nrf51: Implement the support for Nordic's nRF51 devices

Add support for Nordic's nRF51 chip series. Tested with nRF51822.

Change-Id: Id70f6fd76888cc595a353aefb84d25c4cd325d7d
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-on: http://openocd.zylin.com/1945
Tested-by: jenkins
Reviewed-by: Andrey Yurovsky <yurovsky@gmail.com>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

6 files changed, 882 insertions, 2 deletions

diff --git a/README b/README
index a9ccd001..287cc922 100644
--- a/README
+++ b/README
@@ -124,7 +124,7 @@ Flash drivers
 
 ADUC702x, AT91SAM, AVR, CFI, DSP5680xx, EFM32, EM357, FM3, Kinetis,
 LPC2000, LPC2900, LPCSPIFI, Milandr, NuMicro, PIC32mx, Stellaris,
-STM32, STMSMI, STR7x, STR9x; NAND controllers of AT91SAM9, LPC3180,
+STM32, STMSMI, STR7x, STR9x, nRF51; NAND controllers of AT91SAM9, LPC3180,
 LPC32xx, i.MX31, MXC, NUC910, Orion/Kirkwood, S3C24xx, S3C6400.
 
 
diff --git a/doc/openocd.texi b/doc/openocd.texi
index 76e335b8..814a239a 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -5687,6 +5687,23 @@ unlock str9 device.
 
 @end deffn
 
+@deffn {Flash Driver} nrf51
+All members of the nRF51 microcontroller families from Nordic Semiconductor
+include internal flash and use ARM Cortex-M0 core.
+
+@example
+flash bank $_FLASHNAME nrf51 0 0x00000000 0 0 $_TARGETNAME
+@end example
+
+Some nrf51-specific commands are defined:
+
+@deffn Command {nrf51 mass_erase}
+Erases the contents of the code memory and user information
+configuration registers as well. It must be noted that this command
+works only for chips that do not have factory pre-programmed region 0
+code.
+@end deffn
+@end deffn
 
 @section mFlash
 
diff --git a/src/flash/nor/Makefile.am b/src/flash/nor/Makefile.am
index d817cc69..31681473 100644
--- a/src/flash/nor/Makefile.am
+++ b/src/flash/nor/Makefile.am
@@ -42,7 +42,8 @@ NOR_DRIVERS = \
 	dsp5680xx_flash.c \
 	kinetis.c \
 	mini51.c \
-	nuc1x.c
+	nuc1x.c \
+	nrf51.c
 
 noinst_HEADERS = \
 	core.h \
diff --git a/src/flash/nor/drivers.c b/src/flash/nor/drivers.c
index 39c2f9fc..ed631a3b 100644
--- a/src/flash/nor/drivers.c
+++ b/src/flash/nor/drivers.c
@@ -55,6 +55,7 @@ extern struct flash_driver efm32_flash;
 extern struct flash_driver mdr_flash;
 extern struct flash_driver mini51_flash;
 extern struct flash_driver nuc1x_flash;
+extern struct flash_driver nrf51_flash;
 
 /**
  * The list of built-in flash drivers.
