[U-Boot] [PATCH 2/2] i2c: ST33ZP24 I2C TPM driver
Jean-Luc BLANC
stmicroelectronics.tpm at gmail.com
Wed Jul 9 09:40:14 CEST 2014
This driver add support for STMicroelectronics ST33ZP24 I2C TPM.
---
README | 6 +
drivers/tpm/Makefile | 1 +
drivers/tpm/tpm_i2c_stm_st33.c | 633 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 640 insertions(+)
create mode 100644 drivers/tpm/tpm_i2c_stm_st33.c
diff --git a/README b/README
index a4aa28a..c4463d8 100644
--- a/README
+++ b/README
@@ -1426,6 +1426,12 @@ The following options need to be configured:
TPM1_SPI_CS
Define SPI Chip Select ID connected to TPM
+ CONFIG_TPM_ST_I2C
+ Support I2C STMicroelectronics TPM. Require I2C support
+
+ CONFIG_TPM_I2C_BUS
+ Define the i2c bus number for the TPM device
+
- USB Support:
At the moment only the UHCI host controller is
supported (PIP405, MIP405, MPC5200); define
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
index 1ee707e..29e1f80 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_TPM_TIS_I2C) += tpm_tis_i2c.o
obj-$(CONFIG_TPM_TIS_LPC) += tpm_tis_lpc.o
obj-$(CONFIG_TPM_TIS_SANDBOX) += tpm_tis_sandbox.o
obj-$(CONFIG_TPM_ST_SPI) += tpm_spi_stm_st33.o
+obj-$(CONFIG_TPM_ST_I2C) += tpm_i2c_stm_st33.o
diff --git a/drivers/tpm/tpm_i2c_stm_st33.c b/drivers/tpm/tpm_i2c_stm_st33.c
new file mode 100644
index 0000000..6e20f8c
--- /dev/null
+++ b/drivers/tpm/tpm_i2c_stm_st33.c
@@ -0,0 +1,633 @@
+/*
+ * STMicroelectronics TPM I2C UBOOT Linux driver for TPM ST33ZP24
+ * Copyright (C) 2014 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 I2C Protocol Stack Specification version 1.2.0.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * @Author: Jean-Luc BLANC <jean-luc.blanc at st.com>
+ *
+ * @File: tpm_i2c_stm_st33.c
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <linux/types.h>
+#include <tpm.h>
+#include <errno.h>
+#include <asm/unaligned.h>
+
+#define MINOR_NUM_I2C 224
+
+#define TPM_ACCESS 0x0
+#define TPM_STS 0x18
+#define TPM_HASH_END 0x20
+#define TPM_DATA_FIFO 0x24
+#define TPM_HASH_DATA 0x24
+#define TPM_HASH_START 0x28
+#define TPM_INTF_CAPABILITY 0x14
+#define TPM_INT_STATUS 0x10
+#define TPM_INT_ENABLE 0x08
+
+#define TPM_DUMMY_BYTE 0xAA
+#define TPM_WRITE_DIRECTION 0x80
+#define TPM_HEADER_SIZE 10
+#define TPM_BUFSIZE 2048
+
+#define LOCALITY0 0
+#define LOCALITY4 4
+#define LOCALITY0_I2C_ADDR 0x13
+#define LOCALITY4_I2C_ADDR 0x1B
+
+/* Index of Count field in TPM response buffer */
+#define TPM_RSP_SIZE_BYTE 2
+
+/* Maximum command duration */
+#define TPM_MAX_COMMAND_DURATION_MS 120000
+
+enum stm33zp24_access {
+ TPM_ACCESS_VALID = 0x80,
+ TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
+ TPM_ACCESS_REQUEST_PENDING = 0x04,
+ TPM_ACCESS_REQUEST_USE = 0x02,
+};
+
+enum stm33zp24_status {
+ TPM_STS_VALID = 0x80,
+ TPM_STS_COMMAND_READY = 0x40,
+ TPM_STS_GO = 0x20,
+ TPM_STS_DATA_AVAIL = 0x10,
+ TPM_STS_DATA_EXPECT = 0x08,
+};
+
+enum stm33zp24_int_flags {
+ TPM_GLOBAL_INT_ENABLE = 0x80,
