SLIPPY: final changes for FUI

The intel_ddi.c change I thought should be in but I don't see it. It just adds two functions back
that we need.

There are two new files for slippy annotated with comments about how it needs to evolve.

That said, this code has been tested on 3 different panels. Both dev and non-dev usages work.

physbase initialization to static value removed.

Moved spin calls to intel_dp_*

Change-Id: I0480af45c21c7dedcaff7e8be729f0eb554ec78a
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/61136
Commit-Queue: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/4370
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)

src/drivers/intel/gma/intel_dp.c

@@ -621,6 +621,26 @@ static void ironlake_wait_panel_power_cycle(struct intel_dp *intel_dp)
 	ironlake_wait_panel_status(intel_dp, IDLE_CYCLE_MASK, IDLE_CYCLE_VALUE);
 }
 
+void intel_dp_wait_reg(unsigned long addr,
+		       unsigned long val)
+{
+	unsigned long newval;
+	int tries = 0;
+
+	while ((newval = io_i915_read32(addr)) != val) {
+		udelay(1);
+		if (tries++ > 1000) {
+			printk(BIOS_ERR, "%s: Waiting on %08lx to be %08lx, got %08lx\n",
+			       __func__, addr, val, newval);
+			break;
+		}
+	}
+}
+
+void intel_dp_wait_panel_power_control(unsigned long val)
+{
+	intel_dp_wait_reg(PCH_PP_CONTROL, val);
+}
 
 /* Read the current pp_control value, unlocking the register if it
  * is locked