apply.c

/*
 * Copyright (C) 2011 Texas Instruments
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that 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, see <http://www.gnu.org/licenses/>.
 */

#define DSS_SUBSYS_NAME "APPLY"

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>

#include <video/omapdss.h>

#include "dss.h"
#include "dss_features.h"

/*
 * We have 4 levels of cache for the dispc settings. First two are in SW and
 * the latter two in HW.
 *
 * +--------------------+
 * |overlay/manager_info|
 * +--------------------+
 *          v
 *        apply()
 *          v
 * +--------------------+
 * |     dss_cache      |
 * +--------------------+
 *          v
 *      write_regs()
 *          v
 * +--------------------+
 * |  shadow registers  |
 * +--------------------+
 *          v
 * VFP or lcd/digit_enable
 *          v
 * +--------------------+
 * |      registers     |
 * +--------------------+
 */

struct ovl_priv_data {
	/* If true, cache changed, but not written to shadow registers. Set
	 * in apply(), cleared when registers written. */
	bool dirty;
	/* If true, shadow registers contain changed values not yet in real
	 * registers. Set when writing to shadow registers, cleared at
	 * VSYNC/EVSYNC */
	bool shadow_dirty;

	bool enabled;

	struct omap_overlay_info info;

	enum omap_channel channel;

	u32 fifo_low;
	u32 fifo_high;
};

struct manager_cache_data {
	/* If true, cache changed, but not written to shadow registers. Set
	 * in apply(), cleared when registers written. */
	bool dirty;
	/* If true, shadow registers contain changed values not yet in real
	 * registers. Set when writing to shadow registers, cleared at
	 * VSYNC/EVSYNC */
	bool shadow_dirty;

	struct omap_overlay_manager_info info;

	bool manual_update;
	bool do_manual_update;
};

static struct {
	spinlock_t lock;
	struct ovl_priv_data ovl_priv_data_array[MAX_DSS_OVERLAYS];
	struct manager_cache_data manager_cache[MAX_DSS_MANAGERS];

	bool irq_enabled;
} dss_cache;

static struct ovl_priv_data *get_ovl_priv(struct omap_overlay *ovl)
{
	return &dss_cache.ovl_priv_data_array[ovl->id];
}

void dss_apply_init(void)
{
	spin_lock_init(&dss_cache.lock);
}

static bool ovl_manual_update(struct omap_overlay *ovl)
{
	return ovl->manager->device->caps & OMAP_DSS_DISPLAY_CAP_MANUAL_UPDATE;
}

static bool mgr_manual_update(struct omap_overlay_manager *mgr)
{
	return mgr->device->caps & OMAP_DSS_DISPLAY_CAP_MANUAL_UPDATE;
}

static int overlay_enabled(struct omap_overlay *ovl)
{
	return ovl->info.enabled && ovl->manager && ovl->manager->device;
}

int dss_mgr_wait_for_go(struct omap_overlay_manager *mgr)
{
	unsigned long timeout = msecs_to_jiffies(500);
	struct manager_cache_data *mc;
	u32 irq;
	int r;
	int i;
	struct omap_dss_device *dssdev = mgr->device;

	if (!dssdev || dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
		return 0;

	if (mgr_manual_update(mgr))
		return 0;

	irq = dispc_mgr_get_vsync_irq(mgr->id);

	mc = &dss_cache.manager_cache[mgr->id];
	i = 0;
	while (1) {
		unsigned long flags;
		bool shadow_dirty, dirty;

		spin_lock_irqsave(&dss_cache.lock, flags);
		dirty = mc->dirty;
		shadow_dirty = mc->shadow_dirty;
		spin_unlock_irqrestore(&dss_cache.lock, flags);

		if (!dirty && !shadow_dirty) {
			r = 0;
			break;
		}

		/* 4 iterations is the worst case:
		 * 1 - initial iteration, dirty = true (between VFP and VSYNC)
		 * 2 - first VSYNC, dirty = true
		 * 3 - dirty = false, shadow_dirty = true
		 * 4 - shadow_dirty = false */
		if (i++ == 3) {
			DSSERR("mgr(%d)->wait_for_go() not finishing\n",
					mgr->id);
			r = 0;
			break;
		}

		r = omap_dispc_wait_for_irq_interruptible_timeout(irq, timeout);
		if (r == -ERESTARTSYS)
			break;