+ TPM_INTF_CMD_READY_INT = 0x080,
+ TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
+ TPM_INTF_WAKE_UP_READY_INT = 0x020,
+ TPM_INTF_LOCTPM_BUFSIZE4SOFTRELEASE_INT = 0x008,
+ TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
+ TPM_INTF_STS_VALID_INT = 0x002,
+ TPM_INTF_DATA_AVAIL_INT = 0x001,
+};
+
+enum tis_defaults {
+ TIS_SHORT_TIMEOUT_MS = 750, /* ms */
+ TIS_LONG_TIMEOUT_MS = 2000, /* 2 sec */
+};
+
+/**
+ * @addr: TPM I2C address
+ * @i2c_bus: I2C bus ID the TPM is connected to
+ * @is_open: TPM connection establishment information
+ * @locality: active locality of the TPM (0 OR 4)
+ * @buf: command/response buffer
+ * @timeout_*: timeouts for TPM states changes
+ * @duration: maximum time for a TPM command processing
+ */
+struct tpm_chip {
+ uint addr;
+ uint i2c_bus;
+ int is_open;
+ u8 buf[TPM_BUFSIZE];
+ int locality;
+ unsigned long timeout_a, timeout_b, timeout_c, timeout_d; /* msec */
+ unsigned long duration; /* msec */
+};
+
+static struct tpm_chip tpm_dev;
+
+/*
+ * write8_reg(): Send byte to the TIS register according to I2C TPM protocol.
+ * @tpm_register, the tpm tis register where the data should be written
+ * @tpm_data, the tpm_data to write inside the tpm_register
+ * @tpm_size, The length of the data
+ * @return: Returns zero in case of success else the negative error code.
+ */
+static int write8_reg(u8 addr, u8 tpm_register,
+ const u8 *tpm_data, u16 tpm_size)
+{
+ u8 data;
+
+ data = tpm_register;
+ memcpy(&(tpm_dev.buf[0]), &data, sizeof(data));
+ memcpy(&(tpm_dev.buf[0])+1, tpm_data, tpm_size);
+ return i2c_write(addr, 0, 0, &tpm_dev.buf[0], tpm_size + 1);
+}
+
+/*
+* read8_reg(): Recv byte from the TIS register according to I2C TPM protocol.
+* @tpm_register, the tpm tis register where the data should be read
+* @tpm_data, the TPM response
+* @tpm_size, TPM response size to read.
+* @return: Returns zero in case of success else the negative error code.
+*/
+static int read8_reg(u8 addr, u8 tpm_register, u8 *tpm_data, int tpm_size)
+{
+ u8 status = 0;
+ u8 data;
+
+ data = TPM_DUMMY_BYTE;
+ status = write8_reg(addr, tpm_register, &data, 1);
+ if (status == 0)
+ status = i2c_read(addr, 0, 0, tpm_data, tpm_size);
+return status;
+}
+
+/*
+ * I2C_WRITE_DATA(): Send byte to TIS register according to I2C TPM protocol.
+ * @client, the chip description
+ * @tpm_register, TPM tis register where the data should be written
+ * @tpm_data, the tpm_data to write inside the tpm_register
+ * @tpm_size, The length of the data
+ * @return: Returns zero in case of success else the negative error code.
+ */
+#define I2C_WRITE_DATA(client, tpm_register, tpm_data, tpm_size)\
+ (write8_reg(client, tpm_register | \
+ TPM_WRITE_DIRECTION, tpm_data, tpm_size))
+
+/*
+ * I2C_READ_DATA(): Recv byte from TIS register according I2C TPM protocol.
+ * @tpm, the chip description
+ * @tpm_register, the tpm tis register where the data should be read
+ * @tpm_data, the TPM response
+ * @tpm_size, tpm TPM response size to read.
