clk: core: correct clk_set_rate kerneldoc

Remove old and misleading documentation from the previous clk_set_rate
implementaion.

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: core: remove dead code paths

Some static inline dummy functions were left over from before the clock
core was consolidated from several C files down to one.  Remove them.

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: core: clk_calc_new_rates handles NULL parents

It is possible to call clk_set_rate on a clock with a NULL parent.  One
such example is an adjustable-rate root clock.  Ensure that
clk_calc_new_rates does not dereference parent without checking first
and also handle the corner cases gracefully.

Reported-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: core: enforce clk_ops consistency

Documentation/clk.txt has some handsome ASCII art outlining which
clk_ops are mandatory for a given clock, given the capability of the
hardware.  Enforce those mandates with sanity checks in __clk_init.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: use kzalloc in clk_register_mux

Change clk_register_mux to use kzalloc, just like what all other basic
clk registration functions do.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: remove unnecessary EXPORT_SYMBOL_GPL

It makes no sense to have EXPORT_SYMBOL_GPL on static functions.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: add "const" for clk_ops of basic clks

The clk_ops of basic clks should have "const" to match the definition
in "struct clk" and clk_register prototype.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: declare clk_ops of basic clks in clk-provider.h

Besides the static initialization, the clk_ops of basic clks could
also be used by particular clk type being subclass of the basic clks.

For example, clk_busy_divider has the same clk_ops as clk_divider,
except it has to wait for a busy bit before return success with
.set_rate.  clk_busy_divider will somehow reuse clk_ops of clk_divider.

Since clk-provider.h is included by clk-private.h, it's safe to move
those clk_ops declaration of basic clks form  clk-private.h into
clk-provider.h, so that implementation of clks like clk_busy_divider
above do not need to include clk-private.h to access those clk_ops.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: Make clk_get_rate() return 0 on error

Most users of clk_get_rate() actually assume a non zero
return value as a valid rate returned. Returing -EINVAL
might confuse such users, so make it instead return zero
on error.

Besides the return value of clk_get_rate seems to be
'unsigned long'.

Signed-off-by: Rajendra nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: Remove comment for end of CONFIG_COMMON_CLK section

The comment is inaccurate (it actually ends the CONFIG_COMMON_CLK
section, there's no else) and given that we've just got a single level
of ifdef isn't really needed anyway.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: Constify parent name arrays

Drivers should be able to declare their arrays of parent names as const
so the APIs need to accept const arguments.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: constified gate]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: core: copy parent_names & return error codes

This patch cleans up clk_register and solves a few bugs by teaching
clk_register and __clk_init to return error codes (instead of just NULL)
to better align with the existing clk.h api.

Along with that change this patch also introduces a new behavior whereby
clk_register copies the parent_names array, thus allowing platforms to
declare their parent_names arrays as __initdata.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: basic: improve parent_names & return errors

This patch is the basic clk version of 'clk: core: copy parent_names &
return error codes'.

The registration functions are changed to allow the core code to copy
the array of strings and allow platforms to declare those arrays as
__initdata.

This patch also converts all of the basic clk registration functions to
return error codes which better aligns them with the existing clk.h api.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
clk: always pass parent_rate into .round_rate

The parent_rate will likely be used by most .round_rate implementation
no matter whether flag CLK_SET_RATE_PARENT is set or not, so let's
always pass parent_rate into .round_rate.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
clk: pass parent_rate into .set_rate

For most of .set_rate implementation, parent_rate will be used, so just
like passing parent_rate into .recalc_rate, let's pass parent_rate into
.set_rate too.

It also updates the kernel doc for .set_rate ops.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
clk: propagate round_rate for CLK_SET_RATE_PARENT case

Need to propagate round_rate call for the clk that has no .round_rate
operation but with flag CLK_SET_RATE_PARENT set.

For example, clk_mux is a clk with no .round_rate operation.  However,
it could likely be in a clk_set_rate propagation path, saying it has
parent clk who has .round_rate and .set_rate operations.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
clkdev: add clkname to struct clk_lookup

With the generic clock framework we do not necessarily have
a pointer to the struct clk we want to register a lookup
for, so add a const char *clkname field to struct clk_lookup
so that a lookup can be registered with a clock name.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
clk: add a fixed factor clock

Having fixed factors/dividers in hardware is a common pattern, so
add a basic clock type doing this. It basically describes a fixed
factor clock using a nominator and a denominator.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
dmaengine i.MX SDMA: do not depend on grouped clocks

the current i.MX clock support groups together unrelated clocks
to a single clock which is then used by the driver. This can't
be accomplished with the generic clock framework so we instead
request the individual clocks in the driver. For i.MX there are
generally three different clocks:

ipg: bus clock (needed to access registers)
ahb: dma relevant clock, sometimes referred to as hclk in the datasheet
per: bit clock, pixel clock

This patch changes the driver to request the individual clocks.
Currently all clk_get will get the same clock until the SoCs
are converted to the generic clock framework

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
spi i.MX: do not depend on grouped clocks

the current i.MX clock support groups together unrelated clocks
to a single clock which is then used by the driver. This can't
be accomplished with the generic clock framework so we instead
request the individual clocks in the driver. For i.MX there are
generally three different clocks:

ipg: bus clock (needed to access registers)
ahb: dma relevant clock, sometimes referred to as hclk in the datasheet
per: bit clock, pixel clock

This patch changes the driver to request the individual clocks.
Currently all clk_get will get the same clock until the SoCs
are converted to the generic clock framework

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>