flash/nor: flash driver and cfg for SAM E54, E53, E51 and D51

The new Microchip (former Atmel) series powered by Cortex-M4 looks
very similar to older M0+ powered SAM D2x at the first sight.
Unfortunately the new series differs a lot in important details.
NVMCTRL has different register addresses, moved important bits
and even changed binary command set. An universal driver for all SAM D/E
would be very complicated. That's why a new driver was derived.

Tested on Microchip SAM E54 Xplained Pro kit (board cfg included).

Adjusted for the restructured dap support.
Checked by valgrind and clang static analyzer.

Change-Id: I26c67047a552076f4b207b9b89285a53d69b4ca4
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4272
Tested-by: jenkins
Reviewed-by: Andres Vahter <andres.vahter@gmail.com>

6 files changed, 1119 insertions, 3 deletions

diff --git a/doc/openocd.texi b/doc/openocd.texi
index bede1c8..aa37b37 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -5440,9 +5440,16 @@ the flash.
 @anchor{at91samd}
 @deffn {Flash Driver} at91samd
 @cindex at91samd
-All members of the ATSAMD, ATSAMR, ATSAML and ATSAMC microcontroller
+All members of the ATSAM D2x, D1x, D0x, ATSAMR, ATSAML and ATSAMC microcontroller
 families from Atmel include internal flash and use ARM's Cortex-M0+ core.
-This driver uses the same command names/syntax as @xref{at91sam3}.
+
+Do not use for ATSAM D51 and E5x: use @xref{atsame5} instead.
+
+The devices have one flash bank:
+
+@example
+flash bank $_FLASHNAME at91samd 0x00000000 0 1 1 $_TARGETNAME
+@end example
 
 @deffn Command {at91samd chip-erase}
 Issues a complete Flash erase via the Device Service Unit (DSU). This can be
@@ -5604,9 +5611,72 @@ Command is used internally in event event reset-deassert-post.
 @end deffn
 @end deffn
 
+@anchor{atsame5}
+@deffn {Flash Driver} atsame5
+@cindex atsame5
+All members of the SAM E54, E53, E51 and D51 microcontroller
+families from Microchip (former Atmel) include internal flash
+and use ARM's Cortex-M4 core.
+
+The devices have two ECC flash banks with a swapping feature.
+This driver handles both banks together as it were one.
+Bank swapping is not supported yet.
+
+@example
+flash bank $_FLASHNAME atsame5 0x00000000 0 1 1 $_TARGETNAME
+@end example
+
+@deffn Command {atsame5 bootloader}
+Shows or sets the bootloader size configuration, stored in the User Page of the
+Flash. This is called the BOOTPROT region. When setting, the bootloader size
+must be specified in bytes. The nearest bigger protection size is used.
+Settings are written immediately but only take effect on MCU reset.
+Setting the bootloader size to 0 disables bootloader protection.
+
+@example
+atsame5 bootloader
+atsame5 bootloader 16384
+@end example
+@end deffn
+
+@deffn Command {atsame5 chip-erase}
+Issues a complete Flash erase via the Device Service Unit (DSU). This can be
+used to erase a chip back to its factory state and does not require the
+processor to be halted.
+@end deffn
+
+@deffn Command {atsame5 dsu_reset_deassert}
+This command releases internal reset held by DSU
+and prepares reset vector catch in case of reset halt.
+Command is used internally in event event reset-deassert-post.
+@end deffn
+
+@deffn Command {atsame5 userpage}
+Writes or reads the first 64 bits of NVM User Page which is located at
+0x804000. This field includes various fuses.
+Reading is done by invoking this command without any arguments.
+Writing is possible by giving 1 or 2 hex values. The first argument
+is the value to be written and the second one is an optional bit mask
+(a zero bit in the mask means the bit stays unchanged).
+The reserved fields are always masked out and cannot be changed.
+
+@example
+# Read
+>atsame5 userpage
+USER PAGE: 0xAEECFF80FE9A9239
+# Write
+>atsame5 userpage 0xAEECFF80FE9A9239
+# Write 2 to SEESBLK and 4 to SEEPSZ fields but leave other bits unchanged
+# (setup SmartEEPROM of virtual size 8192 bytes)
+>atsame5 userpage 0x4200000000 0x7f00000000
+@end example
+@end deffn
+
+@end deffn
+
 @deffn {Flash Driver} atsamv
 @cindex atsamv
-All members of the ATSAMV, ATSAMS, and ATSAME families from
+All members of the ATSAMV7x, ATSAMS70, and ATSAME70 families from
 Atmel include internal flash and use ARM's Cortex-M7 core.
 This driver uses the same command names/syntax as @xref{at91sam3}.
 @end deffn
diff --git a/src/flash/nor/Makefile.am b/src/flash/nor/Makefile.am
index bbdc312..135128e 100644
--- a/src/flash/nor/Makefile.am
+++ b/src/flash/nor/Makefile.am
@@ -17,6 +17,7 @@ NOR_DRIVERS = \
 	%D%/at91sam7.c \
 	%D%/ath79.c \
 	%D%/atsamv.c \
+	%D%/atsame5.c \
 	%D%/avrf.c \
 	%D%/bluenrg-x.c \
 	%D%/cc3220sf.c \
diff --git a/src/flash/nor/atsame5.c b/src/flash/nor/atsame5.c
new file mode 100644
index 0000000..7490d0e
--- /dev/null
+++ b/src/flash/nor/atsame5.c
@@ -0,0 +1,955 @@
+/***************************************************************************
+ *   Copyright (C) 2017 by Tomas Vanek					   *
+ *   vanekt@fbl.cz							   *
+ *                                                                         *
+ *   Based on at91samd.c                                                   *
+ *   Copyright (C) 2013 by Andrey Yurovsky                                 *
+ *   Andrey Yurovsky <yurovsky@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, see <http://www.gnu.org/licenses/>. *
+ ***************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "imp.h"
+#include "helper/binarybuffer.h"
+
+#include <target/cortex_m.h>
+
+/* A note to prefixing.