		if (r) {
			DSSERR("mgr(%d)->wait_for_go() timeout\n", mgr->id);
			break;
		}
	}

	return r;
}

int dss_mgr_wait_for_go_ovl(struct omap_overlay *ovl)
{
	unsigned long timeout = msecs_to_jiffies(500);
	struct ovl_priv_data *op;
	struct omap_dss_device *dssdev;
	u32 irq;
	int r;
	int i;

	if (!ovl->manager)
		return 0;

	dssdev = ovl->manager->device;

	if (!dssdev || dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
		return 0;

	if (ovl_manual_update(ovl))
		return 0;

	irq = dispc_mgr_get_vsync_irq(ovl->manager->id);

	op = get_ovl_priv(ovl);
	i = 0;
	while (1) {
		unsigned long flags;
		bool shadow_dirty, dirty;

		spin_lock_irqsave(&dss_cache.lock, flags);
		dirty = op->dirty;
		shadow_dirty = op->shadow_dirty;
		spin_unlock_irqrestore(&dss_cache.lock, flags);

		if (!dirty && !shadow_dirty) {
			r = 0;
			break;
		}

		/* 4 iterations is the worst case:
		 * 1 - initial iteration, dirty = true (between VFP and VSYNC)
		 * 2 - first VSYNC, dirty = true
		 * 3 - dirty = false, shadow_dirty = true
		 * 4 - shadow_dirty = false */
		if (i++ == 3) {
			DSSERR("ovl(%d)->wait_for_go() not finishing\n",
					ovl->id);
			r = 0;
			break;
		}

		r = omap_dispc_wait_for_irq_interruptible_timeout(irq, timeout);
		if (r == -ERESTARTSYS)
			break;

		if (r) {
			DSSERR("ovl(%d)->wait_for_go() timeout\n", ovl->id);
			break;
		}
	}

	return r;
}

static int dss_ovl_write_regs(struct omap_overlay *ovl)
{
	struct ovl_priv_data *op;
	struct omap_overlay_info *oi;
	bool ilace, replication;
	int r;

	DSSDBGF("%d", ovl->id);

	op = get_ovl_priv(ovl);
	oi = &op->info;

	if (!op->enabled) {
		dispc_ovl_enable(ovl->id, 0);
		return 0;
	}

	replication = dss_use_replication(ovl->manager->device, oi->color_mode);

	ilace = ovl->manager->device->type == OMAP_DISPLAY_TYPE_VENC;

	dispc_ovl_set_channel_out(ovl->id, op->channel);

	r = dispc_ovl_setup(ovl->id, oi, ilace, replication);
	if (r) {
		/* this shouldn't happen */
		DSSERR("dispc_ovl_setup failed for ovl %d\n", ovl->id);
		dispc_ovl_enable(ovl->id, 0);
		return r;
	}

	dispc_ovl_set_fifo_threshold(ovl->id, op->fifo_low, op->fifo_high);

	dispc_ovl_enable(ovl->id, 1);

	return 0;
}

static void dss_mgr_write_regs(struct omap_overlay_manager *mgr)
{
	struct omap_overlay_manager_info *mi;

	DSSDBGF("%d", mgr->id);

	mi = &dss_cache.manager_cache[mgr->id].info;

	dispc_mgr_setup(mgr->id, mi);
}

/* dss_write_regs() tries to write values from cache to shadow registers.
 * It writes only to those managers/overlays that are not busy.
 * returns 0 if everything could be written to shadow registers.
 * returns 1 if not everything could be written to shadow registers. */
static int dss_write_regs(void)
{
	struct omap_overlay *ovl;
	struct omap_overlay_manager *mgr;
	struct ovl_priv_data *op;
	struct manager_cache_data *mc;
	const int num_ovls = dss_feat_get_num_ovls();
	const int num_mgrs = dss_feat_get_num_mgrs();
	int i;
	int r;
	bool mgr_busy[MAX_DSS_MANAGERS];
	bool mgr_go[MAX_DSS_MANAGERS];
	bool busy;

	r = 0;
	busy = false;

	for (i = 0; i < num_mgrs; i++) {
		mgr_busy[i] = dispc_mgr_go_busy(i);
		mgr_go[i] = false;
	}

