[i2c] Question on ds1339's oscillator

[Rodolfo Giometti]

Hello,

I'm looking at code rtc-ds1307.c in order to add IRQ management support
and I don't understand this code:

                /* oscillator is off; need to turn it on */
                if ((ds1307->regs[0] & DS1337_BIT_nEOSC)
                                || (ds1307->regs[1] & DS1337_BIT_OSF)) {
no_osc_start:
                        printk(KERN_ERR "no %s oscillator code\n",
                                chip->name);
                        goto exit_free;
                }

Why if the oscillator is off we cannot use the RTC? Disabling such
code, and the oscillator, the RTC works perfectly.

Anyway if I wish using the IRQ pin I have to disable the square wave
output (INTCN=1 of register 0Eh) so I can keep the oscillator off...

Rodolfo

-- 

GNU/Linux Solutions                  e-mail:    giometti at enneenne.com
Linux Device Driver                             giometti at gnudd.com
Embedded Systems                     		giometti at linux.it
UNIX programming                     phone:     +39 349 2432127