+ * Definitions and functions ingerited from at91samd.c without
+ * any change retained the original prefix samd_ so they eventualy
+ * may go to samd_common.h and .c
+ * As currently there are olny 3 short functions identical with
+ * the original source, no common file was created. */
+
+#define SAME5_PAGES_PER_BLOCK	16
+#define SAME5_NUM_PROT_BLOCKS	32
+#define SAMD_PAGE_SIZE_MAX	1024
+
+#define SAMD_FLASH		0x00000000	/* physical Flash memory */
+#define SAMD_USER_ROW		0x00804000	/* User Row of Flash */
+
+#define SAME5_PAC		0x40000000	/* Peripheral Access Control */
+
+#define SAMD_DSU		0x41002000	/* Device Service Unit */
+#define SAMD_NVMCTRL		0x41004000	/* Non-volatile memory controller */
+
+#define SAMD_DSU_STATUSA        1               /* DSU status register */
+#define SAMD_DSU_DID		0x18		/* Device ID register */
+#define SAMD_DSU_CTRL_EXT	0x100		/* CTRL register, external access */
+
+#define SAME5_NVMCTRL_CTRLA	0x00		/* NVM control A register */
+#define SAME5_NVMCTRL_CTRLB	0x04		/* NVM control B register */
+#define SAMD_NVMCTRL_PARAM	0x08		/* NVM parameters register */
+#define SAME5_NVMCTRL_INTFLAG	0x10		/* NVM interrupt flag register */
+#define SAME5_NVMCTRL_STATUS	0x12		/* NVM status register */
+#define SAME5_NVMCTRL_ADDR	0x14		/* NVM address register */
+#define SAME5_NVMCTRL_LOCK	0x18		/* NVM Lock section register */
+
+#define SAMD_CMDEX_KEY		0xA5UL
+#define SAMD_NVM_CMD(n)		((SAMD_CMDEX_KEY << 8) | (n & 0x7F))
+
+/* NVMCTRL commands. */
+#define SAME5_NVM_CMD_EP	0x00		/* Erase Page (User Page only) */
+#define SAME5_NVM_CMD_EB	0x01		/* Erase Block */
+#define SAME5_NVM_CMD_WP	0x03		/* Write Page */
+#define SAME5_NVM_CMD_WQW	0x04		/* Write Quad Word */
+#define SAME5_NVM_CMD_LR	0x11		/* Lock Region */
+#define SAME5_NVM_CMD_UR	0x12		/* Unlock Region */
+#define SAME5_NVM_CMD_PBC	0x15		/* Page Buffer Clear */
+#define SAME5_NVM_CMD_SSB	0x16		/* Set Security Bit */
+
+/* NVMCTRL bits */
+#define SAME5_NVMCTRL_CTRLA_WMODE_MASK	0x30
+
+#define SAME5_NVMCTRL_INTFLAG_DONE	(1 << 0)
+#define SAME5_NVMCTRL_INTFLAG_ADDRE	(1 << 1)
+#define SAME5_NVMCTRL_INTFLAG_PROGE	(1 << 2)
+#define SAME5_NVMCTRL_INTFLAG_LOCKE	(1 << 3)
+#define SAME5_NVMCTRL_INTFLAG_ECCSE	(1 << 4)
+#define SAME5_NVMCTRL_INTFLAG_ECCDE	(1 << 5)
+#define SAME5_NVMCTRL_INTFLAG_NVME	(1 << 6)
+
+
+/* Known identifiers */
+#define SAMD_PROCESSOR_M0	0x01
+#define SAMD_PROCESSOR_M4	0x06
+#define SAMD_FAMILY_D		0x00
+#define SAMD_FAMILY_E		0x03
+#define SAMD_SERIES_51		0x06
+#define SAME_SERIES_51		0x01
+#define SAME_SERIES_53		0x03
+#define SAME_SERIES_54		0x04
+
+/* Device ID macros */
+#define SAMD_GET_PROCESSOR(id) (id >> 28)
+#define SAMD_GET_FAMILY(id) (((id >> 23) & 0x1F))
+#define SAMD_GET_SERIES(id) (((id >> 16) & 0x3F))
+#define SAMD_GET_DEVSEL(id) (id & 0xFF)
+
+/* Bits to mask user row */
+#define NVMUSERROW_SAM_E5_D5_MASK	((uint64_t)0x7FFF00FF3C007FFF)
+
+struct samd_part {
+	uint8_t id;
+	const char *name;
+	uint32_t flash_kb;
+	uint32_t ram_kb;
+};
+
+/* See SAM D5x/E5x Family Silicon Errata and Data Sheet Clarification
+ * DS80000748B */
+/* Known SAMD51 parts. */
+static const struct samd_part samd51_parts[] = {
+	{ 0x00, "SAMD51P20A", 1024, 256 },
+	{ 0x01, "SAMD51P19A", 512, 192 },
+	{ 0x02, "SAMD51N20A", 1024, 256 },
+	{ 0x03, "SAMD51N19A", 512, 192 },
+	{ 0x04, "SAMD51J20A", 1024, 256 },
+	{ 0x05, "SAMD51J19A", 512, 192 },
+	{ 0x06, "SAMD51J18A", 256, 128 },
+	{ 0x07, "SAMD51G19A", 512, 192 },
+	{ 0x08, "SAMD51G18A", 256, 128 },
+};
+
+/* Known SAME51 parts. */
+static const struct samd_part same51_parts[] = {
+	{ 0x00, "SAME51N20A", 1024, 256 },
+	{ 0x01, "SAME51N19A", 512, 192 },
+	{ 0x02, "SAME51J19A", 512, 192 },
+	{ 0x03, "SAME51J18A", 256, 128 },
+	{ 0x04, "SAME51J20A", 1024, 256 },
+};
+
+/* Known SAME53 parts. */
+static const struct samd_part same53_parts[] = {
+	{ 0x02, "SAME53N20A", 1024, 256 },
