Device Tree Clock bindings for arch-at91
This binding uses the common clock binding[1].
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
Required properties:
compatible : shall be one of the following:
“atmel,at91sam9x5-sckc” or
“atmel,sama5d4-sckc”:at91 SCKC (Slow Clock Controller) This node contains the slow clock definitions.“atmel,at91sam9x5-clk-slow-osc”:
at91 slow oscillator“atmel,at91sam9x5-clk-slow-rc-osc”:
at91 internal slow RC oscillator“atmel,at91rm9200-pmc” or
“atmel,at91sam9g45-pmc” or
“atmel,at91sam9n12-pmc” or
“atmel,at91sam9x5-pmc” or
“atmel,sama5d3-pmc”:at91 PMC (Power Management Controller) All at91 specific clocks (clocks defined below) must be child node of the PMC node.“atmel,at91sam9x5-clk-slow” (under sckc node)
or
“atmel,at91sam9260-clk-slow” (under pmc node):at91 slow clk“atmel,at91rm9200-clk-main-osc”
“atmel,at91sam9x5-clk-main-rc-osc”at91 main clk sources“atmel,at91sam9x5-clk-main”
“atmel,at91rm9200-clk-main”:at91 main clock“atmel,at91rm9200-clk-master” or
“atmel,at91sam9x5-clk-master”:at91 master clock“atmel,at91sam9x5-clk-peripheral” or
“atmel,at91rm9200-clk-peripheral”:at91 peripheral clocks“atmel,at91rm9200-clk-pll” or
“atmel,at91sam9g45-clk-pll” or
“atmel,at91sam9g20-clk-pllb” or
“atmel,sama5d3-clk-pll”:at91 pll clocks“atmel,at91sam9x5-clk-plldiv”:
at91 plla divisor“atmel,at91rm9200-clk-programmable” or
“atmel,at91sam9g45-clk-programmable” or
“atmel,at91sam9x5-clk-programmable”:at91 programmable clocks“atmel,at91sam9x5-clk-smd”:
at91 SMD (Soft Modem) clock“atmel,at91rm9200-clk-system”:
at91 system clocks“atmel,at91rm9200-clk-usb” or
“atmel,at91sam9x5-clk-usb” or
“atmel,at91sam9n12-clk-usb”:at91 usb clock“atmel,at91sam9x5-clk-utmi”:
at91 utmi clock“atmel,sama5d4-clk-h32mx”:
at91 h32mx clock“atmel,sama5d2-clk-generated”:
at91 generated clock“atmel,sama5d2-clk-audio-pll-frac”:
at91 audio fractional pll“atmel,sama5d2-clk-audio-pll-pad”:
at91 audio pll CLK_AUDIO output pin“atmel,sama5d2-clk-audio-pll-pmc”
at91 audio pll output on AUDIOPLLCLK that feeds the PMC and can be used by peripheral clock or generic clock
Required properties for SCKC node:
- reg : defines the IO memory reserved for the SCKC.
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
For example:
sckc: sckc@fffffe50 {
compatible = “atmel,sama5d3-pmc”;
reg = <0xfffffe50 0x4>
#size-cells = <0>;
#address-cells = <1>;
/* put at91 slow clocks here */
};
Required properties for internal slow RC oscillator:
- #clock-cells : from common clock binding; shall be set to 0.
- clock-frequency : define the internal RC oscillator frequency.
Optional properties:
- clock-accuracy : define the internal RC oscillator accuracy.
For example:
slow_rc_osc: slow_rc_osc {
compatible = “atmel,at91sam9x5-clk-slow-rc-osc”;
clock-frequency = <32768>;
clock-accuracy = <50000000>;
};
Required properties for slow oscillator:
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall encode the main osc source clk sources (see atmel datasheet).
Optional properties:
- atmel,osc-bypass : boolean property. Set this when a clock signal is directly
provided on XIN.
For example:
slow_osc: slow_osc {
compatible = “atmel,at91rm9200-clk-slow-osc”;
#clock-cells = <0>;
clocks = <&slow_xtal>;
};
Required properties for slow clock:
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall encode the slow clk sources (see atmel datasheet).
For example:
clk32k: slck {
compatible = “atmel,at91sam9x5-clk-slow”;
#clock-cells = <0>;
clocks = <&slow_rc_osc &slow_osc>;
};
Required properties for PMC node:
- reg : defines the IO memory reserved for the PMC.
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
- interrupts : shall be set to PMC interrupt line.
- interrupt-controller : tell that the PMC is an interrupt controller.
- #interrupt-cells : must be set to 1. The first cell encodes the interrupt id,
and reflect the bit position in the PMC_ER/DR/SR registers.
You can use the dt macros defined in dt-bindings/clock/at91.h.
