The U-Boot Design Principles[1] clearly say:
Initialize devices only when they are needed within U-Boot, i.e. don't initialize the Ethernet interface(s) unless U-Boot performs a download over Ethernet; don't initialize any IDE or USB devices unless U-Boot actually tries to load files from these, etc. (and don't forget to shut down these devices after using them - otherwise nasty things may happen when you try to boot your OS).
So, do not initialize and read the sensors on startup.
Signed-off-by: Heiko Schocher hs@denx.de cc: Wolfgang Denk wd@denx.de
--- - changes since v1 add comments from Wolfgang Denk use BUILD_BUG_ON to create a compileerror if there are defined more than 32 sensors.
arch/powerpc/lib/board.c | 3 --- common/cmd_dtt.c | 17 +++++++++++++++-- drivers/hwmon/adm1021.c | 27 +++------------------------ drivers/hwmon/adt7460.c | 2 +- drivers/hwmon/ds1621.c | 19 +------------------ drivers/hwmon/ds1775.c | 19 +------------------ drivers/hwmon/lm63.c | 19 +------------------ drivers/hwmon/lm73.c | 20 ++------------------ drivers/hwmon/lm75.c | 29 ++--------------------------- drivers/hwmon/lm81.c | 21 ++------------------- include/dtt.h | 2 +- 11 files changed, 29 insertions(+), 149 deletions(-)
diff --git a/arch/powerpc/lib/board.c b/arch/powerpc/lib/board.c index b21c1d6..f9412a9 100644 --- a/arch/powerpc/lib/board.c +++ b/arch/powerpc/lib/board.c @@ -917,9 +917,6 @@ void board_init_r (gd_t *id, ulong dest_addr)
WATCHDOG_RESET ();
-#if defined(CONFIG_DTT) /* Digital Thermometers and Thermostats */ - dtt_init (); -#endif #if defined(CONFIG_CMD_SCSI) WATCHDOG_RESET (); puts ("SCSI: "); diff --git a/common/cmd_dtt.c b/common/cmd_dtt.c index 3388e43..d86cec5 100644 --- a/common/cmd_dtt.c +++ b/common/cmd_dtt.c @@ -24,16 +24,21 @@ #include <common.h> #include <config.h> #include <command.h> +#include <genutils.h>
#include <dtt.h> #include <i2c.h>
+static unsigned long sensor_initialized = 0; + int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { int i; unsigned char sensors[] = CONFIG_DTT_SENSORS; int old_bus;
+ /* Force a compilation error, if there are more then 32 sensors */ + BUILD_BUG_ON(sizeof(sensors) > 32); /* switch to correct I2C bus */ old_bus = I2C_GET_BUS(); I2C_SET_BUS(CONFIG_SYS_DTT_BUS_NUM); @@ -42,8 +47,16 @@ 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 ((sensor_initialized & (1 << i)) == 0) { + if (dtt_init_one(sensors[i]) != 0) { + printf("DTT%d: Failed init!\n", i); + continue; + } + sensor_initialized |= 1 << i; + } + printf ("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i])); + }
/* switch back to original I2C bus */ I2C_SET_BUS(old_bus); diff --git a/drivers/hwmon/adm1021.c b/drivers/hwmon/adm1021.c index d753e9a..3ef80af 100644 --- a/drivers/hwmon/adm1021.c +++ b/drivers/hwmon/adm1021.c @@ -109,8 +109,8 @@ dtt_write (int sensor, int reg, int val) return 0; } /* dtt_write() */
-static int -_dtt_init (int sensor) +int +dtt_init_one (int sensor) { dtt_cfg_t *dcp = &dttcfg[sensor >> 1]; int reg, val; @@ -164,28 +164,7 @@ _dtt_init (int sensor) return 1;
return 0; -} /* _dtt_init() */ - -int -dtt_init (void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - const char *const header = "DTT: "; - - /* switch to correct I2C bus */ - I2C_SET_BUS(CONFIG_SYS_DTT_BUS_NUM); - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf ("%s%d FAILED INIT\n", header, i+1); - else - printf ("%s%d is %i C\n", header, i+1, - dtt_get_temp(sensors[i])); - } - - return (0); -} /* dtt_init() */ +} /* dtt_init_one() */
int dtt_get_temp (int sensor) diff --git a/drivers/hwmon/adt7460.c b/drivers/hwmon/adt7460.c index caef70a..b7e36fe 100644 --- a/drivers/hwmon/adt7460.c +++ b/drivers/hwmon/adt7460.c @@ -50,7 +50,7 @@ int dtt_write(int sensor, int reg, int val) return 0; }
-int dtt_init(void) +int dtt_init_one(int sensor) { printf("ADT7460 at I2C address 0x%2x\n", ADT7460_ADDRESS);
diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c index 5a2ea62..4e1db6d 100644 --- a/drivers/hwmon/ds1621.c +++ b/drivers/hwmon/ds1621.c @@ -126,7 +126,7 @@ int dtt_write(int sensor, int reg, int val) }
-static int _dtt_init(int sensor) +int dtt_init_one(int sensor) { int val;
@@ -155,23 +155,6 @@ static int _dtt_init(int sensor) return 0; }
- -int dtt_init (void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf("DTT%d: FAILED\n", i + 1); - else - printf("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i])); - } - - return (0); -} - - int dtt_get_temp(int sensor) { int i; diff --git a/drivers/hwmon/ds1775.c b/drivers/hwmon/ds1775.c index 80fb26f..feabdf2 100644 --- a/drivers/hwmon/ds1775.c +++ b/drivers/hwmon/ds1775.c @@ -98,7 +98,7 @@ int dtt_write(int sensor, int reg, int val) }
