clk: qcom: reset: Ensure write completion on reset de/assertion

Trying to toggle the resets in a rapid fashion can lead to the changes
not actually arriving at the clock controller block when we expect them
to. This was observed at least on SM8250.

Read back the value after regmap_update_bits to ensure write completion.

Fixes: b36ba30c8ac6 ("clk: qcom: Add reset controller support")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240105-topic-venus_reset-v2-3-c37eba13b5ce@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

clk: qcom: reset: Commonize the de/assert functions

They do the same thing, except the last argument of the last function
call differs. Commonize them.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240105-topic-venus_reset-v2-2-c37eba13b5ce@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

clk: qcom: reset: Use the correct type of sleep/delay based on length

Use the fsleep() helper that (based on the length of the delay, see: [1])
chooses the correct sleep/delay functions.

[1] https://www.kernel.org/doc/Documentation/timers/timers-howto.txt

Fixes: 2cb8a39b6781 ("clk: qcom: reset: Allow specifying custom reset delay")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230726-topic-qcom_reset-v3-1-5958facd5db2@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

clk: qcom: reset: support resetting multiple bits

This patch adds the support for giving the complete bitmask
in reset structure and reset operation will use this bitmask
for all reset operations.

Currently, reset structure only takes a single bit for each reset
and then calculates the bitmask by using the BIT() macro.

However, this is not sufficient anymore for newer SoC-s like IPQ8074,
IPQ6018 and more, since their networking resets require multiple bits
to be asserted in order to properly reset the HW block completely.

So, in order to allow asserting multiple bits add "bitmask" field to
qcom_reset_map, and then use that bitmask value if its populated in the
driver, if its not populated, then we just default to existing behaviour
and calculate the bitmask on the fly.

Signed-off-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221107132901.489240-1-robimarko@gmail.com

clk: qcom: reset: Allow specifying custom reset delay

The amount of time required between asserting and deasserting the reset
signal can vary depending on the involved hardware component. Sometimes
1 us might not be enough and a larger delay is necessary to conform to
the specifications.

Usually this is worked around in the consuming drivers, by replacing
reset_control_reset() with a sequence of reset_control_assert(), waiting
for a custom delay, followed by reset_control_deassert().

However, in some cases the driver making use of the reset is generic and
can be used with different reset controllers. In this case the reset
time requirement is better handled directly by the reset controller
driver.

Make this possible by adding an "udelay" field to the qcom_reset_map
that allows setting a different reset delay (in microseconds).

Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220706134132.3623415-4-stephan.gerhold@kernkonzept.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282

Based on 1 normalized pattern(s):

this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: qcom: Make reset_control_ops const

The qcom_reset_ops structure is never modified. Make it const.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: qcom: Add reset controller support

Reset controllers and clock controllers are combined into one IP
block on Qualcomm chipsets. Usually a reset signal is associated
with each clock branch but sometimes a reset signal is associated
with a handful of clocks. Either way the register interface is
the same; set a bit to assert a reset and clear a bit to deassert
a reset. Add support for these types of resets signals.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>