0 (AT91_PMC_MOSCS) -> main oscillator ready
1 (AT91_PMC_LOCKA) -> PLL A ready
2 (AT91_PMC_LOCKB) -> PLL B ready
3 (AT91_PMC_MCKRDY) -> master clock ready
6 (AT91_PMC_LOCKU) -> UTMI PLL clock ready
8 .. 15 (AT91_PMC_PCKRDY(id)) -> programmable clock ready
16 (AT91_PMC_MOSCSELS) -> main oscillator selected
17 (AT91_PMC_MOSCRCS) -> RC main oscillator stabilized
18 (AT91_PMC_CFDEV) -> clock failure detected
For example:
pmc: pmc@fffffc00 {
compatible = “atmel,sama5d3-pmc”;
interrupts = <1 4 7>;
interrupt-controller;
#interrupt-cells = <2>;
#size-cells = <0>;
#address-cells = <1>;
/* put at91 clocks here */
};
Required properties for main clock internal RC oscillator:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “<0>”.
- clock-frequency : define the internal RC oscillator frequency.
Optional properties:
- clock-accuracy : define the internal RC oscillator accuracy.
For example:
main_rc_osc: main_rc_osc {
compatible = “atmel,at91sam9x5-clk-main-rc-osc”;
interrupt-parent = <&pmc>;
interrupts = <0>;
clock-frequency = <12000000>;
clock-accuracy = <50000000>;
};
Required properties for main clock oscillator:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “<0>”.
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall encode the main osc source clk sources (see atmel datasheet).
Optional properties:
atmel,osc-bypass : boolean property. Specified if a clock signal is provided
on XIN.clock signal is directly provided on XIN pin.
For example:
main_osc: main_osc {
compatible = “atmel,at91rm9200-clk-main-osc”;
interrupt-parent = <&pmc>;
interrupts = <0>;
#clock-cells = <0>;
clocks = <&main_xtal>;
};
Required properties for main clock:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “<0>”.
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall encode the main clk sources (see atmel datasheet).
For example:
main: mainck {
compatible = “atmel,at91sam9x5-clk-main”;
interrupt-parent = <&pmc>;
interrupts = <0>;
#clock-cells = <0>;
clocks = <&main_rc_osc &main_osc>;
};
Required properties for master clock:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “<3>”.
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the master clock sources (see atmel datasheet) phandles.
e.g. “<&ck32k>, <&main>, <&plla>, <&pllb>”. - atmel,clk-output-range : minimum and maximum clock frequency (two u32
fields). e.g. output = <0 133000000>; <=> 0 to 133MHz. - atmel,clk-divisors : master clock divisors table (four u32 fields).
0 <=> reserved value. e.g. divisors = <1 2 4 6>; - atmel,master-clk-have-div3-pres : some SoC use the reserved value 7 in the
PRES field as CLOCK_DIV3 (e.g sam9x5).
For example:
mck: mck {
compatible = “atmel,at91rm9200-clk-master”;
interrupt-parent = <&pmc>;
interrupts = <3>;
#clock-cells = <0>;
atmel,clk-output-range = <0 133000000>;
atmel,clk-divisors = <1 2 4 0>;
};
Required properties for peripheral clocks:
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
- clocks : shall be the master clock phandle.
e.g. clocks = <&mck>; - name: device tree node describing a specific peripheral clock.
- #clock-cells : from common clock binding; shall be set to 0.
- reg: peripheral id. See Atmel’s datasheets to get a full
list of peripheral ids. - atmel,clk-output-range : minimum and maximum clock frequency
(two u32 fields). Only valid on at91sam9x5-clk-peripheral
compatible IPs.
For example:
periph: periphck {
compatible = “atmel,at91sam9x5-clk-peripheral”;
#size-cells = <0>;
#address-cells = <1>;
clocks = <&mck>;
ssc0_clk {
#clock-cells = <0>;
reg = <2>;
atmel,clk-output-range = <0 133000000>;
};
usart0_clk {
#clock-cells = <0>;
reg = <3>;
atmel,clk-output-range = <0 66000000>;
};
};
Required properties for pll clocks:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “<1>”.
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the main clock phandle.
- reg : pll id.
0 -> PLL A
1 -> PLL B - atmel,clk-input-range : minimum and maximum source clock frequency (two u32
fields). e.g. input = <1 32000000>; <=> 1 to 32MHz. - #atmel,pll-clk-output-range-cells : number of cells reserved for pll output
range description. Sould be set to 2, 3 or 4.- 1st and 2nd cells represent the frequency range (min-max).
- 3rd cell is optional and represents the OUT field value for the given
range. - 4th cell is optional and represents the ICPLL field (PLLICPR
register)
- atmel,pll-clk-output-ranges : pll output frequency ranges + optional parameter
depending on #atmel,pll-output-range-cells property value.
