[U-Boot] [PATCH v2 02/16] [PATCH] I2C: add new command i2c reset.

Ben Warren biggerbadderben at gmail.com
Wed Oct 15 18:39:00 CEST 2008


Heiko Schocher wrote:
> If I2C Bus is blocked (see doc/I2C_Edge_Conditions),
> it is not possible to get out of this, until the
> complete Hardware gets a reset. This new commando
>   
You mean a commando like Chuck Norris?  Seriously, you use this word in 
a lot of these patches and it's not quite appropriate.
> calls again i2c_init (and that calls i2c_init_board
> if defined), which will deblock the I2C Bus.
>
> Signed-off-by: Heiko Schocher <hs at denx.de>
> ---
>  common/cmd_i2c.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/common/cmd_i2c.c b/common/cmd_i2c.c
> index ea80e8a..c0afd11 100644
> --- a/common/cmd_i2c.c
> +++ b/common/cmd_i2c.c
> @@ -1182,6 +1182,12 @@ int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
>  #endif
>
>  #if defined(CONFIG_I2C_CMD_TREE)
> +int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
> +{
> +	i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);
> +	return 0;
> +}
> +
>  #if defined(CONFIG_I2C_MULTI_BUS)
>  int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
>  {
> @@ -1238,6 +1244,8 @@ int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
>  		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], "re", 2))
> +		return do_i2c_reset(cmdtp, flag, --argc, ++argv);
>  	if (!strncmp(argv[1], "lo", 2))
>  		return do_i2c_loop(cmdtp, flag, --argc, ++argv);
>  #if defined(CONFIG_CMD_SDRAM)
> @@ -1266,6 +1274,7 @@ U_BOOT_CMD(
>  	"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 reset - reinit the I2C Controller\n"
>   
re-init or re-initialize would be better.
>  	"i2c loop chip address[.0, .1, .2] [# of objects] - looping read of device\n"
>  #if defined(CONFIG_CMD_SDRAM)
>  	"i2c sdram chip - print SDRAM configuration information\n"
>   
regards,
Ben


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