Messages in this thread |  | | From | Alexandre Courbot <> | Date | Mon, 2 Dec 2013 21:30:42 +0900 | Subject | Re: [PATCH] gpio: better lookup method for platform GPIOs |
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On Mon, Dec 2, 2013 at 8:11 PM, Heikki Krogerus <heikki.krogerus@linux.intel.com> wrote: > Hi, > > On Mon, Dec 02, 2013 at 07:33:35PM +0900, Alex Courbot wrote: >> On 11/29/2013 08:57 PM, Heikki Krogerus wrote: >> >Hi, >> > >> >On Thu, Nov 28, 2013 at 05:46:28PM +0900, Alexandre Courbot wrote: >> >>@@ -88,16 +89,20 @@ Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. >> >> >> >> A lookup table can then be defined as follows: >> >> >> >>- struct gpiod_lookup gpios_table[] = { >> >>- GPIO_LOOKUP_IDX("gpio.0", 15, "foo.0", "led", 0, GPIO_ACTIVE_HIGH), >> >>- GPIO_LOOKUP_IDX("gpio.0", 16, "foo.0", "led", 1, GPIO_ACTIVE_HIGH), >> >>- GPIO_LOOKUP_IDX("gpio.0", 17, "foo.0", "led", 2, GPIO_ACTIVE_HIGH), >> >>- GPIO_LOOKUP("gpio.0", 1, "foo.0", "power", GPIO_ACTIVE_LOW), >> >>- }; >> >>+struct gpiod_lookup_table gpios_table = { >> >>+ .dev_id = "foo.0", >> >>+ .size = 4, >> >>+ .table = { >> >>+ GPIO_LOOKUP_IDX("gpio.0", 15, "led", 0, GPIO_ACTIVE_HIGH), >> >>+ GPIO_LOOKUP_IDX("gpio.0", 16, "led", 1, GPIO_ACTIVE_HIGH), >> >>+ GPIO_LOOKUP_IDX("gpio.0", 17, "led", 2, GPIO_ACTIVE_HIGH), >> >>+ GPIO_LOOKUP("gpio.0", 1, "power", GPIO_ACTIVE_LOW), >> >>+ }, >> >>+}; >> > >> >Instead of using the size variable, wouldn't it be more clear to >> >expect the array to be null terminated? >> >> This is a zero-length array, its entries are not pointers but >> flattened lookup entries. Thus you cannot simply null-terminate it. >> It would be possible to use { NULL } as a terminator, but this would >> expand into a whole gpiod_lookup and is not very pleasant >> esthetically-speaking. So I think the size member is maybe better >> suited here. > > The gpio_loopup_table would look like this, which IMO is more nicer > looking compared to the extra size variable: > > struct gpiod_lookup_table gpios_table = { > .dev_id = "foo.0", > .table = { > GPIO_LOOKUP_IDX("gpio.0", 15, "led", 0, GPIO_ACTIVE_HIGH), > GPIO_LOOKUP_IDX("gpio.0", 16, "led", 1, GPIO_ACTIVE_HIGH), > GPIO_LOOKUP_IDX("gpio.0", 17, "led", 2, GPIO_ACTIVE_HIGH), > GPIO_LOOKUP("gpio.0", 1, "power", GPIO_ACTIVE_LOW), > { }, > }, > }; > > That would also make it more straight forward to handle in gbiolib.c: > > struct gpiod_lookup *p; > ... > for (p = table->table; p->chip_label; p++) { > ...
Ok, you're obviously right here. Will send a v3 tomorrow morning JST.
Thanks for the review!
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