hwrng: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it was merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - fix using wrong clk_disable() in omap_rom_rng_runtime_resume()

'ddata->clk' is enabled by clk_prepare_enable(), it should be disabled
by clk_disable_unprepare().

Fixes: 8d9d4bdc495f ("hwrng: omap3-rom - Use runtime PM instead of custom functions")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

change email address for Pali Rohár

For security reasons I stopped using gmail account and kernel address is
now up-to-date alias to my personal address.

People periodically send me emails to address which they found in source
code of drivers, so this change reflects state where people can contact
me.

[ Added .mailmap entry as per Joe Perches - Linus ]
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hwrng: omap3-rom - Include linux/io.h for virt_to_phys

This patch adds linux/io.h to the header list to ensure that we
get virt_to_phys on all architectures.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Fix unused function warnings

When runtime-pm is disabled, we get a few harmless warnings:

drivers/char/hw_random/omap3-rom-rng.c:65:12: error: unused function 'omap_rom_rng_runtime_suspend' [-Werror,-Wunused-function]
drivers/char/hw_random/omap3-rom-rng.c:81:12: error: unused function 'omap_rom_rng_runtime_resume' [-Werror,-Wunused-function]

Mark these functions as __maybe_unused so gcc can drop them
silently.

Fixes: 8d9d4bdc495f ("hwrng: omap3-rom - Use runtime PM instead of custom functions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Use devm hwrng and runtime PM

This allows us to simplify things more for probe and exit.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Suggested-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Use runtime PM instead of custom functions

Nowadays we have runtime PM, and we can use it with autosuspend_timeout
to idle things automatically. This allows us to get rid of the custom
PM implementation.

We enable clocks and init RNG in runtime_resume, and reset RNG and
disable clocks in runtime_suspend. And then omap3_rom_rng_read()
becomes very simple and we don't need the old functions for
omap3_rom_rng_idle() and omap3_rom_rng_get_random(). We can now also
get rid of pr_fmt as we're using dev_err instead.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Update to use standard driver data

Let's update omap3-rom-rng to use standard driver data to make it easier
to add runtime PM support in the following patch. Just use it for the
rng ops and clock for now. Let's still keep also old rng_clk still around,
we will remove delayed work and rng_clk with runtime PM in the next patch.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Initialize default quality to get data

Similar to commit 62f95ae805fa ("hwrng: omap - Set default quality")
we need to initialize the default quality for the RNG to be used.

The symptoms of this problem is that doing hd /dev/random does not
produce much data at all.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Call clk_disable_unprepare() on exit only if not idled

When unloading omap3-rom-rng, we'll get the following:

WARNING: CPU: 0 PID: 100 at drivers/clk/clk.c:948 clk_core_disable

This is because the clock may be already disabled by omap3_rom_rng_idle().
Let's fix the issue by checking for rng_idle on exit.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: 1c6b7c2108bd ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Fix missing clock by probing with device tree

Commit 0ed266d7ae5e ("clk: ti: omap3: cleanup unnecessary clock aliases")
removed old omap3 clock framework aliases but caused omap3-rom-rng to
stop working with clock not found error.

Based on discussions on the mailing list it was requested by Tero Kristo
that it would be best to fix this issue by probing omap3-rom-rng using
device tree to provide a proper clk property. The other option would be
to add back the missing clock alias, but that does not help moving things
forward with removing old legacy platform_data.

Let's also add a proper device tree binding and keep it together with
the fix.

Cc: devicetree@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: 0ed266d7ae5e ("clk: ti: omap3: cleanup unnecessary clock aliases")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Handle return value of clk_prepare_enable

Here, Clock enable can failed. So adding an error check for
clk_prepare_enable.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - Remove obsoleted functions

Remove omap3_rom_rng_data_present method as it was returning 1 always.
Use .read callback instead of .data_read callback. This avoids use of
obsolete callbacks.

This patch is not tested with hardware as I don't have access to it.

Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: omap3-rom - convert timer to delayed work

We cannot put the HW RNG to idle using a timer because we cannot disable
clocks from atomic context. Use a delayed work instead.

Fixes a warning with CONFIG_DEBUG_MUTEXES on Nokia N900 during boot.

Reported-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

char: hw_random: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

hwrng: omap3-rom - Use devm_clk_get()

Use devm_clk_get() to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: OMAP3 ROM Random Number Generator support

This driver provides kernel-side support for the Random Number
Generator hardware found on OMAP34xx processors.

This driver comes from Maemo 2.6.28 kernel and was tested on Nokia RX-51.
It is platform device because it needs board specific function for smc calls.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>