Commit Graph

49 Commits

Author SHA1 Message Date
Geert Uytterhoeven
a9457ed2eb reset: Align logic and flow in managed helpers
__devm_reset_control_get() and devm_reset_control_array_get() are very
similar, but they do not look similar, due to inverted logic.
Make them more similar, following the "bail out early" paradigm.

Adjust the logic and flow in devm_reset_controller_register() to match
the two other functions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2020-01-02 12:25:05 +01:00
Geert Uytterhoeven
db23808615 reset: Do not register resource data for missing resets
When an optional reset is not present, __devm_reset_control_get() and
devm_reset_control_array_get() still register resource data to release
the non-existing reset on cleanup, which is futile.

Fix this by skipping NULL reset control pointers.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-12-10 11:43:37 +01:00
Geert Uytterhoeven
723c0011c7 reset: Fix {of,devm}_reset_control_array_get kerneldoc return types
of_reset_control_array_get() and devm_reset_control_array_get() return
struct reset_control pointers, not internal struct reset_control_array
pointers, just like all other reset control API calls.

Correct the kerneldoc to match the code.

Fixes: 17c82e206d ("reset: Add APIs to manage array of resets")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-12-10 11:43:37 +01:00
Linus Torvalds
ec939e4c94 Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Olof Johansson:
 "Various driver updates for platforms:

   - A larger set of work on Tegra 2/3 around memory controller and
     regulator features, some fuse cleanups, etc..

   - MMP platform drivers, in particular for USB PHY, and other smaller
     additions.

   - Samsung Exynos 5422 driver for DMC (dynamic memory configuration),
     and ASV (adaptive voltage), allowing the platform to run at more
     optimal operating points.

   - Misc refactorings and support for RZ/G2N and R8A774B1 from Renesas

   - Clock/reset control driver for TI/OMAP

   - Meson-A1 reset controller support

   - Qualcomm sdm845 and sda845 SoC IDs for socinfo"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (150 commits)
  firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
  soc: fsl: add RCPM driver
  dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition
  memory: tegra: Consolidate registers definition into common header
  memory: tegra: Ensure timing control debug features are disabled
  memory: tegra: Introduce Tegra30 EMC driver
  memory: tegra: Do not handle error from wait_for_completion_timeout()
  memory: tegra: Increase handshake timeout on Tegra20
  memory: tegra: Print a brief info message about EMC timings
  memory: tegra: Pre-configure debug register on Tegra20
  memory: tegra: Include io.h instead of iopoll.h
  memory: tegra: Adapt for Tegra20 clock driver changes
  memory: tegra: Don't set EMC rate to maximum on probe for Tegra20
  memory: tegra: Add gr2d and gr3d to DRM IOMMU group
  memory: tegra: Set DMA mask based on supported address bits
  soc: at91: Add Atmel SFR SN (Serial Number) support
  memory: atmel-ebi: switch to SPDX license identifiers
  memory: atmel-ebi: move NUM_CS definition inside EBI driver
  soc: mediatek: Refactor bus protection control
  soc: mediatek: Refactor sram control
  ...
2019-12-05 11:43:31 -08:00
Philipp Zabel
a48108c0c2 reset: improve of_xlate documentation
Mention of_reset_simple_xlate as the default if of_xlate is not set.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-24 10:50:25 +02:00
Philipp Zabel
77d551b9ad reset: fix of_reset_control_get_count kerneldoc comment
Add a newline and remove a superfluous kerneldoc marker before the
of_reset_control_get_count kerneldoc comment, to fix documentation
build warnings:

  ./drivers/reset/core.c:832: warning: Incorrect use of kernel-doc format:  * of_reset_control_get_count - Count number of resets available with a device
  ./drivers/reset/core.c:840: warning: Function parameter or member 'node' not described in 'of_reset_control_get_count'

Fixes: 17c82e206d ("reset: Add APIs to manage array of resets")
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-24 10:26:33 +02:00
Philipp Zabel
47db565251 reset: fix of_reset_simple_xlate kerneldoc comment
The flags parameter never made it into the API, but was erroneously
included in the kerneldoc comment. Remove it to fix a documentation
build warning:

  ./drivers/reset/core.c:86: warning: Excess function parameter 'flags' description in 'of_reset_simple_xlate'

Fixes: 61fc413176 ("reset: Add reset controller API")
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-24 10:26:33 +02:00
Kishon Vijay Abraham I
532f9cd6ee reset: Fix memory leak in reset_control_array_put()
Memory allocated for 'struct reset_control_array' in
of_reset_control_array_get() is never freed in
reset_control_array_put() resulting in kmemleak showing
the following backtrace.

