Generic Zephyr I2C Control

hal/tpm_io.c

@@ -97,6 +97,8 @@ static int TPM2_IoCb_SPI(TPM2_CTX* ctx, const byte* txBuf, byte* rxBuf,
     ret = TPM2_IoCb_Infineon_TriCore_SPI(ctx, txBuf, rxBuf, xferSz, userCtx);
 #elif defined(WOLFTPM_MICROCHIP_HARMONY)
     ret = TPM2_IoCb_Microchip_SPI(ctx, txBuf, rxBuf, xferSz, userCtx);
+#elif defined(WOLFSSL_ZEPHYR)
+    ret = TPM2_IoCb_Zephyr_I2C(ctx, isRead, addr, buf, size, userCtx);
 #else
 
     /* TODO: Add your platform here for HW SPI interface */

hal/tpm_io.h

@@ -91,6 +91,9 @@ WOLFTPM_LOCAL int TPM2_IoCb_Espressif_I2C(TPM2_CTX* ctx, int isRead, word32 addr
 #elif defined(WOLFTPM_MICROCHIP_HARMONY)
 WOLFTPM_LOCAL int TPM2_IoCb_MicrochipHarmony_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
     byte* buf, word16 size, void* userCtx);
+#elif defined(WOLFTPM_ZEPHYR)
+WOLFTPM_LOCAL int TPM2_IoCb_Zephyr_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
+    byte* buf, word16 size, void* userCtx);
 #endif /* __linux__ */
 
