OMAP: DSS2: Display Subsystem Driver core

The core files of DSS2. DSS2 commits are split a bit artificially to
make the individual commits smaller, and DSS2 doesn't compile properly
without the rest of the core commits. This shouldn't be a problem, as no
configuration uses DSS2 yet.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

1 files changed, 919 insertions, 0 deletions

diff --git a/drivers/video/omap2/dss/core.c b/drivers/video/omap2/dss/core.c
new file mode 100644
index 000000000000..29497a0c9a91
--- /dev/null
+++ b/drivers/video/omap2/dss/core.c
@@ -0,0 +1,919 @@
+/*
+ * linux/drivers/video/omap2/dss/core.c
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
+ *
+ * Some code and ideas taken from drivers/video/omap/ driver
+ * by Imre Deak.
+ *
+ * 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 "CORE"
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/device.h>
+
+#include <plat/display.h>
+#include <plat/clock.h>
+
+#include "dss.h"
+
+static struct {
+	struct platform_device *pdev;
+	int		ctx_id;
+
+	struct clk      *dss_ick;
+	struct clk	*dss1_fck;
+	struct clk	*dss2_fck;
+	struct clk      *dss_54m_fck;
+	struct clk	*dss_96m_fck;
+	unsigned	num_clks_enabled;
+} core;
+
+static void dss_clk_enable_all_no_ctx(void);
+static void dss_clk_disable_all_no_ctx(void);
+static void dss_clk_enable_no_ctx(enum dss_clock clks);
+static void dss_clk_disable_no_ctx(enum dss_clock clks);
+
+static char *def_disp_name;
+module_param_named(def_disp, def_disp_name, charp, 0);
+MODULE_PARM_DESC(def_disp_name, "default display name");
+
+#ifdef DEBUG
+unsigned int dss_debug;
+module_param_named(debug, dss_debug, bool, 0644);
+#endif
+
+/* CONTEXT */
+static int dss_get_ctx_id(void)
+{
+	struct omap_dss_board_info *pdata = core.pdev->dev.platform_data;
+	int r;
+
+	if (!pdata->get_last_off_on_transaction_id)
+		return 0;
+	r = pdata->get_last_off_on_transaction_id(&core.pdev->dev);
+	if (r < 0) {
+		dev_err(&core.pdev->dev, "getting transaction ID failed, "
+				"will force context restore\n");
+		r = -1;
+	}
+	return r;
+}
+
+int dss_need_ctx_restore(void)
+{
+	int id = dss_get_ctx_id();
+
+	if (id < 0 || id != core.ctx_id) {
+		DSSDBG("ctx id %d -> id %d\n",
+				core.ctx_id, id);
+		core.ctx_id = id;
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+static void save_all_ctx(void)
+{
+	DSSDBG("save context\n");
+
+	dss_clk_enable_no_ctx(DSS_CLK_ICK | DSS_CLK_FCK1);
+
+	dss_save_context();
+	dispc_save_context();
+#ifdef CONFIG_OMAP2_DSS_DSI
+	dsi_save_context();
+#endif
+
+	dss_clk_disable_no_ctx(DSS_CLK_ICK | DSS_CLK_FCK1);
+}
+
+static void restore_all_ctx(void)
+{
+	DSSDBG("restore context\n");
+
+	dss_clk_enable_all_no_ctx();
+
+	dss_restore_context();
+	dispc_restore_context();
+#ifdef CONFIG_OMAP2_DSS_DSI
+	dsi_restore_context();
+#endif
+
