/*
   * Command for accessing SPI flash.
   *
   * Copyright (C) 2008 Atmel Corporation

   *
   * SPDX-License-Identifier:	GPL-2.0+

   */

  #include <common.h>

  #include <div64.h>

  #include <malloc.h>

  #include <spi_flash.h>
  
  #include <asm/io.h>

  static struct spi_flash *flash;

  
  /*
   * This function computes the length argument for the erase command.
   * The length on which the command is to operate can be given in two forms:
   * 1. <cmd> offset len  - operate on <'offset',  'len')
   * 2. <cmd> offset +len - operate on <'offset',  'round_up(len)')
   * If the second form is used and the length doesn't fall on the
   * sector boundary, than it will be adjusted to the next sector boundary.
   * If it isn't in the flash, the function will fail (return -1).
   * Input:
   *    arg: length specification (i.e. both command arguments)
   * Output:
   *    len: computed length for operation
   * Return:
   *    1: success
   *   -1: failure (bad format, bad address).
   */
  static int sf_parse_len_arg(char *arg, ulong *len)
  {
  	char *ep;
  	char round_up_len; /* indicates if the "+length" form used */
  	ulong len_arg;
  
  	round_up_len = 0;
  	if (*arg == '+') {
  		round_up_len = 1;
  		++arg;
  	}
  
  	len_arg = simple_strtoul(arg, &ep, 16);
  	if (ep == arg || *ep != '\0')
  		return -1;
  
  	if (round_up_len && flash->sector_size > 0)

  		*len = ROUND(len_arg, flash->sector_size);

  	else
  		*len = len_arg;
  
  	return 1;
  }

  /**
   * This function takes a byte length and a delta unit of time to compute the
   * approximate bytes per second
   *
   * @param len		amount of bytes currently processed
   * @param start_ms	start time of processing in ms
   * @return bytes per second if OK, 0 on error
   */
  static ulong bytes_per_second(unsigned int len, ulong start_ms)
  {
  	/* less accurate but avoids overflow */
  	if (len >= ((unsigned int) -1) / 1024)
  		return len / (max(get_timer(start_ms) / 1024, 1));
  	else
  		return 1024 * len / max(get_timer(start_ms), 1);
  }

  static int do_spi_flash_probe(int argc, char * const argv[])

  {

  	unsigned int bus = CONFIG_SF_DEFAULT_BUS;
  	unsigned int cs = CONFIG_SF_DEFAULT_CS;

  	unsigned int speed = CONFIG_SF_DEFAULT_SPEED;
  	unsigned int mode = CONFIG_SF_DEFAULT_MODE;
  	char *endp;
  	struct spi_flash *new;

  	if (argc >= 2) {
  		cs = simple_strtoul(argv[1], &endp, 0);
  		if (*argv[1] == 0 || (*endp != 0 && *endp != ':'))

  			return -1;

  		if (*endp == ':') {
  			if (endp[1] == 0)
  				return -1;
  
  			bus = cs;
  			cs = simple_strtoul(endp + 1, &endp, 0);
  			if (*endp != 0)
  				return -1;
  		}

  	}
  
  	if (argc >= 3) {
  		speed = simple_strtoul(argv[2], &endp, 0);
  		if (*argv[2] == 0 || *endp != 0)

  			return -1;

  	}
  	if (argc >= 4) {

  		mode = simple_strtoul(argv[3], &endp, 16);

  		if (*argv[3] == 0 || *endp != 0)

  			return -1;

  	}
  
  	new = spi_flash_probe(bus, cs, speed, mode);
  	if (!new) {
  		printf("Failed to initialize SPI flash at %u:%u
  ", bus, cs);
  		return 1;
  	}
  
  	if (flash)
  		spi_flash_free(flash);
  	flash = new;

  	return 0;

  }

  /**
   * Write a block of data to SPI flash, first checking if it is different from
   * what is already there.
   *
   * If the data being written is the same, then *skipped is incremented by len.
   *
   * @param flash		flash context pointer
   * @param offset	flash offset to write
   * @param len		number of bytes to write
   * @param buf		buffer to write from
   * @param cmp_buf	read buffer to use to compare data
   * @param skipped	Count of skipped data (incremented by this function)
   * @return NULL if OK, else a string containing the stage which failed
   */
  static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset,
  		size_t len, const char *buf, char *cmp_buf, size_t *skipped)
  {

  	debug("offset=%#x, sector_size=%#x, len=%#zx
  ",

  	      offset, flash->sector_size, len);

