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