Blackfin: implement real write support for OTP

Now that real documentation has been released for the OTP interface and
the on-chip ROM wrt writing/timings, implement support for reading/writing
as well as dumping/locking.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/common/cmd_otp.c b/common/cmd_otp.c
index e27bb29217d4b4181a53c56eaa3e73d50f4e2647..5d85a484d45426226541979560f42d41cc20180e 100644 (file)
--- a/common/cmd_otp.c
+++ b/common/cmd_otp.c
@@ -6,7 +6,7 @@
  * Licensed under the GPL-2 or later.
  */
 
-/* There are 512 128-bit "pages" (0x000 to 0x1FF).
+/* There are 512 128-bit "pages" (0x000 through 0x1FF).
  * The pages are accessable as 64-bit "halfpages" (an upper and lower half).
  * The pages are not part of the memory map.  There is an OTP controller which
  * handles scanning in/out of bits.  While access is done through OTP MMRs,
@@ -17,8 +17,6 @@
 #include <common.h>
 #include <command.h>
 
-#ifdef CONFIG_CMD_OTP
-
 #include <asm/blackfin.h>
 #include <asm/mach-common/bits/otp.h>
 
@@ -40,30 +38,87 @@ static const char *otp_strerror(uint32_t err)
 
 #define lowup(x) ((x) % 2 ? "upper" : "lower")
 
-int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+static int check_voltage(void)
+{
+       /* Make sure voltage limits are within datasheet spec */
+       uint16_t vr_ctl = bfin_read_VR_CTL();
+
+#ifdef __ADSPBF54x__
+       /* 0.9V <= VDDINT <= 1.1V */
+       if ((vr_ctl & 0xc) && (vr_ctl & 0xc0) == 0xc0)
+               return 1;
+#else
+       /* for the parts w/out qualification yet */
+       (void)vr_ctl;
+#endif
+
+       return 0;
+}
+
+static void set_otp_timing(bool write)
 {
-       bool force = false;
-       if (!strcmp(argv[1], "--force")) {
-               force = true;
-               argv[1] = argv[0];
-               argv++;
-               --argc;
+       static uint32_t timing;
+       if (!timing) {
+               uint32_t tp1, tp2, tp3;
+               /* OTP_TP1 = 1000 / sclk_period (in nanoseconds)
+                * OTP_TP1 = 1000 / (1 / get_sclk() * 10^9)
+                * OTP_TP1 = (1000 * get_sclk()) / 10^9
+                * OTP_TP1 = get_sclk() / 10^6
+                */
+               tp1 = get_sclk() / 1000000;
+               /* OTP_TP2 = 400 / (2 * sclk_period)
+                * OTP_TP2 = 400 / (2 * 1 / get_sclk() * 10^9)
+                * OTP_TP2 = (400 * get_sclk()) / (2 * 10^9)
+                * OTP_TP2 = (2 * get_sclk()) / 10^7
+                */
+               tp2 = (2 * get_sclk() / 10000000) << 8;
+               /* OTP_TP3 = magic constant */
+               tp3 = (0x1401) << 15;
+               timing = tp1 | tp2 | tp3;
        }
 
+       bfrom_OtpCommand(OTP_INIT, write ? timing : timing & ~(-1 << 15));
+}
+
+int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+       uint32_t ret, base_flags;
+       bool prompt_user, force_read;
        uint32_t (*otp_func)(uint32_t page, uint32_t flags, uint64_t *page_content);
-       if (!strcmp(argv[1], "read"))
-               otp_func = otp_read;
-       else if (!strcmp(argv[1], "write"))
-               otp_func = otp_write;
-       else {
+
+       if (argc < 4) {
  usage:
                cmd_usage(cmdtp);
                return 1;
        }
 