  	/* Read the entire sector so to allow for rewriting */
  	if (spi_flash_read(flash, offset, flash->sector_size, cmp_buf))

  		return "read";

  	/* Compare only what is meaningful (len) */

  	if (memcmp(cmp_buf, buf, len) == 0) {

  		debug("Skip region %x size %zx: no change
  ",

  		      offset, len);

  		*skipped += len;
  		return NULL;
  	}

  	/* Erase the entire sector */
  	if (spi_flash_erase(flash, offset, flash->sector_size))

  		return "erase";

  	/* Write the initial part of the block from the source */

  	if (spi_flash_write(flash, offset, len, buf))
  		return "write";

  	/* If it's a partial sector, rewrite the existing part */
  	if (len != flash->sector_size) {
  		/* Rewrite the original data to the end of the sector */
  		if (spi_flash_write(flash, offset + len,
  				    flash->sector_size - len, &cmp_buf[len]))
  			return "write";
  	}

  	return NULL;
  }
  
  /**
   * Update an area of SPI flash by erasing and writing any blocks which need
   * to change. Existing blocks with the correct data are left unchanged.
   *
   * @param flash		flash context pointer
   * @param offset	flash offset to write
   * @param len		number of bytes to write
   * @param buf		buffer to write from
   * @return 0 if ok, 1 on error
   */
  static int spi_flash_update(struct spi_flash *flash, u32 offset,
  		size_t len, const char *buf)
  {
  	const char *err_oper = NULL;
  	char *cmp_buf;
  	const char *end = buf + len;
  	size_t todo;		/* number of bytes to do in this pass */

  	size_t skipped = 0;	/* statistics */

  	const ulong start_time = get_timer(0);
  	size_t scale = 1;
  	const char *start_buf = buf;
  	ulong delta;

  	if (end - buf >= 200)
  		scale = (end - buf) / 100;

  	cmp_buf = malloc(flash->sector_size);
  	if (cmp_buf) {

  		ulong last_update = get_timer(0);

  		for (; buf < end && !err_oper; buf += todo, offset += todo) {

  			todo = min(end - buf, flash->sector_size);

  			if (get_timer(last_update) > 100) {
  				printf("   \rUpdating, %zu%% %lu B/s",

  				       100 - (end - buf) / scale,

  					bytes_per_second(buf - start_buf,
  							 start_time));
  				last_update = get_timer(0);
  			}

  			err_oper = spi_flash_update_block(flash, offset, todo,
  					buf, cmp_buf, &skipped);
  		}
  	} else {
  		err_oper = "malloc";
  	}
  	free(cmp_buf);

  	putc('\r');

  	if (err_oper) {
  		printf("SPI flash failed in %s step
  ", err_oper);
  		return 1;
  	}

  
  	delta = get_timer(start_time);
  	printf("%zu bytes written, %zu bytes skipped", len - skipped,

  	       skipped);

  	printf(" in %ld.%lds, speed %ld B/s
  ",

  	       delta / 1000, delta % 1000, bytes_per_second(len, start_time));

  	return 0;
  }

  static int do_spi_flash_read_write(int argc, char * const argv[])

  {
  	unsigned long addr;
  	unsigned long offset;
  	unsigned long len;
  	void *buf;
  	char *endp;

  	int ret = 1;

  
  	if (argc < 4)

  		return -1;

  
  	addr = simple_strtoul(argv[1], &endp, 16);
  	if (*argv[1] == 0 || *endp != 0)

  		return -1;

  	offset = simple_strtoul(argv[2], &endp, 16);
  	if (*argv[2] == 0 || *endp != 0)

  		return -1;

  	len = simple_strtoul(argv[3], &endp, 16);
  	if (*argv[3] == 0 || *endp != 0)

  		return -1;

  	/* Consistency checking */
  	if (offset + len > flash->size) {
  		printf("ERROR: attempting %s past flash size (%#x)
  ",

  		       argv[0], flash->size);

  		return 1;
  	}

  	buf = map_physmem(addr, len, MAP_WRBACK);
  	if (!buf) {
  		puts("Failed to map physical memory
  ");
  		return 1;
  	}

  	if (strcmp(argv[0], "update") == 0) {

  		ret = spi_flash_update(flash, offset, len, buf);