+ * @return: Returns zero in case of success else the negative error code.
+ */
+#define I2C_READ_DATA(client, tpm_register, tpm_data, tpm_size)\
+ (read8_reg(client, tpm_register, tpm_data, tpm_size))
+
+/*
+ * release_locality(): release the active locality
+ * @chip, TPM chip descriptor.
+ * @return: Returns zero in case of success else the negative error code.
+ */
+static int release_locality(struct tpm_chip *chip)
+{
+ u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
+
+ return I2C_WRITE_DATA(tpm_dev.addr, TPM_ACCESS, &data, 1);
+}
+
+/*
+ * check_locality(): check if the locality is active
+ * @chip, TPM chip descriptor.
+ * @return: the active locality or -EIO.
+ */
+static int check_locality(struct tpm_chip *chip)
+{
+ u8 data;
+ u8 status;
+
+ status = I2C_READ_DATA(chip->addr, TPM_ACCESS, &data, 1);
+ if ((status == 0) && (data &
+ (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+ (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
+ return chip->locality;
+ return -EIO;
+}
+
+/*
+ * request_locality(): request the TPM locality
+ * @chip: TPM chip descriptor.
+ * @return: the active locality or -ETIME.
+ */
+static int request_locality(struct tpm_chip *chip)
+{
+ unsigned long start, stop;
+ long rc;
+ u8 data;
+
+ if (check_locality(chip) == chip->locality)
+ return chip->locality;
+
+ data = TPM_ACCESS_REQUEST_USE;
+ rc = I2C_WRITE_DATA(chip->addr, TPM_ACCESS, &data, 1);
+ if (rc < 0)
+ goto end;
+
+ /* wait for locality activated */
+ start = get_timer(0);
+ stop = chip->timeout_a;
+ do {
+ if (check_locality(chip) >= 0)
+ return chip->locality;
+ } while (get_timer(start) < stop);
+ rc = -ETIME;
+end:
+ return rc;
+}
+
+/*
+ * tpm_stm_spi_status(): return the TPM_STS register
+ * @chip: TPM chip descriptor.
+ * @return: the TPM_STS register value.
+ */
+static u8 tpm_stm_i2c_status(struct tpm_chip *chip)
+{
+ u8 data;
+
+ I2C_READ_DATA(chip->addr, TPM_STS, &data, 1);
+ return data;
+}
+
+/*
+ * get_burstcount(): return burstcount value from address 0x19 0x1A
+ * @chip: TPM chip descriptor.
+ * return: the burstcount or negative value in case of error.
+ */
+static int get_burstcount(struct tpm_chip *chip)
+{
+ unsigned long start, stop;
+ int burstcnt, status, ret;
+ u8 tpm_reg, temp;
+
+ /* wait for burstcount */
+ start = get_timer(0);
+ stop = chip->timeout_d;
+ do {
+ tpm_reg = TPM_STS + 1;
+ status = I2C_READ_DATA(chip->addr, tpm_reg, &temp, 1);
+ if (status < 0)
+ break;
+ tpm_reg = tpm_reg + 1;
+ burstcnt = temp;
+ status = I2C_READ_DATA(chip->addr, tpm_reg, &temp, 1);
+ if (status < 0)
+ break;
+ burstcnt |= temp << 8;
+ if (burstcnt) {
+ ret = burstcnt;
+ goto end;
+ }
+ udelay(TIS_SHORT_TIMEOUT_MS*1000);
+ } while (get_timer(start) < stop);
+ ret = -ETIME;
+end:
+ return ret;
+}
+
+/*
+ * tpm_stm_i2c_command_ready(): move TPM state to Command Ready state.
+ * @chip: TPM descriptor.
+ * return: 0 on success or negative value in case of error.