+	{ 0x03, "SAME53N19A", 512, 192 },
+	{ 0x04, "SAME53J20A", 1024, 256 },
+	{ 0x05, "SAME53J19A", 512, 192 },
+	{ 0x06, "SAME53J18A", 256, 128 },
+};
+
+/* Known SAME54 parts. */
+static const struct samd_part same54_parts[] = {
+	{ 0x00, "SAME54P20A", 1024, 256 },
+	{ 0x01, "SAME54P19A", 512, 192 },
+	{ 0x02, "SAME54N20A", 1024, 256 },
+	{ 0x03, "SAME54N19A", 512, 192 },
+};
+
+/* Each family of parts contains a parts table in the DEVSEL field of DID.  The
+ * processor ID, family ID, and series ID are used to determine which exact
+ * family this is and then we can use the corresponding table. */
+struct samd_family {
+	uint8_t processor;
+	uint8_t family;
+	uint8_t series;
+	const struct samd_part *parts;
+	size_t num_parts;
+};
+
+/* Known SAMD families */
+static const struct samd_family samd_families[] = {
+	{ SAMD_PROCESSOR_M4, SAMD_FAMILY_D, SAMD_SERIES_51,
+		samd51_parts, ARRAY_SIZE(samd51_parts) },
+	{ SAMD_PROCESSOR_M4, SAMD_FAMILY_E, SAME_SERIES_51,
+		same51_parts, ARRAY_SIZE(same51_parts) },
+	{ SAMD_PROCESSOR_M4, SAMD_FAMILY_E, SAME_SERIES_53,
+		same53_parts, ARRAY_SIZE(same53_parts) },
+	{ SAMD_PROCESSOR_M4, SAMD_FAMILY_E, SAME_SERIES_54,
+		same54_parts, ARRAY_SIZE(same54_parts) },
+};
+
+struct samd_info {
+	const struct samd_params *par;
+	uint32_t page_size;
+	int num_pages;
+	int sector_size;
+	int prot_block_size;
+
+	bool probed;
+	struct target *target;
+};
+
+
+/**
+ * Gives the family structure to specific device id.
+ * @param id The id of the device.
+ * @return On failure NULL, otherwise a pointer to the structure.
+ */
+static const struct samd_family *samd_find_family(uint32_t id)
+{
+	uint8_t processor = SAMD_GET_PROCESSOR(id);
+	uint8_t family = SAMD_GET_FAMILY(id);
+	uint8_t series = SAMD_GET_SERIES(id);
+
+	for (unsigned i = 0; i < ARRAY_SIZE(samd_families); i++) {
+		if (samd_families[i].processor == processor &&
+			samd_families[i].series == series &&
+			samd_families[i].family == family)
+			return &samd_families[i];
+	}
+
+	return NULL;
+}
+
+/**
+ * Gives the part structure to specific device id.
+ * @param id The id of the device.
+ * @return On failure NULL, otherwise a pointer to the structure.
+ */
+static const struct samd_part *samd_find_part(uint32_t id)
+{
+	uint8_t devsel = SAMD_GET_DEVSEL(id);
+	const struct samd_family *family = samd_find_family(id);
+	if (family == NULL)
+		return NULL;
+
+	for (unsigned i = 0; i < family->num_parts; i++) {
+		if (family->parts[i].id == devsel)
+			return &family->parts[i];
+	}
+
+	return NULL;
+}
+
+static int same5_protect_check(struct flash_bank *bank)
+{
+	int res, prot_block;
+	uint32_t lock;
+
+	res = target_read_u32(bank->target,
+			SAMD_NVMCTRL + SAME5_NVMCTRL_LOCK, &lock);
+	if (res != ERROR_OK)
+		return res;
+
+	/* Lock bits are active-low */
+	for (prot_block = 0; prot_block < bank->num_prot_blocks; prot_block++)
+		bank->prot_blocks[prot_block].is_protected = !(lock & (1u<<prot_block));
+
+	return ERROR_OK;
+}
+
+static int samd_get_flash_page_info(struct target *target,
+		uint32_t *sizep, int *nump)
+{
+	int res;
+	uint32_t param;
+
+	res = target_read_u32(target, SAMD_NVMCTRL + SAMD_NVMCTRL_PARAM, &param);
+	if (res == ERROR_OK) {
+		/* The PSZ field (bits 18:16) indicate the page size bytes as 2^(3+n)
+		 * so 0 is 8KB and 7 is 1024KB. */
+		if (sizep)
+			*sizep = (8 << ((param >> 16) & 0x7));
+		/* The NVMP field (bits 15:0) indicates the total number of pages */
+		if (nump)
+			*nump = param & 0xFFFF;
+	} else {
+		LOG_ERROR("Couldn't read NVM Parameters register");
+	}
+
+	return res;
+}
+
+static int same5_probe(struct flash_bank *bank)
+{
+	uint32_t id;
+	int res;
+	struct samd_info *chip = (struct samd_info *)bank->driver_priv;
+	const struct samd_part *part;
+
+	if (chip->probed)
+		return ERROR_OK;
+
+	res = target_read_u32(bank->target, SAMD_DSU + SAMD_DSU_DID, &id);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't read Device ID register");
