Re: [RFC 2.6.27 1/1] gpiolib: add support for batch set of pins

On Tue, Dec 30, 2008 at 11:55 PM, Robin Getz [off-list ref] wrote:

Yeah, I hadn't thought about spanning more than one gpio_chip. That's a good
point.

The currently posted code already supports spanning more than one gpio_chip.

+       do {
+               chip = gpio_to_chip(gpio + i);
+               WARN_ON(extra_checks && chip->can_sleep);
+
+               if (!chip->set_bus) {
+                       while (((gpio + i) < (chip->base + chip->ngpio))
+                               && bitwidth) {
+                               value = values & (1 << i);
+                               chip->set(chip, gpio + i - chip->base, value);
+                               i++;
+                               bitwidth--;
+                       }
+               } else {
+                       value = values >> i; /* shift off the used stuff */
+                       remwidth = ((chip->base + (int) chip->ngpio) -
+                                       ((int) gpio + i));
+                       width = min(bitwidth, remwidth);
+
+                       chip->set_bus(chip, gpio + i - chip->base, value,
+                                       width);
+                       i += width;
+                       bitwidth -= width;
+               }
+       } while (bitwidth);