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https://github.com/AsahiLinux/u-boot
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74 lines
2.3 KiB
Text
74 lines
2.3 KiB
Text
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* Synopsys DesignWare I2C
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Required properties :
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- compatible : should be "snps,designware-i2c"
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or "mscc,ocelot-i2c" with "snps,designware-i2c" for fallback
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- reg : Offset and length of the register set for the device
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- interrupts : <IRQ> where IRQ is the interrupt number.
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- clocks : phandles for the clocks, see the description of clock-names below.
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The phandle for the "ic_clk" clock is required. The phandle for the "pclk"
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clock is optional. If a single clock is specified but no clock-name, it is
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the "ic_clk" clock. If both clocks are listed, the "ic_clk" must be first.
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Recommended properties :
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- clock-frequency : desired I2C bus clock frequency in Hz.
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Optional properties :
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- clock-names : Contains the names of the clocks:
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"ic_clk", for the core clock used to generate the external I2C clock.
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"pclk", the interface clock, required for register access.
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- reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold
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time, named ICPU_CFG:TWI_DELAY in the datasheet.
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- i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
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This option is only supported in hardware blocks version 1.11a or newer and
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on Microsemi SoCs ("mscc,ocelot-i2c" compatible).
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- i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds.
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This value which is by default 300ns is used to compute the tLOW period.
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- i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
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This value which is by default 300ns is used to compute the tHIGH period.
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Examples :
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i2c@f0000 {
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#address-cells = <1>;
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#size-cells = <0>;
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compatible = "snps,designware-i2c";
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reg = <0xf0000 0x1000>;
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interrupts = <11>;
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clock-frequency = <400000>;
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};
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i2c@1120000 {
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#address-cells = <1>;
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#size-cells = <0>;
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compatible = "snps,designware-i2c";
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reg = <0x1120000 0x1000>;
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interrupt-parent = <&ictl>;
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interrupts = <12 1>;
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clock-frequency = <400000>;
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i2c-sda-hold-time-ns = <300>;
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i2c-sda-falling-time-ns = <300>;
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i2c-scl-falling-time-ns = <300>;
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};x
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i2c@1120000 {
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#address-cells = <1>;
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#size-cells = <0>;
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reg = <0x2000 0x100>;
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clock-frequency = <400000>;
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clocks = <&i2cclk>;
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interrupts = <0>;
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eeprom@64 {
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compatible = "linux,slave-24c02";
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reg = <0x40000064>;
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};
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};
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