clk: Add support for shared gates ...

Sometimes a single software control knob controls multiple gates
in hardware. This patch adds support for shared gates which help
coping this situation. The first gate is registered with the hardware
gate as usual, the others are registered as shared gates which does
not have hardware control itself, but only switches the real hardware
gate.

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

clk: implement CLK_OPS_PARENT_ENABLE ...

Some clocks may only be modified when their parent clocks are enabled.
The kernel has the CLK_OPS_PARENT_ENABLE flag for this purpose.
Implement it for barebox aswell.

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

clk: add clock command completion ...

This adds tab completion for the clk_* commands.

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

clk: of: fix clk_of_table generation ...

We used to collect all sections beginning with __clk_of_table_ in a single
section in the linker using KEEP(*(.__clk_of_table_*)). That the sentinel
entry ended up as the last entry was pure luck, but not always the case.

Instead of putting all entries in different sections we now put all entries
in the same section. Only the sentinel entry gets its own section and is
collected by the linker separately.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reported-by: Andreas Willig <andreas.willig@rafi.de>
Tested-by:  Andreas Willig <andreas.willig@rafi.de>

of: use 'const void *' for struct of_device_id.data ...

Since 2011 barebox' of_device_id struct uses unsigned long type for data field:

    struct of_device_id {
            char *compatible;
            unsigned long data;
    };

Almost always struct of_device_id.data field are used as pointer
and need 'unsigned long' casting.

E.g. see 'git grep -A 4 of_device_id drivers/' output:

    drivers/ata/sata-imx.c:static __maybe_unused struct of_device_id imx_sata_dt_ids[] = {
    drivers/ata/sata-imx.c- {
    drivers/ata/sata-imx.c-         .compatible = "fsl,imx6q-ahci",
    drivers/ata/sata-imx.c-         .data = (unsigned long)&data_imx6,
    drivers/ata/sata-imx.c- }, {

Here is of_device_id struct in linux kernel v4.0:

    struct of_device_id {
            char name[32];
            char type[32];
            char compatible[128];
            const void *data;
    };

Changing of_device_id.data type to 'const void *data' will increase
barebox' linux kernel compatibility and decrease number of 'unsigned
long' casts.

Part of the patch was done using the 'coccinelle' tool with the
following semantic patch:

    @rule1@
    identifier dev;
    identifier type;
    identifier func;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type)
    + dev_get_drvdata(dev, (const void **)&type)
    ...>
    }
    @rule2@
    identifier dev;
    identifier type;
    identifier func;
    identifier data;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type->data)
    + dev_get_drvdata(dev, (const void **)&type->data)
    ...>
    }

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: clk-divider: Respect CLK_DIVIDER_POWER_OF_TWO flag ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: clk-divider: Introduce clk_divider_alloc() and *_free() routines ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: clk-divider: Respect CLK_DIVIDER_HIWORD_MASK flag ...

It is required for Rockchip SoCs where clock settings registers have
write-enable mask in high word.

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: clk-mux: Respect CLK_MUX_HIWORD_MASK flag ...

It is required for Rockchip SoCs where clock settings registers have
write-enable mask in high word.

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: Add fractional divider clock support from Linux kernel ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

CLK: Add support for composite clock from Linux kernel ...

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: gate: add CLK_GATE_HIWORD_MASK flag ...

Clock gates having the CLK_GATE_HIWORD_MASK flag set use the upper 16
bits of the register as a "write enable" mask for the value in the
lower 16 bits.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: gate: add flags argument to clock gate constructor ...

This adds a clk_gate_flags argument to clock gate creation functions
to allow the introduction of new clock gate modifiers.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: move of_clk_get_parent_name() to common clk code ...

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: Add parent round/set rate for mux and gate ...

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

clk: clk-divider: sync with kernel code ...

This updates the clk-divider to Kernel code, but without power-of-two
divider support which we do not need yet. This also adds table based
divider support to the divider.

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

clk: introduce CLK_SET_RATE_PARENT flag ...

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

clk: clk-divider: pass flags to initializers ...

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

clk: clk-fixed-factor: pass flags to initializers ...

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

clk: clk-gate: pass flags to initializers ...

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

clk: clk-mux: pass clk flags from initializers ...

struct clk has a flags field, let the clk-mux initializers set this
field.

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

clk: add of_clk_init and CLK_OF_DECLARE macro ...

This add barebox versions of of_clk_init for parsing and registering
clock providers from DT. Also, a macro CLK_OF_DECLARE is added, that
allows to put init callbacks into its own section that can be linked
in the binary.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: of: introduce of_clk_src_simple_get ...

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

clk: provide static inline wrappers ...

So that drivers can use clk_* functions without having to ifdef
them away.

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

clk: allow to instanciate clk mux without registering it ...

Allows to reuse clk mux code within other clocks.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: allow to instanciate clk gate without registering it ...

Allows to reuse the clk gate code within other clocks.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: add clock lookup from devicetree ...

Taken from the Linuxkernel with some small adjustments for barebox.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: add prototype for clk_is_enabled ...

On MXS we need to poll the busy bit when changing a clock rate, but only
when the parent clocks are enabled. This exposes the already present
function clk_is_enabled which is suitable for this job.

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

clk: gate: Add inverted gate support ...

This adds support for gates which need 0 to enable.

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

clk: divider: Add onebased divider support ...

In some dividers the register value matches the divider value. This
patch adds support for them.

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