Add Espressif SPI support

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_ESPIDF)
+    ret = TPM2_IoCb_Espressif_SPI(ctx, txBuf, rxBuf, xferSz, userCtx);
 #else
 
     /* TODO: Add your platform here for HW SPI interface */

hal/tpm_io_espressif.c

@@ -42,6 +42,8 @@
 
 /* Espressif */
 #include "sdkconfig.h"
+#include <driver/gpio.h>
+#include <driver/spi_master.h>
 
 #define TAG "TPM_IO"
 
@@ -438,20 +440,141 @@ int TPM2_IoCb_Espressif_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
 /* end WOLFTPM_I2C */
 
 #else /* If not I2C, it must be SPI  */
-    /* TODO implement SPI */
-
-    #ifndef TPM2_SPI_HZ
-        /* Use the max speed by default
-         * See tpm2_types.h for chip specific max values */
-        #define TPM2_SPI_HZ TPM2_SPI_MAX_HZ
-    #endif
-    #ifdef WOLFTPM_CHECK_WAIT_STATE
-        #error SPI check wait state logic not supported
-    #endif
-
-    #error TPM2 SPI support on this platform not supported yet
-#endif
 
+// FSPI (HOST_SPI2) on esp32-s3-wroom
+#define PIN_NUM_MISO 13
+#define PIN_NUM_MOSI 11
+#define PIN_NUM_CLK  12
+#define PIN_NUM_CS   10
+
+// NOTE: on esp, 64 byte limit includes data and header!!!
+#define SPI_MAX_TRANSFER 64
+
+// TPM data storing SPI handles & timeouts
+static struct TPM_DATA {
+    spi_device_handle_t spi;
+    gpio_num_t cs_pin;
+    int64_t timeout_expiry;
+} *tpm_data;
+
+static int _is_initialized_spi =    FALSE;
+
+int esp_spi_master_init() {
+    // SPI bus & device configuration
+    spi_bus_config_t bus_cfg = {
+        .miso_io_num = PIN_NUM_MISO,
+        .mosi_io_num = PIN_NUM_MOSI,
+        .sclk_io_num = PIN_NUM_CLK,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1,
+        .max_transfer_sz = 64
+    };
+    spi_device_interface_config_t dev_cfg = {
+        .clock_speed_hz = 10*1000*1000, // 10MHz, but tested up to 22MHz
+        .mode = 0,
+        .spics_io_num = PIN_NUM_CS,
+        .queue_size = 1,
+        .pre_cb = NULL,
+        .post_cb = NULL,
+    };
+
+    // Initializing CS pin
+    esp_rom_gpio_pad_select_gpio(PIN_NUM_CS);
+    gpio_set_direction(PIN_NUM_CS, GPIO_MODE_OUTPUT);
+    gpio_set_level(PIN_NUM_CS, 1);
+
+    // Initialize the SPI bus and device
+    esp_err_t ret;
+    ret = spi_bus_initialize(SPI2_HOST, &bus_cfg, 0);
+    ESP_ERROR_CHECK(ret);
+
+    // Attach the device to the SPI bus
+    spi_device_handle_t spi;
+    ret = spi_bus_add_device(SPI2_HOST, &dev_cfg, &spi);
+    ESP_ERROR_CHECK(ret);
+
+    tpm_data = malloc(sizeof(struct TPM_DATA));
+    tpm_data->spi = spi;
+    tpm_data->cs_pin = PIN_NUM_CS;
+    tpm_data->timeout_expiry = 0;
+
+    _is_initialized_spi = TRUE;
+    return 0;
+}
+
+/* Aquire SPI bus and keep pulling CS */
+int tpm_spi_acquire()
+{
+    int ret;
+    gpio_set_level(tpm_data->cs_pin, 0);
+    ret = spi_device_acquire_bus(tpm_data->spi, portMAX_DELAY);
+    return ret;
+}
+
+/* Release SPI bus and CS */
+int tpm_spi_release ()
+{
+    gpio_set_level(tpm_data->cs_pin, 1);
+    spi_device_release_bus(tpm_data->spi);
+    return 0;
+}
+
+int tpm_spi_raw_transfer (const byte *data_out, byte *data_in, size_t cnt) {
+
+    /* Maximum transfer size is 64 byte because we don't use DMA. */
+    if (cnt > SPI_MAX_TRANSFER) {
+        printf("tpm_io_espressif: cnt %d\n", cnt);
+        return -1;
+    }
+
+    /* At least one of the buffers has to be set. */
+    if (data_out == NULL && data_in == NULL) {
+        return -1;
+    }
+
+    /* Setup transaction */
+    spi_transaction_t t;
+    memset(&t, 0, sizeof(t));
+    t.length = cnt*8;
+    t.tx_buffer = data_out;
+    t.rx_buffer = data_in;
+
+    /* Transmit */
+    esp_err_t ret = spi_device_polling_transmit(tpm_data->spi, &t);
+    if (ret != ESP_OK) {
+        ESP_LOGE(TAG, "spi_transmit returned error %d\n", ret);
+        return -1;
+    }
+
+    return 0;
+} /* tpm_spi_raw_transfer */
+
+int TPM2_IoCb_Espressif_SPI(TPM2_CTX* ctx, const byte* txBuf, byte* rxBuf,
+                            word16 xferSz, void* userCtx) {
+    int ret = TPM_RC_FAILURE;
+
+    if (_is_initialized_spi)
+        ret = ESP_OK;
+    else {
+        ret = esp_spi_master_init(); /* ESP return code, not TPM */
+        ESP_LOGV(TAG, "HAL: Initializing SPI %d", ret);
+    }
+
+    if (ret == ESP_OK) {
+        tpm_spi_acquire();
+        ret = tpm_spi_raw_transfer(txBuf, rxBuf, xferSz);
+        tpm_spi_release();
+    }
+    else {
+        ESP_LOGE(TAG, "SPI Failed to initialize. Error: %d", ret);
+        ret = TPM_RC_FAILURE;
+    }
+
+    (void)ctx;
+    return ret;
+} /* TPM2_IoCb_Espressif_SPI */
+
+#endif /* Espressif SPI */
 #endif /* WOLFSSL_ESPIDF */
 #endif /* WOLFTPM_INCLUDE_IO_FILE */