Commit Graph

11 Commits

Author SHA1 Message Date
Boris Brezillon 7d8d05d114 misc: atmel_tclib: get and use slow clock
Commit dca1a4b5ff ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the timer counters.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06 12:33:14 +02:00
Gaël PORTAY 84f462371c ARM: at91/tclib: mask interruptions at shutdown and probe
Shutdown properly the timer counter block by masking interruptions. Otherwise,
a segmentation may happen when kexec-ing a new kernel (see backtrace below).
An interruption may happen before the handler is set, leading to a kernel
segmentation fault.

Furthermore, we make sure the interruptions are masked when the driver is
initialized. This will prevent freshly kexec-ed kernel from crashing when
launched from a kernel which does not properly mask interruptions at shutdown.

The backtrace below happened after kexec-ing a new kernel, from a kernel
that did not shut down properly leaving interruptions unmasked.

Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 80000005 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0+ #144
task: c1828aa0 ti: c182a000 task.ti: c182a000
PC is at 0x0
LR is at ch2_irq+0x28/0x30
pc : [<00000000>]    lr : [<c01db904>]    psr: 000000d3
sp : c182bd38  ip : c182bd48  fp : c182bd44
r10: c0373390  r9 : c1825b00  r8 : 60000053
r7 : 00000000  r6 : 00000000  r5 : 00000013  r4 : c036e800
r3 : 00000000  r2 : 00002004  r1 : c036e760  r0 : c036e760
Flags: nzcv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
Control: 0005317f  Table: 20004000  DAC: 00000017
Process swapper (pid: 1, stack limit = 0xc182a1c0)
Stack: (0xc182bd38 to 0xc182c000)
bd20:                                                       c182bd7c c182bd48
bd40: c0045430 c01db8ec 00000000 c18c6f40 c182bd74 c1825b00 c035cec4 00000000
bd60: c182be2c 60000053 c1825b34 00000000 c182bd94 c182bd80 c0045570 c0045408
bd80: 00000000 c1825b00 c182bdac c182bd98 c0047f34 c0045550 00000013 c036619c
bda0: c182bdc4 c182bdb0 c0044da4 c0047e98 0000007f 00000013 c182bde4 c182bdc8
bdc0: c0009e34 c0044d8c fefff000 c0046728 60000053 ffffffff c182bdf4 c182bde8
bde0: c00086a8 c0009ddc c182be74 c182bdf8 c000cb80 c0008674 00000000 00000013
be00: 00000000 00014200 c1825b00 c036e800 00000013 c035ed98 60000053 c1825b34
be20: 00000000 c182be74 c182be20 c182be40 c0047994 c0046728 60000053 ffffffff
be40: 00000013 c036e800 c182be64 c1825b00 00000013 c036e800 c035ed98 c03874bc
be60: 00000004 c036e700 c182be94 c182be78 c004689c c0046398 c036e760 c18c6080
be80: 00000000 c035ed10 c182bedc c182be98 c0348b08 c004684c 0000000c c034dac8
bea0: 004c4b3f c028c338 c036e760 00000013 c014ecc8 c18e67e0 c035b9c0 c0348884
bec0: c035b9c0 c182a020 00000000 00000000 c182bf54 c182bee0 c00089fc c0348894
bee0: c00da51c c1ffcc78 c182bf0c c182bef8 c002d100 c002d09c c1ffcc78 00000000
bf00: c182bf54 c182bf10 c002d308 c0336570 c182bf3c c0334e44 00000003 00000003
bf20: 00000030 c0334b44 c0044d74 00000003 00000003 c034dac8 c0350a94 c0373440
bf40: c0373440 00000030 c182bf94 c182bf58 c0336d24 c000890c 00000003 00000003
bf60: c0336560 c182bf64 c182bf64 6e616e0d 00000000 c0272fc8 00000000 00000000
bf80: 00000000 00000000 c182bfac c182bf98 c0272fd8 c0336bd8 c182a000 00000000
bfa0: 00000000 c182bfb0 c00095d0 c0272fd8 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 374d27cd 33cc33e4
Backtrace:
[<c01db8dc>] (ch2_irq) from [<c0045430>] (handle_irq_event_percpu+0x38/0x148)
[<c00453f8>] (handle_irq_event_percpu) from [<c0045570>] (handle_irq_event+0x30/0x40)
 r10:00000000 r9:c1825b34 r8:60000053 r7:c182be2c r6:00000000 r5:c035cec4
 r4:c1825b00
[<c0045540>] (handle_irq_event) from [<c0047f34>] (handle_fasteoi_irq+0xac/0x11c)
 r4:c1825b00 r3:00000000
[<c0047e88>] (handle_fasteoi_irq) from [<c0044da4>] (generic_handle_irq+0x28/0x38)
 r5:c036619c r4:00000013
[<c0044d7c>] (generic_handle_irq) from [<c0009e34>] (handle_IRQ+0x68/0x88)
 r4:00000013 r3:0000007f
[<c0009dcc>] (handle_IRQ) from [<c00086a8>] (at91_aic_handle_irq+0x44/0x4c)
 r6:ffffffff r5:60000053 r4:c0046728 r3:fefff000
[<c0008664>] (at91_aic_handle_irq) from [<c000cb80>] (__irq_svc+0x40/0x4c)
Exception stack(0xc182bdf8 to 0xc182be40)
bde0:                                                       00000000 00000013
be00: 00000000 00014200 c1825b00 c036e800 00000013 c035ed98 60000053 c1825b34
be20: 00000000 c182be74 c182be20 c182be40 c0047994 c0046728 60000053 ffffffff
[<c0046388>] (__setup_irq) from [<c004689c>] (setup_irq+0x60/0x8c)
 r10:c036e700 r9:00000004 r8:c03874bc r7:c035ed98 r6:c036e800 r5:00000013
 r4:c1825b00
[<c004683c>] (setup_irq) from [<c0348b08>] (tcb_clksrc_init+0x284/0x31c)
 r6:c035ed10 r5:00000000 r4:c18c6080 r3:c036e760
[<c0348884>] (tcb_clksrc_init) from [<c00089fc>] (do_one_initcall+0x100/0x1b4)
 r10:00000000 r9:00000000 r8:c182a020 r7:c035b9c0 r6:c0348884 r5:c035b9c0
 r4:c18e67e0
[<c00088fc>] (do_one_initcall) from [<c0336d24>] (kernel_init_freeable+0x15c/0x224)
 r9:00000030 r8:c0373440 r7:c0373440 r6:c0350a94 r5:c034dac8 r4:00000003
[<c0336bc8>] (kernel_init_freeable) from [<c0272fd8>] (kernel_init+0x10/0xec)
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0272fc8 r4:00000000
[<c0272fc8>] (kernel_init) from [<c00095d0>] (ret_from_fork+0x14/0x24)
 r4:00000000 r3:c182a000
Code: bad PC value
---[ end trace 5b30f0017e282e47 ]---
Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08 10:54:03 +02:00
Gaël PORTAY 4930d247af ARM: at91/tclib: move initialization from alloc to probe
Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately
reporting resource related issues when a TC block user request a TC block.

