drm/gma500: Add generic code for clock calculation

This patch aims to unify the bits and pieces that are common (or similar
enough) for pll clock calculations. Nothing makes use of this code yet
That will come in later patches.
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

drivers/gpu/drm/gma500/Makefile

@@ -15,6 +15,7 @@ gma500_gfx-y += \
 	  mmu.o \
 	  power.o \
 	  psb_drv.o \
+	  gma_display.o \
 	  psb_intel_display.o \
 	  psb_intel_lvds.o \
 	  psb_intel_modes.o \

drivers/gpu/drm/gma500/gma_display.c

+/*
+ * Copyright © 2006-2011 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Authors:
+ *	Eric Anholt <eric@anholt.net>
+ *	Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
+ */
+
+#include <drm/drmP.h>
+#include "gma_display.h"
+#include "psb_intel_drv.h"
+#include "psb_intel_reg.h"
+#include "psb_drv.h"
+
+/**
+ * Returns whether any output on the specified pipe is of the specified type
+ */
+bool gma_pipe_has_type(struct drm_crtc *crtc, int type)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_mode_config *mode_config = &dev->mode_config;
+	struct drm_connector *l_entry;
+
+	list_for_each_entry(l_entry, &mode_config->connector_list, head) {
+		if (l_entry->encoder && l_entry->encoder->crtc == crtc) {
+			struct psb_intel_encoder *psb_intel_encoder =
+					psb_intel_attached_encoder(l_entry);
+			if (psb_intel_encoder->type == type)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+#define GMA_PLL_INVALID(s) { /* DRM_ERROR(s); */ return false; }
+
+bool gma_pll_is_valid(struct drm_crtc *crtc,
+		      const struct gma_limit_t *limit,
+		      struct gma_clock_t *clock)
+{
+	if (clock->p1 < limit->p1.min || limit->p1.max < clock->p1)
+		GMA_PLL_INVALID("p1 out of range");
+	if (clock->p < limit->p.min || limit->p.max < clock->p)
+		GMA_PLL_INVALID("p out of range");
+	if (clock->m2 < limit->m2.min || limit->m2.max < clock->m2)
+		GMA_PLL_INVALID("m2 out of range");
+	if (clock->m1 < limit->m1.min || limit->m1.max < clock->m1)
+		GMA_PLL_INVALID("m1 out of range");
+	/* On CDV m1 is always 0 */
+	if (clock->m1 <= clock->m2 && clock->m1 != 0)
+		GMA_PLL_INVALID("m1 <= m2 && m1 != 0");
+	if (clock->m < limit->m.min || limit->m.max < clock->m)
+		GMA_PLL_INVALID("m out of range");
+	if (clock->n < limit->n.min || limit->n.max < clock->n)
+		GMA_PLL_INVALID("n out of range");
+	if (clock->vco < limit->vco.min || limit->vco.max < clock->vco)
+		GMA_PLL_INVALID("vco out of range");
+	/* XXX: We may need to be checking "Dot clock"
+	 * depending on the multiplier, connector, etc.,
+	 * rather than just a single range.
+	 */
+	if (clock->dot < limit->dot.min || limit->dot.max < clock->dot)
+		GMA_PLL_INVALID("dot out of range");
+
+	return true;
+}
+
+bool gma_find_best_pll(const struct gma_limit_t *limit,
+		       struct drm_crtc *crtc, int target, int refclk,
+		       struct gma_clock_t *best_clock)
+{
+	struct drm_device *dev = crtc->dev;
+	const struct gma_clock_funcs *clock_funcs =
+					to_psb_intel_crtc(crtc)->clock_funcs;
+	struct gma_clock_t clock;
+	int err = target;
+
+	if (gma_pipe_has_type(crtc, INTEL_OUTPUT_LVDS) &&
+	    (REG_READ(LVDS) & LVDS_PORT_EN) != 0) {
+		/*
+		 * For LVDS, if the panel is on, just rely on its current
+		 * settings for dual-channel.  We haven't figured out how to
+		 * reliably set up different single/dual channel state, if we
+		 * even can.
+		 */
+		if ((REG_READ(LVDS) & LVDS_CLKB_POWER_MASK) ==
+		    LVDS_CLKB_POWER_UP)
+			clock.p2 = limit->p2.p2_fast;
+		else
+			clock.p2 = limit->p2.p2_slow;
+	} else {
+		if (target < limit->p2.dot_limit)
+			clock.p2 = limit->p2.p2_slow;
+		else
+			clock.p2 = limit->p2.p2_fast;
+	}
+
+	memset(best_clock, 0, sizeof(*best_clock));
+
+	/* m1 is always 0 on CDV so the outmost loop will run just once */
+	for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) {
+		for (clock.m2 = limit->m2.min;
+		     (clock.m2 < clock.m1 || clock.m1 == 0) &&
+		      clock.m2 <= limit->m2.max; clock.m2++) {
+			for (clock.n = limit->n.min;
+			     clock.n <= limit->n.max; clock.n++) {
+				for (clock.p1 = limit->p1.min;
+				     clock.p1 <= limit->p1.max;
+				     clock.p1++) {
+					int this_err;
+
+					clock_funcs->clock(refclk, &clock);
+
+					if (!clock_funcs->pll_is_valid(crtc,
+								limit, &clock))
+						continue;
+
+					this_err = abs(clock.dot - target);
+					if (this_err < err) {
+						*best_clock = clock;
+						err = this_err;
+					}
+				}
+			}
+		}
+	}
+
+	return err != target;
+}

