mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 22:53:55 +08:00
6468276b22
This patch allows to set independantly SCL and SDA falling times. The tLOW period is computed by taking into account the SCL falling time. The tHIGH period is computed by taking into account the SDA falling time. For instance in case the margin on tLOW is considered too small, it can be increased by increasing the SCL falling time which is by default set at 300ns. The same applies for tHIGH period with the help of SDA falling time. Signed-off-by: Romain Baeriswyl <romainba@abilis.com> Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> Acked-by: Shinya Kuribayashi <skuribay@pobox.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
46 lines
1.3 KiB
Plaintext
46 lines
1.3 KiB
Plaintext
* Synopsys DesignWare I2C
|
|
|
|
Required properties :
|
|
|
|
- compatible : should be "snps,designware-i2c"
|
|
- reg : Offset and length of the register set for the device
|
|
- interrupts : <IRQ> where IRQ is the interrupt number.
|
|
|
|
Recommended properties :
|
|
|
|
- clock-frequency : desired I2C bus clock frequency in Hz.
|
|
|
|
Optional properties :
|
|
- i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
|
|
This option is only supported in hardware blocks version 1.11a or newer.
|
|
|
|
- i2c-scl-falling-time : should contain the SCL falling time in nanoseconds.
|
|
This value which is by default 300ns is used to compute the tLOW period.
|
|
|
|
- i2c-sda-falling-time : should contain the SDA falling time in nanoseconds.
|
|
This value which is by default 300ns is used to compute the tHIGH period.
|
|
|
|
Example :
|
|
|
|
i2c@f0000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
compatible = "snps,designware-i2c";
|
|
reg = <0xf0000 0x1000>;
|
|
interrupts = <11>;
|
|
clock-frequency = <400000>;
|
|
};
|
|
|
|
i2c@1120000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
compatible = "snps,designware-i2c";
|
|
reg = <0x1120000 0x1000>;
|
|
interrupt-parent = <&ictl>;
|
|
interrupts = <12 1>;
|
|
clock-frequency = <400000>;
|
|
i2c-sda-hold-time-ns = <300>;
|
|
i2c-sda-falling-time-ns = <300>;
|
|
i2c-scl-falling-time-ns = <300>;
|
|
};
|