[U-Boot] [PATCH][NEXT] hwmon: do not init sensors on startup

[Heiko Schocher <hs@denx.de>]

Hello Wolfgang,

Wolfgang Denk wrote:
> In message <1291903238-29071-1-git-send-email-hs@denx.de> you wrote:
>> --- a/common/cmd_dtt.c
>> +++ b/common/cmd_dtt.c
>> @@ -28,6 +28,8 @@
>>  #include <dtt.h>
>>  #include <i2c.h>
>>  
>> +static unsigned long sensors_init_done = 0;
> 
> What if there are more then 32 sensors?

Ok, that would not work ... Hmm.. I can get the number of DTTs on a board
with ARRAY_SIZE(CONFIG_DTT_SENSORS) ... should I use this info to allocate
an array, which stores the info, if the DTTs are initialized?

>>  int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
>>  {
>>  	int i;
>> @@ -42,8 +44,16 @@ int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
>>  	 * Loop through sensors, read
>>  	 * temperature, and output it.
>>  	 */
>> -	for (i = 0; i < sizeof (sensors); i++)
>> -		printf ("DTT%d: %i C\n", i + 1, dtt_get_temp (sensors[i]));
>> +	for (i = 0; i < sizeof (sensors); i++) {
>> +		if ((sensors_init_done & (1 << i)) != (1 << i)) {
>> +			if (dtt_init_one(sensors[i]) == 0)
>> +				sensors_init_done |= (1 << i);
>> +			else
>> +				printf("DTT%d: Failed init!\n", i);
>> +		}
>> +		if ((sensors_init_done & (1 << i)) == (1 << i))
>> +			printf ("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i]));
>> +	}
> 
> This is overly complicated, it seems.  Why not:
> 
> 	for (i = 0; i < sizeof(sensors); i++) {
> 		if ((sensors_init_done & (1 << i)) == 0) {
> 			if (dtt_init_one(sensors[i]) != 0) {
> 				printf("DTT%d: init failed\n", i);
> 				continue;
> 			}
> 			sensors_init_done |= (1 << i);
> 		}
> 
> 		printf("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i]));
> 	}

Yep, that looks better, change this in v2.

bye,
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany