Dear Maarten,
Thanks for your support.
Following your comment, I have found some different ways to configure the "interrupt" parameters in .dts file:
interrupt-parent = <&gpio3>;
interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
# OR
interrupts = <255 2>; /* high-to-low edge triggered */
# OR
interrupts = <23 0x2>; /* falling edge */
I understand the interrupt signal from sc16is752 is cabled to GPIO3 in the Raspberry.
About parameter "interrupts", do you have any information about the possible values to take and what do they mean? Is there a reference manual where this information is available?
The fact that the ttySC0 and ttySC1 devices are not displayed in Raspberry´s /dev folder let me think that something else in .dts file is not properly settled. As far as I know, the i2c communication is initiated by the master device (Raspberry), so no interrupt signal should be necessary to initiate communication and allow the operating system discover the UARTs ports behind the sc16is752. Please correct me if I am wrong.
I include the .dts file. I hope this time outlook does not scramble the text (set to text without format):
// Definitions for SC16IS752 UART
/dts-v1/;
/plugin/;
/ {
compatible = "brcm,bcm2708";
fragment@0 {
target = <&i2c1>;
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
sc16is752: sc16is752@4d { /*4d is the address identified with i2cdetect command*/
compatible = "nxp,sc16is752";
reg = <0x4D>;
clocks = <&klok>;
interrupt-parent = <&gpio>;
interrupts = <23 0x2>; /* falling edge */
klok: klok {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <100000>;
};
};
};
};
};
Dealing with "/boot/config.txt” file, which of following options is the right one?:
#Option 1
dtparam=i2c_arm=on
#Option 2
dtparam=i2c0=on
dtparam=i2c1=on
Thanks again for your support.
Regards,
Juan.
-----Mensaje original-----
De: Maarten Brock [mailto:m.brock@xxxxxxxxxxxxx]
Enviado el: viernes, 29 de abril de 2016 11:58
Para: Juan García Pastor; linux-serial@xxxxxxxxxxxxxxx
Asunto: Re: Raspberry compute module does not find ttySC0 and ttySC1 with SC16IS752
Hello Juan,
Apart from the two I2C connections you will also need an interrupt signal. And this one also requires a pull up.
Maarten
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
