BIOS5 PSP GPIO Driver Confusion

.....and....

What does this mean?

4.6 Gpio Bank Event Numbers

The bank event numbers are configured for the Gpio banks on the EVM OMAPL138

can be obtained from the SoC reference Guide. This table should be used when

configuring the HWI interrupt select numbers and HWI number for a given bank that

the user wishes to use.

The HWI's are defined at HWI7 = 0, HWI8 = 1, HWI9 = 2, HWI10 = 3 in your example. If I want to use GP2[14], the bank2 EVT is 49. Where do I use EVT 49?

Folks, I'm dead in the water here.........can I get some help? Are you supporting PSP or should I move on to something else?

Mike,

Unfortunately, the PSP experts are not in our time zone -- they are located in India.  I'll push them on them to look at your question first thing, but you will not likely get a response before tonight.

Dave

Dave,

Thanks for the update. Wow, so I get one interaction per work day. I don't think this is going to work out. Guess I'll just go back to doing it the hard way.

MikeH

Hi Mike,

First of all, we are sorry for misleading you because of a wrong comment made in the "Example Description".
It should be -> This example demonstrates the use of GPIO driver/module. The sample does this by taking input on GPIO pin GPIO4_0(configured as input pin), via an MMCSD card inserted in the MMCSD slot.

#define GPIO_BANK_0                 0x00 /* BANK 0 */

#define GPIO_BANK_4                 4u     /* BANK 4 */

#define GPIO4_0_PIN                  65u  /* This is the Pin Number for the 0th pin of GPIO bank 4 (Find details in http://www.ti.com/litv/pdf/sprufl8b Page65 )   */

The GP4[0] is connected to 'SD_INS' pin.And, the 'SD_INS' is connected to 'CD' of the 'MMC'. Whenever, we insert/eject an MMC/SD card, the signal on the SD_INS line changes to low/high. If we have enabled interrupts to be generated on both edges of the GP4[0] pin's transition, then an interrupt is generated on both insertion(falling edge)and ejection(rising edge) of the MMC/SD card. (These details are obtained from the OMAPL138 schematics and unfortunately i donot have the links to it!). 

Hence we program the GPIO4_0_PIN.

Referring to the (omap-l138) Page33 shows: Table 3-1. DSP Interrupt Map

Event    Interrupt Name    Source
54         GPIO_B4INT         GPIO Bank 4 Interrupt

To determine the hardware interrupt numbers for the gpio, following table needs to be considered

The event number to HWI mapping should be as follows:
HWI                                  event number

7                                          0-31

8                                          32-63

9                                          64-95

10                                        96-127

Hence for "OMAPL138"  SOC the event number to HWI mapping should be as below:

Source                             event number     map to  HWI

GPIO Bank 4 Interrupt           54                        8

GPIO Bank 5 Interrupt           59                        8

GPIO Bank 7 Interrupt           72                        9

Only a few are named above. So we have /* gpioParams.BankParams[GPIO_BANK_4].hwiNum  = 8u; */

Secondly,
struct Gpio_PinCmdArg {
    Uint32 pin;       /* This is the Pin number */
    Uint32 value;   /* This is the value to check if the pin direction is input or output */
};

Hope this answers your question..

Thanks & regards,

Raghavendra

Raghavendra,

Thanks for your response.

Raghavendra Maddikery said:

#define GPIO4_0_PIN                  65u  /* This is the Pin Number for the 0th pin of GPIO bank 4 (Find details in http://www.ti.com/litv/pdf/sprufl8b Page65 )   */

There is no page 65 in sprufl8b! Can you point out exactly where this pin number is documented? This is the essence of much of my confusion and frustration. From what I can tell (by methodically stepping through each line of your code), this pin number is calculated by multiplying the bank number by 32, then adding the pin number position in the bank, then adding one. So for my case (GP2P14) it is (16*2)+14+1 = 47. I find it rather interesting that no where in your user manual is this mentioned.

Raghavendra Maddikery said:

To determine the hardware interrupt numbers for the gpio, following table needs to be considered

The event number to HWI mapping should be as follows:
HWI                                  event number

7                                          0-31

8                                          32-63

9                                          64-95

10                                        96-127

Where did this mapping come from? Is this what you have created for your example, or is it documented somewhere? Also, I assume that this mapping needs to be done in the bios .tcf file...? Does this feed and interrupt handler somewhere that identifies the specific interrupt that occurred?

Raghavendra Maddikery said:

Secondly,
struct Gpio_PinCmdArg {
    Uint32 pin;       /* This is the Pin number */
    Uint32 value;   /* This is the value to check if the pin direction is input or output */
};

 

I'm sure this must be obvious to you, but it is not to me. I am using PIN 14 of GPIO bank 2. Therefore, I would expect "pin" to be = 14. If this is not the case, then you should point this out SOMEWHERE in your documentation!

As you can tell, I am very frustrated with your documentation and example software, as well as the time difference between us. I hope you can provide some answers to my above questions.

MikeH

Thank you.