+	dss_clk_disable_all_no_ctx();
+}
+
+/* CLOCKS */
+static void core_dump_clocks(struct seq_file *s)
+{
+	int i;
+	struct clk *clocks[5] = {
+		core.dss_ick,
+		core.dss1_fck,
+		core.dss2_fck,
+		core.dss_54m_fck,
+		core.dss_96m_fck
+	};
+
+	seq_printf(s, "- CORE -\n");
+
+	seq_printf(s, "internal clk count\t\t%u\n", core.num_clks_enabled);
+
+	for (i = 0; i < 5; i++) {
+		if (!clocks[i])
+			continue;
+		seq_printf(s, "%-15s\t%lu\t%d\n",
+				clocks[i]->name,
+				clk_get_rate(clocks[i]),
+				clocks[i]->usecount);
+	}
+}
+
+static int dss_get_clock(struct clk **clock, const char *clk_name)
+{
+	struct clk *clk;
+
+	clk = clk_get(&core.pdev->dev, clk_name);
+
+	if (IS_ERR(clk)) {
+		DSSERR("can't get clock %s", clk_name);
+		return PTR_ERR(clk);
+	}
+
+	*clock = clk;
+
+	DSSDBG("clk %s, rate %ld\n", clk_name, clk_get_rate(clk));
+
+	return 0;
+}
+
+static int dss_get_clocks(void)
+{
+	int r;
+
+	core.dss_ick = NULL;
+	core.dss1_fck = NULL;
+	core.dss2_fck = NULL;
+	core.dss_54m_fck = NULL;
+	core.dss_96m_fck = NULL;
+
+	r = dss_get_clock(&core.dss_ick, "ick");
+	if (r)
+		goto err;
+
+	r = dss_get_clock(&core.dss1_fck, "dss1_fck");
+	if (r)
+		goto err;
+
+	r = dss_get_clock(&core.dss2_fck, "dss2_fck");
+	if (r)
+		goto err;
+
+	r = dss_get_clock(&core.dss_54m_fck, "tv_fck");
+	if (r)
+		goto err;
+
+	r = dss_get_clock(&core.dss_96m_fck, "video_fck");
+	if (r)
+		goto err;
+
+	return 0;
+
+err:
+	if (core.dss_ick)
+		clk_put(core.dss_ick);
+	if (core.dss1_fck)
+		clk_put(core.dss1_fck);
+	if (core.dss2_fck)
+		clk_put(core.dss2_fck);
+	if (core.dss_54m_fck)
+		clk_put(core.dss_54m_fck);
+	if (core.dss_96m_fck)
+		clk_put(core.dss_96m_fck);
+
+	return r;
+}
+
+static void dss_put_clocks(void)
+{
+	if (core.dss_96m_fck)
+		clk_put(core.dss_96m_fck);
+	clk_put(core.dss_54m_fck);
+	clk_put(core.dss1_fck);
+	clk_put(core.dss2_fck);
+	clk_put(core.dss_ick);
+}
+
+unsigned long dss_clk_get_rate(enum dss_clock clk)
+{
+	switch (clk) {
+	case DSS_CLK_ICK:
+		return clk_get_rate(core.dss_ick);
+	case DSS_CLK_FCK1:
+		return clk_get_rate(core.dss1_fck);
+	case DSS_CLK_FCK2:
+		return clk_get_rate(core.dss2_fck);
+	case DSS_CLK_54M:
+		return clk_get_rate(core.dss_54m_fck);
+	case DSS_CLK_96M:
+		return clk_get_rate(core.dss_96m_fck);
+	}
+
+	BUG();
+	return 0;
+}
+
+static unsigned count_clk_bits(enum dss_clock clks)
+{
+	unsigned num_clks = 0;
+
+	if (clks & DSS_CLK_ICK)
+		++num_clks;
+	if (clks & DSS_CLK_FCK1)
+		++num_clks;
+	if (clks & DSS_CLK_FCK2)
+		++num_clks;
+	if (clks & DSS_CLK_54M)
+		++num_clks;
+	if (clks & DSS_CLK_96M)
+		++num_clks;
+
+	return num_clks;
+}
+
+static void dss_clk_enable_no_ctx(enum dss_clock clks)
+{
+	unsigned num_clks = count_clk_bits(clks);
+
+	if (clks & DSS_CLK_ICK)
+		clk_enable(core.dss_ick);
+	if (clks & DSS_CLK_FCK1)
+		clk_enable(core.dss1_fck);