@@ -94,6 +95,7 @@ static struct flash_driver *flash_drivers[] = {
 	&mdr_flash,
 	&mini51_flash,
 	&nuc1x_flash,
+	&nrf51_flash,
 	NULL,
 };
 
diff --git a/src/flash/nor/nrf51.c b/src/flash/nor/nrf51.c
new file mode 100644
index 00000000..79e6d49e
--- /dev/null
+++ b/src/flash/nor/nrf51.c
@@ -0,0 +1,790 @@
+/***************************************************************************
+ *   Copyright (C) 2013 Synapse Product Development                        *
+ *   Andrey Smirnov <andrew.smironv@gmail.com>                             *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
+ ***************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "imp.h"
+
+enum {
+	NRF51_FLASH_BASE = 0x00000000,
+};
+
+enum nrf51_ficr_registers {
+	NRF51_FICR_BASE = 0x10000000, /* Factory Information Configuration Registers */
+
+#define NRF51_FICR_REG(offset) (NRF51_FICR_BASE + offset)
+
+	NRF51_FICR_CODEPAGESIZE		= NRF51_FICR_REG(0x010),
+	NRF51_FICR_CODESIZE		= NRF51_FICR_REG(0x014),
+	NRF51_FICR_CLENR0		= NRF51_FICR_REG(0x028),
+	NRF51_FICR_PPFC			= NRF51_FICR_REG(0x02C),
+	NRF51_FICR_NUMRAMBLOCK		= NRF51_FICR_REG(0x034),
+	NRF51_FICR_SIZERAMBLOCK0	= NRF51_FICR_REG(0x038),
+	NRF51_FICR_SIZERAMBLOCK1	= NRF51_FICR_REG(0x03C),
+	NRF51_FICR_SIZERAMBLOCK2	= NRF51_FICR_REG(0x040),
+	NRF51_FICR_SIZERAMBLOCK3	= NRF51_FICR_REG(0x044),
+	NRF51_FICR_CONFIGID		= NRF51_FICR_REG(0x05C),
+	NRF51_FICR_DEVICEID0		= NRF51_FICR_REG(0x060),
+	NRF51_FICR_DEVICEID1		= NRF51_FICR_REG(0x064),
+	NRF51_FICR_ER0			= NRF51_FICR_REG(0x080),
+	NRF51_FICR_ER1			= NRF51_FICR_REG(0x084),
+	NRF51_FICR_ER2			= NRF51_FICR_REG(0x088),
+	NRF51_FICR_ER3			= NRF51_FICR_REG(0x08C),
+	NRF51_FICR_IR0			= NRF51_FICR_REG(0x090),
+	NRF51_FICR_IR1			= NRF51_FICR_REG(0x094),
+	NRF51_FICR_IR2			= NRF51_FICR_REG(0x098),
+	NRF51_FICR_IR3			= NRF51_FICR_REG(0x09C),
+	NRF51_FICR_DEVICEADDRTYPE	= NRF51_FICR_REG(0x0A0),
+	NRF51_FICR_DEVICEADDR0		= NRF51_FICR_REG(0x0A4),
+	NRF51_FICR_DEVICEADDR1		= NRF51_FICR_REG(0x0A8),
+	NRF51_FICR_OVERRIDEN		= NRF51_FICR_REG(0x0AC),
+	NRF51_FICR_NRF_1MBIT0		= NRF51_FICR_REG(0x0B0),
+	NRF51_FICR_NRF_1MBIT1		= NRF51_FICR_REG(0x0B4),
+	NRF51_FICR_NRF_1MBIT2		= NRF51_FICR_REG(0x0B8),
+	NRF51_FICR_NRF_1MBIT3		= NRF51_FICR_REG(0x0BC),
+	NRF51_FICR_NRF_1MBIT4		= NRF51_FICR_REG(0x0C0),
+	NRF51_FICR_BLE_1MBIT0		= NRF51_FICR_REG(0x0EC),
+	NRF51_FICR_BLE_1MBIT1		= NRF51_FICR_REG(0x0F0),
+	NRF51_FICR_BLE_1MBIT2		= NRF51_FICR_REG(0x0F4),
+	NRF51_FICR_BLE_1MBIT3		= NRF51_FICR_REG(0x0F8),
+	NRF51_FICR_BLE_1MBIT4		= NRF51_FICR_REG(0x0FC),
+};
+
+enum nrf51_uicr_registers {
+	NRF51_UICR_BASE = 0x10001000, /* User Information
+				       * Configuration Regsters */
+
+#define NRF51_UICR_REG(offset) (NRF51_UICR_BASE + offset)
+
+	NRF51_UICR_CLENR0	= NRF51_UICR_REG(0x000),
+	NRF51_UICR_RBPCONF	= NRF51_UICR_REG(0x004),
+	NRF51_UICR_XTALFREQ	= NRF51_UICR_REG(0x008),
+	NRF51_UICR_FWID		= NRF51_UICR_REG(0x010),
+};
+
+enum nrf51_nvmc_registers {
+	NRF51_NVMC_BASE = 0x4001E000, /* Non-Volatile Memory
+				       * Controller Regsters */
+
+#define NRF51_NVMC_REG(offset) (NRF51_NVMC_BASE + offset)
+
+	NRF51_NVMC_READY	= NRF51_NVMC_REG(0x400),
+	NRF51_NVMC_CONFIG	= NRF51_NVMC_REG(0x504),
+	NRF51_NVMC_ERASEPAGE	= NRF51_NVMC_REG(0x508),
+	NRF51_NVMC_ERASEALL	= NRF51_NVMC_REG(0x50C),
