Hi Tony! On Mon, Mar 31, 2008 at 12:37:41AM +0800, Neng-Yu Tu (Tony Tu) wrote: > I think one of the most important thing in mobile device is power > management design, but up to this point, we still don't have clear > picture of power management design abstract layer for application and > lower level hardware.
agreed. > I saw Intel moblin (http://www.moblin.org/projects/projects_ppm.php) has > some power management profile as interface for applications. Do we need > have smiliar design in hardware power bus and software profile parser > middleware? I think there needs to be a lot of research/planning into the high-level power management profiles. I think top-down engineering is the better approach here. > *What PMU should we use for 6400/6410 (if we use) Samsung has designed a special PMU to accompany the 6400/6410. Actually, one of their partners in Germany or Austria did the PMU design. I think it is very hard to find any other stock component > **WLAN (SDIO/SPI?) SDIO has better software support. SPI only if high-speed SPI (higher clock rates, e.g. 25-40MHz) > **Bluetooth (USB/others?) USB is a bad choice since it both consumes a lot of power in the software stack and host cpu, as well as the lack for proper wakeup handling (separate gpio/irq lines, complex software resume path, etc.) > **Accelerometer (SPI) > **GPS (UART) > **GSM/EDGE (UART) Only GSM/GPRS/EDGE will run on traditional UART. 3G chipset usually have dual-ported memory interface. I strongly recommend to not use USB here for the same reasons as with bluetooth. > **Debug (UART/Others?) UART + JTAG is just fine > **lots LED > **Some mechanical button, some other types those two don't have particular power management aspects > **Wolfson I2S there's litte alternative. well, AC97. but I think it's not that mcuh different from I2S > *Any bus design in hardware we could do for better power management design I think USB is probably the worst. If you keep away from it, everything else that the SoC supports, preferrably simple protocols with DMA-capable host controllers, should be fine. > *Any power management project existing in open source project that could > suit for device power management? the problem is mostly that the existing software deals a lot with what I would call 'power control', i.e. setting the devices into their power states. high-level power management will have to come from product specification. The product specification would have to include individual power states of the device, and specify power consumption targets for the individual stages. -- - Harald Welte <[EMAIL PROTECTED]> http://openmoko.org/ ============================================================================ Software for the world's first truly open Free Software mobile phone