+	if (clks & DSS_CLK_FCK2)
+		clk_enable(core.dss2_fck);
+	if (clks & DSS_CLK_54M)
+		clk_enable(core.dss_54m_fck);
+	if (clks & DSS_CLK_96M)
+		clk_enable(core.dss_96m_fck);
+
+	core.num_clks_enabled += num_clks;
+}
+
+void dss_clk_enable(enum dss_clock clks)
+{
+	dss_clk_enable_no_ctx(clks);
+
+	if (cpu_is_omap34xx() && dss_need_ctx_restore())
+		restore_all_ctx();
+}
+
+static void dss_clk_disable_no_ctx(enum dss_clock clks)
+{
+	unsigned num_clks = count_clk_bits(clks);
+
+	if (clks & DSS_CLK_ICK)
+		clk_disable(core.dss_ick);
+	if (clks & DSS_CLK_FCK1)
+		clk_disable(core.dss1_fck);
+	if (clks & DSS_CLK_FCK2)
+		clk_disable(core.dss2_fck);
+	if (clks & DSS_CLK_54M)
+		clk_disable(core.dss_54m_fck);
+	if (clks & DSS_CLK_96M)
+		clk_disable(core.dss_96m_fck);
+
+	core.num_clks_enabled -= num_clks;
+}
+
+void dss_clk_disable(enum dss_clock clks)
+{
+	if (cpu_is_omap34xx()) {
+		unsigned num_clks = count_clk_bits(clks);
+
+		BUG_ON(core.num_clks_enabled < num_clks);
+
+		if (core.num_clks_enabled == num_clks)
+			save_all_ctx();
+	}
+
+	dss_clk_disable_no_ctx(clks);
+}
+
+static void dss_clk_enable_all_no_ctx(void)
+{
+	enum dss_clock clks;
+
+	clks = DSS_CLK_ICK | DSS_CLK_FCK1 | DSS_CLK_FCK2 | DSS_CLK_54M;
+	if (cpu_is_omap34xx())
+		clks |= DSS_CLK_96M;
+	dss_clk_enable_no_ctx(clks);
+}
+
+static void dss_clk_disable_all_no_ctx(void)
+{
+	enum dss_clock clks;
+
+	clks = DSS_CLK_ICK | DSS_CLK_FCK1 | DSS_CLK_FCK2 | DSS_CLK_54M;
+	if (cpu_is_omap34xx())
+		clks |= DSS_CLK_96M;
+	dss_clk_disable_no_ctx(clks);
+}
+
+static void dss_clk_disable_all(void)
+{
+	enum dss_clock clks;
+
+	clks = DSS_CLK_ICK | DSS_CLK_FCK1 | DSS_CLK_FCK2 | DSS_CLK_54M;
+	if (cpu_is_omap34xx())
+		clks |= DSS_CLK_96M;
+	dss_clk_disable(clks);
+}
+
+/* DEBUGFS */
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_OMAP2_DSS_DEBUG_SUPPORT)
+static void dss_debug_dump_clocks(struct seq_file *s)
+{
+	core_dump_clocks(s);
+	dss_dump_clocks(s);
+	dispc_dump_clocks(s);
+#ifdef CONFIG_OMAP2_DSS_DSI
+	dsi_dump_clocks(s);
+#endif
+}
+
+static int dss_debug_show(struct seq_file *s, void *unused)
+{
+	void (*func)(struct seq_file *) = s->private;
+	func(s);
+	return 0;
+}
+
+static int dss_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dss_debug_show, inode->i_private);
+}
+
+static const struct file_operations dss_debug_fops = {
+	.open           = dss_debug_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+static struct dentry *dss_debugfs_dir;
+
+static int dss_initialize_debugfs(void)
+{
+	dss_debugfs_dir = debugfs_create_dir("omapdss", NULL);
+	if (IS_ERR(dss_debugfs_dir)) {
+		int err = PTR_ERR(dss_debugfs_dir);
+		dss_debugfs_dir = NULL;
+		return err;
+	}
+
+	debugfs_create_file("clk", S_IRUGO, dss_debugfs_dir,
+			&dss_debug_dump_clocks, &dss_debug_fops);
+
