Document: add PLAT_PL061_MAX_GPIOS define
ARM PL061 GPIO driver requires the "PLAT_PL061_MAX_GPIOS" definition.
By default, it's defined to 32 in PL061 GPIO driver. If user wants
more PL061 controllers in platform, user should define the build
flag in platform.mk instead.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
diff --git a/docs/porting-guide.md b/docs/porting-guide.md
index bdbdbc2..89d8251 100644
--- a/docs/porting-guide.md
+++ b/docs/porting-guide.md
@@ -466,6 +466,18 @@
Defines the maximum address that the TSP's progbits sections can occupy.
+If the platform port uses the PL061 GPIO driver, the following constant may
+optionally be defined:
+
+* **PLAT_PL061_MAX_GPIOS**
+ Maximum number of GPIOs required by the platform. This allows control how
+ much memory is allocated for PL061 GPIO controllers. The default value is
+ 32.
+ [For example, define the build flag in platform.mk]:
+ PLAT_PL061_MAX_GPIOS := 160
+ $(eval $(call add_define,PLAT_PL061_MAX_GPIOS))
+
+
### File : plat_macros.S [mandatory]
Each platform must ensure a file of this name is in the system include path with
