cpufreq: sun50i: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Acked-by: Jernej Škrabec <jernej.skrabec@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: sun50i: Add explicit include for cpu.h

Removing the include of cpu.h from of_device.h causes an error:

drivers/cpufreq/sun50i-cpufreq-nvmem.c:42:19: error: implicit declaration of function ‘get_cpu_device’; did you mean ‘get_device’? [-Werror=implicit-function-declaration]

As of_device.h is not otherwise needed, it can be replaced with of.h
(also implicitly included).

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-15-581e2605fe47@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

cpufreq: sun50i: Switch to use dev_err_probe() helper

In the probe path, convert pr_err() to dev_err_probe() which will
check if error code is -EPROBE_DEFER and prints the error name.
It also sets the defer probe reason which can be checked later
through debugfs. It's more simple in error path.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

OPP: Migrate set-prop-name helper API to use set-config helpers

Now that we have a central API to handle all OPP table configurations,
migrate the set-prop-name family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Acked-by: Samuel Holland <samuel@sholland.org> # sun50i
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: fix memory leak in sun50i_cpufreq_nvmem_probe

--------------------------------------------
unreferenced object 0xffff000010742a00 (size 128):
comm "swapper/0", pid 1, jiffies 4294902015 (age 1187.652s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000b4dfebaa>] __kmalloc+0x338/0x474
[<00000000d6e716db>] sun50i_cpufreq_nvmem_probe+0xc4/0x36c
[<000000007d6082a0>] platform_probe+0x98/0x11c
[<00000000c990f549>] really_probe+0x234/0x5a0
[<000000002d9fecc6>] __driver_probe_device+0x194/0x224
[<00000000cf0b94fa>] driver_probe_device+0x64/0x13c
[<00000000f238e4cf>] __device_attach_driver+0xf8/0x180
[<000000006720e418>] bus_for_each_drv+0xf8/0x160
[<00000000df4f14f6>] __device_attach+0x174/0x29c
[<00000000782002fb>] device_initial_probe+0x20/0x30
[<00000000c2681b06>] bus_probe_device+0xfc/0x110
[<00000000964cf3bd>] device_add+0x5f0/0xcd0
[<000000004b9264e3>] platform_device_add+0x198/0x390
[<00000000fa82a9d0>] platform_device_register_full+0x178/0x210
[<000000009a5daf13>] sun50i_cpufreq_init+0xf8/0x168
[<000000000377cc7c>] do_one_initcall+0xe4/0x570
--------------------------------------------

if sun50i_cpufreq_get_efuse failed, then opp_tables leak.

Fixes: f328584f7bff ("cpufreq: Add sun50i nvmem based CPU scaling driver")
Signed-off-by: Xiaobing Luo <luoxiaobing0926@gmail.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: sun50i: Add missing MODULE_DEVICE_TABLE

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this cpufreq driver when it is
compiled as an external module.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: f328584f7bff8 ("cpufreq: Add sun50i nvmem based CPU scaling driver")
Reviewed-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: sun50i: Fix CPU speed bin detection

I have observed failures to boot on Orange Pi 3, because this driver
determined that my SoC is from the normal bin, but my SoC only works
reliably with the OPP values for the slowest bin.

By querying H6 owners, it was found that e-fuse values found in the wild
are in the range of 1-3, value of 7 was not reported, yet. From this and
from unused defines in BSP code, it can be assumed that meaning of efuse
values on H6 actually is:

- 1 = slowest bin
- 2 = normal bin
- 3 = fastest bin

Vendor code actually treats 0 and 2 as invalid efuse values, but later
treats all invalid values as a normal bin. This looks like a mistake in
bin detection code, that was plastered over by a hack in cpufreq code,
so let's not repeat it here. It probably only works because there are no
SoCs in the wild with efuse value of 0, and fast bin SoCs are made to
use normal bin OPP tables, which is also safe.

Let's play it safe and interpret 0 as the slowest bin, but fix detection
of other bins to match this research. More research will be done before
actual OPP tables are merged.

Fixes: f328584f7bff ("cpufreq: Add sun50i nvmem based CPU scaling driver")
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

cpufreq: Add sun50i nvmem based CPU scaling driver

For some SoCs, the CPU frequency subset and voltage value of each OPP
varies based on the silicon variant in use. The sun50i-cpufreq-nvmem
driver reads the efuse value from the SoC to provide the OPP framework
with required information.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>