drivers: entropy: add maxq10xx

add maxq10xx entropy device.

Signed-off-by: Fin Maaß <[email protected]>

drivers/entropy/CMakeLists.txt

@@ -34,6 +34,7 @@ zephyr_library_sources_ifdef(CONFIG_ENTROPY_GECKO_SE        entropy_gecko_se.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_PSA_CRYPTO_RNG  entropy_psa_crypto.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_NPCX_DRBG       entropy_npcx_drbg.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_MAX32_TRNG      entropy_max32.c)
+zephyr_library_sources_ifdef(CONFIG_ENTROPY_MAXQ10XX_RNG    entropy_maxq10xx.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_RENESAS_RA      entropy_renesas_ra.c)
 
 zephyr_library_link_libraries_ifdef(CONFIG_BUILD_WITH_TFM tfm_api)

drivers/entropy/Kconfig

@@ -37,6 +37,7 @@ source "drivers/entropy/Kconfig.bt_hci"
 source "drivers/entropy/Kconfig.psa_crypto"
 source "drivers/entropy/Kconfig.npcx"
 source "drivers/entropy/Kconfig.max32"
+source "drivers/entropy/Kconfig.maxq10xx"
 source "drivers/entropy/Kconfig.renesas_ra"
 
 config ENTROPY_HAS_DRIVER

drivers/entropy/Kconfig.maxq10xx

@@ -0,0 +1,33 @@
+# MAXQ10XX entropy generator driver configuration
+
+# Copyright (c) 2025 Vogl Electronic GmbH
+# SPDX-License-Identifier: Apache-2.0
+
+config ENTROPY_MAXQ10XX_RNG
+	bool "MAXQ10xx entropy number generator driver"
+	default y
+	depends on DT_HAS_ADI_MAXQ10XX_TRNG_ENABLED
+	select ENTROPY_HAS_DRIVER
+	select SPI
+	select CRC
+	help
+	  This option enables the entropy number generator driver for the
+	  MAXQ10xx crypto chips.
+
+# Don't use use the MAXQ10XX RNG as a random source since it can be quite slow.
+# Instead, use the software implemented xoshiro RNG.
+choice RNG_GENERATOR_CHOICE
+	default XOSHIRO_RANDOM_GENERATOR if ENTROPY_MAXQ10XX_RNG
+endchoice
+
+if ENTROPY_MAXQ10XX_RNG
+
+config ENTROPY_MAXQ10XX_RNG_INIT_PRIORITY
+	int "MAXQ10xx entropy init priority"
+	default 51
+	help
+	  Device driver initialization priority.
+	  Device is connected to SPI bus, it has to
+	  be initialized after SPI driver.
+
+endif # ENTROPY_MAXQ10XX_RNG