  backtrace:
    [<00000000c5f17595>] __kmalloc+0x1b0/0x2b0
    [<00000000bd499e13>] of_reset_control_array_get+0xa4/0x180
    [<000000004cc02754>] 0xffff800008c669e4
    [<0000000050a83b24>] platform_drv_probe+0x50/0xa0
    [<00000000d3a0b0bc>] really_probe+0x108/0x348
    [<000000005aa458ac>] driver_probe_device+0x58/0x100
    [<000000008853626c>] device_driver_attach+0x6c/0x90
    [<0000000085308d19>] __driver_attach+0x84/0xc8
    [<00000000080d35f2>] bus_for_each_dev+0x74/0xc8
    [<00000000dd7f015b>] driver_attach+0x20/0x28
    [<00000000923ba6e6>] bus_add_driver+0x148/0x1f0
    [<0000000061473b66>] driver_register+0x60/0x110
    [<00000000c5bec167>] __platform_driver_register+0x40/0x48
    [<000000007c764b4f>] 0xffff800008c6c020
    [<0000000047ec2e8c>] do_one_initcall+0x5c/0x1b0
    [<0000000093d4b50d>] do_init_module+0x54/0x1d0

Fixes: 17c82e206d ("reset: Add APIs to manage array of resets")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-22 10:56:41 +02:00
Andy Shevchenko
b89a8da92d reset: Remove copy'n'paste redundancy in the comments
It seems the commit bb475230b8
("reset: make optional functions really optional")
brought couple of redundant lines in the comments.

Drop them here.

Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-03 19:56:51 +02:00
Olof Johansson
d9deea28a8 Merge tag 'reset-fixes-for-v5.2' of git://git.pengutronix.de/git/pza/linux into arm/drivers
Reset controller fix for v5.2

This tag removes a redundant device pointer NULL check from
__reset_control_get_from_lookup to fix a static code checker
warning.

* tag 'reset-fixes-for-v5.2' of git://git.pengutronix.de/git/pza/linux:
  reset: remove redundant null check on pointer dev

Link: https://lore.kernel.org/r/1562236626.6641.13.camel@pengutronix.de
Signed-off-by: Olof Johansson <olof@lixom.net>
2019-07-04 07:04:15 -07:00
Colin Ian King
a71dcd3757 reset: remove redundant null check on pointer dev
Pointer dev is being dereferenced when passed to the inlined
functon dev_name, however, dev is later being null checked
so at first this seems like a potential null pointer dereference.

In fact, _reset_control_get_from_lookup is only ever called from
__reset_control_get, right after checking dev->of_node hence
dev can never be null.  Clean this up by removing the redundant
null check.

Thanks to Philipp Zabel for spotting that dev can never be null.

Addresses-Coverity: ("Dereference before null check")
Fixes: 6691dffab0 ("reset: add support for non-DT systems")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-07-04 12:10:55 +02:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 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 as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Thierry Reding
22815f1825 reset: Add acquire/release support for arrays
Add implementations that apply acquire and release operations to all
reset controls part of a reset control array.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-03-20 11:18:53 +01:00
Thierry Reding
f31d5c24fb reset: Add acquired flag to of_reset_control_array_get()
In order to be able to request an array of reset controls in acquired or
released mode, add the acquired flag to of_reset_control_array_get() and
pass the flag to subsequent calls of __of_reset_control_get().

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-03-20 11:18:36 +01:00
Philipp Zabel
c84b0326d5 reset: add acquired/released state for exclusive reset controls
There are cases where a driver needs explicit control over a reset line
that is exclusively conneted to its device, but this control has to be
temporarily handed over to the power domain controller to handle reset
requirements during power transitions.
Allow multiple exclusive reset controls to be requested in 'released'
state for the same physical reset line, only one of which can be
acquired at the same time.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-20 11:16:55 +01:00
Colin Ian King
151f72f493 reset: fix null pointer dereference on dev by dev_name
The call to dev_name will dereference dev, however, dev is later
being null checked, so there is a possibility of a null pointer
dereference on dev by the call to dev_name. Fix this by null
checking dev first before the call to dev_name

Detected by CoverityScan, CID#1475475 ("Dereference before null check")

Fixes: 2a6cb2b1d83b ("reset: Add reset_control_get_count()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-01-07 16:38:26 +01:00
Geert Uytterhoeven
eaf91db0ab reset: Add reset_control_get_count()
Currently the reset core has internal support for counting the number of
resets for a device described in DT.  Generalize this to devices using
lookup resets, and export it for public use.