-static int _dtt_init(int sensor) +int dtt_init_one(int sensor) { int val;
@@ -133,23 +133,6 @@ static int _dtt_init(int sensor) return 0; }
- -int dtt_init (void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf("DTT%d: FAILED\n", i+1); - else - printf("DTT%d: %i C\n", i+1, dtt_get_temp(sensors[i])); - } - - return (0); -} - - int dtt_get_temp(int sensor) { return (dtt_read(sensor, DTT_READ_TEMP) / 256); diff --git a/drivers/hwmon/lm63.c b/drivers/hwmon/lm63.c index 03616e1..2e49258 100644 --- a/drivers/hwmon/lm63.c +++ b/drivers/hwmon/lm63.c @@ -93,7 +93,7 @@ int dtt_write(int sensor, int reg, int val) return 0; } /* dtt_write() */
-static int _dtt_init(int sensor) +int dtt_init_one(int sensor) { int i; int val; @@ -155,20 +155,3 @@ int dtt_get_temp(int sensor) /* Ignore LSB for now, U-Boot only prints natural numbers */ return temp >> 8; } - -int dtt_init(void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - const char *const header = "DTT: "; - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf("%s%d FAILED INIT\n", header, i + 1); - else - printf("%s%d is %i C\n", header, i + 1, - dtt_get_temp(sensors[i])); - } - - return 0; -} diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c index 7b5d893..45cc6db 100644 --- a/drivers/hwmon/lm73.c +++ b/drivers/hwmon/lm73.c @@ -112,7 +112,7 @@ int dtt_write(int const sensor, int const reg, int const val) dlen); } /* dtt_write() */
-static int _dtt_init(int const sensor) +int dtt_init_one(int const sensor) { int val;
@@ -148,23 +148,7 @@ static int _dtt_init(int const sensor)
dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */ return 0; -} /* _dtt_init() */ - -int dtt_init(void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - const char *const header = "DTT: "; - - for (i = 0; i < sizeof(sensors); i++) { - if (0 != _dtt_init(sensors[i])) - printf("%s%d FAILED INIT\n", header, i + 1); - else - printf("%s%d is %i C\n", header, i + 1, - dtt_get_temp(sensors[i])); - } - return 0; -} /* dtt_init() */ +} /* dtt_init_one() */
int dtt_get_temp(int const sensor) { diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index 8119821..29c1a39 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -119,7 +119,7 @@ int dtt_write(int sensor, int reg, int val) } /* dtt_write() */
-static int _dtt_init(int sensor) +int dtt_init_one(int sensor) { int val;
@@ -145,32 +145,7 @@ static int _dtt_init(int sensor) return 1;
return 0; -} /* _dtt_init() */ - - -int dtt_init (void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - const char *const header = "DTT: "; - int old_bus; - - /* switch to correct I2C bus */ - old_bus = I2C_GET_BUS(); - I2C_SET_BUS(CONFIG_SYS_DTT_BUS_NUM); - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf("%s%d FAILED INIT\n", header, i+1); - else - printf("%s%d is %i C\n", header, i+1, - dtt_get_temp(sensors[i])); - } - /* switch back to original I2C bus */ - I2C_SET_BUS(old_bus); - - return (0); -} /* dtt_init() */ +} /* dtt_init_one() */
int dtt_get_temp(int sensor) { diff --git a/drivers/hwmon/lm81.c b/drivers/hwmon/lm81.c index afe5b0d..f1572ba 100644 --- a/drivers/hwmon/lm81.c +++ b/drivers/hwmon/lm81.c @@ -89,7 +89,7 @@ int dtt_write(int sensor, int reg, int val) #define DTT_CONFIG 0x40 #define DTT_ADR 0x48
-static int _dtt_init(int sensor) +int dtt_init_one(int sensor) { int man; int adr; @@ -111,26 +111,9 @@ static int _dtt_init(int sensor)
debug ("DTT: Found LM81@%x Rev: %d\n", adr, rev); return 0; -} /* _dtt_init() */ +} /* dtt_init_one() */
-int dtt_init (void) -{ - int i; - unsigned char sensors[] = CONFIG_DTT_SENSORS; - const char *const header = "DTT: "; - - for (i = 0; i < sizeof(sensors); i++) { - if (_dtt_init(sensors[i]) != 0) - printf("%s%d FAILED INIT\n", header, i+1); - else - printf("%s%d is %i C\n", header, i+1, - dtt_get_temp(sensors[i])); - } - - return (0); -} /* dtt_init() */ - #define TEMP_FROM_REG(temp) \ ((temp)<256?((((temp)&0x1fe) >> 1) * 10) + ((temp) & 1) * 5: \ ((((temp)&0x1fe) >> 1) -255) * 10 - ((temp) & 1) * 5) \ diff --git a/include/dtt.h b/include/dtt.h index 399b64a..bbaa033 100644 --- a/include/dtt.h +++ b/include/dtt.h @@ -52,7 +52,7 @@ #endif #endif /* CONFIG_DTT_ADM1021 */
-extern int dtt_init (void); +extern int dtt_init_one (int); extern int dtt_read(int sensor, int reg); extern int dtt_write(int sensor, int reg, int val); extern int dtt_get_temp(int sensor);