drivers/entropy/entropy_maxq10xx.c

@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 2024 Vogl Electronic GmbH
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT adi_maxq10xx_trng
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/spi.h>
+#include <zephyr/drivers/entropy.h>
+#include <zephyr/sys/crc.h>
+#include <zephyr/sys/byteorder.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(entropy_maxq10xx, CONFIG_ENTROPY_LOG_LEVEL);
+
+#define MAXQ10XX_CMD_HEADER                0xAA
+#define MAXQ10XX_CMD_GET_RANDOM            0xC9
+#define MAXQ10XX_CMD_GET_RANDOM_INPUT_DATA 0x02
+#define MAXQ10XX_CMD_READ_READY            0x55
+
+#define MAXQ10XX_CRC16_POLYNOMIAL    0xA001
+#define MAXQ10XX_CRC16_INITIAL_VALUE 0x0000
+
+#define MAXQ10XX_WAIT_TIME K_MSEC(1)
+
+struct entropy_maxq10xx_config {
+	struct spi_dt_spec spi;
+};
+
+struct entropy_maxq10xx_data {
+	struct k_sem sem_lock;
+};
+
+static int entropy_maxq10xx_send_cmd(const struct device *dev, uint16_t length)
+{
+	const struct entropy_maxq10xx_config *config = dev->config;
+
+	uint8_t buffer_tx[9];
+	uint16_t crc;
+	int ret;
+
+	buffer_tx[0] = MAXQ10XX_CMD_HEADER;
+	buffer_tx[1] = 0x00;
+	buffer_tx[2] = MAXQ10XX_CMD_GET_RANDOM;
+	buffer_tx[3] = 0x00;
+	buffer_tx[4] = MAXQ10XX_CMD_GET_RANDOM_INPUT_DATA;
+
+	sys_put_be16(length, &buffer_tx[5]);
+
+	crc = crc16_reflect(MAXQ10XX_CRC16_POLYNOMIAL, MAXQ10XX_CRC16_INITIAL_VALUE, buffer_tx, 7);
+
+	sys_put_le16(crc, &buffer_tx[7]);
+
+	const struct spi_buf tx_buf[] = {{
+		.buf = buffer_tx,
+		.len = ARRAY_SIZE(buffer_tx),
+	}};
+	const struct spi_buf_set tx = {
+		.buffers = tx_buf,
+		.count = ARRAY_SIZE(tx_buf),
+	};
+
+	LOG_HEXDUMP_DBG(buffer_tx, sizeof(buffer_tx), "TX buffer");
+
+	ret = spi_write_dt(&config->spi, &tx);
+
+	return ret;
+}
+
+static int entropy_maxq10xx_wait(const struct device *dev)
+{
+	const struct entropy_maxq10xx_config *config = dev->config;
+	uint8_t buffer_rx[1];
+	int ret;
+
+	const struct spi_buf rx_buf[] = {{
+		.buf = buffer_rx,
+		.len = ARRAY_SIZE(buffer_rx),
+	}};
+	const struct spi_buf_set rx = {
+		.buffers = rx_buf,
+		.count = ARRAY_SIZE(rx_buf),
+	};
+
+	while (1) {
+		ret = spi_read_dt(&config->spi, &rx);
+		if ((ret < 0) || (buffer_rx[0] == MAXQ10XX_CMD_READ_READY)) {
+			break;
+		}
+
+		k_sleep(MAXQ10XX_WAIT_TIME);
+	};
+
+	return ret;
+}
+
+static int entropy_maxq10xx_read(const struct device *dev, uint8_t *buffer, uint16_t length)
+{
+	const struct entropy_maxq10xx_config *config = dev->config;
+	uint8_t execution_status[2];
+	uint8_t length_data[2];
+	uint8_t crc[2];
+	uint16_t crc_calc;
+	int ret;
+
+	const struct spi_buf rx_buf[] = {
+		{
+			.buf = execution_status,
+			.len = ARRAY_SIZE(execution_status),
+		},
+		{
+			.buf = length_data,
+			.len = ARRAY_SIZE(length_data),
+		}
+	};
+	const struct spi_buf_set rx = {
+		.buffers = rx_buf,
+		.count = ARRAY_SIZE(rx_buf),
+	};
+
+	ret = spi_read_dt(&config->spi, &rx);
+	if (ret < 0) {
+		return ret;
+	}
+
+	if (execution_status[0] != 0x00 || execution_status[1] != 0x00) {
+		LOG_DBG("Execution status: 0x%02X 0x%02X", execution_status[0],
+			execution_status[1]);
+		return -EIO;
+	}
+
+	if (length != sys_get_be16(length_data)) {