+		return res;
+	}
+
+	part = samd_find_part(id);
+	if (part == NULL) {
+		LOG_ERROR("Couldn't find part corresponding to DID %08" PRIx32, id);
+		return ERROR_FAIL;
+	}
+
+	bank->size = part->flash_kb * 1024;
+
+	res = samd_get_flash_page_info(bank->target, &chip->page_size,
+			&chip->num_pages);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't determine Flash page size");
+		return res;
+	}
+
+	/* Sanity check: the total flash size in the DSU should match the page size
+	 * multiplied by the number of pages. */
+	if (bank->size != chip->num_pages * chip->page_size) {
+		LOG_WARNING("SAM: bank size doesn't match NVM parameters. "
+				"Identified %" PRIu32 "KB Flash but NVMCTRL reports %u %" PRIu32 "B pages",
+				part->flash_kb, chip->num_pages, chip->page_size);
+	}
+
+	/* Erase granularity = 1 block = 16 pages */
+	chip->sector_size = chip->page_size * SAME5_PAGES_PER_BLOCK;
+
+	/* Allocate the sector table */
+	bank->num_sectors = chip->num_pages / SAME5_PAGES_PER_BLOCK;
+	bank->sectors = alloc_block_array(0, chip->sector_size, bank->num_sectors);
+	if (!bank->sectors)
+		return ERROR_FAIL;
+
+	/* 16 protection blocks per device */
+	chip->prot_block_size = bank->size / SAME5_NUM_PROT_BLOCKS;
+
+	/* Allocate the table of protection blocks */
+	bank->num_prot_blocks = SAME5_NUM_PROT_BLOCKS;
+	bank->prot_blocks = alloc_block_array(0, chip->prot_block_size, bank->num_prot_blocks);
+	if (!bank->prot_blocks)
+		return ERROR_FAIL;
+
+	same5_protect_check(bank);
+
+	/* Done */
+	chip->probed = true;
+
+	LOG_INFO("SAM MCU: %s (%" PRIu32 "KB Flash, %" PRIu32 "KB RAM)", part->name,
+			part->flash_kb, part->ram_kb);
+
+	return ERROR_OK;
+}
+
+static int same5_wait_and_check_error(struct target *target)
+{
+	int ret, ret2;
+	int rep_cnt = 100;
+	uint16_t intflag;
+
+	do {
+		ret = target_read_u16(target,
+			SAMD_NVMCTRL + SAME5_NVMCTRL_INTFLAG, &intflag);
+		if (ret == ERROR_OK && intflag & SAME5_NVMCTRL_INTFLAG_DONE)
+			break;
+	} while (--rep_cnt);
+
+	if (ret != ERROR_OK) {
+		LOG_ERROR("Can't read NVM INTFLAG");
+		return ret;
+	}
+#if 0
+	if (intflag & SAME5_NVMCTRL_INTFLAG_ECCSE)
+		LOG_ERROR("SAM: ECC Single Error");
+
+	if (intflag & SAME5_NVMCTRL_INTFLAG_ECCDE) {
+		LOG_ERROR("SAM: ECC Double Error");
+		ret = ERROR_FLASH_OPERATION_FAILED;
+	}
+#endif
+	if (intflag & SAME5_NVMCTRL_INTFLAG_ADDRE) {
+		LOG_ERROR("SAM: Addr Error");
+		ret = ERROR_FLASH_OPERATION_FAILED;
+	}
+
+	if (intflag & SAME5_NVMCTRL_INTFLAG_NVME) {
+		LOG_ERROR("SAM: NVM Error");
+		ret = ERROR_FLASH_OPERATION_FAILED;
+	}
+
+	if (intflag & SAME5_NVMCTRL_INTFLAG_LOCKE) {
+		LOG_ERROR("SAM: NVM lock error");
+		ret = ERROR_FLASH_PROTECTED;
+	}
+
+	if (intflag & SAME5_NVMCTRL_INTFLAG_PROGE) {
+		LOG_ERROR("SAM: NVM programming error");
+		ret = ERROR_FLASH_OPER_UNSUPPORTED;
+	}
+
+	/* Clear the error conditions by writing a one to them */
+	ret2 = target_write_u16(target,
+			SAMD_NVMCTRL + SAME5_NVMCTRL_INTFLAG, intflag);
+	if (ret2 != ERROR_OK)
+		LOG_ERROR("Can't clear NVM error conditions");
+
+	return ret;
+}
+
+static int same5_issue_nvmctrl_command(struct target *target, uint16_t cmd)
+{
+	int res;
+
+	if (target->state != TARGET_HALTED) {
+		LOG_ERROR("Target not halted");
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	/* Issue the NVM command */
+	/* 32-bit write is used to ensure atomic operation on ST-Link */
+	res = target_write_u32(target,
+			SAMD_NVMCTRL + SAME5_NVMCTRL_CTRLB, SAMD_NVM_CMD(cmd));
+	if (res != ERROR_OK)
+		return res;
+
+	/* Check to see if the NVM command resulted in an error condition. */
+	return same5_wait_and_check_error(target);
+}
+
+/**
+ * Erases a flash block or page at the given address.
+ * @param target Pointer to the target structure.
+ * @param address The address of the row.
+ * @return On success ERROR_OK, on failure an errorcode.
