diff options
Diffstat (limited to 'drivers/tpm/tpm_tis_st33zp24_i2c.c')
| -rw-r--r-- | drivers/tpm/tpm_tis_st33zp24_i2c.c | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/tpm/tpm_tis_st33zp24_i2c.c b/drivers/tpm/tpm_tis_st33zp24_i2c.c new file mode 100644 index 0000000..9e4829f --- /dev/null +++ b/drivers/tpm/tpm_tis_st33zp24_i2c.c @@ -0,0 +1,543 @@ +/* + * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver + * + * Copyright (C) 2016 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. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <fdtdec.h> +#include <i2c.h> +#include <tpm.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, 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) { + 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), +}; |