+       prompt_user = false;
+       base_flags = 0;
+       if (!strcmp(argv[1], "read"))
+               otp_func = bfrom_OtpRead;
+       else if (!strcmp(argv[1], "dump")) {
+               otp_func = bfrom_OtpRead;
+               force_read = true;
+       } else if (!strcmp(argv[1], "write")) {
+               otp_func = bfrom_OtpWrite;
+               base_flags = OTP_CHECK_FOR_PREV_WRITE;
+               if (!strcmp(argv[2], "--force")) {
+                       argv[2] = argv[1];
+                       argv++;
+                       --argc;
+               } else
+                       prompt_user = false;
+       } else if (!strcmp(argv[1], "lock")) {
+               if (argc != 4)
+                       goto usage;
+               otp_func = bfrom_OtpWrite;
+               base_flags = OTP_LOCK;
+       } else
+               goto usage;
+
        uint64_t *addr = (uint64_t *)simple_strtoul(argv[2], NULL, 16);
        uint32_t page = simple_strtoul(argv[3], NULL, 16);
-       uint32_t flags, ret;
+       uint32_t flags;
        size_t i, count;
        ulong half;
 
@@ -81,8 +136,15 @@ int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
        } else
                half = 0;
 
+       /* "otp lock" has slightly different semantics */
+       if (base_flags & OTP_LOCK) {
+               count = page;
+               page = (uint32_t)addr;
+               addr = NULL;
+       }
+
        /* do to the nature of OTP, make sure users are sure */
-       if (!force && otp_func == otp_write) {
+       if (prompt_user) {
                printf(
                        "Writing one time programmable memory\n"
                        "Make sure your operating voltages and temperature are within spec\n"
@@ -111,30 +173,42 @@ int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
                                }
                        }
                }
-
-               /* Only supported in newer silicon ... enable writing */
-#if (0)
-               otp_command(OTP_INIT, ...);
-#else
-               *pOTP_TIMING = 0x32149485;
-#endif
        }
 
        printf("OTP memory %s: addr 0x%08lx  page 0x%03X  count %ld ... ",
                argv[1], addr, page, count);
 
+       set_otp_timing(otp_func == bfrom_OtpWrite);
+       if (otp_func == bfrom_OtpWrite && check_voltage()) {
+               puts("ERROR: VDDINT voltage is out of spec for writing\n");
+               return -1;
+       }
+
+       /* Do the actual reading/writing stuff */
        ret = 0;
        for (i = half; i < count + half; ++i) {
-               flags = (i % 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF;
+               flags = base_flags | (i % 2 ? OTP_UPPER_HALF : OTP_LOWER_HALF);
+ try_again:
                ret = otp_func(page, flags, addr);
-               if (ret & 0x1)
-                       break;
-               else if (ret)
+               if (ret & OTP_MASTER_ERROR) {
+                       if (force_read) {
+                               if (flags & OTP_NO_ECC)
+                                       break;
+                               else
+                                       flags |= OTP_NO_ECC;
+                               puts("E");
+                               goto try_again;
+                       } else
+                               break;
+               } else if (ret)
                        puts("W");
                else
                        puts(".");
-               ++addr;
-               if (i % 2)
+               if (!(base_flags & OTP_LOCK)) {
+                       ++addr;
+                       if (i % 2)
+                               ++page;
+               } else
                        ++page;
        }
        if (ret & 0x1)
@@ -143,21 +217,20 @@ int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
        else
                puts(" done\n");
 
-       if (otp_func == otp_write)
-               /* Only supported in newer silicon ... disable writing */
-#if (0)
-               otp_command(OTP_INIT, ...);
-#else
-               *pOTP_TIMING = 0x1485;
-#endif
+       /* Make sure we disable writing */
+       set_otp_timing(false);
+       bfrom_OtpCommand(OTP_CLOSE, 0);
 
        return ret;
 }
 
-U_BOOT_CMD(otp, 6, 0, do_otp,
-       "One-Time-Programmable sub-system",
+U_BOOT_CMD(otp, 7, 0, do_otp,
+       "One-Time-Programmable sub-system\n",
        "read <addr> <page> [count] [half]\n"
+       " - read 'count' half-pages starting at 'page' (offset 'half') to 'addr'\n"
+       "otp dump <addr> <page> [count] [half]\n"
+       " - like 'otp read', but skip read errors\n"
        "otp write [--force] <addr> <page> [count] [half]\n"
-       "    - read/write 'count' half-pages starting at page 'page' (offset 'half')\n");
-
-#endif
+       " - write 'count' half-pages starting at 'page' (offset 'half') from 'addr'\n"
+       "otp lock <page> <count>\n"
+       " - lock 'count' pages starting at 'page'\n");