+	NRF51_NVMC_ERASEUICR	= NRF51_NVMC_REG(0x514),
+};
+
+enum nrf51_nvmc_config_bits {
+	NRF51_NVMC_CONFIG_REN = 0x00,
+	NRF51_NVMC_CONFIG_WEN = 0x01,
+	NRF51_NVMC_CONFIG_EEN = 0x02,
+
+};
+
+struct nrf51_info {
+	uint32_t code_page_size;
+	uint32_t code_memory_size;
+
+	bool probed;
+	struct target *target;
+};
+
+static int nrf51_probe(struct flash_bank *bank);
+
+static int nrf51_get_probed_chip_if_halted(struct flash_bank *bank, struct nrf51_info **chip)
+{
+	if (bank->target->state != TARGET_HALTED) {
+		LOG_ERROR("Target not halted");
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	*chip = (struct nrf51_info *)bank->driver_priv;
+
+	if (!(*chip)->probed)
+		return nrf51_probe(bank);
+
+	return ERROR_OK;
+}
+
+static int nrf51_wait_for_nvmc(struct nrf51_info *chip)
+{
+	uint32_t ready;
+	int res;
+	int timeout = 100;
+
+	do {
+		res = target_read_u32(chip->target, NRF51_NVMC_READY, &ready);
+		if (res != ERROR_OK) {
+			LOG_ERROR("Couldn't read NVMC_READY register");
+			return res;
+		}
+
+		if (ready == 0x00000001)
+			return ERROR_OK;
+
+		alive_sleep(1);
+	} while (timeout--);
+
+	return ERROR_FLASH_BUSY;
+}
+
+static int nrf51_nvmc_erase_enable(struct nrf51_info *chip)
+{
+	int res;
+	res = target_write_u32(chip->target,
+			       NRF51_NVMC_CONFIG,
+			       NRF51_NVMC_CONFIG_EEN);
+
+	if (res != ERROR_OK) {
+		LOG_ERROR("Failed to enable erase operation");
+		return res;
+	}
+
+	/*
+	  According to NVMC examples in Nordic SDK busy status must be
+	  checked after writing to NVMC_CONFIG
+	 */
+	res = nrf51_wait_for_nvmc(chip);
+	if (res != ERROR_OK)
+		LOG_ERROR("Erase enable did not complete");
+
+	return res;
+}
+
+static int nrf51_nvmc_write_enable(struct nrf51_info *chip)
+{
+	int res;
+	res = target_write_u32(chip->target,
+			       NRF51_NVMC_CONFIG,
+			       NRF51_NVMC_CONFIG_WEN);
+
+	if (res != ERROR_OK) {
+		LOG_ERROR("Failed to enable write operation");
+		return res;
+	}
+
+	/*
+	  According to NVMC examples in Nordic SDK busy status must be
+	  checked after writing to NVMC_CONFIG
+	 */
+	res = nrf51_wait_for_nvmc(chip);
+	if (res != ERROR_OK)
+		LOG_ERROR("Write enable did not complete");
+
+	return res;
+}
+
+static int nrf51_nvmc_read_only(struct nrf51_info *chip)
+{
+	int res;
+	res = target_write_u32(chip->target,
+			       NRF51_NVMC_CONFIG,
+			       NRF51_NVMC_CONFIG_REN);
+
+	if (res != ERROR_OK) {
+		LOG_ERROR("Failed to enable read-only operation");
+		return res;
+	}
+	/*
+	  According to NVMC examples in Nordic SDK busy status must be
+	  checked after writing to NVMC_CONFIG
+	 */
+	res = nrf51_wait_for_nvmc(chip);
+	if (res != ERROR_OK)
+		LOG_ERROR("Read only enable did not complete");
+
+	return res;
+}
+
+static int nrf51_nvmc_generic_erase(struct nrf51_info *chip,
+			       uint32_t erase_register, uint32_t erase_value)
+{
+	int res;
+
+	res = nrf51_nvmc_erase_enable(chip);
+	if (res != ERROR_OK)
+		goto error;
+
+	res = target_write_u32(chip->target,
+			       erase_register,
+			       erase_value);
+	if (res != ERROR_OK)
+		goto set_read_only;
+
+	res = nrf51_wait_for_nvmc(chip);
+	if (res != ERROR_OK)
+		goto set_read_only;
+
+	return nrf51_nvmc_read_only(chip);
+
+set_read_only:
+	nrf51_nvmc_read_only(chip);
+error:
+	LOG_ERROR("Failed to erase reg: 0x%08"PRIx32" val: 0x%08"PRIx32,