This will be used by generic drivers that need to be sure a device is
controlled by a single, dedicated reset line (e.g. vfio-platform).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[p.zabel@pengutronix.de: fixed a typo in reset_control_get_count comment]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-01-07 16:38:26 +01:00
Geert Uytterhoeven
b790c8ea55 reset: Fix potential use-after-free in __of_reset_control_get()
Calling of_node_put() decreases the reference count of a device tree
object, and may free some data.

However, the of_phandle_args structure embedding it is passed to
reset_controller_dev.of_xlate() after that, so it may still be accessed.

Move the call to of_node_put() down to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[p.zabel@pengutronix.de: moved of_node_put after mutex_unlock]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2018-10-08 15:25:21 +02:00
Kees Cook
acafe7e302 treewide: Use struct_size() for kmalloc()-family
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06 11:15:43 -07:00
Bartosz Golaszewski
e2749bb998 reset: modify the way reset lookup works for board files
Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files.

The routine used to register lookup entries takes the corresponding
reset_controlled_dev structure as argument.

It's been determined however that for the first user of this new
interface - davinci psc driver - it will be easier to register the
lookup entries using the reset controller device name.

This patch changes the way lookup entries are added.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
[p.zabel@pengutronix.de: added missing ERR_PTR]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2018-03-27 10:39:47 +02:00
Bartosz Golaszewski
6691dffab0 reset: add support for non-DT systems
The reset framework only supports device-tree. There are some platforms
however, which need to use it even in legacy, board-file based mode.

An example of such architecture is the DaVinci family of SoCs which
supports both device tree and legacy boot modes and we don't want to
introduce any regressions.

We're currently working on converting the platform from its hand-crafted
clock API to using the common clock framework. Part of the overhaul will
be representing the chip's power sleep controller's reset lines using
the reset framework.

This changeset extends the core reset code with a new reset lookup
entry structure. It contains data allowing the reset core to associate
reset lines with devices by comparing the dev_id and con_id strings.

It also provides a function allowing drivers to register lookup entries
with the framework.

The new lookup function is only called as a fallback in case the
of_node field is NULL and doesn't change anything for current users.

Tested with a dummy reset driver with several lookup entries.

An example lookup table registration from a driver can be found below:

static struct reset_control_lookup foobar_reset_lookup[] = {
	RESET_LOOKUP("foo.0", "foo", 15),
	RESET_LOOKUP("bar.0", NULL,   5),
};

foobar_probe()
{
...

        reset_controller_add_lookup(&rcdev, foobar_reset_lookup,
                                    ARRAY_SIZE(foobar_reset_lookup));

...
}

Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: David Lechner <david@lechnology.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2018-03-27 10:39:47 +02:00
Masahiro Yamada
1554bbd4ad reset: make device_reset_optional() really optional
Commit bb475230b8 ("reset: make optional functions really optional")
converted *_get_optional* functions, but device_reset_optional() was
left behind.  Convert it in the same way.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-27 09:16:39 +01:00
Philipp Zabel
21240eb94f reset: make (de)assert report success for self-deasserting reset drivers
By now there are drivers using shared reset controls and (de)assert
calls on platforms with self-deasserting reset lines and thus reset
drivers that do not implement .assert() and .deassert().
As long as the initial state of the reset line is deasserted, there
is no reason for a reset_control_assert call to return an error for
shared reset controls, or for a reset_control_deassert call to return
an error for either shared or exclusive reset controls: after a call
to reset_control_deassert the reset line is guaranteed to be deasserted,
and after a call to reset_control_assert it is valid for the reset
line to stay deasserted for shared reset controls.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-07-19 12:10:48 +02:00
Vivek Gautam
17c82e206d reset: Add APIs to manage array of resets
Many devices may want to request a bunch of resets and control them. So
it's better to manage them as an array. Add APIs to _get() an array of
reset_control, reusing the _assert(), _deassert(), and _reset() APIs for
single reset controls. Since reset controls already may control multiple
reset lines with a single hardware bit, from the user perspective, reset
control arrays are not at all different from single reset controls.
Note that these APIs don't guarantee that the reset lines managed in the
array are handled in any particular order.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
[p.zabel@pengutronix.de: changed API to hide reset control arrays behind
 struct reset_control]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-07-19 10:28:12 +02:00
Philipp Zabel
d25e4334c2 reset: use kref for reference counting
Use kref for reference counting and enjoy the advantages of refcount_t.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-06-06 09:39:20 +02:00