Hi Lesly, On Thu, Apr 14, 2011 at 05:57:54PM +0530, Lesly A M wrote: > Workaround for TWL5030 Silicon Errata 27 & 28: > 27 - VDD1, VDD2, may have glitches when their output value is updated. > 28 - VDD1 and / or VDD2 DCDC clock may stop working when internal clock > is switched from internal to external. > > Erratum 27: > If the DCDC regulators is running on their internal oscillator, > negative glitches may occur on VDD1, VDD2 output when voltage is changed. > The OMAP device may reboot if the VDD1 or VDD2 go below the > core minimum operating voltage. > > WORKAROUND > Set up the TWL5030 DC-DC power supplies to use the HFCLKIN instead of > the internal oscillator. > > Erratum 28: > VDD1/VDD2 clock system may hang during switching the clock source from > internal oscillator to external. VDD1/VDD2 output voltages may collapse > if clock stops. > > WORKAROUND > If HFCLK is disabled in OFFMODE, modify the sleep/wakeup sequence and > setuptimes to make sure the switching will happen only when HFCLKIN is stable. > Also use the TWL5030 watchdog to safeguard the first switching from > internal oscillator to HFCLKIN during the TWL5030 init. > > IMPACT > power sequence is changed. > sleep/wakeup time values will be changed. > > The workaround changes are called from twl4030_power_init(), since we have to > make some i2c_read calls to check the TWL4030 version & the i2c will not be > initialized in the early stage. > > This workaround is required for TWL5030 Silicon version less than ES1.2 > The power script & setup time changes are recommended by TI HW team. > > http://omapedia.org/wiki/TWL4030_power_scripts > > Changes taken from TWL4030 Erratum 27 workaround patch by Nishanth Menon. This patch and the following one depend on patch#4. Please re-send it once you agreed with Tony about where it should go. Cheers, Samuel. -- Intel Open Source Technology Centre http://oss.intel.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
