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Add support for multiple I2C buses

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Hello,

Attached is a patch providing support for multiple I2C buses at the
command level.  The second part of the patch includes an implementation
for the MPC834x CPU and MPC8349EMDS board.

/*** Note: This patch replaces ticket DNX#2006083042000018 ***/

Signed-off-by: Ben Warren <bwarren@qstreams.com>

Overview:

1. Include new 'i2c' command (based on USB implementation) using
CONFIG_I2C_CMD_TREE.

2. Allow multiple buses by defining CONFIG_I2C_MULTI_BUS.  Note that
the commands to change bus number and speed are only available under the
new 'i2c' command mentioned in the first bullet.

3. The option CFG_I2C_NOPROBES has been expanded to work in multi-bus
systems.  When CONFIG_I2C_MULTI_BUS is used, this option takes the form
of an array of bus-device pairs.  Otherwise, it is an array of uchar.

CHANGELOG:
        Added new 'i2c' master command for all I2C interaction.  This is
conditionally compiled with CONFIG_I2C_CMD_TREE.  New commands added for
setting I2C bus speed as well as changing the active bus if the board
has more than one (conditionally compiled with
CONFIG_I2C_MULTI_BUS).  Updated NOPROBE logic to handle multiple buses.
Updated README.

regards,
Ben
This commit is contained in:
Ben Warren
2006-09-07 16:50:54 -04:00
committed by Kim Phillips
parent bed85caf87
commit bb99ad6d82
3 changed files with 240 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