+	debugfs_create_file("dss", S_IRUGO, dss_debugfs_dir,
+			&dss_dump_regs, &dss_debug_fops);
+	debugfs_create_file("dispc", S_IRUGO, dss_debugfs_dir,
+			&dispc_dump_regs, &dss_debug_fops);
+#ifdef CONFIG_OMAP2_DSS_RFBI
+	debugfs_create_file("rfbi", S_IRUGO, dss_debugfs_dir,
+			&rfbi_dump_regs, &dss_debug_fops);
+#endif
+#ifdef CONFIG_OMAP2_DSS_DSI
+	debugfs_create_file("dsi", S_IRUGO, dss_debugfs_dir,
+			&dsi_dump_regs, &dss_debug_fops);
+#endif
+#ifdef CONFIG_OMAP2_DSS_VENC
+	debugfs_create_file("venc", S_IRUGO, dss_debugfs_dir,
+			&venc_dump_regs, &dss_debug_fops);
+#endif
+	return 0;
+}
+
+static void dss_uninitialize_debugfs(void)
+{
+	if (dss_debugfs_dir)
+		debugfs_remove_recursive(dss_debugfs_dir);
+}
+#endif /* CONFIG_DEBUG_FS && CONFIG_OMAP2_DSS_DEBUG_SUPPORT */
+
+/* PLATFORM DEVICE */
+static int omap_dss_probe(struct platform_device *pdev)
+{
+	struct omap_dss_board_info *pdata = pdev->dev.platform_data;
+	int skip_init = 0;
+	int r;
+	int i;
+
+	core.pdev = pdev;
+
+	dss_init_overlay_managers(pdev);
+	dss_init_overlays(pdev);
+
+	r = dss_get_clocks();
+	if (r)
+		goto fail0;
+
+	dss_clk_enable_all_no_ctx();
+
+	core.ctx_id = dss_get_ctx_id();
+	DSSDBG("initial ctx id %u\n", core.ctx_id);
+
+#ifdef CONFIG_FB_OMAP_BOOTLOADER_INIT
+	/* DISPC_CONTROL */
+	if (omap_readl(0x48050440) & 1)	/* LCD enabled? */
+		skip_init = 1;
+#endif
+
+	r = dss_init(skip_init);
+	if (r) {
+		DSSERR("Failed to initialize DSS\n");
+		goto fail0;
+	}
+
+#ifdef CONFIG_OMAP2_DSS_RFBI
+	r = rfbi_init();
+	if (r) {
+		DSSERR("Failed to initialize rfbi\n");
+		goto fail0;
+	}
+#endif
+
+	r = dpi_init();
+	if (r) {
+		DSSERR("Failed to initialize dpi\n");
+		goto fail0;
+	}
+
+	r = dispc_init();
+	if (r) {
+		DSSERR("Failed to initialize dispc\n");
+		goto fail0;
+	}
+#ifdef CONFIG_OMAP2_DSS_VENC
+	r = venc_init(pdev);
+	if (r) {
+		DSSERR("Failed to initialize venc\n");
+		goto fail0;
+	}
+#endif
+	if (cpu_is_omap34xx()) {
+#ifdef CONFIG_OMAP2_DSS_SDI
+		r = sdi_init(skip_init);
+		if (r) {
+			DSSERR("Failed to initialize SDI\n");
+			goto fail0;
+		}
+#endif
+#ifdef CONFIG_OMAP2_DSS_DSI
+		r = dsi_init(pdev);
+		if (r) {
+			DSSERR("Failed to initialize DSI\n");
+			goto fail0;
+		}
+#endif
+	}
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_OMAP2_DSS_DEBUG_SUPPORT)
+	r = dss_initialize_debugfs();
+	if (r)
+		goto fail0;
+#endif
+
+	for (i = 0; i < pdata->num_devices; ++i) {
+		struct omap_dss_device *dssdev = pdata->devices[i];
+
+		r = omap_dss_register_device(dssdev);
+		if (r)
+			DSSERR("device reg failed %d\n", i);
+
+		if (def_disp_name && strcmp(def_disp_name, dssdev->name) == 0)
+			pdata->default_device = dssdev;
+	}
+
+	dss_clk_disable_all();
+
+	return 0;
+
+	/* XXX fail correctly */
+fail0:
+	return r;
+}
+
+static int omap_dss_remove(struct platform_device *pdev)
+{