+ */
+static int tpm_stm_i2c_command_ready(struct tpm_chip *chip)
+{
+ unsigned long start, stop;
+ int ret;
+ u8 status;
+ u8 data;
+
+ data = TPM_STS_COMMAND_READY;
+ I2C_WRITE_DATA(chip->addr, TPM_STS, &data, 1);
+ start = get_timer(0);
+ stop = tpm_dev.timeout_b;
+ do {
+ status = tpm_stm_i2c_status(chip);
+ debug("%s:%d - status = %d\n", __FILE__, __LINE__, status);
+ if ((status & data) == data)
+ return 0;
+ } while (get_timer(start) < stop);
+ ret = -ETIME;
+return ret;
+}
+
+/*
+ * recv_data(): receive data
+ * @chip: TPM chip descriptor.
+ * @buf, the buffer where the data are received
+ * @count, the number of data to receive
+ * @return: the number of bytes read from TPM FIFO.
+ */
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+ int size = 0, burstcnt, len;
+
+ while (size < count) {
+ burstcnt = get_burstcount(chip);
+ len = count - size;
+ if ((len) > burstcnt)
+ len = burstcnt;
+ if (I2C_READ_DATA(chip->addr, TPM_DATA_FIFO, buf + size, len)
+ == 0)
+ size += len;
+ else
+ break;
+ }
+ return size;
+}
+
+/*
+ * tpm_stm_i2c_pool_command_completion(): pool the TPM_STS register until
+ * command execution complete
+ * @chip:TPM chip descriptor.
+ * @return: O when TPM complete command execution or negative error code.
+ */
+static int tpm_stm_i2c_pool_command_completion(struct tpm_chip *chip)
+{
+ unsigned long start, stop;
+ long rc;
+ u8 status;
+
+ start = get_timer(0);
+ stop = tpm_dev.duration;
+ do {
+ status = tpm_stm_i2c_status(chip);
+ if ((status & TPM_STS_DATA_AVAIL) ==
+ TPM_STS_DATA_AVAIL)
+ return 0;
+ } while (get_timer(start) < stop);
+ rc = -ETIME;
+ return rc;
+}
+
+/*
+ * tpm_stm_i2c_recv(): received TPM response through the I2C bus.
+ * @chip: TPM chip descriptor.
+ * @buf: the buffer to store data.
+ * @count: the number of bytes that can be received max (sizeof buf).
+ * @return: Returns zero in case of success else negative error code.
+ */
+static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
+ size_t count)
+{
+ int size = 0;
+ int expected;
+
+ if (chip == NULL)
+ return -ENODEV;
+ if (count < TPM_HEADER_SIZE) {
+ size = -EIO;
+ goto out;
+ }
+ size = recv_data(chip, buf, TPM_HEADER_SIZE);
+ if (size < TPM_HEADER_SIZE) {
+ error("%s:%d - Unable to read header\n",
+ __FILE__, __LINE__);
+ goto out;
+ }
+ expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
+ if (expected > count) {
+ size = -EIO;
+ goto out;
+ }
+ size += recv_data(chip, &buf[TPM_HEADER_SIZE],
+ expected - TPM_HEADER_SIZE);
+ if (size < expected) {
+ error("%s:%d - Unable to read remaining bytes of result\n",
+ __FILE__, __LINE__);
+ size = -EIO;
+ goto out;
+ }
+out:
+ tpm_stm_i2c_command_ready(chip);
+ release_locality(chip);
+ return size;
+}
+
+/*
+ * tpm_stm_i2c_send(): send TPM commands through the I2C bus.
+ * @chip: TPM descriptor.
+ * @buf: the buffer to send.
+ * @len: the number of bytes to send.
+ * @return: Returns zero in case of success else the negative error code.