+ */
+static int same5_erase_block(struct target *target, uint32_t address)
+{
+	int res;
+
+	/* Set an address contained in the block to be erased */
+	res = target_write_u32(target,
+			SAMD_NVMCTRL + SAME5_NVMCTRL_ADDR, address);
+
+	/* Issue the Erase Block command. */
+	if (res == ERROR_OK)
+		res = same5_issue_nvmctrl_command(target,
+				address == SAMD_USER_ROW ? SAME5_NVM_CMD_EP : SAME5_NVM_CMD_EB);
+
+	if (res != ERROR_OK)  {
+		LOG_ERROR("Failed to erase block containing %08" PRIx32, address);
+		return ERROR_FAIL;
+	}
+
+	return ERROR_OK;
+}
+
+
+static int same5_pre_write_check(struct target *target)
+{
+	int res;
+	uint32_t nvm_ctrla;
+
+	if (target->state != TARGET_HALTED) {
+		LOG_ERROR("Target not halted");
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	/* Check if manual write mode is set */
+	res = target_read_u32(target, SAMD_NVMCTRL + SAME5_NVMCTRL_CTRLA, &nvm_ctrla);
+	if (res != ERROR_OK)
+		return res;
+
+	if (nvm_ctrla & SAME5_NVMCTRL_CTRLA_WMODE_MASK) {
+		LOG_ERROR("The flash controller must be in manual write mode. Issue 'reset init' and retry.");
+		return ERROR_FAIL;
+	}
+
+	return res;
+}
+
+
+/**
+ * Modify the contents of the User Row in Flash. The User Row itself
+ * has a size of one page and contains a combination of "fuses" and
+ * calibration data. Bits which have a value of zero in the mask will
+ * not be changed.
+ * @param target Pointer to the target structure.
+ * @param data Pointer to the value to write.
+ * @param mask Pointer to bitmask, 0 -> value stays untouched.
+ * @param offset Offset in user row where new data will be applied.
+ * @param count Size of buffer and mask in bytes.
+ * @return On success ERROR_OK, on failure an errorcode.
+ */
+static int same5_modify_user_row_masked(struct target *target,
+		const uint8_t *data, const uint8_t *mask,
+		uint32_t offset, uint32_t count)
+{
+	int res;
+
+	/* Retrieve the MCU's flash page size, in bytes. */
+	uint32_t page_size;
+	res = samd_get_flash_page_info(target, &page_size, NULL);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't determine Flash page size");
+		return res;
+	}
+
+	/* Make sure the size is sane. */
+	assert(page_size <= SAMD_PAGE_SIZE_MAX &&
+		page_size >= offset + count);
+
+	uint8_t buf[SAMD_PAGE_SIZE_MAX];
+	/* Read the user row (comprising one page) by words. */
+	res = target_read_memory(target, SAMD_USER_ROW, 4, page_size / 4, buf);
+	if (res != ERROR_OK)
+		return res;
+
+	/* Modify buffer and check if really changed */
+	bool changed = false;
+	uint32_t i;
+	for (i = 0; i < count; i++) {
+		uint8_t old_b = buf[offset+i];
+		uint8_t new_b = (old_b & ~mask[i]) | (data[i] & mask[i]);
+		buf[offset+i] = new_b;
+		if (old_b != new_b)
+			changed = true;
+	}
+
+	if (!changed)
+		return ERROR_OK;
+
+	res = same5_pre_write_check(target);
+	if (res != ERROR_OK)
+		return res;
+
+	res = same5_erase_block(target, SAMD_USER_ROW);
+	if (res != ERROR_OK) {
+		LOG_ERROR("Couldn't erase user row");
+		return res;
+	}
+
+	/* Write the page buffer back out to the target using Write Quad Word */
+	for (i = 0; i < page_size; i += 4 * 4) {
+		res = target_write_memory(target, SAMD_USER_ROW + i, 4, 4, buf + i);
+		if (res != ERROR_OK)
+			return res;
+
+		/* Trigger flash write */
+		res = same5_issue_nvmctrl_command(target, SAME5_NVM_CMD_WQW);
+		if (res != ERROR_OK)
+			return res;
+	}
+
+	return res;
+}
+
+/**
+ * Modifies the user row register to the given value.
+ * @param target Pointer to the target structure.
+ * @param value The value to write.
+ * @param startb The bit-offset by which the given value is shifted.
+ * @param endb The bit-offset of the last bit in value to write.
+ * @return On success ERROR_OK, on failure an errorcode.
+ */
+static int same5_modify_user_row(struct target *target, uint32_t value,
+		uint8_t startb, uint8_t endb)
+{
+	uint8_t buf_val[8] = { 0 };
+	uint8_t buf_mask[8] = { 0 };
+
+	assert(startb <= endb && endb < 64);
+	buf_set_u32(buf_val, startb, endb + 1 - startb, value);
+	buf_set_u32(buf_mask, startb, endb + 1 - startb, 0xffffffff);
+
+	return same5_modify_user_row_masked(target,
+			buf_val, buf_mask, 0, 8);
+}
+
+static int same5_protect(struct flash_bank *bank, int set, int first_prot_bl, int last_prot_bl)
+{
+	int res = ERROR_OK;
+	int prot_block;
+
+	/* We can issue lock/unlock region commands with the target running but
+	 * the settings won't persist unless we're able to modify the LOCK regions
+	 * and that requires the target to be halted. */
+	if (bank->target->state != TARGET_HALTED) {
+		LOG_ERROR("Target not halted");
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	for (prot_block = first_prot_bl; prot_block <= last_prot_bl; prot_block++) {
+		if (set != bank->prot_blocks[prot_block].is_protected) {
+			/* Load an address that is within this protection block (we use offset 0) */
+			res = target_write_u32(bank->target,
+					SAMD_NVMCTRL + SAME5_NVMCTRL_ADDR,
+					bank->prot_blocks[prot_block].offset);
+			if (res != ERROR_OK)
+				goto exit;
+
+			/* Tell the controller to lock that block */
+			res = same5_issue_nvmctrl_command(bank->target,
+					set ? SAME5_NVM_CMD_LR : SAME5_NVM_CMD_UR);
+			if (res != ERROR_OK)
+				goto exit;
+		}
+	}
+
+	/* We've now applied our changes, however they will be undone by the next
+	 * reset unless we also apply them to the LOCK bits in the User Page.
