iommu/omap: add pdata ops for omap_device_enable/idle

Add two new platform data ops to allow the OMAP iommu driver to
be able to invoke the omap_device_enable and omap_device_idle
from within the driver. These are being added to streamline the
sequence between managing the hard reset lines and the clocks
during the suspend path, as the default device pm_domain callback
sequences in omap_device layer are not conducive for the OMAP
IOMMU driver.

This could have been done by expanding the existing pdata ops
for reset management (like in the OMAP remoteproc driver), but
this was chosen to avoid adding additional code in the separate
file in the mach-omap2 layer.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: fix boot issue on remoteprocs with AMMU/Unicache

Support has been added to the OMAP IOMMU driver to fix a boot hang
issue on OMAP remoteprocs with AMMU/Unicache, caused by an improper
AMMU/Unicache state upon initial deassertion of the processor reset.
The issue is described in detail in the next three paragraphs.

All the Cortex M3/M4 IPU processor subsystems in OMAP SoCs have a
AMMU/Unicache IP that dictates the memory attributes for addresses
seen by the processor cores. The AMMU/Unicache is configured/enabled
by the SCACHE_CONFIG.BYPASS bit - a value of 1 enables the cache and
mandates all addresses accessed by M3/M4 be defined in the AMMU. This
bit is not programmable from the host processor. The M3/M4 boot
sequence starts out with the AMMU/Unicache in disabled state, and
SYS/BIOS programs the AMMU regions and enables the Unicache during
one of its initial boot steps. This SCACHE_CONFIG.BYPASS bit is
however enabled by default whenever a RET reset is applied to the IP,
irrespective of whether it was previously enabled or not. The AMMU
registers lose their context whenever this reset is applied. The reset
is effective as long as the MMU portion of the subsystem is enabled
and clocked. This behavior is common to all the IPU and DSP subsystems
that have an AMMU/Unicache.

The IPU boot sequence involves enabling and programming the MMU, and
loading the processor and releasing the reset(s) for the processor.
The PM setup code currently sets the target state for most of the
power domains to RET. The L2 MMU can be enabled, programmed and
accessed properly just fine with the domain in hardware supervised
mode, while the power domain goes through a RET->ON->RET transition
during the programming sequence. However, the ON->RET transition
asserts a RET reset, and the SCACHE_CONFIG.BYPASS bit gets auto-set.
An AMMU fault is thrown immediately when the M3/M4 core's reset is
released since the first instruction address itself will not be
defined in any valid AMMU regions. The ON->RET transition happens
automatically on the power domain after enabling the iommu due to
the hardware supervised mode.

This patch adds and invokes the .set_pwrdm_constraint pdata ops, if
present, during the OMAP IOMMU enable and disable functions to resolve
the above boot hang issue. The ops will allow to invoke a mach-omap2
layer API pwrdm_set_next_pwrst() in a multi-arch kernel environment.
The ops also returns the current power domain state while enforcing
the constraint so that the driver can store it and use it to set back
the power domain state while releasing the constraint. The pdata ops
implementation restricts the target power domain to ON during enable,
and back to the original power domain state during disable, and thereby
eliminating the conditions for the boot issue. The implementation is
effective only when the original power domain state is either RET or
OFF, and is a no-op when it is ON or INACTIVE.

The .set_pwrdm_constraint ops need to be plugged in pdata-quirks
for the affected remote processors to be able to boot properly.

Note that the current issue is seen only on kernels with the affected
power domains programmed to enter RET. For eg., IPU1 on DRA7xx is in a
separate domain and is susceptible to this bug, while the IPU2 subsystem
is within CORE power domain, and CORE RET is not supported on this SoC.
IPUs on OMAP4 and OMAP5 are also susceptible since they are in CORE power
domain, and CORE RET is a valid power target on these SoCs.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iommu/omap: Move data structures to omap-iommu.h

The internal data-structures are scattered over various
header and C files. Consolidate them in omap-iommu.h.

While at this, add the kerneldoc comment for the missing
iommu domain variable and revise the iommu_arch_data name.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
[s-anna@ti.com: revise kerneldoc comments]
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Drop legacy-style device support

All the supported boards that have OMAP IOMMU devices do support
DT boot only now. So, drop the support for the non-DT legacy-style
devices from the OMAP IOMMU driver. Couple of the fields from the
iommu platform data would no longer be required, so they have also
been cleaned up. The IOMMU platform data is still needed though for
performing reset management properly in a multi-arch environment.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

ARM: OMAP2+: Remove omap_mmu_dev_attr structure

The structure omap_mmu_dev_attr was used in the hwmod data for
supplying device-specific data through the .dev_attr field and
used in constructing the platform data for legacy device creation.
The legacy device creation of OMAP IOMMU devices has been cleaned
up, and this structure is no longer needed, so remove it.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

iommu/omap: Remove platform data da_start and da_end fields

The fields were used by the now gone omap-iovmm driver. They're not used
anymore, remove them.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Adapt to runtime pm

Use runtime PM functionality interfaced with hwmod enable/idle
functions, to replace direct clock operations and sysconfig
handling.

Due to reset sequence, pm_runtime_[get|put]_sync must be used, to
avoid possible operations with the module under reset. Because of
this and given that the driver uses spin_locks to protect their
critical sections, we must use pm_runtime_irq_safe in order for the
runtime ops to be happy, otherwise might_sleep_if checks in runtime
framework will complain.

The remaining pm_runtime out of iommu_enable and iommu_disable
corresponds to paths that can be accessed through debugfs, some of
them doesn't work if the module is not enabled first, but in future
if the mmu is idled withouth freeing, these are needed to debug.

Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

iommu/omap: Migrate to hwmod framework

Use hwmod data and device attributes to build and register an
omap device for iommu driver.

- Update the naming convention in isp module.
- Remove unneeded check for number of resources, as this is now
handled by omap_device and prevents driver from loading.
- Now unused, remove platform device and resource data, handling
of sysconfig register for softreset purposes, use default
latency structure.
- Use hwmod API for reset handling.

Signed-off-by: Omar Ramirez Luna <omar.luna@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

ARM: OMAP2+: Move iommu/iovmm headers to platform_data

Move iommu/iovmm headers from plat/ to platform_data/ as part of the
single zImage work.

Partially based on an earlier version by Ido Yariv <ido@wizery.com>.

Cc: Ido Yariv <ido@wizery.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>