+		  erase_register, erase_value);
+	return ERROR_FAIL;
+}
+
+static int nrf51_protect_check(struct flash_bank *bank)
+{
+	int res;
+	uint32_t clenr0;
+
+	struct nrf51_info *chip = (struct nrf51_info *)bank->driver_priv;
+
+	assert(chip != NULL);
+
+	res = target_read_u32(chip->target, NRF51_FICR_CLENR0,
+			      &clenr0);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read code region 0 size[FICR]");
+		return res;
+	}
+
+	if (clenr0 == 0xFFFFFFFF) {
+		res = target_read_u32(chip->target, NRF51_UICR_CLENR0,
+				      &clenr0);
+		if (res != ERROR_OK) {
+			LOG_ERROR("Couldn't read code region 0 size[UICR]");
+			return res;
+		}
+	}
+
+	for (int i = 0; i < bank->num_sectors; i++)
+		bank->sectors[i].is_protected =
+			clenr0 != 0xFFFFFFFF && bank->sectors[i].offset < clenr0;
+
+	return ERROR_OK;
+}
+
+static int nrf51_protect(struct flash_bank *bank, int set, int first, int last)
+{
+	int res;
+	uint32_t clenr0, ppfc;
+	struct nrf51_info *chip;
+
+	res = nrf51_get_probed_chip_if_halted(bank, &chip);
+	if (res != ERROR_OK)
+		return res;
+
+	if (first != 0) {
+		LOG_ERROR("Code region 0 must start at the begining of the bank");
+		return ERROR_FAIL;
+	}
+
+	res = target_read_u32(chip->target, NRF51_FICR_PPFC,
+			      &ppfc);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read PPFC register");
+		return res;
+	}
+
+	if ((ppfc & 0xFF) == 0x00) {
+		LOG_ERROR("Code region 0 size was pre-programmed at the factory, can't change flash protection settings");
+		return ERROR_FAIL;
+	};
+
+	res = target_read_u32(chip->target, NRF51_UICR_CLENR0,
+			      &clenr0);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read code region 0 size[UICR]");
+		return res;
+	}
+
+	if (clenr0 == 0xFFFFFFFF) {
+		res = target_write_u32(chip->target, NRF51_UICR_CLENR0,
+				       clenr0);
+		if (res != ERROR_OK) {
+			LOG_ERROR("Couldn't write code region 0 size[UICR]");
+			return res;
+		}
+
+	} else {
+		LOG_ERROR("You need to perform chip erase before changing the protection settings");
+	}
+
+	nrf51_protect_check(bank);
+
+	return ERROR_OK;
+}
+
+static int nrf51_probe(struct flash_bank *bank)
+{
+	uint32_t id;
+	int res;
+	struct nrf51_info *chip = (struct nrf51_info *)bank->driver_priv;
+
+	res = target_read_u32(chip->target, NRF51_FICR_DEVICEID0, &id);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read Device ID 0 register");
+		return res;
+	}
+
+	res = target_read_u32(chip->target, NRF51_FICR_DEVICEID1, &id);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read Device ID 1 register");
+		return res;
+	}
+
+	res = target_read_u32(chip->target, NRF51_FICR_CODEPAGESIZE,
+			      &chip->code_page_size);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read code page size");
+		return res;
+	}
+
+	res = target_read_u32(chip->target, NRF51_FICR_CODESIZE,
+			      &chip->code_memory_size);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read code memory size");
+		return res;
+	}
+
+	bank->size = chip->code_memory_size * 1024;
+	bank->num_sectors = bank->size / chip->code_page_size;
+	bank->sectors = calloc(bank->num_sectors,
+			       sizeof((bank->sectors)[0]));
+	if (!bank->sectors)
+		return ERROR_FLASH_BANK_NOT_PROBED;
+
+	/* Fill out the sector information: all NRF51 sectors are the same size and
+	 * there is always a fixed number of them. */