  	} else if (strncmp(argv[0], "read", 4) == 0 ||

  			strncmp(argv[0], "write", 5) == 0) {
  		int read;
  
  		read = strncmp(argv[0], "read", 4) == 0;
  		if (read)
  			ret = spi_flash_read(flash, offset, len, buf);
  		else
  			ret = spi_flash_write(flash, offset, len, buf);
  
  		printf("SF: %zu bytes @ %#x %s: %s
  ", (size_t)len, (u32)offset,

  		       read ? "Read" : "Written", ret ? "ERROR" : "OK");

  	}

  
  	unmap_physmem(buf, len);

  	return ret == 0 ? 0 : 1;

  }

  static int do_spi_flash_erase(int argc, char * const argv[])

  {
  	unsigned long offset;
  	unsigned long len;
  	char *endp;
  	int ret;
  
  	if (argc < 3)

  		return -1;

  
  	offset = simple_strtoul(argv[1], &endp, 16);
  	if (*argv[1] == 0 || *endp != 0)

  		return -1;

  
  	ret = sf_parse_len_arg(argv[2], &len);
  	if (ret != 1)

  		return -1;

  	/* Consistency checking */
  	if (offset + len > flash->size) {
  		printf("ERROR: attempting %s past flash size (%#x)
  ",

  		       argv[0], flash->size);

  		return 1;
  	}

  	ret = spi_flash_erase(flash, offset, len);

  	printf("SF: %zu bytes @ %#x Erased: %s
  ", (size_t)len, (u32)offset,

  	       ret ? "ERROR" : "OK");

  	return ret == 0 ? 0 : 1;

  }

  #ifdef CONFIG_CMD_SF_TEST
  enum {
  	STAGE_ERASE,
  	STAGE_CHECK,
  	STAGE_WRITE,
  	STAGE_READ,
  
  	STAGE_COUNT,
  };
  
  static char *stage_name[STAGE_COUNT] = {
  	"erase",
  	"check",
  	"write",
  	"read",
  };
  
  struct test_info {
  	int stage;
  	int bytes;
  	unsigned base_ms;
  	unsigned time_ms[STAGE_COUNT];
  };
  
  static void show_time(struct test_info *test, int stage)
  {
  	uint64_t speed;	/* KiB/s */
  	int bps;	/* Bits per second */
  
  	speed = (long long)test->bytes * 1000;

  	if (test->time_ms[stage])
  		do_div(speed, test->time_ms[stage] * 1024);

  	bps = speed * 8;
  
  	printf("%d %s: %d ticks, %d KiB/s %d.%03d Mbps
  ", stage,
  	       stage_name[stage], test->time_ms[stage],
  	       (int)speed, bps / 1000, bps % 1000);
  }
  
  static void spi_test_next_stage(struct test_info *test)
  {
  	test->time_ms[test->stage] = get_timer(test->base_ms);
  	show_time(test, test->stage);
  	test->base_ms = get_timer(0);
  	test->stage++;
  }
  
  /**
   * Run a test on the SPI flash
   *
   * @param flash		SPI flash to use
   * @param buf		Source buffer for data to write
   * @param len		Size of data to read/write
   * @param offset	Offset within flash to check
   * @param vbuf		Verification buffer
   * @return 0 if ok, -1 on error
   */

  static int spi_flash_test(struct spi_flash *flash, uint8_t *buf, ulong len,
  			   ulong offset, uint8_t *vbuf)

  {
  	struct test_info test;
  	int i;
  
  	printf("SPI flash test:
  ");
  	memset(&test, '\0', sizeof(test));
  	test.base_ms = get_timer(0);
  	test.bytes = len;
  	if (spi_flash_erase(flash, offset, len)) {
  		printf("Erase failed
  ");
  		return -1;
  	}
  	spi_test_next_stage(&test);
  
  	if (spi_flash_read(flash, offset, len, vbuf)) {
  		printf("Check read failed
  ");
  		return -1;
  	}
  	for (i = 0; i < len; i++) {
  		if (vbuf[i] != 0xff) {
  			printf("Check failed at %d
  ", i);
  			print_buffer(i, vbuf + i, 1, min(len - i, 0x40), 0);
  			return -1;
  		}
  	}
  	spi_test_next_stage(&test);
  
  	if (spi_flash_write(flash, offset, len, buf)) {
  		printf("Write failed
  ");
  		return -1;
  	}
  	memset(vbuf, '\0', len);
  	spi_test_next_stage(&test);
  
