/* * 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. * * 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), };