+	for (int i = 0; i < bank->num_sectors; i++) {
+		bank->sectors[i].size = chip->code_page_size;
+		bank->sectors[i].offset	= i * chip->code_page_size;
+
+		/* mark as unknown */
+		bank->sectors[i].is_erased = -1;
+		bank->sectors[i].is_protected = -1;
+	}
+
+	nrf51_protect_check(bank);
+
+	chip->probed = true;
+
+	return ERROR_OK;
+}
+
+static int nrf51_auto_probe(struct flash_bank *bank)
+{
+	struct nrf51_info *chip = (struct nrf51_info *)bank->driver_priv;
+
+	if (chip->probed)
+		return ERROR_OK;
+
+	return nrf51_probe(bank);
+}
+
+static struct flash_sector *nrf51_find_sector_by_address(struct flash_bank *bank, uint32_t address)
+{
+	struct nrf51_info *chip = (struct nrf51_info *)bank->driver_priv;
+
+	for (int i = 0; i < bank->num_sectors; i++)
+		if (bank->sectors[i].offset <= address &&
+		    address < (bank->sectors[i].offset + chip->code_page_size))
+			return &bank->sectors[i];
+	return NULL;
+}
+
+static int nrf51_erase_all(struct nrf51_info *chip)
+{
+	return nrf51_nvmc_generic_erase(chip,
+					NRF51_NVMC_ERASEALL,
+					0x00000001);
+}
+
+static int nrf51_erase_page(struct nrf51_info *chip, struct flash_sector *sector)
+{
+	int res;
+
+	if (sector->is_protected)
+		return ERROR_FAIL;
+
+	res = nrf51_nvmc_generic_erase(chip,
+				       NRF51_NVMC_ERASEPAGE,
+				       sector->offset);
+	if (res == ERROR_OK)
+		sector->is_erased = 1;
+
+	return res;
+}
+
+static int nrf51_write_page(struct flash_bank *bank, uint32_t offset, uint8_t *buffer)
+{
+	assert(offset % 4 == 0);
+
+	int res = ERROR_FAIL;
+	struct nrf51_info *chip = (struct nrf51_info *)bank->driver_priv;
+	struct flash_sector *sector = nrf51_find_sector_by_address(bank, offset);
+
+	if (!sector)
+		goto error;
+
+	if (sector->is_protected)
+		goto error;
+
+	if (!sector->is_erased) {
+		res = nrf51_erase_page(chip, sector);
+		if (res != ERROR_OK)
+			goto error;
+	}
+
+	res = nrf51_nvmc_write_enable(chip);
+	if (res != ERROR_OK)
+		goto error;
+
+	sector->is_erased = 0;
+	res = target_write_memory(bank->target, offset, 4,
+				  chip->code_page_size / 4, buffer);
+	if (res != ERROR_OK)
+		goto set_read_only;
+
+	return nrf51_nvmc_read_only(chip);
+
+set_read_only:
+	nrf51_nvmc_read_only(chip);
+error:
+	LOG_ERROR("Failed to write sector @ 0x%08"PRIx32, sector->offset);
+	return res;
+}
+
+static int nrf51_erase(struct flash_bank *bank, int first, int last)
+{
+	int res;
+	struct nrf51_info *chip;
+
+	res = nrf51_get_probed_chip_if_halted(bank, &chip);
+	if (res != ERROR_OK)
+		return res;
+
+	/* For each sector to be erased */
+	for (int s = first; s <= last && res == ERROR_OK; s++)
+		res = nrf51_erase_page(chip, &bank->sectors[s]);
+
+	return res;
+}
+
+static int nrf51_write(struct flash_bank *bank, uint8_t *buffer,
+		       uint32_t offset, uint32_t count)
+{
+	int res;
+	struct {
+		uint32_t start, end;
+	} region;
+	struct nrf51_info *chip;
+
+	res = nrf51_get_probed_chip_if_halted(bank, &chip);
+	if (res != ERROR_OK)
+		return res;
+
+	region.start = offset;
+	region.end   = offset + count;
+
+	struct {
+		size_t   length;
+		uint8_t *buffer;
+	}  start_extra, end_extra;
+
+	start_extra.length	= region.start % chip->code_page_size;
+	start_extra.buffer	= buffer;
+	end_extra.length	= region.end  % chip->code_page_size;
