drivers: flash: introduce new Telink B91 Flash driver

Flash driver basic support for Telink B91 platform.

Signed-off-by: Yuriy Vynnychek <yura.vynnychek@telink-semi.com>

CODEOWNERS

@@ -220,6 +220,7 @@
 /drivers/ethernet/*w5500*                 @parthitce
 /drivers/ethernet/*xlnx_gem*              @ibirnbaum
 /drivers/flash/                           @nashif @nvlsianpu
+/drivers/flash/*b91*                      @yurvyn
 /drivers/flash/*nrf*                      @nvlsianpu
 /drivers/gpio/                            @mnkp
 /drivers/gpio/*b91*                       @yurvyn

drivers/flash/CMakeLists.txt

@@ -2,6 +2,7 @@
 
 zephyr_library()
 
+zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_TELINK_B91 soc_flash_b91.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_NOR spi_nor.c)
 zephyr_library_sources_ifdef(CONFIG_NORDIC_QSPI_NOR nrf_qspi_nor.c)
 zephyr_library_sources_ifdef(CONFIG_FLASH_SIMULATOR flash_simulator.c)

drivers/flash/Kconfig

@@ -58,6 +58,8 @@ config FLASH_PAGE_LAYOUT
 	help
 	  Enables API for retrieving the layout of flash memory pages.
 
+source "drivers/flash/Kconfig.b91"
+
 source "drivers/flash/Kconfig.at45"
 
 source "drivers/flash/Kconfig.esp32"

drivers/flash/Kconfig.b91

@@ -0,0 +1,11 @@
+# Copyright (c) 2021 Telink Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+config SOC_FLASH_TELINK_B91
+	bool "Telink Semiconductor B91 flash driver"
+	depends on SOC_RISCV_TELINK_B91
+	select FLASH_HAS_PAGE_LAYOUT
+	select FLASH_HAS_DRIVER_ENABLED
+	default y
+	help
+	  Enables Telink B91 flash driver.

drivers/flash/soc_flash_b91.c

@@ -0,0 +1,183 @@
+/*
+ * Copyright (c) 2021 Telink Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT telink_b91_flash_controller
+#define FLASH_SIZE DT_REG_SIZE(DT_INST(0, soc_nv_flash))
+
+#include "flash.h"
+#include <device.h>
+#include <drivers/flash.h>
+
+
+/* driver data structure */
+struct flash_b91_data {
+	struct k_sem write_lock;
+};
+
+/* driver parameters structure */
+static const struct flash_parameters flash_b91_parameters = {
+	.write_block_size = DT_PROP(DT_INST(0, soc_nv_flash), write_block_size),
+	.erase_value = 0xff,
+};
+
+
+/* Check for correct offset and length */
+static bool flash_b91_is_range_valid(off_t offset, size_t len)
+{
+	/* check for min value */
+	if ((offset < 0) || (len < 1)) {
+		return false;
+	}
+
+	/* check for max value */
+	if ((offset + len) > FLASH_SIZE) {
+		return false;
+	}
+
+	return true;
+}
+
+/* API implementation: driver initialization */
+static int flash_b91_init(const struct device *dev)
+{
+	struct flash_b91_data *dev_data = dev->data;
+
+	k_sem_init(&dev_data->write_lock, 1, 1);
+
+	return 0;
+}
+
+/* API implementation: erase */
+static int flash_b91_erase(const struct device *dev, off_t offset, size_t len)
+{
+	int page_nums = len / PAGE_SIZE;
+	struct flash_b91_data *dev_data = dev->data;
+
+	/* return SUCCESS if len equals 0 (required by tests/drivers/flash) */
+	if (!len) {
+		return 0;
+	}
+
+	/* check for valid range */
+	if (!flash_b91_is_range_valid(offset, len)) {
+		return -EINVAL;
+	}
+
+	/* Erase can be done only by pages */
+	if (((offset % PAGE_SIZE) != 0) || ((len % PAGE_SIZE) != 0)) {
+		return -EINVAL;
+	}
+
+	/* take semaphore */
+	if (k_sem_take(&dev_data->write_lock, K_NO_WAIT)) {
+		return -EACCES;
+	}
+
+	/* erase flash page by page */
+	for (int i = 0; i < page_nums; i++) {
+		flash_erase_page(offset);
+		offset += PAGE_SIZE;
+	}
+
+	/* release semaphore */
+	k_sem_give(&dev_data->write_lock);
+
+	return 0;
+}
+
+/* API implementation: write */
+static int flash_b91_write(const struct device *dev, off_t offset,
+			   const void *data, size_t len)
+{
+	struct flash_b91_data *dev_data = dev->data;
+
+	/* return SUCCESS if len equals 0 (required by tests/drivers/flash) */
+	if (!len) {
+		return 0;
+	}
+
+	/* check for valid range */
+	if (!flash_b91_is_range_valid(offset, len)) {
+		return -EINVAL;
+	}
+
+	/* take semaphore */
+	if (k_sem_take(&dev_data->write_lock, K_NO_WAIT)) {
+		return -EACCES;
+	}
+
+	/* write flash */
+	flash_write_page(offset, len, (unsigned char *)data);
+
+	/* release semaphore */
+	k_sem_give(&dev_data->write_lock);
+
+	return 0;
+}
+
+/* API implementation: read */
+static int flash_b91_read(const struct device *dev, off_t offset,
+			  void *data, size_t len)
+{
+	ARG_UNUSED(dev);
+
+	/* return SUCCESS if len equals 0 (required by tests/drivers/flash) */
+	if (!len) {
+		return 0;
+	}
+
+	/* check for valid range */
+	if (!flash_b91_is_range_valid(offset, len)) {
+		return -EINVAL;
+	}
+
+	/* read flash */
+	flash_read_page(offset, len, (unsigned char *)data);
+
+	return 0;
+}
+
+/* API implementation: get_parameters */
+static const struct flash_parameters *
+flash_b91_get_parameters(const struct device *dev)
+{
+	ARG_UNUSED(dev);
+
+	return &flash_b91_parameters;
+}
+
+/* API implementation: page_layout */
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+static const struct flash_pages_layout dev_layout = {
+	.pages_count = FLASH_SIZE / PAGE_SIZE,
+	.pages_size = PAGE_SIZE,
+};
+
+static void flash_b91_pages_layout(const struct device *dev,
+				   const struct flash_pages_layout **layout,
+				   size_t *layout_size)
+{
+	*layout = &dev_layout;
+	*layout_size = 1;
+}
+#endif /* CONFIG_FLASH_PAGE_LAYOUT */
+
+static struct flash_b91_data flash_data;
+
+static const struct flash_driver_api flash_b91_api = {
+	.erase = flash_b91_erase,
+	.write = flash_b91_write,
+	.read = flash_b91_read,
+	.get_parameters = flash_b91_get_parameters,
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+	.page_layout = flash_b91_pages_layout,
+#endif
+};
+
+/* Driver registration */
+DEVICE_DT_INST_DEFINE(0, flash_b91_init,
+		      NULL, &flash_data, NULL, POST_KERNEL,
+		      CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &flash_b91_api);