Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / Documentation / arm / OMAP / omap_pm

diff --git a/Documentation/arm/OMAP/omap_pm b/Documentation/arm/OMAP/omap_pm
index 5389440aade37f50358924239d28f934be15f468..9012bb03909443e4978d9d3a9fd6bbf0f095d907 100644 (file)
--- a/Documentation/arm/OMAP/omap_pm
+++ b/Documentation/arm/OMAP/omap_pm
@@ -127,3 +127,28 @@ implementation needs:
 10. (*pdata->cpu_set_freq)(unsigned long f)
 
 11. (*pdata->cpu_get_freq)(void)
+
+Customizing OPP for platform
+============================
+Defining CONFIG_PM should enable OPP layer for the silicon
+and the registration of OPP table should take place automatically.
+However, in special cases, the default OPP table may need to be
+tweaked, for e.g.:
+ * enable default OPPs which are disabled by default, but which
+   could be enabled on a platform
+ * Disable an unsupported OPP on the platform
+ * Define and add a custom opp table entry
+in these cases, the board file needs to do additional steps as follows:
+arch/arm/mach-omapx/board-xyz.c
+       #include "pm.h"
+       ....
+       static void __init omap_xyz_init_irq(void)
+       {
+               ....
+               /* Initialize the default table */
+               omapx_opp_init();
+               /* Do customization to the defaults */
+               ....
+       }
+NOTE: omapx_opp_init will be omap3_opp_init or as required
+based on the omap family.