Moreover, resources retrieval are usually done in the probe function,
thus moving them add some consistency with other drivers.

Initialization is done once, ie not every time a tc block is requested.
If it fails, the device is not appended to the list of tc blocks.

Furhermore, the device id is retrieved at probe as well, avoiding parsing
DT every time the user requests of tc block.

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08 10:54:03 +02:00
Gaël PORTAY 8495497f92 ARM: at91/tclib: prefer using of devm_* functions
Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08 10:54:03 +02:00
Nicolas Ferre 8e315a7b0c ARM: at91/tc/clocksource: Add 32 bit variant to Timer Counter
Some SoC have a 32 bit variant of Timer Counter Blocks. We do not
need the chaining of two 16 bit counters anymore for them.

The SoC nature is deduced from the device tree "compatible" string.
For non-device-tree configurations, backward compatibility is maintained
by using the default 16 bit counter configuration.

This patch addresses both the atmel_tclib and its user: tcb_clksrc
clocksource.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2012-03-01 13:38:49 +01:00
Nicolas Ferre 3a61a5dae4 ARM: at91/tc: add device tree support to atmel_tclib
Device tree support added to atmel_tclib: the generic Timer Counter
library. This is used by the clocksource/clockevent driver tcb_clksrc.

The current DT enabled platforms are also modified to use it:
- .dtsi files are modified to add Timer Counter Block entries
- alias are created to allow identification of each block
- clkdev lookup tables are added for clocks identification.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2012-03-01 13:38:48 +01:00
Nicolas Ferre 298312971b ARM: at91/tclib: take iomem size from resource
Requesting iomem region and ioremaping is now done using
the resource size specified instead of a constant value.

Each <SoC>_device.c file is modified accordingly to reflect
actual user interface size.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
2012-03-01 13:38:48 +01:00
Paul Gortmaker 7a32129a42 drivers/misc: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.
We will need this to avoid build failures pending a future implicit
module.h presence cleanup.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:54 -04:00
Axel Lin a844b43ca0 drivers/misc/atmel_tclib.c: fix a memory leak
request_mem_region() will call kzalloc to allocate memory for struct
resource.  release_resource() unregisters the resource but does not free
the allocated memory, thus use release_mem_region() instead to fix the
memory leak.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:11 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
David Brownell 2a341f5cf5 atmel_tc library
Create <linux/atmel_tc.h> based on <asm-arm/arch-at91/at91-tc.h> and the
at91sam9263 and at32ap7000 datasheets.  Most AT91 and AT32 SOCs have one
or two of these TC blocks, which include three 16-bit timers that can be
interconnected in various ways.

These TC blocks can be used for external interfacing (such as PWM and
measurement), or used as somewhat quirky sixteen-bit timers.

Changes relative to the original version:
  * Drop unneeded inclusion of <linux/mutex.h>
  * Support an arbitrary number of TC blocks
  * Return a struct with information about a TC block from
    atmel_tc_alloc() instead of using a combination of return values
    and "out" parameters.
  * ioremap() the I/O registers on allocation
  * Look up clocks and irqs for all channels
  * Add "name" parameter to atmel_tc_alloc() and use this when
    requesting the iomem resource.
  * Check if the platform provided the necessary resources at probe()
    time instead of when the TCB is allocated.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-03-04 13:41:23 +01:00