159
common/cmd_i2c.c
View File

@@ -101,8 +101,31 @@ static uchar i2c_mm_last_chip;
static uint i2c_mm_last_addr;
static uint i2c_mm_last_alen;
/* If only one I2C bus is present, the list of devices to ignore when
* the probe command is issued is represented by a 1D array of addresses.
* When multiple buses are present, the list is an array of bus-address
* pairs. The following macros take care of this */
#if defined(CFG_I2C_NOPROBES)
#if defined(CONFIG_I2C_MULTI_BUS)
static struct
{
uchar bus;
uchar addr;
} i2c_no_probes[] = CFG_I2C_NOPROBES;
#define GET_BUS_NUM i2c_get_bus_num()
#define COMPARE_BUS(b,i) (i2c_no_probes[(i)].bus == (b))
#define COMPARE_ADDR(a,i) (i2c_no_probes[(i)].addr == (a))
#define NO_PROBE_ADDR(i) i2c_no_probes[(i)].addr
#else /* single bus */
static uchar i2c_no_probes[] = CFG_I2C_NOPROBES;
#define GET_BUS_NUM 0
#define COMPARE_BUS(b,i) ((b) == 0) /* Make compiler happy */
#define COMPARE_ADDR(a,i) (i2c_no_probes[(i)] == (a))
#define NO_PROBE_ADDR(i) i2c_no_probes[(i)]
#endif /* CONFIG_MULTI_BUS */
#define NUM_ELEMENTS_NOPROBE (sizeof(i2c_no_probes)/sizeof(i2c_no_probes[0]))
#endif
static int
@@ -538,14 +561,17 @@ int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
int j;
#if defined(CFG_I2C_NOPROBES)
int k, skip;
#endif
uchar bus = GET_BUS_NUM;
#endif /* NOPROBES */
puts ("Valid chip addresses:");
for(j = 0; j < 128; j++) {
#if defined(CFG_I2C_NOPROBES)
skip = 0;
for (k = 0; k < sizeof(i2c_no_probes); k++){
if (j == i2c_no_probes[k]){
for(k=0; k < NUM_ELEMENTS_NOPROBE; k++)
{
if(COMPARE_BUS(bus, k) && COMPARE_ADDR(j, k))
{
skip = 1;
break;
}
@@ -561,8 +587,11 @@ int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
#if defined(CFG_I2C_NOPROBES)
puts ("Excluded chip addresses:");
for( k = 0; k < sizeof(i2c_no_probes); k++ )
printf(" %02X", i2c_no_probes[k] );
for(k=0; k < NUM_ELEMENTS_NOPROBE; k++)
{
if(COMPARE_BUS(bus,k))
printf(" %02X", NO_PROBE_ADDR(k));
}
putc ('\n');
#endif
@@ -873,6 +902,104 @@ int do_sdram ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
}
#endif /* CFG_CMD_SDRAM */
#if defined(CONFIG_I2C_CMD_TREE)
#if defined(CONFIG_I2C_MULTI_BUS)
int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
int bus_idx, ret=0;
if (argc == 1) /* querying current setting */
{
printf("Current bus is %d\n", i2c_get_bus_num());
}
else
{
bus_idx = simple_strtoul(argv[1], NULL, 10);
printf("Setting bus to %d\n", bus_idx);
ret = i2c_set_bus_num(bus_idx);
if(ret)
{
printf("Failure changing bus number (%d)\n", ret);
}
}
return ret;
}
#endif /* CONFIG_I2C_MULTI_BUS */
int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
int speed, ret=0;
if (argc == 1) /* querying current speed */
{
printf("Current bus speed=%d\n", i2c_get_bus_speed());
}
else
{
speed = simple_strtoul(argv[1], NULL, 10);
printf("Setting bus speed to %d Hz\n", speed);
ret = i2c_set_bus_speed(speed);
if(ret)
{
printf("Failure changing bus speed (%d)\n", ret);
}
}
return ret;
}
int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
#if defined(CONFIG_I2C_MULTI_BUS)
if(!strncmp(argv[1], "de", 2))
{
return do_i2c_bus_num(cmdtp, flag, --argc, ++argv);
}
#endif /* CONFIG_I2C_MULTI_BUS */
if(!strncmp(argv[1], "sp", 2))
{
return do_i2c_bus_speed(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "md", 2))
{
return do_i2c_md(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "mm", 2))
{
return do_i2c_mm(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "mw", 2))
{
return do_i2c_mw(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "nm", 2))
{
return do_i2c_nm(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "cr", 2))
{
return do_i2c_crc(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "pr", 2))
{
return do_i2c_probe(cmdtp, flag, --argc, ++argv);
}
if(!strncmp(argv[1], "lo", 2))
{
return do_i2c_loop(cmdtp, flag, --argc, ++argv);
}
#if (CONFIG_COMMANDS & CFG_CMD_SDRAM)
if(!strncmp(argv[1], "sd", 2))
{
return do_sdram(cmdtp, flag, --argc, ++argv);
}
#endif /* CFG_CMD_SDRAM */
else
{
printf ("Usage:\n%s\n", cmdtp->usage);
}
return 0;
}
#endif /* CONFIG_I2C_CMD_TREE */
/***************************************************/
@@ -930,4 +1057,26 @@ U_BOOT_CMD(
" (valid chip values 50..57)\n"
);
#endif
#if defined(CONFIG_I2C_CMD_TREE)
U_BOOT_CMD(
i2c, 6, 1, do_i2c,
"i2c - I2C sub-system\n",
#if defined(CONFIG_I2C_MULTI_BUS)
"dev [dev] - show or set current I2C bus\n"
#endif /* CONFIG_I2C_MULTI_BUS */
"i2c speed [speed] - show or set I2C bus speed\n"
"i2c md chip address[.0, .1, .2] [# of objects] - read from I2C device\n"
"i2c mm chip address[.0, .1, .2] - write to I2C device (auto-incrementing)\n"
"i2c mw chip address[.0, .1, .2] value [count] - write to I2C device (fill)\n"
"i2c nm chip address[.0, .1, .2] - write to I2C device (constant address)\n"
"i2c crc32 chip address[.0, .1, .2] count - compute CRC32 checksum\n"
"i2c probe - show devices on the I2C bus\n"
"i2c loop chip address[.0, .1, .2] [# of objects] - looping read of device\n"
#if (CONFIG_COMMANDS & CFG_CMD_SDRAM)
"i2c sdram chip - print SDRAM configuration information\n"
#endif /* CFG_CMD_SDRAM */
);
#endif /* CONFIG_I2C_CMD_TREE */
#endif /* CFG_CMD_I2C */