+	 * A '1' means unlocked and a '0' means locked. */
+	const uint8_t lock[4] = { 0, 0, 0, 0 };
+	const uint8_t unlock[4] = { 0xff, 0xff, 0xff, 0xff };
+	uint8_t mask[4] = { 0, 0, 0, 0 };
+
+	buf_set_u32(mask, first_prot_bl, last_prot_bl + 1 - first_prot_bl, 0xffffffff);
+
+	res = same5_modify_user_row_masked(bank->target,
+			set ? lock : unlock, mask, 8, 4);
+	if (res != ERROR_OK)
+		LOG_WARNING("SAM: protect settings were not made persistent!");
+
+	res = ERROR_OK;
+
+exit:
+	same5_protect_check(bank);
+
+	return res;
+}
+
+static int same5_erase(struct flash_bank *bank, int first_sect, int last_sect)
+{
+	int res, s;
+	struct samd_info *chip = (struct samd_info *)bank->driver_priv;
+
+	if (bank->target->state != TARGET_HALTED) {
+		LOG_ERROR("Target not halted");
+
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	if (!chip->probed)
+		return ERROR_FLASH_BANK_NOT_PROBED;
+
+	/* For each sector to be erased */
+	for (s = first_sect; s <= last_sect; s++) {
+		res = same5_erase_block(bank->target, bank->sectors[s].offset);
+		if (res != ERROR_OK) {
+			LOG_ERROR("SAM: failed to erase sector %d at 0x%08" PRIx32, s, bank->sectors[s].offset);
+			return res;
+		}
+	}
+
+	return ERROR_OK;
+}
+
+
+static int same5_write(struct flash_bank *bank, const uint8_t *buffer,
+		uint32_t offset, uint32_t count)
+{
+	int res;
+	uint32_t address;
+	uint32_t pg_offset;
+	uint32_t nb;
+	uint32_t nw;
+	struct samd_info *chip = (struct samd_info *)bank->driver_priv;
+	uint8_t *pb = NULL;
+
+	res = same5_pre_write_check(bank->target);
+	if (res != ERROR_OK)
+		return res;
+
+	if (!chip->probed)
+		return ERROR_FLASH_BANK_NOT_PROBED;
+
+	res = same5_issue_nvmctrl_command(bank->target, SAME5_NVM_CMD_PBC);
+	if (res != ERROR_OK) {
+		LOG_ERROR("%s: %d", __func__, __LINE__);
+		return res;
+	}
+
+	while (count) {
+		nb = chip->page_size - offset % chip->page_size;
+		if (count < nb)
+			nb = count;
+
+		address = bank->base + offset;
+		pg_offset = offset % chip->page_size;
+
+		if (offset % 4 || (offset + nb) % 4) {
+			/* Either start or end of write is not word aligned */
+			if (!pb) {
+				pb = malloc(chip->page_size);
+				if (!pb)
+					return ERROR_FAIL;
+			}
+
+			/* Set temporary page buffer to 0xff and overwrite the relevant part */
+			memset(pb, 0xff, chip->page_size);
+			memcpy(pb + pg_offset, buffer, nb);
+
+			/* Align start address to a word boundary */
+			address -= offset % 4;
+			pg_offset -= offset % 4;
+			assert(pg_offset % 4 == 0);
+
+			/* Extend length to whole words */
+			nw = (nb + offset % 4 + 3) / 4;
+			assert(pg_offset + 4 * nw <= chip->page_size);
+
+			/* Now we have original data extended by 0xff bytes
+			 * to the nearest word boundary on both start and end */
+			res = target_write_memory(bank->target, address, 4, nw, pb + pg_offset);
+		} else {
+			assert(nb % 4 == 0);
+			nw = nb / 4;
+			assert(pg_offset + 4 * nw <= chip->page_size);
+
+			/* Word aligned data, use direct write from buffer */
+			res = target_write_memory(bank->target, address, 4, nw, buffer);
+		}
+		if (res != ERROR_OK) {
+			LOG_ERROR("%s: %d", __func__, __LINE__);
+			goto free_pb;
+		}
+
+		res = same5_issue_nvmctrl_command(bank->target, SAME5_NVM_CMD_WP);
+		if (res != ERROR_OK) {
+			LOG_ERROR("%s: write failed at address 0x%08" PRIx32, __func__, address);
+			goto free_pb;
+		}
+
+		/* We're done with the page contents */
+		count -= nb;
+		offset += nb;
+		buffer += nb;
+	}
+
+free_pb:
+	if (pb)
+		free(pb);
+
+	return res;
+}
+
+
+FLASH_BANK_COMMAND_HANDLER(same5_flash_bank_command)
+{
+	if (bank->base != SAMD_FLASH) {
+		LOG_ERROR("Address 0x%08" PRIx32 " invalid bank address (try 0x%08" PRIx32
+				"[same5] )",
+				bank->base, SAMD_FLASH);
+		return ERROR_FAIL;
+	}
+
+	struct samd_info *chip;
+	chip = calloc(1, sizeof(*chip));
+	if (!chip) {
+		LOG_ERROR("No memory for flash bank chip info");
+		return ERROR_FAIL;
+	}
+
+	chip->target = bank->target;
+	chip->probed = false;
+
+	bank->driver_priv = chip;
+
+	return ERROR_OK;
+}
+
+
+COMMAND_HANDLER(same5_handle_chip_erase_command)
+{
+	struct target *target = get_current_target(CMD_CTX);
+	if (!target)
