i2cdump: code rework

Split i2cdump_main() into shorter functions. Simplify the code a bit.
Make block an array of ints so that we can store negative results of
read functions (fixes a bug found by Denys Vlasenko).

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 167 insertions, 149 deletions

diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
index 16784e948..2f501cd9c 100644
--- a/miscutils/i2c_tools.c
+++ b/miscutils/i2c_tools.c
@@ -816,6 +816,163 @@ int i2cset_main(int argc, char **argv)
 #endif /* ENABLE_I2CSET */
 
 #if ENABLE_I2CDUMP
+static int read_block_data(int buf_fd, int mode, int *block)
+{
+        uint8_t cblock[I2C_SMBUS_BLOCK_MAX + I2C_MAX_REGS];
+        int res, blen = 0, tmp, i;
+
+        if (mode == I2C_SMBUS_BLOCK_DATA || mode == I2C_SMBUS_I2C_BLOCK_DATA) {
+                res = i2c_smbus_read_block_data(buf_fd, 0, cblock);
+                blen = res;
+        } else {
+                for (res = 0; res < I2C_MAX_REGS; res += tmp) {
+                        tmp = i2c_smbus_read_i2c_block_data(
+                                        buf_fd, res, I2C_SMBUS_BLOCK_MAX,
+                                        cblock + res);
+                        if (tmp < 0) {
+                                bb_error_msg_and_die("block read failed");
+                        }
+                }
+
+                if (res >= I2C_MAX_REGS)
+                        res = I2C_MAX_REGS;
+
+                for (i = 0; i < res; i++)
+                        block[i] = cblock[i];
+
+                if (mode != I2C_SMBUS_BLOCK_DATA)
+                        for (i = res; i < I2C_MAX_REGS; i++)
+                                block[i] = -1;
+        }
+
+        return blen;
+}
+
+/* Dump all but word data. */
+static void dump_data(int bus_fd, int mode, unsigned first,
+                      unsigned last, int *block, int blen)
+{
+        int i, j, res;
+
+        printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f"
+               "    0123456789abcdef\n");
+
+        for (i = 0; i < I2C_MAX_REGS; i += 0x10) {
+                if (mode == I2C_SMBUS_BLOCK_DATA && i >= blen)
+                        break;
+                if (i/16 < first/16)
+                        continue;
+                if (i/16 > last/16)
+                        break;
+
+                printf("%02x: ", i);
+                for (j = 0; j < 16; j++) {
+                        fflush_all();
+                        /* Skip unwanted registers */
+                        if (i+j < first || i+j > last) {
+                                printf("   ");
+                                if (mode == I2C_SMBUS_WORD_DATA) {
+                                        printf("   ");
+                                        j++;
+                                }
+                                continue;
+                        }
+
+                        switch (mode) {
+                        case I2C_SMBUS_BYTE_DATA:
+                                res = i2c_smbus_read_byte_data(bus_fd, i+j);
+                                block[i+j] = res;
+                                break;
+                        case I2C_SMBUS_WORD_DATA:
+                                res = i2c_smbus_read_word_data(bus_fd, i+j);
+                                if (res < 0) {
+                                        block[i+j] = res;
+                                        block[i+j+1] = res;
+                                } else {
+                                        block[i+j] = res & 0xff;
+                                        block[i+j+1] = res >> 8;
+                                }
+                                break;
+                        case I2C_SMBUS_BYTE:
+                                res = i2c_smbus_read_byte(bus_fd);
+                                block[i+j] = res;
+                                break;
+                        default:
+                                res = block[i+j];
+                        }
+
+                        if (mode == I2C_SMBUS_BLOCK_DATA &&
+                            i+j >= blen) {
+                                printf("   ");
+                        } else if (res < 0) {
+                                printf("XX ");
+                                if (mode == I2C_SMBUS_WORD_DATA)
+                                        printf("XX ");
+                        } else {
+                                printf("%02x ", block[i+j]);
+                                if (mode == I2C_SMBUS_WORD_DATA)
+                                        printf("%02x ", block[i+j+1]);
+                        }
+
+                        if (mode == I2C_SMBUS_WORD_DATA)
+                                j++;
+                }
+                printf("   ");
+
+                for (j = 0; j < 16; j++) {
+                        if (mode == I2C_SMBUS_BLOCK_DATA && i+j >= blen)
+                                break;
+                        /* Skip unwanted registers */
+                        if (i+j < first || i+j > last) {
+                                printf(" ");
+                                continue;
+                        }
+
+                        res = block[i+j];
+                        if (res < 0) {
+                                printf("X");
+                        } else if (res == 0x00 || res == 0xff) {
+                                printf(".");
+                        } else if (res < 32 || res >= 127) {
+                                printf("?");
+                        } else {
+                                printf("%c", res);
+                        }
+                }
+                printf("\n");
+        }
+}
+
+static void dump_word_data(int bus_fd, unsigned first, unsigned last)
+{
+        int i, j, rv;
+
+        /* Word data. */
+        printf("     0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f\n");
+        for (i = 0; i < 256; i += 8) {
+                if (i/8 < first/8)
+                        continue;
+                if (i/8 > last/8)
+                        break;
+
+                printf("%02x: ", i);
+                for (j = 0; j < 8; j++) {
+                        /* Skip unwanted registers. */
+                        if (i+j < first || i+j > last) {
+                                printf("     ");
+                                continue;
+                        }
+
+                        rv = i2c_smbus_read_word_data(bus_fd, i+j);
+                        if (rv < 0)
+                                printf("XXXX ");
+                        else
+                                printf("%04x ", rv & 0xffff);
+                }
+                printf("\n");
+        }
+}
+
 //usage:#define i2cdump_trivial_usage
 //usage:       "[-f] [-r FIRST-LAST] [-y] BUS ADDR [MODE]"
 //usage:#define i2cdump_full_usage "\n\n"
@@ -842,12 +999,10 @@ int i2cdump_main(int argc UNUSED_PARAM, char **argv)
         const char *const optstr = "fyr:";
 