 #else /* SPI */

hal/tpm_io_zephyr.c

@@ -0,0 +1,203 @@
+/* tpm_io_zephyr.c
+ *
+ * Copyright (C) 2006-2025 wolfSSL Inc.
+ *
+ * This file is part of wolfTPM.
+ *
+ * wolfTPM is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfTPM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+/* This example shows IO interfaces for Microchip micro-controllers using
+ * MPLAB X and Harmony
+ */
+
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
+#include <wolftpm/tpm2.h>
+#include <wolftpm/tpm2_tis.h>
+#include "tpm_io.h"
+
+/*****************************************************************************/
+/* --- BEGIN IO Callback Logic -- */
+/*****************************************************************************/
+
+/* Included via tpm_io.c if WOLFTPM_INCLUDE_IO_FILE is defined */
+#ifdef WOLFTPM_INCLUDE_IO_FILE
+
+#ifdef WOLFTPM_ZEPHYR
+
+/* Zephyr Inlcudes Start */
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+#include <zephyr/drivers/i2c.h>
+/* Zephyr Includes End */
+
+#ifdef WOLFTPM_I2C
+
+/* Zephyr Configurations Start */
+
+/* Infineon 9673 I2C at 0x2e */
+#define TPM2_INFINEON_9673_ADDR     0x2e
+
+/* Set I2C device Address */
+#if defined(WOLFTPM_I2C_CUST_ADDR)
+    #define TPM2_I2C_ADDR           WOLFTPM_I2C_CUST_ADDR
+#elif defined(WOLFTPM_SLB9673)
+    #define TPM2_I2C_ADDR           TPM2_INFINEON_9673_ADDR
+#else
+    #error Set WOLFTPM_I2C_CUST_ADDR to i2c device ID or use supported device
+#endif
+
+/* Set to slowest speed supported in zephyr as default */
+#if !defined(WOLFTPM_ZEPHYR_I2C_SPEED)
+    #warning WOLFTPM_ZEPHYR_I2C_SPEED set to slowest Zephyr supports
+    #define WOLFTPM_ZEPHYR_I2C_SPEED I2C_SPEED_STANDARD
+#endif
+
+/* Need to set devicetree label of the i2c bus being used */
+#if !defined(WOLFTPM_ZEPHYR_I2C_BUS)
+    #error Set WOLFTPM_ZEPHYR_I2C_BUS to devicetree node label for i2c bus
+#endif
+
+/* Zephyr Configurations End */
+
+
+/* Init to False */
+static int _is_initialized_i2c = 0;
+
+/* Grab pointer from device tree label */
+const struct device *i2c_dev = \
+                DEVICE_DT_GET(DT_NODELABEL(WOLFTPM_ZEPHYR_I2C_BUS));
+
+
+/* Setup the i2c tmp device */
+/* Pass in pointer to the target */
+int TPM2_I2C_Zephyr_Init(void)
+{
+    int ret = 0;
+    uint32_t config = 0;
+
+    /* Allows to set the speed of the I2C Controller */
+    config = I2C_MODE_CONTROLLER | I2C_SPEED_SET(WOLFTPM_ZEPHYR_I2C_SPEED);
+    ret = i2c_configure(i2c_dev, config);
+
+    return ret;
+}
+
+int TPM2_IoCb_Zephyr_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
+                            byte* buf, word16 size, void* userCtx)
+{
+    int ret = 0;
+    byte* tempBuf = NULL;
+
+    if (buf == NULL) {
+        printf("Buffer passed is NULL");
+        return BAD_FUNC_ARG;
+    }
+
+    if (i2c_dev == NULL) {
+        printf("I2C device not found in Device Tree!\n");
+        return BAD_FUNC_ARG;
+    }
+
+    /* Confirm i2c bus is ready */
+    if (!device_is_ready(i2c_dev)) {
+        printf("I2C Device is not ready");
+        return BAD_FUNC_ARG;
+    }
+
+    /* Init Zephyr I2C Driver */
+    if (_is_initialized_i2c == 0) {
+        if (TPM2_I2C_Zephyr_Init() != 0) {
+            printf("Could Not Init I2C Bus\n");
+            return BAD_FUNC_ARG;
+        }
+        _is_initialized_i2c = 1;
+    }
+
+    if (isRead) {
+        /* Read operation: First send register address via a write, */
+        /* then read data from the wanted register and length */
+
+        /* Just needs to be a buffer to hold wanted register */
+        /* Only use lower 8bits of addr input */
+        tempBuf = (byte*)XMALLOC(1, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+        if (tempBuf == NULL) {
+            printf("Failed to allocate temp buffer\n");
+        }
+        tempBuf[0] = (byte)(addr & 0xFF);
+
+        /* Zephyr API i2c_write_read() will use the DT bus line and perform */
+        /* a write then read command via specified i2c bus */
+        ret = i2c_write_read(i2c_dev, TPM2_I2C_ADDR, tempBuf, 1, buf, size);
+        if (ret < 0) {
+            printf("Failed to read from TPM at register 0x%02X! Error: %d\n", addr, ret);
+        }
+
+        XFREE(tempBuf, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    else {
+        /* Write operation: write to a specified register and length */
+
+        /* Need to include lower 8bits of addr input at the start of the */
+        /* write buffer */
+        tempBuf = (byte*)XMALLOC(size + 1, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+        if (tempBuf == NULL) {
+            printf("Failed to allocate temp buffer\n");
+        }
+        tempBuf[0] = (byte)(addr & 0xFF);
+        /* copy over the wanted write date to rest of the temp buffer*/
+        XMEMCPY((tempBuf + 1), buf, size);
+
+        /* Zephyr API i2c_write will use the DT bus line and perform the */
+        /* write operation using the given buffer, register address you want */
+        /* to write too needs to be the first byte of said buffer */
+        ret = i2c_write(i2c_dev, tempBuf, size + 1, TPM2_I2C_ADDR);
+        if (ret < 0) {
+            printf("Failed to write to TPM at register 0x%02X! Error: %d\n", addr, ret);
+        }
+
+        XFREE(tempBuf, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+
+    if (ret != 0) {
+        printf("Could not perform I2C read/write operation: %d\n", ret);
+        if (ret == -EIO) {
+            printf("\tInput/Output Error Returned\n");
+        }
+    }
+
+    /* Not used Inputs */
+    (void)userCtx;
+    (void)ctx;
+
+    return ret;
+}
+
+/* end WOLFTPM_I2C */
+
+#else /* If not I2C, it must be SPI  */
+    /* TODO implement SPI */
+    #error TPM2 SPI support on zephyr yet
+#endif
+
+#endif /* WOLFSSL_ZEPHYR */
+#endif /* WOLFTPM_INCLUDE_IO_FILE */
+
+/******************************************************************************/
+/* --- END IO Callback Logic -- */
+/******************************************************************************/