+		return ERROR_FAIL;
+
+	/* Enable access to the DSU by disabling the write protect bit */
+	target_write_u32(target, SAME5_PAC, (1<<16) | (1<<5) | (1<<1));
+	/* intentionally without error checking - not accessible on secured chip */
+
+	/* Tell the DSU to perform a full chip erase.  It takes about 240ms to
+	 * perform the erase. */
+	int res = target_write_u8(target, SAMD_DSU + SAMD_DSU_CTRL_EXT, (1<<4));
+	if (res == ERROR_OK)
+		command_print(CMD_CTX, "chip erase started");
+	else
+		command_print(CMD_CTX, "write to DSU CTRL failed");
+
+	return res;
+}
+
+
+COMMAND_HANDLER(same5_handle_userpage_command)
+{
+	int res = ERROR_OK;
+	struct target *target = get_current_target(CMD_CTX);
+	if (!target)
+		return ERROR_FAIL;
+
+	if (CMD_ARGC > 2) {
+		command_print(CMD_CTX, "Too much Arguments given.");
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	}
+
+	if (CMD_ARGC >= 1) {
+		uint64_t mask = NVMUSERROW_SAM_E5_D5_MASK;
+		uint64_t value = strtoull(CMD_ARGV[0], NULL, 0);
+
+		if (CMD_ARGC == 2) {
+			uint64_t mask_temp = strtoull(CMD_ARGV[1], NULL, 0);
+			mask &= mask_temp;
+		}
+
+		uint8_t val_buf[8], mask_buf[8];
+		target_buffer_set_u64(target, val_buf, value);
+		target_buffer_set_u64(target, mask_buf, mask);
+
+		res = same5_modify_user_row_masked(target,
+				val_buf, mask_buf, 0, sizeof(val_buf));
+	}
+
+	uint8_t buffer[8];
+	int res2 = target_read_memory(target, SAMD_USER_ROW, 4, 2, buffer);
+	if (res2 == ERROR_OK) {
+		uint64_t value = target_buffer_get_u64(target, buffer);
+		command_print(CMD_CTX, "USER PAGE: 0x%016"PRIX64, value);
+	} else {
+		LOG_ERROR("USER PAGE could not be read.");
+	}
+
+	if (CMD_ARGC >= 1)
+		return res;
+	else
+		return res2;
+}
+
+
+COMMAND_HANDLER(same5_handle_bootloader_command)
+{
+	int res = ERROR_OK;
+	struct target *target = get_current_target(CMD_CTX);
+	if (!target)
+		return ERROR_FAIL;
+
+	if (CMD_ARGC >= 1) {
+		unsigned long size = strtoul(CMD_ARGV[0], NULL, 0);
+		uint32_t code = (size + 8191) / 8192;
+		if (code > 15) {
+			command_print(CMD_CTX, "Invalid bootloader size.  Please "
+						"see datasheet for a list valid sizes.");
+			return ERROR_COMMAND_SYNTAX_ERROR;
+		}
+
+		res = same5_modify_user_row(target, 15 - code, 26, 29);
+	}
+
+	uint32_t val;
+	int res2 = target_read_u32(target, SAMD_USER_ROW, &val);
+	if (res2 == ERROR_OK) {
+		uint32_t code = (val >> 26) & 0xf; /* grab size code */
+		uint32_t size = (15 - code) * 8192;
+		command_print(CMD_CTX, "Bootloader protected in the first %"
+				      PRIu32 " bytes", size);
+	}
+
+	if (CMD_ARGC >= 1)
+		return res;
+	else
+		return res2;
+}
+
+
+COMMAND_HANDLER(samd_handle_reset_deassert)
+{
+	struct target *target = get_current_target(CMD_CTX);
+	int res = ERROR_OK;
+	enum reset_types jtag_reset_config = jtag_get_reset_config();
+	if (!target)
+		return ERROR_FAIL;
+
+	/* If the target has been unresponsive before, try to re-establish
+	 * communication now - CPU is held in reset by DSU, DAP is working */
+	if (!target_was_examined(target))
+		target_examine_one(target);
+	target_poll(target);
+
+	/* In case of sysresetreq, debug retains state set in cortex_m_assert_reset()
+	 * so we just release reset held by DSU
+	 *
+	 * n_RESET (srst) clears the DP, so reenable debug and set vector catch here
+	 *
+	 * After vectreset DSU release is not needed however makes no harm
+	 */
+	if (target->reset_halt && (jtag_reset_config & RESET_HAS_SRST)) {
+		res = target_write_u32(target, DCB_DHCSR, DBGKEY | C_HALT | C_DEBUGEN);
+		if (res == ERROR_OK)
+			res = target_write_u32(target, DCB_DEMCR,
+				TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
+		/* do not return on error here, releasing DSU reset is more important */
+	}
+
+	/* clear CPU Reset Phase Extension bit */
+	int res2 = target_write_u8(target, SAMD_DSU + SAMD_DSU_STATUSA, (1<<1));
+	if (res2 != ERROR_OK)
+		return res2;
+
+	return res;
+}
+
+static const struct command_registration same5_exec_command_handlers[] = {
+	{
+		.name = "dsu_reset_deassert",
+		.handler = samd_handle_reset_deassert,
+		.mode = COMMAND_EXEC,
+		.help = "Deasert internal reset held by DSU."
