Nios V i2c ALT_AVALON_I2C_STATUS_CODE

[andy25]

altera_avalon_i2c.h defines:

typedef alt_u32 ALT_AVALON_I2C_STATUS_CODE;

Which is an unsigned type, which is a problem because the errors are all negative.

This compiles with a warning:

   ALT_AVALON_I2C_STATUS_CODE status = alt_avalon_i2c_master_tx(
         i2c_dev,
         txbuffer,
         2,
         ALT_AVALON_I2C_NO_INTERRUPTS
   );
   if (status == ALT_AVALON_I2C_ERROR) {
      uart.println("error");
   }

main.cpp:221:15: warning: comparison of integer expressions of different signedness: 'ALT_AVALON_I2C_STATUS_CODE' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  221 |    if (status == ALT_AVALON_I2C_ERROR) {

And a switch(status) errors:

freertos_bsp/drivers/inc/altera_avalon_i2c.h:102:33: error: narrowing conversion of '-1' from 'int' to 'long unsigned int' [-Wnarrowing]
  102 | #define ALT_AVALON_I2C_ERROR (-1)

Please change  ALT_AVALON_I2C_STATUS_CODE to a signed type.

-Andy

[EBERLAZARE_I_Intel]

Hi,

Thanks for the feedback, let me verify it on our side.

[EBERLAZARE_I_Intel]

Hi,

Could you share your design that faced this error? That would be helpful.

[andy25]

Not easily.  But I can tell you how to recreate it pretty easy.

1) create a platform designer with a NiosV and an i2c master.  Just enough to generate the .socpinfo file, you dont need anything in quartus.

2) create a default hal bsp, make sure altera_avalon_i2c is being included.

3) create an app, add this to your CMakeLists.txt:

target_compile_options(app.elf PRIVATE
   -fno-exceptions
   -fno-common
   -fno-rtti
   -fvisibility=hidden
   -fvisibility-inlines-hidden
   -D_FORTIFY_SOURCE=2
   -fstack-protector
   -Wall
   -Wextra
   -Wshadow
   -Wdouble-promotion
   -Wnon-virtual-dtor
   -Wcast-align
   -Wunused
   -Wundef
   -Woverloaded-virtual
   -Wpedantic
   -Wconversion # warn on type conversions that may lose data
   -Wsign-conversion
   -Wnull-dereference
   -Wformat=2
   -Wmisleading-indentation
   -Wduplicated-cond
   -Wduplicated-branches
   -Wlogical-op
)

4) In your main add something like:

   ALT_AVALON_I2C_DEV_t *i2c_dev = alt_avalon_i2c_open(IPMB_0_I2C_MASTER_NAME);

   if (i2c_dev == nullptr)
   {
      uart.println("Error: Cannot find /dev/i2c_0");
      return;
   }

   // set remote address
   alt_avalon_i2c_master_target_set(i2c_dev, addr);

   ALT_AVALON_I2C_STATUS_CODE status = alt_avalon_i2c_master_tx(
         i2c_dev,
         txbuffer,
         numValues,
         ALT_AVALON_I2C_NO_INTERRUPTS
   );
    // this gives warnings
   if (status == ALT_AVALON_I2C_SUCCESS) {
      uart.println("send success (staus = %d)", status);
   }
   // this errors
   switch(status) {
      case ALT_AVALON_I2C_SUCCESS:
         uart.println("send success (staus = %d)", status);
         break;
   }

[EBERLAZARE_I_Intel]

Hi,

Thanks a lot for the inputs, I will test and channel this to our internal team as feedback.

[EBERLAZARE_I_Intel]

Hi,

I got it, just to confirm again, is this warning is on the FreeRTOS? Did you see same warning on the Altera HAL?

[andy25]

In the steps posed above:

   Step 2) create a default hal bsp

Its in HAL. 

[EBERLAZARE_I_Intel]

Hi,

Reason I ask was because in the initial post, it was calling out the "freertos_bsp" folder regarding the switch(status) error.

[EBERLAZARE_I_Intel]

Hi,

Thanks again, this feedback have been channeled to our internal team.

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