	/* Commit overlay settings */
	for (i = 0; i < num_ovls; ++i) {
		ovl = omap_dss_get_overlay(i);
		op = get_ovl_priv(ovl);
		mc = &dss_cache.manager_cache[op->channel];

		if (!op->dirty)
			continue;

		if (mc->manual_update && !mc->do_manual_update)
			continue;

		if (mgr_busy[op->channel]) {
			busy = true;
			continue;
		}

		r = dss_ovl_write_regs(ovl);
		if (r)
			DSSERR("dss_ovl_write_regs %d failed\n", i);

		op->dirty = false;
		op->shadow_dirty = true;
		mgr_go[op->channel] = true;
	}

	/* Commit manager settings */
	for (i = 0; i < num_mgrs; ++i) {
		mgr = omap_dss_get_overlay_manager(i);
		mc = &dss_cache.manager_cache[i];

		if (!mc->dirty)
			continue;

		if (mc->manual_update && !mc->do_manual_update)
			continue;

		if (mgr_busy[i]) {
			busy = true;
			continue;
		}

		dss_mgr_write_regs(mgr);
		mc->dirty = false;
		mc->shadow_dirty = true;
		mgr_go[i] = true;
	}

	/* set GO */
	for (i = 0; i < num_mgrs; ++i) {
		mc = &dss_cache.manager_cache[i];

		if (!mgr_go[i])
			continue;

		/* We don't need GO with manual update display. LCD iface will
		 * always be turned off after frame, and new settings will be
		 * taken in to use at next update */
		if (!mc->manual_update)
			dispc_mgr_go(i);
	}

	if (busy)
		r = 1;
	else
		r = 0;

	return r;
}

void dss_mgr_start_update(struct omap_overlay_manager *mgr)
{
	struct manager_cache_data *mc;
	struct ovl_priv_data *op;
	struct omap_overlay *ovl;

	mc = &dss_cache.manager_cache[mgr->id];

	mc->do_manual_update = true;
	dss_write_regs();
	mc->do_manual_update = false;

	list_for_each_entry(ovl, &mgr->overlays, list) {
		op = get_ovl_priv(ovl);
		op->shadow_dirty = false;
	}

	mc = &dss_cache.manager_cache[mgr->id];
	mc->shadow_dirty = false;

	dispc_mgr_enable(mgr->id, true);
}

static void dss_apply_irq_handler(void *data, u32 mask);

static void dss_register_vsync_isr(void)
{
	const int num_mgrs = dss_feat_get_num_mgrs();
	u32 mask;
	int r, i;

	mask = 0;
	for (i = 0; i < num_mgrs; ++i)
		mask |= dispc_mgr_get_vsync_irq(i);

	r = omap_dispc_register_isr(dss_apply_irq_handler, NULL, mask);
	WARN_ON(r);

	dss_cache.irq_enabled = true;
}

static void dss_unregister_vsync_isr(void)
{
	const int num_mgrs = dss_feat_get_num_mgrs();
	u32 mask;
	int r, i;

	mask = 0;
	for (i = 0; i < num_mgrs; ++i)
		mask |= dispc_mgr_get_vsync_irq(i);

	r = omap_dispc_unregister_isr(dss_apply_irq_handler, NULL, mask);
	WARN_ON(r);

	dss_cache.irq_enabled = false;
}

static void dss_apply_irq_handler(void *data, u32 mask)
{
	struct omap_overlay *ovl;
	struct manager_cache_data *mc;
	struct ovl_priv_data *op;
	const int num_ovls = dss_feat_get_num_ovls();
	const int num_mgrs = dss_feat_get_num_mgrs();
	int i, r;
	bool mgr_busy[MAX_DSS_MANAGERS];

	for (i = 0; i < num_mgrs; i++)
		mgr_busy[i] = dispc_mgr_go_busy(i);

	spin_lock(&dss_cache.lock);

	for (i = 0; i < num_ovls; ++i) {
		ovl = omap_dss_get_overlay(i);
		op = get_ovl_priv(ovl);
		if (!mgr_busy[op->channel])
			op->shadow_dirty = false;
	}

	for (i = 0; i < num_mgrs; ++i) {
		mc = &dss_cache.manager_cache[i];
		if (!mgr_busy[i])
			mc->shadow_dirty = false;
	}

	r = dss_write_regs();
	if (r == 1)
		goto end;

	/* re-read busy flags */
	for (i = 0; i < num_mgrs; i++)
		mgr_busy[i] = dispc_mgr_go_busy(i);

