DEVOFF event of TPS65950 will result Restart of the system instead of power off

dilan

Other Parts Discussed in Thread: TPS65950

Hi all,

I am using Beagle board rev C4 with android 2.0 .to shut down (power off ) the omap +tps completly i used the following piece of code,

err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, PWR_P1_SW_EVENTS);

if (err)

{

printk(KERN_WARNING "I2C error %d while reading TWL4030" "PM_MASTER P1_SW_EVENTS\n", err);

}

val |= PWR_DEVOFF;

err = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, PWR_P1_SW_EVENTS);

if (err)

{

printk(KERN_WARNING "I2C error %d while writing TWL4030" "PM_MASTER P1_SW_EVENTS\n", err);

}

it seems above piece of code works. instead of power OFF omap restarts.

1.do i have to setup some other registers in tps65950 before do the above SW device off?

2.Other electrical design consideration i have look in to?

Thanks!

over 15 years ago

0 dilan over 15 years ago

Prodigy 50 points

Ultimately i found the cause of the problem. This Restart happens in the Beagle board because VBUS is always powerd by 5V supply. So when tps65950 enter WAIT-ON mode. it dtectet that VBUS is high and switch -on the omap again.This can be avoid by set CFG_Px_TRANSITION STARTON_VBUS to logic 0.

0 Javier Martin19423 over 14 years ago in reply to dilan

Intellectual 455 points

Hi,

I know it's been a while since this question came up.

I'm experiencing the same problem with a Beagleboard xM, where VBUS is also always powered by 5V supply, and I have tried to follow dilan's advice, disabling VBUS wakeup with the following code:

               /* Set STARTON_VBUS to logic 0 in CFG_P1_TRANSITION */
               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P1_TRANSITION);
           val &= ~0x20;
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P1_TRANSITION);

               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P2_TRANSITION);
           val &= ~0x20;
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P2_TRANSITION);

               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P3_TRANSITION);
           val &= ~0x20;
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P3_TRANSITION);

             /* Activate DEVOFF bit of P1_SW_EVENTS */
          twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_P1_SW_EVENTS);
           val |= 0x01;
             twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_P1_SW_EVENTS);

However, I still have the problem, when I enter the last I2C command, the board restarts instead of being powered off.

Am I missing something here?

Thank you.

0 Gandhar Dighe over 14 years ago in reply to Javier Martin19423

TI__Genius 15100 points

Please read the config register to check if you can read back the correct value.

0 Javier Martin19423 over 14 years ago in reply to Gandhar Dighe

Intellectual 455 points

No, I can't.

[ 241.225982] setting TWL4030_PM_MASTER_CFG_P1_TRANSITION: 0xdf
[ 241.232238] TWL4030_PM_MASTER_CFG_P1_TRANSITION: 0xff
[ 241.237701] setting TWL4030_PM_MASTER_CFG_P2_TRANSITION: 0xdf
[ 241.243927] TWL4030_PM_MASTER_CFG_P2_TRANSITION: 0xff
[ 241.249328] setting TWL4030_PM_MASTER_CFG_P3_TRANSITION: 0xdf
[ 241.255584] TWL4030_PM_MASTER_CFG_P3_TRANSITION: 0xff

I try to write 0xdf but I readback 0xff.

I used the following code:

               /* Set STARTON_VBUS to logic 0 in CFG_P1_TRANSITION */
               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P1_TRANSITION);
           val &= ~0x20;
        printk("setting TWL4030_PM_MASTER_CFG_P1_TRANSITION: 0x%02x\n", val);
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P1_TRANSITION);
               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P1_TRANSITION);
           printk("TWL4030_PM_MASTER_CFG_P1_TRANSITION: 0x%02x\n", val);

               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P2_TRANSITION);
           val &= ~0x20;
        printk("setting TWL4030_PM_MASTER_CFG_P2_TRANSITION: 0x%02x\n", val);
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P2_TRANSITION);
               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P2_TRANSITION);
           printk("TWL4030_PM_MASTER_CFG_P2_TRANSITION: 0x%02x\n", val);

               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P3_TRANSITION);
           val &= ~0x20;
        printk("setting TWL4030_PM_MASTER_CFG_P3_TRANSITION: 0x%02x\n", val);
               twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_CFG_P3_TRANSITION);
               twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_CFG_P3_TRANSITION);
           printk("TWL4030_PM_MASTER_CFG_P3_TRANSITION: 0x%02x\n", val);

             /* Activate DEVOFF bit of P1_SW_EVENTS */
              twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val, TWL4030_PM_MASTER_P1_SW_EVENTS);
           val |= 0x01;
             twl_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val, TWL4030_PM_MASTER_P1_SW_EVENTS);
         while(1);

This way I can assure that setting DEVOFF to 1 is working since the board is getting reset instead of getting stuck.

However, writing to CFG registers does not work. What can be the reason?

Thank you.

0 Javier Martin19423 over 14 years ago in reply to Javier Martin19423

Intellectual 455 points

OK,

that registers are write protected.

I had to write 0xc0 + 0x0c to KEY_CONFIG register and now it works fine.

Thank you.

Power management

Power management forum

DEVOFF event of TPS65950 will result Restart of the system instead of power off