AM3358: The INTC interrupt is not getting triggered in AM3358

Hello Anand,

Please note that the subject owner may be on winter holiday.

* This is on a custom board, right?
* What version of software are you running?
* Please show the part of your device tree with the LCD and the interrupt getting included.

Regards,

Nick

Hi Nick,

Thank you for response.

I am still not able to resolve why the INTC  is not getting triggered.

The software version is on a Debian Linux and this is on a BBB.

Please have the details below: (Please note that the LCD is working fine and the display is appearing)

//**************************************************************************In Device tree, the lines where we have enabled the interrupts are as below***************************************************//

fragment@1 {
                target = <&ocp>;
                __overlay__ {
                #address-cells = <1>;
                #size-cells = <1>;
                /*ranges = <0x4830e000 0x1000>;*/
                        lidd_regs: lidd_regs@4830e000 {
                                compatible = "bone-pinmux-helper";
                                pinctrl-names = "default";
                                pinctrl-0 = <&bb_lidd_lcd_pins>;
                                reg = <0x4830e000 0x1000>;
                                interrupt-parent = <&intc>;
                                interrupts = <36>;
                                ti,hwmods = "lcdc";
                                status = "okay";
                        };
                };
};

//**************************************************************************Below are the lines from /proc/interrupts***************************************************//

Driver# cat /proc/interrupts

           CPU0
 16:     178060      INTC  68 Level     gp_timer
 18:          0      INTC   3 Level     arm-pmu
 20:          1      INTC  78 Level     wkup_m3_txev
 21:       5035      INTC  12 Level     49000000.edma_ccint
 23:         41      INTC  14 Level     49000000.edma_ccerrint
 27:          0      INTC  96 Level     44e07000.gpio
 28:          0      INTC  98 Level     4804c000.gpio
 29:          0      INTC  32 Level     481ac000.gpio
 30:          0      INTC  62 Level     481ae000.gpio
 31:         12      INTC  72 Level     44e09000.serial
 36:          0      INTC  46 Level     anufb
 37:       1451      INTC  70 Level     44e0b000.i2c
 38:          0      INTC  71 Level     4802a000.i2c
 39:          0      INTC  30 Level     4819c000.i2c
 40:      14279      INTC  64 Level     mmc0
 41:        908      INTC  28 Level     mmc1
 45:          0      INTC  77 Level     wkup_m3
 51:          0      INTC  75 Level     rtc0
 52:          0      INTC  76 Level     rtc0
 56:          0      INTC  41 Level     4a100000.ethernet
 57:          0      INTC  42 Level     4a100000.ethernet

//****************************************************************************************************************************************************************//

Even though the display works right, the INTC interrupt never gets called. I saw similar issues related to INTC interrupt not appearing.

I even tried to check if the issue was something related to INTC controller. So i enabled all the clocks and was able to write and read to INTC registers, as shown below.

//**************************************************************************Below are the lines from writing and reading to registers of the interrupt controller***************************************************//

                Read INTC_PROTECTION configuration: 00000001
[ 1586.211136]
                Read INTC_PROTECTION configuration:   (null)
[ 1586.211142]
                Read INTC_SYSCONFIG configuration: 00000001
[ 1586.211148]
                Read INTC_IDLE configuration:   (null)
[ 1586.211153]
                Read INTC_IDLE configuration:   (null)
[ 1586.211159]
                Read (INTC_ILR_0 + 36) configuration:   (null)
[ 1586.211165]
                Read (INTC_ILR_0 + 36) configuration:   (null)
[ 1586.211171]
                Read INTC_MIR1 configuration: bffff9fe
[ 1586.211176]
                Read INTC_MIR1 configuration: bffff9ee
[ 1586.211182]
                Read INTC_CONTROL configuration:   (null)
[ 1586.211188]
                Read INTC_CONTROL configuration:   (null)
//****************************************************************************************************************************************************************//

But even after all this I never see the INTC getting called or triggered in /proc/interrupts.

So can you please share some thoughts/ suggestions on this.

Regards

Anand

Hello Anand,

Please note that we do not support Debian on these forums, so the assistance we can offer will be limited. I am reassigning this to our display owner to take a look.

Regards,

Nick

Hello Anand,

Please correct me if I am wrong but based on your observation the DONE bit in the LIDD_CTRL register is set and an interrupt on the CPU side is not generated.

Regards,
Krunal

Hi Krunal,

You are right. When I do a polling on the LIDD_CTRL, the DONE bit gets set. This happens correctly.

But in the driver I need to call a interrupt handler and the LCDC_INT number is 36.

I registered a interrupt request successfully during the initialization of the driver.  But even though the DONE bit gets set based on LCD events, I never see the LCDC_INT (36) getting incremented in the /proc/interrupts. And because of this interrupt handler function never gets called.

Regards

Anand

Hi Anand,

Unfortunately, we do not test Debian and I would recommend you to check with Debian community if there are any bugs associated with the interrupt driver. 

Regards,
Krunal

Hi Krunal,

Thank you. I will try to get answers from other communities.

But could you please clarify one doubt.

In /proc/interrupts (a copy provided below), what does the number in fourth column represent, ie 46?.

Query 1:

The LCD INTC interrupt number is 36 as per the TRM of AM3358.

So in the device tree should I put 36 or 46 as INTC?.

Query 2:

And also, when I do a interrupt request, should I put 36 or 46?. like in the statement below

"ret = request_irq(36, lcd_irq_handler, IRQF_TRIGGER_HIGH, CH_DEVICE_NAME, NULL);"

The value of ret is 0root@beaglebone:/home/SD_Card_LCD/LCD/userspace# cat /proc/interrupts
           CPU0
 16:      61285      INTC  68 Level     gp_timer
 18:          0      INTC   3 Level     arm-pmu
 20:          1      INTC  78 Level     wkup_m3_txev
 21:       5870      INTC  12 Level     49000000.edma_ccint
 23:         67      INTC  14 Level     49000000.edma_ccerrint
 27:          0      INTC  96 Level     44e07000.gpio
 28:          0      INTC  98 Level     4804c000.gpio
 29:          0      INTC  32 Level     481ac000.gpio
 30:          0      INTC  62 Level     481ae000.gpio
 31:         12      INTC  72 Level     44e09000.serial
 36:          0      INTC  46 Level     anufb
 37:       1451      INTC  70 Level     44e0b000.i2c
 38:          0      INTC  71 Level     4802a000.i2c
 39:          0      INTC  30 Level     4819c000.i2c

Regards

Anand

Hello Anand,

The number in the fourth column represent the HW IRQ and it is defined in the DTS+TRM. For example, in the am33xx.dtsi file, the SGX interrupt number is set to 37 and that matches the int number present in Table 6-1.

Regards,
Krunal