	/* keep running as long as there are busy managers, so that
	 * we can collect overlay-applied information */
	for (i = 0; i < num_mgrs; ++i) {
		if (mgr_busy[i])
			goto end;
	}

	dss_unregister_vsync_isr();

end:
	spin_unlock(&dss_cache.lock);
}

static int omap_dss_mgr_apply_ovl(struct omap_overlay *ovl)
{
	struct ovl_priv_data *op;
	struct omap_dss_device *dssdev;

	op = get_ovl_priv(ovl);

	if (ovl->manager_changed) {
		ovl->manager_changed = false;
		ovl->info_dirty  = true;
	}

	if (!overlay_enabled(ovl)) {
		if (op->enabled) {
			op->enabled = false;
			op->dirty = true;
		}
		return 0;
	}

	if (!ovl->info_dirty)
		return 0;

	dssdev = ovl->manager->device;

	if (dss_check_overlay(ovl, dssdev)) {
		if (op->enabled) {
			op->enabled = false;
			op->dirty = true;
		}
		return -EINVAL;
	}

	ovl->info_dirty = false;
	op->dirty = true;
	op->info = ovl->info;

	op->channel = ovl->manager->id;

	op->enabled = true;

	return 0;
}

static void omap_dss_mgr_apply_mgr(struct omap_overlay_manager *mgr)
{
	struct manager_cache_data *mc;

	mc = &dss_cache.manager_cache[mgr->id];

	if (mgr->device_changed) {
		mgr->device_changed = false;
		mgr->info_dirty  = true;
	}

	if (!mgr->info_dirty)
		return;

	if (!mgr->device)
		return;

	mgr->info_dirty = false;
	mc->dirty = true;
	mc->info = mgr->info;

	mc->manual_update = mgr_manual_update(mgr);
}

static void omap_dss_mgr_apply_ovl_fifos(struct omap_overlay *ovl)
{
	struct ovl_priv_data *op;
	struct omap_dss_device *dssdev;
	u32 size, burst_size;

	op = get_ovl_priv(ovl);

	if (!op->enabled)
		return;

	dssdev = ovl->manager->device;

	size = dispc_ovl_get_fifo_size(ovl->id);

	burst_size = dispc_ovl_get_burst_size(ovl->id);

	switch (dssdev->type) {
	case OMAP_DISPLAY_TYPE_DPI:
	case OMAP_DISPLAY_TYPE_DBI:
	case OMAP_DISPLAY_TYPE_SDI:
	case OMAP_DISPLAY_TYPE_VENC:
	case OMAP_DISPLAY_TYPE_HDMI:
		default_get_overlay_fifo_thresholds(ovl->id, size,
				burst_size, &op->fifo_low,
				&op->fifo_high);
		break;
#ifdef CONFIG_OMAP2_DSS_DSI
	case OMAP_DISPLAY_TYPE_DSI:
		dsi_get_overlay_fifo_thresholds(ovl->id, size,
				burst_size, &op->fifo_low,
				&op->fifo_high);
		break;
#endif
	default:
		BUG();
	}
}

int omap_dss_mgr_apply(struct omap_overlay_manager *mgr)
{
	int r;
	unsigned long flags;
	struct omap_overlay *ovl;

	DSSDBG("omap_dss_mgr_apply(%s)\n", mgr->name);

	r = dispc_runtime_get();
	if (r)
		return r;

	spin_lock_irqsave(&dss_cache.lock, flags);

	/* Configure overlays */
	list_for_each_entry(ovl, &mgr->overlays, list)
		omap_dss_mgr_apply_ovl(ovl);

	/* Configure manager */
	omap_dss_mgr_apply_mgr(mgr);

	/* Configure overlay fifos */
	list_for_each_entry(ovl, &mgr->overlays, list)
		omap_dss_mgr_apply_ovl_fifos(ovl);

	r = 0;
	if (mgr->enabled && !mgr_manual_update(mgr)) {
		if (!dss_cache.irq_enabled)
			dss_register_vsync_isr();

		dss_write_regs();
	}

	spin_unlock_irqrestore(&dss_cache.lock, flags);

	dispc_runtime_put();

	return r;
}

void dss_mgr_enable(struct omap_overlay_manager *mgr)
{
	dispc_mgr_enable(mgr->id, true);
	mgr->enabled = true;
}

void dss_mgr_disable(struct omap_overlay_manager *mgr)
{
	dispc_mgr_enable(mgr->id, false);
	mgr->enabled = false;
}