+ */
+static int tpm_stm_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+ u32 ret = 0,
+ status,
+ burstcnt = 0, i, size;
+ u8 data;
+
+ if (chip == NULL)
+ return -ENODEV;
+ if (len < TPM_HEADER_SIZE)
+ return -EIO;
+ ret = request_locality(chip);
+ if (ret < 0)
+ return ret;
+ status = tpm_stm_i2c_status(chip);
+ if ((status & TPM_STS_COMMAND_READY) == 0)
+ ret = tpm_stm_i2c_command_ready(chip);
+ if (ret < 0)
+ goto out_err;
+ for (i = 0; i < len - 1;) {
+ burstcnt = get_burstcount(chip);
+ size = len - i - 1;
+ if ((size) > burstcnt)
+ size = burstcnt;
+ ret = I2C_WRITE_DATA(chip->addr, TPM_DATA_FIFO, buf, size);
+ if (ret < 0)
+ goto out_err;
+ i += size;
+ }
+ status = tpm_stm_i2c_status(chip);
+ if ((status & TPM_STS_DATA_EXPECT) == 0) {
+ ret = -EIO;
+ goto out_err;
+ }
+ ret = I2C_WRITE_DATA(chip->addr, TPM_DATA_FIFO, buf + len - 1, 1);
+ if (ret < 0)
+ goto out_err;
+ status = tpm_stm_i2c_status(chip);
+ if ((status & TPM_STS_DATA_EXPECT) != 0) {
+ ret = -EIO;
+ goto out_err;
+ }
+ data = TPM_STS_GO;
+ ret = I2C_WRITE_DATA(chip->addr, TPM_STS, &data, 1);
+ if (ret < 0)
+ goto out_err;
+ return len;
+
+out_err:
+ ret = tpm_stm_i2c_command_ready(chip);
+ release_locality(chip);
+ return ret;
+}
+
+/*
+ * tpm_stm_i2c_send_hash(): send TPM locality 4 hash datas through the I2C bus
+ * to update the PCR[17].
+ * @chip: TPM chip descriptor.
+ * @buf: the data buffer to send.
+ * @len: the number of bytes to send.
+ * @return: Returns zero in case of success else a negative error code.
+ */
+static int tpm_stm_i2c_send_hash(struct tpm_chip *chip, const uint8_t *buf,
+ size_t len)
+{
+ int ret = 0;
+ u8 data;
+
+ if (chip == NULL)
+ return -EBUSY;
+ release_locality(chip);
+ chip->addr = LOCALITY4_I2C_ADDR;
+ chip->locality = LOCALITY4;
+ data = TPM_DUMMY_BYTE;
+ ret = I2C_WRITE_DATA(chip->addr, TPM_HASH_START, &data, 1);
+ if (ret != 0)
+ goto end;
+ ret = I2C_WRITE_DATA(chip->addr, TPM_DATA_FIFO, buf, len);
+ if (ret != 0)
+ goto end;
+ ret = I2C_WRITE_DATA(chip->addr, TPM_HASH_END, &data, 1);
+ if (ret != 0)
+ goto end;
+
+end:
+ release_locality(chip);
+ chip->locality = LOCALITY0;
+ chip->addr = LOCALITY0_I2C_ADDR;
+ ret |= request_locality(chip);
+ return ret;
+}
+
+/*
+ * tpm_vendor_init(): initialize the TPM device
+ * @dev_addr: the i2c address of TPM.
+ * @return: 0 in case of success, negative value in case of error.
+ */
+int tpm_vendor_init(uint32_t dev_addr, uint32_t dev_bus)
+{
+ int rc = 0;
+
+ tpm_dev.addr = dev_addr;
+ tpm_dev.i2c_bus = dev_bus;
+ if (i2c_set_bus_num(tpm_dev.i2c_bus) != 0) {
+ rc = -ENODEV;
+ goto out_err;
+ }
+ /* Default timeouts */
+ tpm_dev.timeout_a = TIS_SHORT_TIMEOUT_MS;
+ tpm_dev.timeout_b = TIS_LONG_TIMEOUT_MS;
+ tpm_dev.timeout_c = TIS_SHORT_TIMEOUT_MS;
+ tpm_dev.timeout_d = TIS_SHORT_TIMEOUT_MS;
+ tpm_dev.locality = LOCALITY0;
+ tpm_dev.duration = TPM_MAX_COMMAND_DURATION_MS;
+ if (request_locality(&tpm_dev) != 0) {
+ rc = -EIO;
+ goto out_err;
+ }
+ tpm_dev.is_open = 1;
+ debug("%s:%d - ST33ZP24 I2C TPM from STMicroelectronics found\n",
+ __FILE__, __LINE__);
+ return 0;
+
+out_err:
+ tpm_dev.is_open = 0;
+ return rc;
+}
+
+
+/*
+ * tis_init() verify presence of ST33ZP24 I2C TPM device and configure driver
+ * for it.
