On Tue, Oct 25, 2011 at 02:01:27PM +0200, Stephen Warren wrote: > *_pinmux_init() register the GPIO and pinmux devices so that they're ready > before any other device needs them. > > *_pinmux_init() are also called by board-dt.c in order to set up the GPIO > and pinmux configurations. In this case, if we register the devices, they > end up being probed once due to this registration, and a second time due > to a device-tree node (or vice-versa). The second probe fails since the > memory regions are already requested. Besides, we don't actually want the > duplicated devices. > > To avoid this duplicate registration, modify *_pinmux_init() to check > whether it's running on a DT machine. If not, register the pinmux devices. > If so, don't register them. > > Finally, modify board-dt.c to call the *_pinmux_init() after all devices have > been instantiated from device-tree. This allows the GPIO and pinmux devices > to be instantiated and initialized before calling functions to configure the > hardware. > > This has one disadvantage: The pinmux and GPIO initialization now happens > after /all/ devices are instantiated, rather than after just gpio and > pinmux but before anything else. So the correct HW configuration is not > in place when e.g. the SD/MMC device is probed. Long-term, this should be > solved by doing both: > > a) Initializing the HW state from DT nodes during GPIO and pinmux device > probe. > b) Using the deferred driver probe mechanism, so that drivers can defer > their probe until after the gpio and pinmux drivers have probed. > > v2: s/int is_dt/bool is_dt/ > v3: Use of_machine_is_compatible inside *_pinmux_init() rather than passing > an explicit parameter into the function from outside. > > Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> > --- > arch/arm/mach-tegra/board-dt.c | 13 +++++++------ > arch/arm/mach-tegra/board-harmony-pinmux.c | 6 +++++- > arch/arm/mach-tegra/board-paz00-pinmux.c | 6 +++++- > arch/arm/mach-tegra/board-seaboard-pinmux.c | 5 ++++- > arch/arm/mach-tegra/board-trimslice-pinmux.c | 5 ++++- > 5 files changed, 25 insertions(+), 10 deletions(-) This looks pretty good. Given the fact that current behavior is buggy, merging it for 3.2 makes sense. Grant, you OK with that for the prerequisite OF patch? -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