+	end_extra.buffer	= buffer + count - end_extra.length;
+
+	if (start_extra.length) {
+		uint8_t page[chip->code_page_size];
+
+		res = target_read_memory(bank->target,
+					 region.start - start_extra.length,
+					 1, start_extra.length, page);
+		if (res != ERROR_OK)
+			return res;
+
+		memcpy(page + start_extra.length,
+		       start_extra.buffer,
+		       chip->code_page_size - start_extra.length);
+
+		res = nrf51_write_page(bank,
+				       region.start - start_extra.length,
+				       page);
+		if (res != ERROR_OK)
+			return res;
+	}
+
+	if (end_extra.length) {
+		uint8_t page[chip->code_page_size];
+
+		/* Retrieve the full row contents from Flash */
+		res = target_read_memory(bank->target,
+					 region.end,
+					 1,
+					 (chip->code_page_size - end_extra.length),
+					 page + end_extra.length);
+		if (res != ERROR_OK)
+			return res;
+
+		memcpy(page, end_extra.buffer, end_extra.length);
+
+		res = nrf51_write_page(bank,
+				       region.end - end_extra.length,
+				       page);
+		if (res != ERROR_OK)
+			return res;
+	}
+
+
+	region.start += start_extra.length;
+	region.end   -= end_extra.length;
+
+	for (uint32_t address = region.start; address < region.end;
+	     address += chip->code_page_size) {
+		res = nrf51_write_page(bank, address, &buffer[address - region.start]);
+
+		if (res != ERROR_OK)
+			return res;
+
+	}
+
+	return ERROR_OK;
+}
+
+FLASH_BANK_COMMAND_HANDLER(nrf51_flash_bank_command)
+{
+	struct nrf51_info *chip;
+
+	/* Create a new chip */
+	chip = calloc(1, sizeof(*chip));
+	if (!chip)
+		return ERROR_FAIL;
+
+	chip->target = bank->target;
+	chip->probed = false;
+
+	bank->driver_priv = chip;
+
+	if (bank->base != NRF51_FLASH_BASE) {
+		LOG_ERROR("Address 0x%08" PRIx32 " invalid bank address (try 0x%08" PRIx32
+				"[nrf51 series] )",
+				bank->base, NRF51_FLASH_BASE);
+		return ERROR_FAIL;
+	}
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(nrf51_handle_mass_erase_command)
+{
+	int res;
+	struct flash_bank *bank;
+
+	res = get_flash_bank_by_num(0, &bank);
+	if (res != ERROR_OK)
+		return res;
+
+	struct nrf51_info *chip;
+
+	res = nrf51_get_probed_chip_if_halted(bank, &chip);
+	if (res != ERROR_OK)
+		return res;
+
+	uint32_t ppfc;
+
+	res = target_read_u32(chip->target, NRF51_FICR_PPFC,
+			      &ppfc);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read PPFC register");
+		return res;
+	}
+
+	if ((ppfc & 0xFF) == 0x00) {
+		LOG_ERROR("Code region 0 size was pre-programmed at the factory, "
+			  "mass erase command won't work.");
+		return ERROR_FAIL;
+	};
+
+	res = nrf51_erase_all(chip);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Failed to erase the chip");
+		nrf51_protect_check(bank);
+		return res;
+	}
+
+	for (int i = 0; i < bank->num_sectors; i++)
+		bank->sectors[i].is_erased = 1;
+
+	return nrf51_protect_check(bank);
+}
+
+static int nrf51_info(struct flash_bank *bank, char *buf, int buf_size)
+{
+	int res;
+
+	struct nrf51_info *chip;
+
+	res = nrf51_get_probed_chip_if_halted(bank, &chip);
+	if (res != ERROR_OK)
+		return res;
+
+	struct {
+		uint32_t address, value;
+	} ficr[] = {
+		{ .address = NRF51_FICR_CODEPAGESIZE	},
+		{ .address = NRF51_FICR_CODESIZE	},
+		{ .address = NRF51_FICR_CLENR0		},
+		{ .address = NRF51_FICR_PPFC		},
+		{ .address = NRF51_FICR_NUMRAMBLOCK	},