drivers/gpu/drm/gma500/gma_display.h

+/*
+ * Copyright © 2006-2011 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Authors:
+ *	Eric Anholt <eric@anholt.net>
+ *	Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
+ */
+
+#ifndef _GMA_DISPLAY_H_
+#define _GMA_DISPLAY_H_
+
+struct gma_clock_t {
+	/* given values */
+	int n;
+	int m1, m2;
+	int p1, p2;
+	/* derived values */
+	int dot;
+	int vco;
+	int m;
+	int p;
+};
+
+struct gma_range_t {
+	int min, max;
+};
+
+struct gma_p2_t {
+	int dot_limit;
+	int p2_slow, p2_fast;
+};
+
+struct gma_limit_t {
+	struct gma_range_t dot, vco, n, m, m1, m2, p, p1;
+	struct gma_p2_t p2;
+	bool (*find_pll)(const struct gma_limit_t *, struct drm_crtc *,
+			 int target, int refclk,
+			 struct gma_clock_t *best_clock);
+};
+
+struct gma_clock_funcs {
+	void (*clock)(int refclk, struct gma_clock_t *clock);
+	const struct gma_limit_t *(*limit)(struct drm_crtc *crtc, int refclk);
+	bool (*pll_is_valid)(struct drm_crtc *crtc,
+			     const struct gma_limit_t *limit,
+			     struct gma_clock_t *clock);
+};
+
+/* Common pipe related functions */
+extern bool gma_pipe_has_type(struct drm_crtc *crtc, int type);
+
+/* Common clock related functions */
+extern const struct gma_limit_t *gma_limit(struct drm_crtc *crtc, int refclk);
+extern void gma_clock(int refclk, struct gma_clock_t *clock);
+extern bool gma_pll_is_valid(struct drm_crtc *crtc,
+			     const struct gma_limit_t *limit,
+			     struct gma_clock_t *clock);
+extern bool gma_find_best_pll(const struct gma_limit_t *limit,
+			      struct drm_crtc *crtc, int target, int refclk,
+			      struct gma_clock_t *best_clock);
+#endif

drivers/gpu/drm/gma500/psb_drv.h

@@ -27,6 +27,7 @@
 #include <drm/gma_drm.h>
 #include "psb_reg.h"
 #include "psb_intel_drv.h"
+#include "gma_display.h"
 #include "intel_bios.h"
 #include "gtt.h"
 #include "power.h"
@@ -675,6 +676,7 @@ struct psb_ops {
 	/* Sub functions */
 	struct drm_crtc_helper_funcs const *crtc_helper;
 	struct drm_crtc_funcs const *crtc_funcs;
+	const struct gma_clock_funcs *clock_funcs;
 
 	/* Setup hooks */
 	int (*chip_setup)(struct drm_device *dev);

drivers/gpu/drm/gma500/psb_intel_display.c

@@ -1251,6 +1251,9 @@ void psb_intel_crtc_init(struct drm_device *dev, int pipe,
 	/* Set the CRTC operations from the chip specific data */
 	drm_crtc_init(dev, &psb_intel_crtc->base, dev_priv->ops->crtc_funcs);
 
+	/* Set the CRTC clock functions from chip specific data */
+	psb_intel_crtc->clock_funcs = dev_priv->ops->clock_funcs;
+
 	drm_mode_crtc_set_gamma_size(&psb_intel_crtc->base, 256);
 	psb_intel_crtc->pipe = pipe;
 	psb_intel_crtc->plane = pipe;

drivers/gpu/drm/gma500/psb_intel_drv.h

@@ -24,6 +24,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
 #include <linux/gpio.h>
+#include "gma_display.h"
 
 /*
  * Display related stuff
@@ -188,6 +189,8 @@ struct psb_intel_crtc {
 
 	/* Saved Crtc HW states */
 	struct psb_intel_crtc_state *crtc_state;
+
+	const struct gma_clock_funcs *clock_funcs;
 };
 
 #define to_psb_intel_crtc(x)	\