  	if (spi_flash_read(flash, offset, len, vbuf)) {
  		printf("Read failed
  ");
  		return -1;
  	}
  	spi_test_next_stage(&test);
  
  	for (i = 0; i < len; i++) {
  		if (buf[i] != vbuf[i]) {
  			printf("Verify failed at %d, good data:
  ", i);
  			print_buffer(i, buf + i, 1, min(len - i, 0x40), 0);
  			printf("Bad data:
  ");
  			print_buffer(i, vbuf + i, 1, min(len - i, 0x40), 0);
  			return -1;
  		}
  	}
  	printf("Test passed
  ");
  	for (i = 0; i < STAGE_COUNT; i++)
  		show_time(&test, i);
  
  	return 0;
  }
  
  static int do_spi_flash_test(int argc, char * const argv[])
  {
  	unsigned long offset;
  	unsigned long len;

  	uint8_t *buf, *from;

  	char *endp;

  	uint8_t *vbuf;

  	int ret;

  	if (argc < 3)
  		return -1;

  	offset = simple_strtoul(argv[1], &endp, 16);
  	if (*argv[1] == 0 || *endp != 0)
  		return -1;
  	len = simple_strtoul(argv[2], &endp, 16);
  	if (*argv[2] == 0 || *endp != 0)
  		return -1;
  
  	vbuf = malloc(len);
  	if (!vbuf) {

  		printf("Cannot allocate memory (%lu bytes)
  ", len);

  		return 1;
  	}
  	buf = malloc(len);
  	if (!buf) {
  		free(vbuf);

  		printf("Cannot allocate memory (%lu bytes)
  ", len);

  		return 1;
  	}

  	from = map_sysmem(CONFIG_SYS_TEXT_BASE, 0);
  	memcpy(buf, from, len);

  	ret = spi_flash_test(flash, buf, len, offset, vbuf);
  	free(vbuf);
  	free(buf);
  	if (ret) {
  		printf("Test failed
  ");
  		return 1;
  	}
  
  	return 0;
  }
  #endif /* CONFIG_CMD_SF_TEST */

  static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc,
  			char * const argv[])

  {
  	const char *cmd;

  	int ret;

  
  	/* need at least two arguments */
  	if (argc < 2)
  		goto usage;
  
  	cmd = argv[1];

  	--argc;
  	++argv;

  	if (strcmp(cmd, "probe") == 0) {
  		ret = do_spi_flash_probe(argc, argv);
  		goto done;
  	}

  
  	/* The remaining commands require a selected device */
  	if (!flash) {
  		puts("No SPI flash selected. Please run `sf probe'
  ");
  		return 1;
  	}

  	if (strcmp(cmd, "read") == 0 || strcmp(cmd, "write") == 0 ||
  	    strcmp(cmd, "update") == 0)

  		ret = do_spi_flash_read_write(argc, argv);
  	else if (strcmp(cmd, "erase") == 0)
  		ret = do_spi_flash_erase(argc, argv);

  #ifdef CONFIG_CMD_SF_TEST
  	else if (!strcmp(cmd, "test"))
  		ret = do_spi_flash_test(argc, argv);
  #endif

  	else
  		ret = -1;
  
  done:
  	if (ret != -1)
  		return ret;

  
  usage:

  	return CMD_RET_USAGE;

  }

  #ifdef CONFIG_CMD_SF_TEST
  #define SF_TEST_HELP "
  sf test offset len		" \
  		"- run a very basic destructive test"
  #else
  #define SF_TEST_HELP
  #endif

  U_BOOT_CMD(
  	sf,	5,	1,	do_spi_flash,

  	"SPI flash sub-system",

  	"probe [[bus:]cs] [hz] [mode]	- init flash device on given SPI bus
  "

  	"				  and chip select
  "

  	"sf read addr offset len	- read `len' bytes starting at
  "

  	"				  `offset' to memory at `addr'
  "
  	"sf write addr offset len	- write `len' bytes from memory
  "
  	"				  at `addr' to flash at `offset'
  "

  	"sf erase offset [+]len		- erase `len' bytes from `offset'
  "

  	"				  `+len' round up `len' to block size
  "
  	"sf update addr offset len	- erase and write `len' bytes from memory
  "
  	"				  at `addr' to flash at `offset'"

  	SF_TEST_HELP

  );