+	struct omap_dss_board_info *pdata = pdev->dev.platform_data;
+	int i;
+	int c;
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_OMAP2_DSS_DEBUG_SUPPORT)
+	dss_uninitialize_debugfs();
+#endif
+
+#ifdef CONFIG_OMAP2_DSS_VENC
+	venc_exit();
+#endif
+	dispc_exit();
+	dpi_exit();
+#ifdef CONFIG_OMAP2_DSS_RFBI
+	rfbi_exit();
+#endif
+	if (cpu_is_omap34xx()) {
+#ifdef CONFIG_OMAP2_DSS_DSI
+		dsi_exit();
+#endif
+#ifdef CONFIG_OMAP2_DSS_SDI
+		sdi_exit();
+#endif
+	}
+
+	dss_exit();
+
+	/* these should be removed at some point */
+	c = core.dss_ick->usecount;
+	if (c > 0) {
+		DSSERR("warning: dss_ick usecount %d, disabling\n", c);
+		while (c-- > 0)
+			clk_disable(core.dss_ick);
+	}
+
+	c = core.dss1_fck->usecount;
+	if (c > 0) {
+		DSSERR("warning: dss1_fck usecount %d, disabling\n", c);
+		while (c-- > 0)
+			clk_disable(core.dss1_fck);
+	}
+
+	c = core.dss2_fck->usecount;
+	if (c > 0) {
+		DSSERR("warning: dss2_fck usecount %d, disabling\n", c);
+		while (c-- > 0)
+			clk_disable(core.dss2_fck);
+	}
+
+	c = core.dss_54m_fck->usecount;
+	if (c > 0) {
+		DSSERR("warning: dss_54m_fck usecount %d, disabling\n", c);
+		while (c-- > 0)
+			clk_disable(core.dss_54m_fck);
+	}
+
+	if (core.dss_96m_fck) {
+		c = core.dss_96m_fck->usecount;
+		if (c > 0) {
+			DSSERR("warning: dss_96m_fck usecount %d, disabling\n",
+					c);
+			while (c-- > 0)
+				clk_disable(core.dss_96m_fck);
+		}
+	}
+
+	dss_put_clocks();
+
+	dss_uninit_overlays(pdev);
+	dss_uninit_overlay_managers(pdev);
+
+	for (i = 0; i < pdata->num_devices; ++i)
+		omap_dss_unregister_device(pdata->devices[i]);
+
+	return 0;
+}
+
+static void omap_dss_shutdown(struct platform_device *pdev)
+{
+	DSSDBG("shutdown\n");
+	dss_disable_all_devices();
+}
+
+static int omap_dss_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	DSSDBG("suspend %d\n", state.event);
+
+	return dss_suspend_all_devices();
+}
+
+static int omap_dss_resume(struct platform_device *pdev)
+{
+	DSSDBG("resume\n");
+
+	return dss_resume_all_devices();
+}
+
+static struct platform_driver omap_dss_driver = {
+	.probe          = omap_dss_probe,
+	.remove         = omap_dss_remove,
+	.shutdown	= omap_dss_shutdown,
+	.suspend	= omap_dss_suspend,
+	.resume		= omap_dss_resume,
+	.driver         = {
+		.name   = "omapdss",
+		.owner  = THIS_MODULE,
+	},
+};
+
+/* BUS */
+static int dss_bus_match(struct device *dev, struct device_driver *driver)
+{
+	struct omap_dss_device *dssdev = to_dss_device(dev);
+
+	DSSDBG("bus_match. dev %s/%s, drv %s\n",
+			dev_name(dev), dssdev->driver_name, driver->name);
+
+	return strcmp(dssdev->driver_name, driver->name) == 0;
+}
+
+static ssize_t device_name_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct omap_dss_device *dssdev = to_dss_device(dev);
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			dssdev->name ?