         int bus_num, bus_addr, mode = I2C_SMBUS_BYTE_DATA, even = 0, pec = 0;
-        unsigned first = 0x00, last = 0xff;
-        int fd, i, j, res, blen = 0, tmp;
-        unsigned char cblock[I2C_SMBUS_BLOCK_MAX + I2C_MAX_REGS];
-        unsigned char block[I2C_SMBUS_BLOCK_MAX];
+        unsigned first = 0x00, last = 0xff, opts;
+        int *block = (int *)bb_common_bufsiz1;
         char *opt_r_str, *dash;
-        unsigned opts;
+        int fd, res, blen;
 
         opt_complementary = "-2:?3"; /* from 2 to 3 args */
         opts = getopt32(argv, optstr, &opt_r_str);
@@ -858,7 +1013,7 @@ int i2cdump_main(int argc UNUSED_PARAM, char **argv)
 
         if (argv[2]) {
                 switch (argv[2][0]) {
-                case 'b': /* Already set */                     break;
+                case 'b': /* Already set. */                    break;
                 case 'c': mode = I2C_SMBUS_BYTE;                break;
                 case 'w': mode = I2C_SMBUS_WORD_DATA;           break;
                 case 'W':
@@ -887,7 +1042,7 @@ int i2cdump_main(int argc UNUSED_PARAM, char **argv)
                         bb_error_msg_and_die("invalid range");
                 last = xstrtou_range(++dash, 0, first, 0xff);
 
-                /* Range is not available for every mode */
+                /* Range is not available for every mode. */
                 switch (mode) {
                 case I2C_SMBUS_BYTE:
                 case I2C_SMBUS_BYTE_DATA:
@@ -912,156 +1067,19 @@ int i2cdump_main(int argc UNUSED_PARAM, char **argv)
         if (!(opts & opt_y))
                 confirm_action(bus_addr, mode, -1 /* data_addr */, pec);
 
-        /* All but word data */
+        /* All but word data. */
         if (mode != I2C_SMBUS_WORD_DATA || even) {
-                /*
-                 * FIXME This section has been ported from upstream i2cdump.
-                 * It has been reworked a bit but is still pretty spaghetti
-                 * and needs splitting into several functions.
-                 */
-                if (mode == I2C_SMBUS_BLOCK_DATA ||
-                    mode == I2C_SMBUS_I2C_BLOCK_DATA) {
-                        res = i2c_smbus_read_block_data(fd, 0, cblock);
-                        blen = res;
-                } else {
-                        for (res = 0; res < I2C_MAX_REGS; res += tmp) {
-                                tmp = i2c_smbus_read_i2c_block_data(
-                                        fd, res, I2C_SMBUS_BLOCK_MAX,
-                                        cblock + res);
-                                if (tmp < 0) {
-                                        bb_error_msg_and_die(
-                                                "block read failed");
-                                }
-                        }
-                        if (res >= I2C_MAX_REGS)
-                                res = I2C_MAX_REGS;
-                        for (i = 0; i < res; i++)
-                                block[i] = cblock[i];
-                        if (mode != I2C_SMBUS_BLOCK_DATA)
-                                for (i = res; i < I2C_MAX_REGS; i++)
-                                        cblock[i] = -1;
-                }
+                blen = read_block_data(fd, mode, block);
 
                 if (mode == I2C_SMBUS_BYTE) {
                         res = i2c_smbus_write_byte(fd, first);
                         if (res < 0)
-                                bb_perror_msg_and_die(
-                                        "write start address failed");
+                                bb_perror_msg_and_die("write start address");
                 }
 
