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>

clk: at91: move DT compatibility code to its own file

Move all the DT backward compatibility code to its own file so it can be
deleted later.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: at91: allow clock registration from C code

Remove static keyword to allow functions to be used from other units. Also
move some struct and function declarations to pmc.h

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
[sboyd@kernel.org: Include pmc.h]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: at91: move slow clock controller clocks to sckc.c

Move all clocks related to the slow clock controller to sckc.c. This avoids
extern definitions and allows to remove sckc.h

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
[sboyd@codeaurora.org: Mark some functions static]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: Migrate to clk_hw based registration and OF APIs

Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers in this driver, allowing us to
move closer to a clear split of consumer and provider clk APIs.

Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: Remove CLK_IS_ROOT

This flag is a no-op now. Remove usage of the flag.

Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: Remove impossible checks for of_clk_get_parent_count()

These checks for < 0 are impossible now that
of_clk_get_parent_count() returns an unsigned int. Change the
checks for == 0 and update the type.

Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: remove useless includes

Over time, some includes were copy pasted from other clocks drivers but are
not necessary.

Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

clk: at91: make use of syscon/regmap internally

Use the regmap coming from syscon to access the registers instead of using
pmc_read/pmc_write. This allows to avoid passing the at91_pmc structure to
the child nodes of the PMC.

The final benefit is to have each clock register itself instead of having
to iterate over the children.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

clk: at91: Revert "keep slow clk enabled to prevent system hang"

Commit dca1a4b5ff6e ("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.

Now that the slow clock is taken properly by the drivers, this workaround
is not necessary anymore, revert it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: make use of of_clk_parent_fill helper function

Use of_clk_parent_fill to fill in the parent clock names' array.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: Include clk.h and slab.h

This clock provider uses the consumer API, so include clk.h
explicitly. Also include slab.h instead of relying on clkdev.h
for it.

Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: Use of_clk_get_parent_count() instead of open coding

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: at91: keep slow clk enabled to prevent system hang

All slow clk users are not properly claiming it (get + prepare + enable)
before using it.
If all users properly claiming this clock release it, the clock is
disabled, but faulty users still depends on it, and the system hangs.

This fix prevents the slow clock from being disabled, and should solve the
hanging issue, but offending drivers should be patched to properly claim
this clock.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Bo Shen <voice.shen@atmel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Turquette <mturquette@linaro.org>

clk: at91: fix num_parents test in at91sam9260 slow clk implementation

The slow clk block provided by at91sam9260 and derived SoCs should always
have 2 parents.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: at91: add slow clks driver

AT91 slow clk is a clk multiplexer.

In some SoCs (sam9x5, sama5, sam9g45 families) this multiplexer can
choose among 2 sources: an internal RC oscillator circuit and an oscillator
using an external crystal.

In other Socs (sam9260 family) the multiplexer source is hardcoded with
the OSCSEL signal.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>