+		{ .address = NRF51_FICR_SIZERAMBLOCK0	},
+		{ .address = NRF51_FICR_SIZERAMBLOCK1	},
+		{ .address = NRF51_FICR_SIZERAMBLOCK2	},
+		{ .address = NRF51_FICR_SIZERAMBLOCK3	},
+		{ .address = NRF51_FICR_CONFIGID	},
+		{ .address = NRF51_FICR_DEVICEID0	},
+		{ .address = NRF51_FICR_DEVICEID1	},
+		{ .address = NRF51_FICR_ER0		},
+		{ .address = NRF51_FICR_ER1		},
+		{ .address = NRF51_FICR_ER2		},
+		{ .address = NRF51_FICR_ER3		},
+		{ .address = NRF51_FICR_IR0		},
+		{ .address = NRF51_FICR_IR1		},
+		{ .address = NRF51_FICR_IR2		},
+		{ .address = NRF51_FICR_IR3		},
+		{ .address = NRF51_FICR_DEVICEADDRTYPE	},
+		{ .address = NRF51_FICR_DEVICEADDR0	},
+		{ .address = NRF51_FICR_DEVICEADDR1	},
+		{ .address = NRF51_FICR_OVERRIDEN	},
+		{ .address = NRF51_FICR_NRF_1MBIT0	},
+		{ .address = NRF51_FICR_NRF_1MBIT1	},
+		{ .address = NRF51_FICR_NRF_1MBIT2	},
+		{ .address = NRF51_FICR_NRF_1MBIT3	},
+		{ .address = NRF51_FICR_NRF_1MBIT4	},
+		{ .address = NRF51_FICR_BLE_1MBIT0	},
+		{ .address = NRF51_FICR_BLE_1MBIT1	},
+		{ .address = NRF51_FICR_BLE_1MBIT2	},
+		{ .address = NRF51_FICR_BLE_1MBIT3	},
+		{ .address = NRF51_FICR_BLE_1MBIT4	},
+	}, uicr[] = {
+		{ .address = NRF51_UICR_CLENR0,		},
+		{ .address = NRF51_UICR_RBPCONF		},
+		{ .address = NRF51_UICR_XTALFREQ	},
+		{ .address = NRF51_UICR_FWID		},
+	};
+
+	for (size_t i = 0; i < ARRAY_SIZE(ficr); i++) {
+		res = target_read_u32(chip->target, ficr[i].address,
+				      &ficr[i].value);
+		if (res != ERROR_OK) {
+			LOG_ERROR("Couldn't read %" PRIx32, ficr[i].address);
+			return res;
+		}
+	}
+
+	for (size_t i = 0; i < ARRAY_SIZE(uicr); i++) {
+		res = target_read_u32(chip->target, uicr[i].address,
+				      &uicr[i].value);
+		if (res != ERROR_OK) {
+			LOG_ERROR("Couldn't read %" PRIx32, uicr[i].address);
+			return res;
+		}
+	}
+
+	snprintf(buf, buf_size,
+		 "\n[factory information control block]\n\n"
+		 "code page size: %"PRIu32"B\n"
+		 "code memory size: %"PRIu32"kB\n"
+		 "code region 0 size: %"PRIu32"kB\n"
+		 "pre-programmed code: %s\n"
+		 "number of ram blocks: %"PRIu32"\n"
+		 "ram block 0 size: %"PRIu32"B\n"
+		 "ram block 1 size: %"PRIu32"B\n"
+		 "ram block 2 size: %"PRIu32"B\n"
+		 "ram block 3 size: %"PRIu32 "B\n"
+		 "encryption root: 0x%08"PRIx32"%08"PRIx32"%08"PRIx32"%08"PRIx32"\n"
+		 "identity root: 0x%08"PRIx32"%08"PRIx32"%08"PRIx32"%08"PRIx32"\n"
+		 "device address type: 0x%"PRIx32"\n"
+		 "device address: 0x%"PRIx32"%08"PRIx32"\n"
+		 "override enable: %"PRIu32"\n"
+		 "NRF_1MBIT values: %"PRIx32" %"PRIx32" %"PRIx32" %"PRIx32" %"PRIx32"\n"
+		 "BLE_1MBIT values: %"PRIx32" %"PRIx32" %"PRIx32" %"PRIx32" %"PRIx32"\n"
+		 "\n[user information control block]\n\n"
+		 "code region 0 size: %"PRIu32"kB\n"
+		 "read back protection configuration: %"PRIx32"\n"
+		 "reset value for XTALFREQ: %"PRIx32"\n"
+		 "firmware id: 0x%04"PRIx32,
+		 ficr[0].value,
+		 ficr[1].value,
+		 (ficr[2].value == 0xFFFFFFFF) ? 0 : ficr[2].value / 1024,
+		 ((ficr[3].value & 0xFF) == 0x00) ? "present" : "not present",
+		 ficr[4].value,
+		 ficr[5].value,
+		 (ficr[6].value == 0xFFFFFFFF) ? 0 : ficr[6].value,
+		 (ficr[7].value == 0xFFFFFFFF) ? 0 : ficr[7].value,
+		 (ficr[8].value == 0xFFFFFFFF) ? 0 : ficr[8].value,
+		 ficr[9].value, ficr[9].value, ficr[9].value, ficr[9].value,
