buf, the buffer where the data are received
272	* @param: count, the number of data to receive
273	* @return: the number of bytes read from TPM FIFO.
274	*/
275	static int st33zp24_i2c_recv_data(struct udevice dev, u8 buf, size_t count)
276	{
277	struct tpm_chip *chip = dev_get_priv(dev);
278	int size = 0, burstcnt, len, ret, status;
279
280	while (size < count &&
281	st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL \| TPM_STS_VALID,
282	chip->timeout_c, &status) == 0) {
283	burstcnt = st33zp24_i2c_get_burstcount(dev);
284	if (burstcnt < 0)
285	return burstcnt;
286	len = min_t(int, burstcnt, count - size);
287	ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len);
288	if (ret < 0)
289	return ret;
290
291	size += len;
292	}
293
294	return size;
295	}
296
297	/*
298	* st33zp24_i2c_recv received TPM response through TPM phy.
299	* @param: chip, tpm_chip description.
300	* @param: buf, the buffer to store data.
301	* @param: count, the number of bytes that can received (sizeof buf).
302	* @return: Returns zero in case of success else -EIO.
303	*/
304	static int st33zp24_i2c_recv(struct udevice dev, u8 buf, size_t count)
305	{
306	struct tpm_chip *chip = dev_get_priv(dev);
12e0ab32 JB	307	int size;
12e0ab32 JB	308	unsigned int expected;
3aa74088 CR	309
	310	if (!chip)
	311	return -ENODEV;
	312
	313	if (count < TPM_HEADER_SIZE) {
	314	size = -EIO;
	315	goto out;
	316	}
	317
	318	size = st33zp24_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
	319	if (size < TPM_HEADER_SIZE) {
	320	debug("TPM error, unable to read header\n");
	321	goto out;
	322	}
	323
	324	expected = get_unaligned_be32(buf + 2);
12e0ab32	325	if (expected > count \|\| expected < TPM_HEADER_SIZE) {
3aa74088 CR	326	size = -EIO;
	327	goto out;
	328	}
	329
	330	size += st33zp24_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
	331	expected - TPM_HEADER_SIZE);
	332	if (size < expected) {
	333	debug("TPM error, unable to read remaining bytes of result\n");
	334	size = -EIO;
	335	goto out;
	336	}
	337
	338	out:
	339	st33zp24_i2c_cancel(dev);
	340	st33zp24_i2c_release_locality(dev);
	341
	342	return size;
	343	}
	344
	345	/*
	346	* st33zp24_i2c_send send TPM commands through TPM phy.
	347	* @param: chip, tpm_chip description.
	348	* @param: buf, the buffer to send.
	349	* @param: len, the number of bytes to send.
	350	* @return: Returns zero in case of success else the negative error code.
	351	*/
	352	static int st33zp24_i2c_send(struct udevice dev, const u8 buf, size_t len)
	353	{
	354	struct tpm_chip *chip = dev_get_priv(dev);
	355	u32 i, size;
	356	int burstcnt, ret, status;
	357	u8 data, tpm_stat;
	358
	359	if (!chip)
	360	return -ENODEV;
	361	if (len < TPM_HEADER_SIZE)
	362	return -EIO;
	363
	364	ret = st33zp24_i2c_request_locality(dev);
	365	if (ret < 0)
	366	return ret;
	367
	368	tpm_stat = st33zp24_i2c_status(dev);
	369	if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
	370	st33zp24_i2c_cancel(dev);
	371	if (st33zp24_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
	372	chip->timeout_b, &status) < 0) {
	373	ret = -ETIME;
	374	goto out_err;
	375	}
	376	}
	377
	378	for (i = 0; i < len - 1;) {
	379	burstcnt = st33zp24_i2c_get_burstcount(dev);
	380	if (burstcnt < 0)
	381	return burstcnt;
	382
	383	size = min_t(int, len - i - 1, burstcnt);
	384	ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size);
	385	if (ret < 0)
	386	goto out_err;
	387
	388	i += size;
	389	}
390
391	tpm_stat = st33zp24_i2c_status(dev);
392	if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
393	ret = -EIO;
394	goto out_err;
395	}
396
397	ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
