Rename struct gpio_t to struct gpio to distinguish from gpio_t

[martinling]

We've been using gpio_t as both the name of a struct, and a typedef for a pointer to that struct.

In C that's possible because struct gpio_t names a different type from gpio_t , but it's confusing, and causes problems when trying to include the types elsewhere.

[martinling]

@antoinevg This will conflict badly with your work in #1657, so if you'd rather include this change in that PR somehow, I can drop this one.

[antoinevg]

@antoinevg This will conflict badly with your work in #1657, so if you'd rather include this change in that PR somehow, I can drop this one.

Thank you @martinling, good call!

Commit with the change is here for perusal and/or any feedback: fd6ab3b

[martinling]

@antoinevg You have the same problem in that commit, just with both types being named gpio instead of both named gpio_t. This causes problems when the code is used elsewhere, like:

firmware/common/gpio.h:28:30: error: conflicting declaration 'typedef const struct gpio_t* gpio_t'
   28 | typedef const struct gpio_t* gpio_t;
      |                              ^~~~~~
firmware/common/gpio.h:28:22: note: previous declaration as 'struct gpio_t'
   28 | typedef const struct gpio_t* gpio_t;
      |                      ^~~~~~

[antoinevg]

Oh doh, it's worse than I thought… Tx!

Updated commit: 10710f0

[martinling]

@antoinevg Yup that looks good. I'll close this one.

[antoinevg]

Re-opened and rebased against main.

[mossmann]

@antoinevg It looks like there are some stragglers in ui_portapack.c that I think should be included.

[antoinevg]

We originally had two types sharing the name gpio_t:

1. A struct called gpio_t

struct gpio {
    const uint32_t mask;
    gpio_port_t* const port;
    volatile uint32_t* const gpio_w;
};

2. …and a typedef which represented a pointer to a const struct gpio_t:

typedef const struct gpio_t* gpio_t;

The struct has been renamed to gpio so now gpio_t only means a const pointer to a struct gpio:

struct gpio {
    const uint32_t mask;
    gpio_port_t* const port;
    volatile uint32_t* const gpio_w;
};

typedef const struct gpio* gpio_t;

The gpio_t's in portapack.c are meant to be const pointers to a struct gpio :-)

(See exchange between me and @martinling above for my shared initial confuzzlement)

[mossmann]

Thank you both!