Hello Simon,
On wo, 2014-06-11 at 17:12 -0600, Simon Glass wrote:
Hi Jeroen,
On 11 June 2014 15:37, Jeroen Hofstee jeroen@myspectrum.nl wrote:
Hello Simon,
in commit 95a260a9
dm: Enable gpio command to support driver model
Now that named GPIO banks are supported, along with a way of obtaining the status of a GPIO (input or output), we can provide an enhanced GPIO command for driver model. Where the driver provides its own operation for obtaining the GPIO state, this is used, otherwise a generic version is sufficient.
you made the following change:
int gpio;
unsigned int gpio;This breaks the code after it though:
/* turn the gpio name into a gpio number */ gpio = name_to_gpio(str_gpio); if (gpio < 0) goto show_usage;And causes warnings with clang like:
common/cmd_gpio.c:159:11: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare] if (gpio < 0) ~~~~ ^ ~
Do you recall why it is made unsigned?
This is because gpio_lookup_name() needs an unsigned (-ve values have no meaning). I think that is what we want ultimately, but perhaps we need to go back to int in the meantime. The simplest fix would probably be to use a separate unsigned variable for the driver model code, and go back to an int for the current (old) code. The difference is that driver model returns a separate error code, whereas the old code combines the GPIO and error into a single value.
ok thanks. I will leave it alone then for now. Since the default lookup, simple_strtoul, is unsigned as well, it won't solve a common problem anyway.
Regards, Jeroen