Create a new sh_mtu2_channel structure to hold the channel-specific
fields in preparation for multiple channels per device support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Wolfram Sang <wsa@sang-engineering.com>

The rate and periodic fields are used in a single function only, as
local variables. Remove them from the structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Wolfram Sang <wsa@sang-engineering.com>

The driver claims it needs to register an interrupt handler too early
for request_irq(). This might have been true in the past, but the only
meaningful difference between request_irq() and setup_irq() today is an
additional kzalloc() call in request_irq(). As the driver calls
kmalloc() itself we know that the slab allocator is available, we can
thus switch to request_irq().
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Wolfram Sang <wsa@sang-engineering.com>

This helps locating duplicates and inserting new headers.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Do not include the paragraph about writing to the Free Software
Foundation's mailing address from the sample GPL notice. The FSF has
changed addresses in the past, and may do so again. Linux already
includes a copy of the GPL.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The sh_tmu driver gets the TMU functional clock using a connection ID of
"tmu_fck". While all SH SoCs create clock lookup entries with a NULL
device ID and a "tmu_fck" connection ID, the ARM SoCs use the device ID
only with a NULL connection ID. This works on legacy platforms but will
break on ARM with DT boot.

Fix the situation by using a connection ID of "fck" in the non-legacy
platform data case. Clock lookup entries will be renamed to use the
device ID as well as the connection ID as platforms get moved to new
platform data. The legacy code will eventually be dropped, leaving us
with device ID based clock lookup, compatible with DT boot.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

TMU hardware devices can support multiple channels, with global
registers and per-channel registers. The sh_tmu driver currently models
the hardware with one Linux device per channel. This model makes it
difficult to handle global registers in a clean way.

Add support for a new model that uses one Linux device per timer with
multiple channels per device. This requires changes to platform data,
add new channel configuration fields.

Support for the legacy model is kept and will be removed after all
platforms switch to the new model.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All boards use clock event and clock source ratings of 200 for the TMU,
hardcode it in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Define symbolic macros for all used registers bits.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This prepares the driver for multi-channel support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

One kzalloc a day keeps the bugs away.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use the index as the timer start/stop bit and when printing messages to
identify the channel.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The channel memory base is channel-specific, add it to the channel
structure in preparation for support of multiple channels per device.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The name argument is assigned to const structure fields only, constify
it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Move the channel setup code from sh_tmu_setup to a new
sh_tmu_setup_channel function and call it from sh_tmu_setup.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Channel data is private as well, rename priv to device to make the
distrinction between the core device and the channels clearer.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_tmu_channel structure to hold the channel-specific
field in preparation for multiple channels per device support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The driver claims it needs to register an interrupt handler too early
for request_irq(). This might have been true in the past, but the only
meaningful difference between request_irq() and setup_irq() today is an
additional kzalloc() call in request_irq(). As the driver calls
kmalloc() itself we know that the slab allocator is available, we can
thus switch to request_irq().
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Clock sources don't need an IRQ, request the IRQ only for channels used
as clock event devices.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This helps locating duplicates and inserting new headers.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Do not include the paragraph about writing to the Free Software
Foundation's mailing address from the sample GPL notice. The FSF has
changed addresses in the past, and may do so again. Linux already
includes a copy of the GPL.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The sh_cmt driver gets the CMT functional clock using a connection ID of
"cmt_fck". While all SH SoCs create clock lookup entries with a NULL
device ID and a "cmt_fck" connection ID, the ARM SoCs use the device ID
only with a NULL connection ID. This works on legacy platforms but will
break on ARM with DT boot.

Fix the situation by using a connection ID of "fck" in the non-legacy
platform data case. Clock lookup entries will be renamed to use the
device ID as well as the connection ID as platforms get moved to new
platform data. The legacy code will eventually be dropped, leaving us
with device ID based clock lookup, compatible with DT boot.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

CMT hardware devices can support multiple channels, with global
registers and per-channel registers. The sh_cmt driver currently models
the hardware with one Linux device per channel. This model makes it
difficult to handle global registers in a clean way.

Add support for a new model that uses one Linux device per timer with
multiple channels per device. This requires changes to platform data,
add new channel configuration fields.

Support for the legacy model is kept and will be removed after all
platforms switch to the new model.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All boards use or should use a clock source rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All boards use or should use a clock event rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The CMT is a global timer not restricted to a single CPU. It has a lower
rating than the TMU or ARM architected timer, but is still useful on
systems where the other timers are stopped during CPU sleep.

When multiple timers are available the timers core selects which timer
to use based on timer ratings.

On SMP systems where timer broadcasting is required, one dummy timer is
instantiated per CPU with a rating of 100. On those systems the CMT
timer has a rating of 80, which makes the dummy timer selected by
default on all CPUs. The CMT is then available, and will be used as a
broadcast timer.

On UP systems no dummy timer is instantiated. The CMT timer has a rating
of 125 on those systems and is used directly as a clock event device for
CPU0 without broadcasting.

The CMT rating shouldn't depend on whether we boot a UP or SMP system.
We can't raise the CMT rating to 125 on SMP systems. This would select
CMT as the clock event device for CPU0 as its rating is higher than the
dummy timer rating, and would leave the system without a broadcast
timer. We could instead lower the rating to 80 on all systems, but that
wouldn't reflect reality as ratings between 1 and 99 are documented as
"unfit for real use".

We should raise the rating above 99 and still have the CMT selected as a
broadcast timer. This can be done by changing the cpumask from
cpumask_of(0) to cpu_possible_mask. In that case the timer selection
logic will prefer the previously probed and already selected dummy timer
for all CPUs based on the fact that already selected per-cpu timers are
preferred over new global timers, regardless of their respective
ratings. This also better reflects reality, as the CMT is not tied to
the boot CPU.

Ideally the timer selection logic should realize that the CMT needs to
be used as a broadcast timer on SMP systems as no other broadcast timer
is available, regardless of the cpumask and rating.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Define symbolic macros for all used registers bits.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_cmt_info structure to hold static information about the
device model and reference that structure from the sh_cmt_device
structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This prepares the driver for multi-channel support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

One kzalloc a day keeps the bugs away.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use the index when printing messages to identify the channel.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The channel memory base is channel-specific, add it to the channel
structure in preparation for support of multiple channels per device.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The mapbase variable points to the mapped base address of the channel,
rename it to mapbase_sh. mapbase_str points to the mapped base address
of the CMT device, rename it to mapbase.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The name argument is assigned to const structure fields only, constify
it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Move the channel setup code from sh_cmt_setup to a new
sh_cmt_setup_channel function and call it from sh_cmt_setup.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Channel data is private as well, rename priv to device to make the
distrinction between the core device and the channels clearer.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_cmt_channel structure to hold the channel-specific
field in preparation for multiple channels per device support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The driver claims it needs to register an interrupt handler too early
for request_irq(). This might have been true in the past, but the only
meaningful difference between request_irq() and setup_irq() today is an
additional kzalloc() call in request_irq(). As the driver calls
kmalloc() itself we know that the slab allocator is available, we can
thus switch to request_irq().
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Some versions of gcc even warn about it:

  mm/shmem.c: In function ‘shmem_file_aio_read’:
  mm/shmem.c:1414: warning: ‘error’ may be used uninitialized in this function

If the loop is aborted during the first iteration by one of the two
first break statements, error will be uninitialized.

Introduced by commit 6e58e79d ("introduce copy_page_to_iter, kill
loop over iovec in generic_file_aio_read()").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>