+		 ficr[10].value, ficr[11].value, ficr[12].value, ficr[13].value,
+		 ficr[14].value,
+		 ficr[15].value, ficr[16].value,
+		 ficr[17].value,
+		 ficr[18].value, ficr[19].value, ficr[20].value, ficr[21].value, ficr[22].value,
+		 ficr[23].value, ficr[24].value, ficr[25].value, ficr[26].value, ficr[27].value,
+		 (uicr[0].value == 0xFFFFFFFF) ? 0 : uicr[0].value / 1024,
+		 uicr[1].value & 0xFFFF,
+		 uicr[2].value & 0xFF,
+		 uicr[3].value & 0xFFFF);
+
+	return ERROR_OK;
+}
+
+static const struct command_registration nrf51_exec_command_handlers[] = {
+	{
+		.name		= "mass_erase",
+		.handler	= nrf51_handle_mass_erase_command,
+		.mode		= COMMAND_EXEC,
+		.help		= "Erase all flash contents of the chip.",
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration nrf51_command_handlers[] = {
+	{
+		.name	= "nrf51",
+		.mode	= COMMAND_ANY,
+		.help	= "nrf51 flash command group",
+		.usage	= "",
+		.chain	= nrf51_exec_command_handlers,
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+struct flash_driver nrf51_flash = {
+	.name			= "nrf51",
+	.commands		= nrf51_command_handlers,
+	.flash_bank_command	= nrf51_flash_bank_command,
+	.info			= nrf51_info,
+	.erase			= nrf51_erase,
+	.protect		= nrf51_protect,
+	.write			= nrf51_write,
+	.read			= default_flash_read,
+	.probe			= nrf51_probe,
+	.auto_probe		= nrf51_auto_probe,
+	.erase_check		= default_flash_blank_check,
+	.protect_check		= nrf51_protect_check,
+};
diff --git a/tcl/target/nrf51_stlink.tcl b/tcl/target/nrf51_stlink.tcl
new file mode 100644
index 00000000..d37ec943
--- /dev/null
+++ b/tcl/target/nrf51_stlink.tcl
@@ -0,0 +1,70 @@
+#
+# script for Nordic nRF51 series, a CORTEX-M0 chip
+#
+
+source [find target/swj-dp.tcl]
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME nrf51
+}
+
+if { [info exists ENDIAN] } {
+   set _ENDIAN $ENDIAN
+} else {
+   set _ENDIAN little
+}
+
+# Work-area is a space in RAM used for flash programming
+# By default use 2kB
+if { [info exists WORKAREASIZE] } {
+   set _WORKAREASIZE $WORKAREASIZE
+} else {
+   set _WORKAREASIZE 0x800
+}
+
+if { [info exists CPUTAPID] } {
+   set _CPUTAPID $CPUTAPID
+} else {
+   set _CPUTAPID 0x0bb11477
+}
+
+if { [info exists TRANSPORT] } {
+   set _TRANSPORT $TRANSPORT
+   if { $TRANSPORT == "hla_jtag" } {
+      if { [info exists CPUTAPID] == 0 } {
+         # jtag requires us to use the jtag tap id
+         set _CPUTAPID 0x3ba00477
+      }
+   }
+} else {
+   set _TRANSPORT hla_swd
+}
+
+# add deprecated transport name check
+if { $_TRANSPORT == "stlink_swd" } {
+	set _TRANSPORT "hla_swd"
+	echo "DEPRECATED! use 'hla_swd' transport not 'stlink_swd'"
+}
+
+if { $_TRANSPORT == "stlink_jtag" } {
+	set _TRANSPORT "hla_jtag"
+	echo "DEPRECATED! use 'hla_jtag' transport not 'stlink_jtag'"
+}
+# end deprecated checks
+
+transport select $_TRANSPORT
+hla newtap $_CHIPNAME cpu -expected-id $_CPUTAPID
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME hla_target -chain-position $_TARGETNAME
+
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
+
+# The chip supports standard ARM/Cortex-M0 SYSRESETREQ signal, so for
+# non-"hla" targets it would be useful to have the following in the config.
+# cortex_m reset_config sysresetreq
+
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME nrf51 0x00000000 0 1 1 $_TARGETNAME