Re: [U-Boot] [PATCH 3/5] Add fuse API and commands

On 14/08/2012 14:52, Benoît Thébaudeau wrote:

This can be useful for fuse-like hardware, OTP SoC options, etc.

Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Wolfgang Denk wd@denx.de Cc: Stefano Babic sbabic@denx.de

---

CC to Anatolji, he knows very well the MPC5121 that has currently support of fuses.

{u-boot-4d3c95f.orig => u-boot-4d3c95f}/README | 1 + .../common/Makefile | 1 + /dev/null => u-boot-4d3c95f/common/cmd_fuse.c | 182 ++++++++++++++++++++ .../include/config_cmd_all.h | 1 + /dev/null => u-boot-4d3c95f/include/fuse.h | 49 ++++++ 5 files changed, 234 insertions(+) create mode 100644 u-boot-4d3c95f/common/cmd_fuse.c create mode 100644 u-boot-4d3c95f/include/fuse.h

diff --git u-boot-4d3c95f.orig/README u-boot-4d3c95f/README index fb9d904..c40fd34 100644 --- u-boot-4d3c95f.orig/README +++ u-boot-4d3c95f/README @@ -780,6 +780,7 @@ The following options need to be configured: CONFIG_CMD_FDOS * Dos diskette Support CONFIG_CMD_FLASH flinfo, erase, protect CONFIG_CMD_FPGA FPGA device initialization support

• CONFIG_CMD_FUSE		  Device fuse support
  

  CONFIG_CMD_GO * the 'go' command (exec code) CONFIG_CMD_GREPENV * search environment CONFIG_CMD_HWFLOW * RTS/CTS hw flow control

Agree in this split: we have a general fuse command and each SOC / SOC family can add its own implementation.

+static int do_fuse(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) +{

• u32 bank, row, bit, cnt, val;
• int ret, i;
• if (argc < 4 || strtou32(argv[2], 0, &bank) ||

• 	strtou32(argv[3], 0, &row))
  

• return CMD_RET_USAGE;
  

• if (!strcmp(argv[1], "read.bit")) {

• if (argc != 5 || strtou32(argv[4], 0, &bit))
  

• 	return CMD_RET_USAGE;
  

• printf("Reading bank %u row 0x%.8x bit %u: ", bank, row, bit);
  

• ret = fuse_read_bit(bank, row, bit, &val);
  

• if (ret)
  

• 	goto err;
  

• printf("%u\n", val);
  

• } else if (!strcmp(argv[1], "read.row")) {

• if (argc == 4)
  

• 	cnt = 1;
  

• else if (argc != 5 || strtou32(argv[4], 0, &cnt))
  

• 	return CMD_RET_USAGE;
  

• printf("Reading bank %u:\n", bank);
  

• for (i = 0; i < cnt; i++, row++) {
  

• 	if (!(i % 4))
  

• 		printf("\nRow 0x%.8x:", row);
  

• 	ret = fuse_read_row(bank, row, &val);
  

• 	if (ret)
  

• 		goto err;
  

• 	printf(" %.8x", val);
  

• }
  

• putc('\n');
  

• } else if (!strcmp(argv[1], "sense.bit")) {

• if (argc != 5 || strtou32(argv[4], 0, &bit))
  

• 	return CMD_RET_USAGE;
  

• printf("Sensing bank %u row 0x%.8x bit %u: ", bank, row, bit);
  

Each command sends this output to the console. I am thinking about if instead of printf() we shoud use debug()

+U_BOOT_CMD(

• fuse, CONFIG_SYS_MAXARGS, 0, do_fuse,
• "Fuse sub-system",

•     "read.bit <bank> <row> <bit> - read a fuse bit\n"
  

• "fuse read.row <bank> <row> [<cnt>] - read 1 or 'cnt' fuse rows,\n"
• " starting at 'row'\n"
• "fuse sense.bit <bank> <row> <bit> - sense a fuse bit\n"
• "fuse sense.row <bank> <row> [<cnt>] - sense 1 or 'cnt' fuse rows,\n"
• " starting at 'row'\n"
• "fuse prog.bit <bank> <row> <bit> - program a fuse bit (PERMANENT)\n"
• "fuse prog.row <bank> <row> <hexval> [<hexval>...] - program 1 or\n"
• " several fuse rows, starting at 'row' (PERMANENT)\n"
• "fuse ovride.bit <bank> <row> <bit> <val> - override a fuse bit\n"
• "fuse ovride.row <bank> <row> <hexval> [<hexval>...] - override 1 or\n"
• " several fuse rows, starting at 'row'"

+);

General question: why do we need the "bit" interface ? I have thought it is enough the read row / prog row interface (even if there is a bit programming).

Best regards, Stefano Babic