ARM: OMAP3: Fix I/O chain clock line assertion timed out error
We are getting "PRM: I/O chain clock line assertion timed out" errors on early omaps for device tree based booting. This is because we are unconditionally calling reconfigure_io_chain while legacy booting has omap3_has_io_chain_ctrl() checks in place in omap_hwmod.c. For device tree based booting, we are calling reconfigure_io_chain unconditionally from pinctrl framework. So we need to add a check for omap3_has_io_chain_ctrl() to avoid the errors for trying to access a register that does not exist. For es3.0, the documentation in "4.11.2 Device Off-Mode Configuration" just mentions PM_WKEN_WKUP[8] bit. For es3.1, there's a new chapter in documentation for "4.11.2.2 I/O Wake-Up Mechanism" that describes the PM_WKEN_WKUP[16] ST_IO_CHAIN bit. So PM_WKEN_WKUP[16] bit did not get added until in es3.1 probaly to fix issues with flakey wake-up events. We are doing proper checks for ST_IO_CHAIN already in id.c and with omap3_has_io_chain_ctrl(). For more information, see also commit b02b9172 ("ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection"). Let's fix the issue by selecting the right function during init for reconfigure_io_chain depending on the omap revision. For es3.0 and earlier we need to just toggle EN_IO. By doing this, we can move the check for omap3_has_io_chain_ctrl() from omap_hwmod.c to the init code in prm_3xxx.c. And then we can unconditionally call reconfigure_io_chain. Thanks to Paul Walmsley and Nishanth Menon for help with debugging the issue. Fixes: 30a69ef7 ("ARM: OMAP: Move DT wake-up event handling over to use pinctrl-single-omap") Cc: Kevin Hilman <khilman@kernel.org> Cc: Paul Walmsley <paul@pwsan.com> Cc: Tero Kristo <t-kristo@ti.com> Reviewed-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
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