nvram: Add generic SPI connected NVRAM interface.

drivers/include/nvram-spi.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2015 Eistec AB
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup     nvram
+ * @{
+ *
+ * @file
+ *
+ * @brief       Device interface for various SPI connected NVRAM.
+ *
+ * Tested on:
+ * - Cypress/Ramtron FM25L04B.
+ *
+ * @author      Joakim Gebart <joakim.gebart@eistec.se>
+ */
+
+#ifndef DRIVERS_NVRAM_SPI_H_
+#define DRIVERS_NVRAM_SPI_H_
+
+#include <stdint.h>
+#include "nvram.h"
+#include "periph/spi.h"
+#include "periph/gpio.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Bus parameters for SPI NVRAM.
+ */
+typedef struct nvram_spi_params {
+    /** @brief RIOT SPI device */
+    spi_t spi;
+    /** @brief Chip select pin */
+    gpio_t cs;
+    /** @brief Number of address bytes following each read/write command. */
+    uint8_t address_count;
+} nvram_spi_params_t;
+
+/**
+ * @brief Initialize an nvram_t structure with SPI settings.
+ *
+ * This will also initialize the CS pin as a GPIO output, without pull resistors.
+ *
+ * @param[out] dev          Pointer to NVRAM device descriptor
+ * @param[out] spi_params   Pointer to SPI settings
+ * @param[in]  size         Device capacity
+ *
+ * @return                  0 on success
+ * @return                  <0 on errors
+ */
+int nvram_spi_init(nvram_t *dev, nvram_spi_params_t *spi_params, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* DRIVERS_NVRAM_SPI_H_ */
+/** @} */