-                printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f"
-                       "    0123456789abcdef\n");
-
-                for (i = 0; i < I2C_MAX_REGS; i += 0x10) {
-                        if (mode == I2C_SMBUS_BLOCK_DATA && i >= blen)
-                                break;
-                        if (i/16 < first/16)
-                                continue;
-                        if (i/16 > last/16)
-                                break;
-
-                        printf("%02x: ", i);
-                        for (j = 0; j < 16; j++) {
-                                fflush_all();
-                                /* Skip unwanted registers */
-                                if (i+j < first || i+j > last) {
-                                        printf("   ");
-                                        if (mode == I2C_SMBUS_WORD_DATA) {
-                                                printf("   ");
-                                                j++;
-                                        }
-                                        continue;
-                                }
-
-                                switch (mode) {
-                                case I2C_SMBUS_BYTE_DATA:
-                                        res = i2c_smbus_read_byte_data(fd, i+j);
-                                        block[i+j] = res;
-                                        break;
-                                case I2C_SMBUS_WORD_DATA:
-                                        res = i2c_smbus_read_word_data(fd, i+j);
-                                        if (res < 0) {
-                                                block[i+j] = res;
-                                                block[i+j+1] = res;
-                                        } else {
-                                                block[i+j] = res & 0xff;
-                                                block[i+j+1] = res >> 8;
-                                        }
-                                        break;
-                                case I2C_SMBUS_BYTE:
-                                        res = i2c_smbus_read_byte(fd);
-                                        block[i+j] = res;
-                                        break;
-                                default:
-                                        res = block[i+j];
-                                }
-
-                                if (mode == I2C_SMBUS_BLOCK_DATA &&
-                                    i+j >= blen) {
-                                        printf("   ");
-                                } else if (res < 0) {
-                                        printf("XX ");
-                                        if (mode == I2C_SMBUS_WORD_DATA)
-                                                printf("XX ");
-                                } else {
-                                        printf("%02x ", block[i+j]);
-                                        if (mode == I2C_SMBUS_WORD_DATA)
-                                                printf("%02x ", block[i+j+1]);
-                                }
-
-                                if (mode == I2C_SMBUS_WORD_DATA)
-                                        j++;
-                        }
-                        printf("   ");
-
-                        for (j = 0; j < 16; j++) {
-                                if (mode == I2C_SMBUS_BLOCK_DATA && i+j >= blen)
-                                        break;
-                                /* Skip unwanted registers */
-                                if (i+j < first || i+j > last) {
-                                        printf(" ");
-                                        continue;
-                                }
-
-                                res = block[i+j];
-                                if (res < 0) {
-//FIXME: impossible, block[] is uchar[]
-                                        printf("X");
-                                } else if (res == 0x00 || res == 0xff) {
-                                        printf(".");
-                                } else if (res < 32 || res >= 127) {
-                                        printf("?");
-                                } else {
-                                        printf("%c", res);
-                                }
-                        }
-                        printf("\n");
-                }
+                dump_data(fd, mode, first, last, block, blen);
         } else {
-                /* Word data. */
-                printf("     0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f\n");
-                for (i = 0; i < 256; i += 8) {
-                        if (i/8 < first/8)
-                                continue;
-                        if (i/8 > last/8)
-                                break;
-
-                        printf("%02x: ", i);
-                        for (j = 0; j < 8; j++) {
-                                /* Skip unwanted registers. */
-                                if (i+j < first || i+j > last) {
-                                        printf("     ");
-                                        continue;
-                                }
-
-                                res = i2c_smbus_read_word_data(fd, i+j);
-                                if (res < 0)
-                                        printf("XXXX ");
-                                else
-                                        printf("%04x ", res & 0xffff);
-                        }
-                        printf("\n");
-                }
+                dump_word_data(fd, first, last);
         }
 
         return 0;