+	},
+	{
+		.name = "chip-erase",
+		.handler = same5_handle_chip_erase_command,
+		.mode = COMMAND_EXEC,
+		.help = "Erase the entire Flash by using the Chip-"
+			"Erase feature in the Device Service Unit (DSU).",
+	},
+	{
+		.name = "bootloader",
+		.usage = "[size_in_bytes]",
+		.handler = same5_handle_bootloader_command,
+		.mode = COMMAND_EXEC,
+		.help = "Show or set the bootloader protection size, stored in the User Row. "
+			"Changes are stored immediately but take affect after the MCU is "
+			"reset.",
+	},
+	{
+		.name = "userpage",
+		.usage = "[value] [mask]",
+		.handler = same5_handle_userpage_command,
+		.mode = COMMAND_EXEC,
+		.help = "Show or set the first 64-bit part of user page "
+			"located at address 0x804000. Use the optional mask argument "
+			"to prevent changes at positions where the bitvalue is zero. "
+			"For security reasons the reserved-bits are masked out "
+			"in background and therefore cannot be changed.",
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration same5_command_handlers[] = {
+	{
+		.name = "atsame5",
+		.mode = COMMAND_ANY,
+		.help = "atsame5 flash command group",
+		.usage = "",
+		.chain = same5_exec_command_handlers,
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+struct flash_driver atsame5_flash = {
+	.name = "atsame5",
+	.commands = same5_command_handlers,
+	.flash_bank_command = same5_flash_bank_command,
+	.erase = same5_erase,
+	.protect = same5_protect,
+	.write = same5_write,
+	.read = default_flash_read,
+	.probe = same5_probe,
+	.auto_probe = same5_probe,
+	.erase_check = default_flash_blank_check,
+	.protect_check = same5_protect_check,
+	.free_driver_priv = default_flash_free_driver_priv,
+};
diff --git a/src/flash/nor/drivers.c b/src/flash/nor/drivers.c
index d1bbb27..31caa5a 100644
--- a/src/flash/nor/drivers.c
+++ b/src/flash/nor/drivers.c
@@ -29,6 +29,7 @@ extern struct flash_driver at91sam4l_flash;
 extern struct flash_driver at91sam7_flash;
 extern struct flash_driver at91samd_flash;
 extern struct flash_driver ath79_flash;
+extern struct flash_driver atsame5_flash;
 extern struct flash_driver atsamv_flash;
 extern struct flash_driver avr_flash;
 extern struct flash_driver bluenrgx_flash;
@@ -97,6 +98,7 @@ static struct flash_driver *flash_drivers[] = {
 	&at91sam7_flash,
 	&at91samd_flash,
 	&ath79_flash,
+	&atsame5_flash,
 	&atsamv_flash,
 	&avr_flash,
 	&bluenrgx_flash,
diff --git a/tcl/board/microchip_same54_xplained_pro.cfg b/tcl/board/microchip_same54_xplained_pro.cfg
new file mode 100644
index 0000000..db8a856
--- /dev/null
+++ b/tcl/board/microchip_same54_xplained_pro.cfg
@@ -0,0 +1,13 @@
+#
+# Microchip (former Atmel) SAM E54 Xplained Pro evaluation kit.
+# http://www.microchip.com/developmenttools/productdetails.aspx?partno=atsame54-xpro
+#
+
+source [find interface/cmsis-dap.cfg]
+
+set CHIPNAME same54
+
+source [find target/atsame5x.cfg]
+
+reset_config srst_only
+
diff --git a/tcl/target/atsame5x.cfg b/tcl/target/atsame5x.cfg
new file mode 100644
index 0000000..61949cf
--- /dev/null
+++ b/tcl/target/atsame5x.cfg
@@ -0,0 +1,75 @@
+#
+# Microchip (former Atmel) SAM E54, E53, E51 and D51 devices
+# with a Cortex-M4 core
+#
+
+#
+# Devices only support SWD transports.
+#
+source [find target/swj-dp.tcl]
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME atsame5
+}
+
+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 32kB (the smallest RAM size is 128kB)
+if { [info exists WORKAREASIZE] } {
+   set _WORKAREASIZE $WORKAREASIZE
+} else {
+   set _WORKAREASIZE 0x8000
+}
+
+if { [info exists CPUTAPID] } {
+   set _CPUTAPID $CPUTAPID
+} else {
+   set _CPUTAPID 0x4ba00477
+}
+
+swj_newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
+dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME cortex_m -endian $_ENDIAN -dap $_CHIPNAME.dap
+
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
+
+# SAM DSU will hold the CPU in reset if TCK is low when RESET_N
+# deasserts
+#
+# dsu_reset_deassert configures whether we want to run or halt out of reset,
+# then instruct the DSU to let us out of reset.
+$_TARGETNAME configure -event reset-deassert-post {
+        atsame5 dsu_reset_deassert
+}
+
+# SRST (wired to RESET_N) resets debug circuitry
+# srst_pulls_trst is not configured here to avoid an error raised in reset halt
+reset_config srst_gates_jtag
+
+# Do not use a reset button with other SWD adapter than Atmel's EDBG.
+# DSU usually locks MCU in reset state until you issue a reset command
+# in OpenOCD.
+
+# SAM E5x/D51 runs at SYSCLK = 48 MHz from RC oscillator after reset.
+# Atmel's EDBG (on-board cmsis-dap adapter of Xplained kits) works
+# without problem at clock speed over 5000 khz. Atmel recommends
+# adapter speed less than 10 * CPU clock.
+adapter_khz 2000
+
+if {![using_hla]} {
+   # if srst is not fitted use SYSRESETREQ to
+   # perform a soft reset
+   cortex_m reset_config sysresetreq
+}
+
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME atsame5 0x00000000 0 1 1 $_TARGETNAME