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The current implementation of gpio-gate-clk enables/disables the clock
using the GPIO in the ->enable() and ->disable() clock callbacks. This
requires the GPIO to be configurable in atomic contexts. While it is
the case for most memory-mapped GPIO controllers, it is not the case
for GPIO expanders on I2C or SPI.

This commit extends the gpio-gate-clk to check whether the GPIO calls
require sleeping or not. If sleeping is not required, the current
implementation based on ->enable()/->disable() is kept. However, if
sleeping is needed, we instead implement the logic in the ->prepare()
and ->unprepare() hooks. Thanks to this, a gate clock connected to a
GPIO on a GPIO expander can be controlled with the existing driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[sboyd@kernel.org: Mark clk ops static]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

These are all GPL-2.0 files per the existing license text. Replace the
boiler plate with the tag.
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

When changing or retrieving clock parents, the caller is in a sleepable
state (like prepare) so the GPIO operation need not be atomic. Replace
gpiod_{g|s}et_value with gpiod_{g|s}et_value_cansleep in the {g|s}et_parent
calls for the GPIO based clock mux.

This fixes a "slowpath" warning when the GPIO controller is an I2C expander
or something similar.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Requesting the GPIOD_OUT_LOW low will make sure the GPIO is
deasserted when requested. The gpiolib core will make sure that
if the GPIO line is active low, it will be logically driven high
when deasserted, see drivers/gpiolib.c gpiod_configure_flags().

Cc: Sergej Sawazki <ce3a@gmx.de>
Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

After som grep:ing it turns out nothing in the kernel is really calling
clk_[hw_]_register_gpio_[gate|mux](). All existing instances are just
created directly from the device tree probe functions at the bottom of
the clk-gpio.c clock provider file.

This means we can change the signature of the function without any
consequences! Everyone should be using GPIO descriptors now, so let's
just go in and enforce that.

This saves a bit of code since GPIO descriptors know inherently if they
are active low so no need for the code keeping track of that.

We leave it to the caller to come up with the GPIO descriptor. It is
nowadays possible to do that even without a corresponding device, so
no excuse not to pass them around. The one in-kernel user lifecycles
it using devm_gpiod_get() in gpio_clk_driver_probe().

Cc: Sergej Sawazki <ce3a@gmx.de>
Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Add registration APIs in the clk gpio code to return struct
clk_hw pointers instead of struct clk pointers. This way we hide
the struct clk pointer from providers unless they need to use
consumer facing APIs.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

The check for < 0 is impossible now that
of_clk_get_parent_count() returns an unsigned int. Simplify the
code and update the type here.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

We mis-merged the original patch from Russell here and so the
patch went almost all the way, except that we still failed to
probe when there wasn't a clocks property in the DT node. Allow
that case by making a negative value from
of_clk_get_parent_count() into "no parents", like the original
patch did.

Fixes: 7ed88aa2

 ("clk: fix clk-gpio.c with optional clock= DT property")
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk_get() for DT based clks already returns EPROBE_DEFER when the
OF clk provider is not present. So having all this code in the
clk provider to return EPROBE_DEFER when the gpio isn't ready yet
can be replaced with a platform driver that doesn't add the clk
provider until the gpio can be requested. Get rid of the
OF_CLK_DECLARE and convert this to a platform driver instead.
Tested-by: Jyri Sarha <jsarha@ti.com>
Cc: Sergej Sawazki <ce3a@gmx.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Jon Nettleton <jon@solid-run.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

to_clk_*(_hw) macros have been repeatedly defined in many places.
This patch moves all the to_clk_*(_hw) definitions in the common
clock framework to public header clk-provider.h, and drop the local
definitions.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

When the clock DT property is not given, of_clk_get_parent_count()
returns -ENOENT, which then tries to allocate -2 x 4 bytes of memory,
which of course fails, causing the whole driver to fail to create
the clock.

This causes the SolidRun platforms to fail probing the SDHCI1 interface
which is connected to the WiFi.

Fix this by detecting errno codes, skipping the allocation, and fixing
of_clk_gpio_gate_delayed_register_get() to handle a NULL parent_names
array.

Fixes: 80eeb1f0

 ("clk: add gpio controlled clock multiplexer")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>

We might make bad memory allocations if we get (e.g.) -ENOSYS from
of_clk_get_parent_count().

Noticed by Coverity.

Fixes: f66541ba

 ("clk: gpio: Get parent clk names in of_gpio_clk_setup()")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Sergej Sawazki <ce3a@gmx.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>

If we fail to allocate parent_name then we are returning but we missed
freeing data which has already been allocated.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>

Get parent clk names in of_gpio_clk_setup() and store the names
in struct clk_gpio_delayed_register_data instead of doing it from
the clk provider's get() callback. of_clk_get_parent_name() can't
be called in struct of_clk_provider's get() callback since it may
make a call to of_clk_get_from_provider() and this in turn tries
to recursively lock of_clk_mutex.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Cc: Sergej Sawazki <ce3a@gmx.de>
Fixes: 0a4807c2

 ("clk: Make of_clk_get_parent_name() robust with #clock-cells = 1")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Let's encourage const arrays of parent names like other basic
clock types.

Cc: Sergej Sawazki <ce3a@gmx.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

We don't unlock the mutex if we fail to allocate the parent names
array. Unlock it and return an error in this case as well.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Cc: Sergej Sawazki <ce3a@gmx.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

The file clk-gpio-gate.c does not only contain the gate clock, but also
the mux clock. Rename the file to clk-gpio.c.

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Add a common clock driver for basic gpio controlled clock multiplexers.
This driver can be used for devices like 5V41068A or 831721I from IDT
or for discrete multiplexer circuits. The 'select' pin selects one of
two parent clocks.

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
[sboyd@codeaurora.org: Fix error paths to free memory and do it
in the correct order]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Do not output an error message if requesting gpio failes with EPROBE_DEFER.

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Include export.h for EXPORT_SYMBOL_GPL, no need to include module.h.

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

This function is marked as __init, so exposing it to modules
doesn't make any sense and it isn't used by modules anyway.

drivers/clk/clk-gpio-gate.c:192:13: warning: symbol 'of_gpio_gate_clk_setup' was not declared. Should it be static?

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

The active low flag in the DT cell is currently ignored.

This occurs because of_get_named_gpio_flags() does not apply the flags
to the underlying struct gpio_desc so the test in clk_register_gpio_gate()
was bogus.

Note that this patch changes the internal kernel API for
clk_register_gpio_gate() but there are currently no other users.
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Acked-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

The gpio-gate clock uses the gpiod_ APIs but does not directly include the
header for them causing build failures in some configurations including ARM
allnoconfig. Include the header directly.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The added gpio-gate-clock is a basic clock that can be enabled and
disabled trough a gpio output. The DT binding document for the clock
is also added. For EPROBE_DEFER handling the registering of the clock
has to be delayed until of_clk_get() call time.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>