398	if (ret < 0)
399	goto out_err;
400
401	tpm_stat = st33zp24_i2c_status(dev);
402	if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
403	ret = -EIO;
404	goto out_err;
405	}
406
407	data = TPM_STS_GO;
408	ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1);
409	if (ret < 0)
410	goto out_err;
411
412	return len;
413
414	out_err:
415	st33zp24_i2c_cancel(dev);
416	st33zp24_i2c_release_locality(dev);
417
418	return ret;
419	}
420
421	static int st33zp24_i2c_cleanup(struct udevice *dev)
422	{
423	st33zp24_i2c_cancel(dev);
424	/*
425	* The TPM needs some time to clean up here,
426	* so we sleep rather than keeping the bus busy
427	*/
428	mdelay(2);
429	st33zp24_i2c_release_locality(dev);
430
431	return 0;
432	}
433
434	static int st33zp24_i2c_init(struct udevice *dev)
435	{
436	struct tpm_chip *chip = dev_get_priv(dev);
437
438	chip->is_open = 1;
439
440	/* Default timeouts - these could move to the device tree */
441	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
442	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
443	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
444	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
445
446	chip->locality = LOCALITY0;
447
448	/*
449	* A timeout query to TPM can be placed here.
450	* Standard timeout values are used so far
451	*/
452
453	return 0;
454	}
455
456	static int st33zp24_i2c_open(struct udevice *dev)
457	{
458	struct tpm_chip *chip = dev_get_priv(dev);
459	int rc;
460
461	debug("%s: start\n", __func__);
462	if (chip->is_open)
463	return -EBUSY;
464
465	rc = st33zp24_i2c_init(dev);
466	if (rc < 0)
467	chip->is_open = 0;
468
469	return rc;
470	}
471
472	static int st33zp24_i2c_close(struct udevice *dev)
473	{
474	struct tpm_chip *chip = dev_get_priv(dev);
475
476	if (chip->is_open) {
477	st33zp24_i2c_release_locality(dev);
478	chip->is_open = 0;
479	chip->vend_dev = 0;
480	}
481
482	return 0;
483	}
484
485	static int st33zp24_i2c_get_desc(struct udevice dev, char buf, int size)
486	{
487	struct tpm_chip *chip = dev_get_priv(dev);
488
489	if (size < 50)
490	return -ENOSPC;
491
492	return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
493	chip->is_open ? "open" : "closed",
494	dev->name,
495	chip->vend_dev >> 16);
496	}
497
498	static const struct tpm_ops st33zp24_i2c_tpm_ops = {
499	.open = st33zp24_i2c_open,
500	.close = st33zp24_i2c_close,
501	.recv = st33zp24_i2c_recv,
502	.send = st33zp24_i2c_send,
503	.cleanup = st33zp24_i2c_cleanup,
504	.get_desc = st33zp24_i2c_get_desc,
505	};
506
507	static int st33zp24_i2c_probe(struct udevice *dev)
508	{
509	struct tpm_chip *chip = dev_get_priv(dev);
510
511	/* Default timeouts */
512	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
513	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
514	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
515	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
516
517	chip->locality = LOCALITY0;
518
519	i2c_set_chip_offset_len(dev, 0);
520
521	debug("ST33ZP24 I2C TPM from STMicroelectronics found\n");
522
523	return 0;
524	}
525
526	static int st33zp24_i2c_remove(struct udevice *dev)
527	{
528	st33zp24_i2c_release_locality(dev);
529
530	return 0;
531	}
532
533	static const struct udevice_id st33zp24_i2c_ids[] = {
534	{ .compatible = "st,st33zp24-i2c" },
535	{ }
536	};
537
538	U_BOOT_DRIVER(st33zp24_i2c) = {
539	.name = "st33zp24-i2c",
540	.id = UCLASS_TPM,
541	.of_match = of_match_ptr(st33zp24_i2c_ids),
542	.probe = st33zp24_i2c_probe,
543	.remove = st33zp24_i2c_remove,
544	.ops = &st33zp24_i2c_tpm_ops,
41575d8e	545	.priv_auto = sizeof(struct tpm_chip),
3aa74088	546	};