device_tree binding for "amba bus"
From: Stephen Neuendorffer <hidden>
Date: 2011-05-17 20:28:33
Also in:
linux-arm-kernel
Grant, I've taken a quick look at the arm trace buffer driver (arch/arm/kernel/etm.c). This driver uses the amba bus driver (drivers/amba/bus.c). It appears that this driver does three things: 1) ensures that the clock named "apb_pclk" is running. 2) ensures that the regulator named "vcore" is on. 3) queries the core to verify that a hardcoded register has the correct value. None of this seems terribly interesting enough to justify a bus that has a small number of users: drivers/tty/serial/amba-pl010.c, line 788 drivers/tty/serial/amba-pl011.c, line 1477 drivers/input/serio/ambakmi.c, line 197 drivers/watchdog/sp805_wdt.c, line 359 drivers/rtc/rtc-pl031.c, line 478 drivers/rtc/rtc-pl030.c, line 183 drivers/char/hw_random/nomadik-rng.c, line 97 drivers/mmc/host/mmci.c, line 1049 drivers/video/amba-clcd.c, line 538 drivers/gpio/pl061.c, line 344 drivers/spi/amba-pl022.c, line 2284 drivers/dma/amba-pl08x.c, line 2062 drivers/dma/pl330.c, line 841 sound/arm/aaci.c, line 1125 arch/arm/kernel/etm.c: line 421 line 625 And at the very least the hardcoded nature of the names seems, well... hardcoded. Any thoughts about how to abstract this in a device tree? (My thoughts: devices need to reference a clock, devices need to reference a regulator, and it seems to me that the register check could be pulled out into a single call that the devices that care about it can do themselves during probe() ) Steve This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.