From: Purna Chandra Mandal <purna.mandal@xxxxxxxxxxxxx> Document the devicetree bindings for the clock driver found on Microchip PIC32 class devices. Signed-off-by: Purna Chandra Mandal <purna.mandal@xxxxxxxxxxxxx> Signed-off-by: Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Acked-by: Rob Herring <robh@xxxxxxxxxx> --- .../devicetree/bindings/clock/microchip,pic32.txt | 257 ++++++++++++++++++++ 1 file changed, 257 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/microchip,pic32.txt diff --git a/Documentation/devicetree/bindings/clock/microchip,pic32.txt b/Documentation/devicetree/bindings/clock/microchip,pic32.txt new file mode 100644 index 0000000..06540e4 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/microchip,pic32.txt @@ -0,0 +1,257 @@ +Binding for a Clock hardware block found on +certain Microchip PIC32 MCU devices. + +Microchip SoC clocks-node consists of few oscillators, PLL, multiplexer +and few divider nodes. + +We will find only the base address of the clock tree, this base +address is common for some of the subnodes, not all. If no address is +specified for any of subnode base address of the clock tree will be +treated as its base. Each of subnodes follow the same common clock +binding with some additional optional properties. + + clocks_node { + reg = <>; + + spll_node { + ... + }; + + frcdiv_node { + ... + }; + + sysclk_mux_node { + ... + }; + + pbdiv_node { + ... + }; + + refoclk_node { + ... + }; + ... + }; + +This binding uses the common clock binding[1]. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : should be one of "microchip,pic32mzda-clk", + "microchip,pic32mzda-sosc", "microchip,pic32mzda-frcdivclk", + "microchip,pic32mzda-syspll", "microchip,pic32mzda-sysclk-v2", + "microchip,pic32mzda-pbclk", "microchip,pic32mzda-refoclk". +- reg : A Base address and length of the register set. +- interrupts : source of interrupt. + +Optional properties (for subnodes): +- #clock-cells: From common clock binding, should be 0. +- microchip,clock-indices: in multiplexer node clock sources always aren't linear + and contiguous. This property helps define clock-sources with respect to + the mux clock node. +- microchip,ignore-unused : ignore gate request even if the gated clock is unused. +- microchip,status-bit-mask: bitmask for status check. This will be used to confirm + particular operation by clock sub-node is completed. It is dependent sub-node. +- microchip,bit-mask: enable mask, similar to microchip,status-bit-mask. +- microchip,slew-step: enable frequency slewing(stepping) during rate change; + applicable only to sys-clock subnode. + +Example: + +/* PIC32 specific clks */ +pic32_clktree { + #address-cells = <1>; + #size-cells = <1>; + reg = <0x1f801200 0x200>; + compatible = "microchip,pic32mzda-clk"; + ranges = <0 0x1f801200 0x200>; + + /* secondary oscillator; external input on SOSCI pin */ + SOSC:sosc_clk@0 { + #clock-cells = <0>; + compatible = "microchip,pic32mzda-sosc"; + clock-frequency = <32768>; + reg = <0x000 0x10>, /* enable reg */ + <0x1d0 0x10>; /* status reg */ + microchip,bit-mask = <0x02>; /* enable mask */ + microchip,status-bit-mask = <0x10>; /* status-mask*/ + }; + + FRCDIV:frcdiv_clk { + #clock-cells = <0>; + compatible = "microchip,pic32mzda-frcdivclk"; + clocks = <&FRC>; + clock-output-names = "frcdiv_clk"; + }; + + /* System PLL clock */ + SYSPLL:spll_clk@20 { + #clock-cells = <0>; + compatible = "microchip,pic32mzda-syspll"; + reg = <0x020 0x10>, /* SPLL register */ + <0x1d0 0x10>; /* CLKSTAT register */ + clocks = <&POSC>, <&FRC>; + clock-output-names = "sys_pll"; + microchip,status-bit-mask = <0x80>; /* SPLLRDY */ + }; + + /* system clock; mux with postdiv & slew */ + SYSCLK:sys_clk@1c0 { + #clock-cells = <0>; + compatible = "microchip,pic32mzda-sysclk-v2"; + reg = <0x1c0 0x04>; /* SLEWCON */ + clocks = <&FRCDIV>, <&SYSPLL>, <&POSC>, <&SOSC>, + <&LPRC>, <&FRCDIV>; + microchip,clock-indices = <0>, <1>, <2>, <4>, + <5>, <7>; + clock-output-names = "sys_clk"; + }; + + /* UPLL is integral part of USB PHY; UTMI clk for USBCORE */ + UPLL:usb_phy_clk { + #clock-cells = <0>; + compatible = "fixed-clocks"; + clock-frequency = <24000000>; + clock-output-names = "usbphy_clk"; + }; + + /* Peripheral bus1 clock */ + PBCLK1:pb1_clk@140 { + reg = <0x140 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + clock-output-names = "pb1_clk"; + /* used by system modules, not gateable */ + microchip,ignore-unused; + }; + + /* Peripheral bus2 clock */ + PBCLK2:pb2_clk@150 { + reg = <0x150 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + clock-output-names = "pb2_clk"; + /* avoid gating even if unused */ + microchip,ignore-unused; + }; + + /* Peripheral bus3 clock */ + PBCLK3:pb3_clk@160 { + reg = <0x160 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + clock-output-names = "pb3_clk"; + }; + + /* Peripheral bus4 clock(I/O ports, GPIO) */ + PBCLK4:pb4_clk@170 { + reg = <0x170 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + clock-output-names = "pb4_clk"; + }; + + /* Peripheral bus clock */ + PBCLK5:pb5_clk@180 { + reg = <0x180 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + clock-output-names = "pb5_clk"; + }; + + /* Peripheral Bus6 clock; */ + PBCLK6:pb6_clk@190 { + reg = <0x190 0x10>; + compatible = "microchip,pic32mzda-pbclk"; + clocks = <&SYSCLK>; + #clock-cells = <0>; + }; + + /* Peripheral bus7 clock */ + PBCLK7:pb7_clk@1a0 { + reg = <0x1a0 0x10>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-pbclk"; + /* CPU is driven by this clock; so named */ + clock-output-names = "cpu_clk"; + clocks = <&SYSCLK>; + }; + + /* Reference Oscillator clock for SPI/I2S */ + REFCLKO1:refo1_clk@80 { + reg = <0x080 0x20>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-refoclk"; + clocks = <&SYSCLK>, <&PBCLK1>, <&POSC>, <&FRC>, <&LPRC>, + <&SOSC>, <&SYSPLL>, <&REFIx>, <&BFRC>; + microchip,clock-indices = <0>, <1>, <2>, <3>, <4>, + <5>, <7>, <8>, <9>; + clock-output-names = "refo1_clk"; + }; + + /* Reference Oscillator clock for SQI */ + REFCLKO2:refo2_clk@a0 { + reg = <0x0a0 0x20>; + #clock-cells = <0>; + compatible = "microchip,pic32mzda-refoclk"; + clocks = <&SYSCLK>, <&PBCLK1>, <&POSC>, <&FRC>, <&LPRC>, + <&SOSC>, <&SYSPLL>, <&REFIx>, <&BFRC>; + microchip,clock-indices = <0>, <1>, <2>, <3>, <4>, + <5>, <7>, <8>, <9>; + clock-output-names = "refo2_clk"; + }; + + /* Reference Oscillator clock, ADC */ + REFCLKO3:refo3_clk@c0 { + reg = <0x0c0 0x20>; + compatible = "microchip,pic32mzda-refoclk"; + clocks = <&SYSCLK>, <&PBCLK1>, <&POSC>, <&FRC>, <&LPRC>, + <&SOSC>, <&SYSPLL>, <&REFIx>, <&BFRC>; + microchip,clock-indices = <0>, <1>, <2>, <3>, <4>, + <5>, <7>, <8>, <9>; + #clock-cells = <0>; + clock-output-names = "refo3_clk"; + }; + + /* Reference Oscillator clock */ + REFCLKO4:refo4_clk@e0 { + reg = <0x0e0 0x20>; + compatible = "microchip,pic32mzda-refoclk"; + clocks = <&SYSCLK>, <&PBCLK1>, <&POSC>, <&FRC>, <&LPRC>, + <&SOSC>, <&SYSPLL>, <&REFIx>, <&BFRC>; + microchip,clock-indices = <0>,<1>,<2>,<3>,<4>, + <5>,<7>,<8>,<9>; + #clock-cells = <0>; + clock-output-names = "refo4_clk"; + }; + + /* Reference Oscillator clock, LCD */ + REFCLKO5:refo5_clk@100 { + reg = <0x100 0x20>; + compatible = "microchip,pic32mzda-refoclk"; + clocks = <&SYSCLK>,<&PBCLK1>,<&POSC>,<&FRC>,<&LPRC>, + <&SOSC>,<&SYSPLL>,<&REFIx>,<&BFRC>; + microchip,clock-indices = <0>, <1>, <2>, <3>, <4>, + <5>, <7>, <8>,<9>; + #clock-cells = <0>; + clock-output-names = "refo5_clk"; + }; +}; + +The clock consumer should specify the desired clock by having the clocks in its +"clock" phandle cell. For example for UART: + +uart2: serial@<> { + compatible = "microchip,pic32mzda-uart"; + reg = <>; + interrupts = <>; + clocks = <&PBCLK2>; +} -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html