drivers: flash: SoC KSDK

This KSDK flash shim driver supports the device in the FRDM K64F
platform (enabled with this commit).

WARNING: the driver disables the system interrupts for potentially
long periods of time. This is required to avoid Read-While-Write
issues since most platforms run in XIP mode.

For more detailed information see the link below:
http://cache.freescale.com/files/32bit/doc/app_note/AN4695.pdf

Change-Id: I70f8d09080251033ce2f45be0c2eb95c19fded08
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>

arch/arm/soc/nxp_kinetis/k6x/Kconfig.defconfig.mk64f12

@@ -77,4 +77,11 @@ config RANDOM_KSDK
 
 endif # RANDOM_GENERATOR
 
+if FLASH
+
+config SOC_FLASH_KSDK
+	def_bool y
+
+endif # FLASH
+
 endif # SOC_MK64F12

drivers/flash/Kconfig

@@ -132,6 +132,24 @@ config SOC_FLASH_NRF5_DEV_NAME
 	help
 	  Specify the device name for the flash driver.
 
+config SOC_FLASH_KSDK
+	bool "KSDK flash shim driver"
+	depends on FLASH && HAS_KSDK
+	default n
+	help
+	  Enables the KSDK flash shim driver.
+	  WARNING: This driver will disable the system interrupts for
+	  the duration of the flash erase/write operations. This will
+	  have an impact on the overall system performance - whether
+	  this is acceptable or not will depend on the use case.
+
+config SOC_FLASH_KSDK_DEV_NAME
+	string "KSDK flash device name"
+	depends on SOC_FLASH_KSDK
+	default "KSDK_FLASH"
+	help
+	  Specify the device name for the flash driver.
+
 config SOC_FLASH_QMSI_API_REENTRANCY
 	bool
 	prompt "flash driver API reentrancy for QMSI shim driver"

drivers/flash/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_SPI_FLASH_W25QXXDV) += spi_flash_w25qxxdv.o
 obj-$(CONFIG_SOC_FLASH_QMSI) += soc_flash_qmsi.o
 obj-$(CONFIG_SOC_FLASH_NRF5) += soc_flash_nrf5.o
+obj-$(CONFIG_SOC_FLASH_KSDK) += soc_flash_ksdk.o

drivers/flash/soc_flash_ksdk.c

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2016 Linaro Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <misc/sys_log.h>
+#include <nanokernel.h>
+#include <device.h>
+#include <string.h>
+#include <flash.h>
+#include <errno.h>
+#include <init.h>
+#include <soc.h>
+
+#include "fsl_common.h"
+#include "fsl_flash.h"
+
+struct flash_priv {
+	flash_config_t config;
+};
+
+/*
+ * Interrupt vectors could be executed from flash hence the need for locking.
+ * The underlying KDSK driver takes care of copying the functions to SRAM.
+ *
+ * For more information, see the application note below on Read-While-Write
+ * http://cache.freescale.com/files/32bit/doc/app_note/AN4695.pdf
+ *
+ */
+
+static int flash_ksdk_erase(struct device *dev, off_t offset, size_t len)
+{
+	struct flash_priv *priv = dev->driver_data;
+	uint32_t addr;
+	status_t rc;
+	int key;
+
+	addr = offset + priv->config.PFlashBlockBase;
+
+	key = irq_lock();
+	rc = FLASH_Erase(&priv->config, addr, len, kFLASH_apiEraseKey);
+	irq_unlock(key);
+
+	return (rc == kStatus_Success) ? 0 : -EINVAL;
+}
+
+static int flash_ksdk_read(struct device *dev, off_t offset,
+				void *data, size_t len)
+{
+	struct flash_priv *priv = dev->driver_data;
+	uint32_t addr;
+
+	/*
+	 * The KSDK supports different flash chips whose valid ranges are
+	 * hidden below the API: until the API export these ranges, we can not
+	 * do any generic validation
+	 */
+	addr = offset + priv->config.PFlashBlockBase;
+
+	memcpy(data, (void *) addr, len);
+
+	return 0;
+}
+
+static int flash_ksdk_write(struct device *dev, off_t offset,
+				const void *data, size_t len)
+{
+	struct flash_priv *priv = dev->driver_data;
+	uint32_t addr;
+	status_t rc;
+	int key;
+
+	addr = offset + priv->config.PFlashBlockBase;
+
+	key = irq_lock();
+	rc = FLASH_Program(&priv->config, addr, (uint32_t *) data, len);
+	irq_unlock(key);
+
+	return (rc == kStatus_Success) ? 0 : -EINVAL;
+}
+
+static int flash_ksdk_write_protection(struct device *dev, bool enable)
+{
+	return -EIO;
+}
+
+static struct flash_priv flash_data;
+
+static const struct flash_driver_api flash_ksdk_api = {
+	.write_protection = flash_ksdk_write_protection,
+	.erase = flash_ksdk_erase,
+	.write = flash_ksdk_write,
+	.read = flash_ksdk_read,
+};
+
+static int flash_ksdk_init(struct device *dev)
+{
+	struct flash_priv *priv = dev->driver_data;
+	status_t rc;
+
+	rc = FLASH_Init(&priv->config);
+
+	return (rc == kStatus_Success) ? 0 : -EIO;
+}
+
+DEVICE_AND_API_INIT(flash_ksdk, CONFIG_SOC_FLASH_KSDK_DEV_NAME,
+			flash_ksdk_init, &flash_data, NULL, SECONDARY,
+			CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &flash_ksdk_api);
+

ext/hal/ksdk/drivers/Makefile

@@ -17,3 +17,5 @@
 obj-$(CONFIG_ETH_KSDK) += fsl_enet.o
 obj-$(CONFIG_I2C_KSDK) += fsl_i2c.o
 obj-$(CONFIG_RANDOM_KSDK) += fsl_rnga.o
+obj-$(CONFIG_SOC_FLASH_KSDK) += fsl_flash.o
+