+		LOG_ERR("Length mismatch: %d != %d", length, sys_get_be16(length_data));
+		return -EIO;
+	}
+
+	const struct spi_buf rx_data_buf[] = {
+		{
+			.buf = buffer,
+			.len = length,
+		},
+		{
+			.buf = crc,
+			.len = sizeof(crc),
+		}
+	};
+
+	const struct spi_buf_set rx_data = {
+		.buffers = rx_data_buf,
+		.count = ARRAY_SIZE(rx_data_buf),
+	};
+
+	ret = spi_read_dt(&config->spi, &rx_data);
+	if (ret < 0) {
+		return ret;
+	}
+
+	uint8_t header_tx[1] = {MAXQ10XX_CMD_READ_READY};
+
+	crc_calc = crc16_reflect(MAXQ10XX_CRC16_POLYNOMIAL, MAXQ10XX_CRC16_INITIAL_VALUE, header_tx,
+				 sizeof(header_tx));
+	crc_calc = crc16_reflect(MAXQ10XX_CRC16_POLYNOMIAL, crc_calc, execution_status,
+				 sizeof(execution_status));
+	crc_calc = crc16_reflect(MAXQ10XX_CRC16_POLYNOMIAL, crc_calc, length_data,
+				 sizeof(length_data));
+	crc_calc = crc16_reflect(MAXQ10XX_CRC16_POLYNOMIAL, crc_calc, buffer, length);
+
+	if (crc_calc != sys_get_le16(crc)) {
+		LOG_ERR("CRC error: 0x%04X != 0x%04X", crc_calc, sys_get_le16(crc));
+		return -EIO;
+	}
+
+	return ret;
+}
+
+static int entropy_maxq10xx_get_entropy(const struct device *dev, uint8_t *buffer, uint16_t length)
+{
+	struct entropy_maxq10xx_data *dev_data = dev->data;
+
+	int ret;
+
+	k_sem_take(&dev_data->sem_lock, K_FOREVER);
+
+	ret = entropy_maxq10xx_send_cmd(dev, length);
+	if (ret < 0) {
+		LOG_ERR("Failed to send command");
+		goto exit;
+	}
+
+	ret = entropy_maxq10xx_wait(dev);
+	if (ret < 0) {
+		LOG_ERR("Failed to wait for ready");
+		goto exit;
+	}
+
+	ret = entropy_maxq10xx_read(dev, buffer, length);
+	if (ret < 0) {
+		LOG_ERR("Failed to read data");
+	}
+exit:
+	k_sem_give(&dev_data->sem_lock);
+	return ret;
+}
+
+static int entropy_maxq10xx_init(const struct device *dev)
+{
+	struct entropy_maxq10xx_data *dev_data = dev->data;
+
+	k_sem_init(&dev_data->sem_lock, 1, 1);
+
+	return 0;
+}
+
+static DEVICE_API(entropy, entropy_maxq10xx_api) = {
+	.get_entropy = entropy_maxq10xx_get_entropy
+};
+
+BUILD_ASSERT(CONFIG_SPI_INIT_PRIORITY < CONFIG_ENTROPY_MAXQ10XX_RNG_INIT_PRIORITY,
+	     "SPI driver must be initialized before maxq10 entropy driver");
+
+#define DEFINE_MAXQ10XX_ENTROPY(_num)                                                              \
+	static const struct entropy_maxq10xx_config entropy_maxq10xx_config##_num = {              \
+		.spi = SPI_DT_SPEC_INST_GET(_num, SPI_WORD_SET(8), 0),                             \
+	};                                                                                         \
+	static struct entropy_maxq10xx_data entropy_maxq10xx_data##_num;                           \
+	DEVICE_DT_INST_DEFINE(_num, entropy_maxq10xx_init, NULL, &entropy_maxq10xx_data##_num,     \
+			      &entropy_maxq10xx_config##_num, POST_KERNEL,                         \
+			      CONFIG_ENTROPY_MAXQ10XX_RNG_INIT_PRIORITY, &entropy_maxq10xx_api);
+
+DT_INST_FOREACH_STATUS_OKAY(DEFINE_MAXQ10XX_ENTROPY);

dts/bindings/rng/adi,maxq10xx-trng.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2024 Vogl Electronic GmbH
+# SPDX-License-Identifier: Apache-2.0
+
+description: ADI MAXQ10XX RNG
+
+compatible: "adi,maxq10xx-trng"
+
+include: spi-device.yaml