hwmon: do not init sensors on startup

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>
cc: Holger Brunck <holger.brunck@keymile.com>

diff --git a/arch/powerpc/lib/board.c b/arch/powerpc/lib/board.c
index 22bbc52da55066b0387d9dc09f6c5cf256ca69be..9885b143ac244f5024ac8eeaa6efc0c6dd83673b 100644 (file)
--- a/arch/powerpc/lib/board.c
+++ b/arch/powerpc/lib/board.c
@@ -944,9 +944,6 @@ 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 3388e43ca046acd6ef92cac03ce41f6715135aa4..5bba12d4d02af5ec9f38d22f397616bf3f9aed1c 100644 (file)
--- a/common/cmd_dtt.c
+++ b/common/cmd_dtt.c
@@ -28,12 +28,16 @@
 #include <dtt.h>
 #include <i2c.h>
 
+static unsigned long sensor_initialized;
+
 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 +46,16 @@ 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 d753e9a72f778d5fbc03233ee382bcf7e2be12db..d074cb72311ab529e519304765e47fab73f0aef8 100644 (file)
--- 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 caef70aff5dc3fcb2ed571a9f18f1f4d3592db7a..b7e36fe461e096c5e8b40699efb4b8828b21c3dd 100644 (file)
--- 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 5a2ea62899711cb0c1763df9793c615430dc4c07..4e1db6dc0bdbaec98b229cfe15ee8842562e7177 100644 (file)
--- 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 80fb26f7b5ae9e40277a8a2239583e68fed1c7ef..feabdf2210ceb05deb427fc15950debbbaaf81f2 100644 (file)
--- 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 2f1f3cfabf2086ecba00275582a7351eb16d2b4d..f3adf6485997e5fde82a8c14ad0806527a0118b3 100644 (file)
--- a/drivers/hwmon/lm63.c
+++ b/drivers/hwmon/lm63.c
@@ -101,7 +101,7 @@ static int is_lm64(int sensor)
        return sensor && (sensor != DTT_I2C_LM63_ADDR);
 }
 
-static int _dtt_init(int sensor)
+int dtt_init_one(int sensor)
 {
        int i;
        int val;
@@ -175,20 +175,3 @@ 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 7b5d893ff26447f1d7de3ac5aacef40cf8f1c3da..45cc6db58b0e74f89b58abda3f15bc09fa5a36ef 100644 (file)
--- 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 81198215ff6cdf867df3ffd1ac88a06d6fd6b772..29c1a392ee25ea736c839f427775537900a931ce 100644 (file)
--- 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 afe5b0de3fa06ceb8304298de61b62c59b9c6cbc..f1572ba2707482206776e5f669b4d181ad3cb377 100644 (file)
--- 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 399b64abac133c978af74909d4b09d35be28964d..9e6c08c5c8422e47838ddbb50679b128e3438a4f 100644 (file)
--- 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);