For example:
plla: pllack {
compatible = “atmel,at91sam9g45-clk-pll”;
interrupt-parent = <&pmc>;
interrupts = <1>;
#clock-cells = <0>;
clocks = <&main>;
reg = <0>;
atmel,clk-input-range = <2000000 32000000>;
#atmel,pll-clk-output-range-cells = <4>;
atmel,pll-clk-output-ranges = <74500000 800000000 0 0
69500000 750000000 1 0
64500000 700000000 2 0
59500000 650000000 3 0
54500000 600000000 0 1
49500000 550000000 1 1
44500000 500000000 2 1
40000000 450000000 3 1>;
};
Required properties for plldiv clocks (plldiv = pll / 2):
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the plla clock phandle.
The pll divisor is equal to 2 and cannot be changed.
For example:
plladiv: plladivck {
compatible = “atmel,at91sam9x5-clk-plldiv”;
#clock-cells = <0>;
clocks = <&plla>;
};
Required properties for programmable clocks:
- interrupt-parent : must reference the PMC node.
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
- clocks : shall be the programmable clock source phandles.
e.g. clocks = <&clk32k>, <&main>, <&plla>, <&pllb>; - name: device tree node describing a specific prog clock.
- #clock-cells : from common clock binding; shall be set to 0.
- reg : programmable clock id (register offset from PCKx
register). - interrupts : shall be set to “<(8 + id)>”.
For example:
prog: progck {
compatible = “atmel,at91sam9g45-clk-programmable”;
#size-cells = <0>;
#address-cells = <1>;
interrupt-parent = <&pmc>;
clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>;
prog0 {
#clock-cells = <0>;
reg = <0>;
interrupts = <8>;
};
prog1 {
#clock-cells = <0>;
reg = <1>;
interrupts = <9>;
};
};
Required properties for smd clock:
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the smd clock source phandles.
e.g. clocks = <&plladiv>, <&utmi>;
For example:
smd: smdck {
compatible = “atmel,at91sam9x5-clk-smd”;
#clock-cells = <0>;
clocks = <&plladiv>, <&utmi>;
};
Required properties for system clocks:
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
- name: device tree node describing a specific system clock.
- #clock-cells : from common clock binding; shall be set to 0.
- reg: system clock id (bit position in SCER/SCDR/SCSR registers).
See Atmel's datasheet to get a full list of system clock ids.
For example:
system: systemck {
compatible = “atmel,at91rm9200-clk-system”;
#address-cells = <1>;
#size-cells = <0>;
ddrck {
#clock-cells = <0>;
reg = <2>;
clocks = <&mck>;
};
uhpck {
#clock-cells = <0>;
reg = <6>;
clocks = <&usb>;
};
udpck {
#clock-cells = <0>;
reg = <7>;
clocks = <&usb>;
};
};
Required properties for usb clock:
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the smd clock source phandles.
e.g. clocks = <&pllb>; - atmel,clk-divisors (only available for “atmel,at91rm9200-clk-usb”):
usb clock divisor table.
e.g. divisors = <1 2 4 0>;
For example:
usb: usbck {
compatible = “atmel,at91sam9x5-clk-usb”;
#clock-cells = <0>;
clocks = <&plladiv>, <&utmi>;
};
usb: usbck {
compatible = "atmel,at91rm9200-clk-usb";
#clock-cells = <0>;
clocks = <&pllb>;
atmel,clk-divisors = <1 2 4 0>;
};
Required properties for utmi clock:
- interrupt-parent : must reference the PMC node.
- interrupts : shall be set to “
“. - #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the main clock source phandle.
For example:
utmi: utmick {
compatible = “atmel,at91sam9x5-clk-utmi”;
interrupt-parent = <&pmc>;
interrupts =
#clock-cells = <0>;
clocks = <&main>;
};
Required properties for 32 bits bus Matrix clock (h32mx clock):
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : shall be the master clock source phandle.
For example:
h32ck: h32mxck {
#clock-cells = <0>;
compatible = “atmel,sama5d4-clk-h32mx”;
clocks = <&mck>;
};
Required properties for generated clocks:
- #size-cells : shall be 0 (reg is used to encode clk id).
- #address-cells : shall be 1 (reg is used to encode clk id).
- clocks : shall be the generated clock source phandles.
e.g. clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>, <&audio_pll_pmc>; - name: device tree node describing a specific generated clock.
- #clock-cells : from common clock binding; shall be set to 0.
- reg: peripheral id. See Atmel’s datasheets to get a full
list of peripheral ids. - atmel,clk-output-range : minimum and maximum clock frequency
(two u32 fields).
For example:
gck {
compatible = “atmel,sama5d2-clk-generated”;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>, <&audio_pll_pmc>;
tcb0_gclk: tcb0_gclk {
#clock-cells = <0>;
reg = <35>;
atmel,clk-output-range = <0 83000000>;
};
pwm_gclk: pwm_gclk {
#clock-cells = <0>;
reg = <38>;
atmel,clk-output-range = <0 83000000>;
};
};