+ * @return: 0 on success (the device is found or was found during an earlier
+ * invocation) or negative value if the device is not found.
+ */
+int tis_init(void)
+{
+ int rc;
+ uint32_t dev_addr, dev_bus;
+
+ dev_addr = LOCALITY0_I2C_ADDR;
+ dev_bus = CONFIG_TPM_I2C_BUS;
+ rc = tpm_vendor_init(dev_addr, dev_bus);
+ return rc;
+}
+
+/*
+ * tis_sendrecv() send the requested data to the TPM and then try to get
+ * its response
+ * @sendbuf: buffer of the data to send
+ * @sbuf_size: size of the data to send
+ * @recvbuf: buffer to save the response to
+ * @recv_len: pointer to the size of the response buffer
+ * @return: 0 on success (and places the number of response bytes at recv_len)
+ * or negative value on failure.
+ */
+int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+ uint8_t *recvbuf, size_t *rbuf_len)
+{
+ int len, i;
+ uint8_t buf[TPM_BUFSIZE];
+
+ if (tpm_dev.is_open == 0)
+ return -ENXIO;
+ if (sizeof(buf) < sbuf_size)
+ return -EIO;
+ memcpy(buf, sendbuf, sbuf_size);
+ len = tpm_stm_i2c_send(&tpm_dev, buf, sbuf_size);
+ if (len != sbuf_size) {
+ error(" %s:%d - Command not fully transmitted\n",
+ __FILE__, __LINE__);
+ return -EIO;
+ }
+ if (tpm_stm_i2c_pool_command_completion(&tpm_dev) != 0)
+ return -ETIME;
+ len = tpm_stm_i2c_recv(&tpm_dev, buf, sizeof(buf));
+ if (len < 10) {
+ *rbuf_len = 0;
+ return -EIO;
+ }
+ memcpy(recvbuf, buf, len);
+ *rbuf_len = len;
+ return 0;
+}
+
+/*
+ * tis_sendhashloc4() perform a hash in locality 4 in order to extend PCR17
+ * @sendbuf: buffer of the data to send
+ * @send_size: size of the data to send
+ * @return: 0 on success or negative value on failure.
+ */
+int tis_sendhashloc4(const uint8_t *sendbuf, size_t sbuf_size)
+{
+ int ret;
+
+ if (tpm_dev.is_open == 0) {
+ error("%s:%d - TPM not yet initialized\n",
+ __FILE__, __LINE__);
+ error("Perform \"tpm init\" first\n");
+ return -EIO;
+ }
+ ret = tpm_stm_i2c_send_hash(&tpm_dev, sendbuf, sbuf_size);
+ return ret;
+}
+
+/*
+ * tis_open(): requests access to locality 0 for the caller. After all
+ * commands have been completed the caller is supposed to call tis_close().
+ * @return: 0 on success, negative value on failure.
+ */
+int tis_open(void)
+{
+ if (tis_close())
+ return -EIO;
+
+ /* now request access to locality. */
+ if (request_locality(&tpm_dev) != 0) {
+ error("%s:%d - failed to lock locality 0\n",
+ __FILE__, __LINE__);
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
+ * tis_close() terminate the current session with the TPM by releasing
+ * the locked locality.
+ * @return: 0 on success or negative value on failure.
+ */
+int tis_close(void)
+{
+ return release_locality(&tpm_dev);
+}
--
1.7.9.5
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