clk: at91: add PMC base support

This patch adds at91 PMC (Power Management Controller) base support.

All at91 clocks managed by the PMC unit will use this framework.

This framework provides the following fonctionalities:
- define a new struct at91_pmc to hide PMC internals (lock, PMC memory
  mapping, irq domain, ...)
- read/write helper functions (pmc_read/write) to access PMC registers
- lock/unlock helper functions (pmc_lock/unlock) to lock/unlock access to
  pmc registers
- a new irq domain and its associated irq chip to request PMC specific
  interrupts (useful for clk prepare callbacks)

The PMC unit is declared as a dt clk provider (CLK_OF_DECLARE), and every
clk using this framework will declare a table of of_at91_clk_init_cb_t
and add it to the pmc_clk_ids table.

When the pmc dt clock setup function is called (by of_clk_init function),
it triggers the registration of every supported child clk (those matching
the definitions in pmc_clk_ids).

This patch copies at91_pmc_base (memory mapping) and at91sam9_idle
(function) from arch/arm/mach-at91/clock.c (which is not compiled if
COMMON_CLK_AT91 is enabled).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC macro file for dt definitions

This patch adds a new macro file for PMC macros.

This macro file includes the definitions of SR (status register) bit
offsets and will be use to reference PMC irqs.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC main clock

This patch adds new at91 main oscillator clock implementation using common
clk framework.

If rate is not provided during clock registration it is calculated using
the slow clock (main clk parent in this case) rate and MCFR register.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC pll clocks

This patch adds new at91 pll clock implementation using common clk framework.

The pll clock layout describe the PLLX register layout.
There are four pll clock layouts:
- at91rm9200
- at91sam9g20
- at91sam9g45
- sama5d3

PLL clocks are given characteristics:
- min/max clock source rate
- ranges of valid clock output rates
- values to set in out and icpll fields for each supported output range

These characteristics are checked during rate change to avoid
over/underclocking.

These characteristics are described in atmel's SoC datasheet in
"Electrical Characteristics" paragraph.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC master clock

This patch adds new at91 master clock implementation using common clk
framework.

The master clock layout describe the MCKR register layout.
There are 2 master clock layouts:
- at91rm9200
- at91sam9x5

Master clocks are given characteristics:
- min/max clock output rate

These characteristics are checked during rate change to avoid
over/underclocking.

These characteristics are described in atmel's SoC datasheet in
"Electrical Characteristics" paragraph.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC system clocks

This patch adds new at91 system clock implementation using common clk
framework.

Some peripherals need to enable a "system" clock in order to work properly.
Each system clock is given an id based on the bit position in SCER/SCDR
registers.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC peripheral clocks

This patch adds new at91 peripheral clock implementation using common clk
framework.

Almost all peripherals provided by at91 SoCs need a clock to work properly.
This clock is enabled/disabled using PCER/PCDR resgisters.

Each peripheral is given an id (see atmel's datasheets) which is used to
define and reference peripheral clocks.

Some new SoCs (at91sam9x5 and sama5d3) provide a new register (PCR) where you
can configure the peripheral clock as a division of the master clock.
This will help reducing the peripherals power comsumption.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC programmable clocks

This patch adds new at91 programmable clocks implementation using common clk
framework.
A programmable clock is a clock which can be exported on a given pin to clock
external devices.
Each programmable clock is given an id (from 0 to 8).
The number of available programmable clocks depends on the SoC you're using.
Programmable clock driver only implements the clock setting (clock rate and
parent setting). It must be chained to a system clock in order to
enable/disable the generated clock.
The PCKX pins used to output the clock signals must be assigned to the
appropriate peripheral (see atmel's datasheets).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC utmi clock

This adds new at91 utmi clock implementation using common clk framework.

This clock is a pll with a fixed factor (x40).
It is used as a source for usb clock.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC usb clock

This patch adds new at91 usb clock implementation using common clk framework.
This clock is used to clock usb ports (ohci, ehci and udc).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clk: at91: add PMC smd clock

This patch adds at91 smd (Soft Modem) clock implementation using common clk
framework.

Not used by any driver right now.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
dt: binding: add at91 clks dt bindings documentation

This patch adds new at91 clks dt bindings documentation.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: move pit timer to common clk framework

Use device tree to get the source clock of the PIT (Periodic Interval Timer).
If the clock is not found in device tree (or dt is not enabled) we'll try to
get it using clk_lookup definitions.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: add new compatible strings for pmc driver

This patch adds new compatible string for PMC node to prepare the
transition to common clk.

These compatible string come from pmc driver in clk subsystem and are
needed to provide new device tree compatibility with old at91 clks
(device tree using common clks will use the new compatible strings).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: prepare sama5 dt boards transition to common clk

This patch prepare the transition to common clk for sama5 dt boards by
replacing the timer init callback.

Clocks registration cannot be done in early init callback (as formerly done
by the old clk implementation) because it requires dynamic allocation
which is not ready yet during early init.

In the other hand, at91 clocks must be registered before
at91sam926x_pit_init is called because PIT (Periodic Interval Timer) driver
request the master clk (mck).

A new function (at91sama5_dt_timer_init) is created to fullfil these needs.
This function registers all at91 clks using the dt definition before
calling the PIT init function.
The device tree clock registration is enabled only if common clk is
selected. Else the old clk registration is been done during
at91_dt_initialize call.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: prepare common clk transition for sama5d3 SoC

This patch encloses sama5d3 old clk registration in
"#if defined(CONFIG_OLD_CLK_AT91) #endif" sections.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/dt: define sama5d3 clocks

Define sama5d3 clocks in sama5d3 device tree.
Add references to the appropriate clocks in each peripheral.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/dt: define sama5d3xek's main clk frequency

Define the main clock frequency for the new main clock node
in sama5d3xcm.dtsi.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: move sama5d3 SoC to common clk

This patch removes the selection of AT91_USE_OLD_CLK when selecting sama5d3
SoC support. This will enable automatically enable COMMON_CLK_AT91 option
and add support for at91 common clk implementation.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/dt: remove old clk material

This patch removes the old main clk node which is now useless as sama5d3
SoCs and boards are no longer compatible with the old at91 clk
implementations.

It also remove old clock definitions (clock definitions using at91 old clk
framework).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>