+			dssdev->name : "");
+}
+
+static struct device_attribute default_dev_attrs[] = {
+	__ATTR(name, S_IRUGO, device_name_show, NULL),
+	__ATTR_NULL,
+};
+
+static ssize_t driver_name_show(struct device_driver *drv, char *buf)
+{
+	struct omap_dss_driver *dssdrv = to_dss_driver(drv);
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			dssdrv->driver.name ?
+			dssdrv->driver.name : "");
+}
+static struct driver_attribute default_drv_attrs[] = {
+	__ATTR(name, S_IRUGO, driver_name_show, NULL),
+	__ATTR_NULL,
+};
+
+static struct bus_type dss_bus_type = {
+	.name = "omapdss",
+	.match = dss_bus_match,
+	.dev_attrs = default_dev_attrs,
+	.drv_attrs = default_drv_attrs,
+};
+
+static void dss_bus_release(struct device *dev)
+{
+	DSSDBG("bus_release\n");
+}
+
+static struct device dss_bus = {
+	.release = dss_bus_release,
+};
+
+struct bus_type *dss_get_bus(void)
+{
+	return &dss_bus_type;
+}
+
+/* DRIVER */
+static int dss_driver_probe(struct device *dev)
+{
+	int r;
+	struct omap_dss_driver *dssdrv = to_dss_driver(dev->driver);
+	struct omap_dss_device *dssdev = to_dss_device(dev);
+	struct omap_dss_board_info *pdata = core.pdev->dev.platform_data;
+	bool force;
+
+	DSSDBG("driver_probe: dev %s/%s, drv %s\n",
+				dev_name(dev), dssdev->driver_name,
+				dssdrv->driver.name);
+
+	dss_init_device(core.pdev, dssdev);
+
+	/* skip this if the device is behind a ctrl */
+	if (!dssdev->panel.ctrl) {
+		force = pdata->default_device == dssdev;
+		dss_recheck_connections(dssdev, force);
+	}
+
+	r = dssdrv->probe(dssdev);
+
+	if (r) {
+		DSSERR("driver probe failed: %d\n", r);
+		return r;
+	}
+
+	DSSDBG("probe done for device %s\n", dev_name(dev));
+
+	dssdev->driver = dssdrv;
+
+	return 0;
+}
+
+static int dss_driver_remove(struct device *dev)
+{
+	struct omap_dss_driver *dssdrv = to_dss_driver(dev->driver);
+	struct omap_dss_device *dssdev = to_dss_device(dev);
+
+	DSSDBG("driver_remove: dev %s/%s\n", dev_name(dev),
+			dssdev->driver_name);
+
+	dssdrv->remove(dssdev);
+
+	dss_uninit_device(core.pdev, dssdev);
+
+	dssdev->driver = NULL;
+
+	return 0;
+}
+
+int omap_dss_register_driver(struct omap_dss_driver *dssdriver)
+{
+	dssdriver->driver.bus = &dss_bus_type;
+	dssdriver->driver.probe = dss_driver_probe;
+	dssdriver->driver.remove = dss_driver_remove;
+	return driver_register(&dssdriver->driver);
+}
+EXPORT_SYMBOL(omap_dss_register_driver);
+
+void omap_dss_unregister_driver(struct omap_dss_driver *dssdriver)
+{
+	driver_unregister(&dssdriver->driver);
+}
+EXPORT_SYMBOL(omap_dss_unregister_driver);
+
+/* DEVICE */
+static void reset_device(struct device *dev, int check)
+{
+	u8 *dev_p = (u8 *)dev;
+	u8 *dev_end = dev_p + sizeof(*dev);
+	void *saved_pdata;
+
+	saved_pdata = dev->platform_data;
+	if (check) {
+		/*
+		 * Check if there is any other setting than platform_data
+		 * in struct device; warn that these will be reset by our
+		 * init.
+		 */
+		dev->platform_data = NULL;
+		while (dev_p < dev_end) {
+			if (*dev_p) {
+				WARN("%s: struct device fields will be "
+						"discarded\n",
+				     __func__);
+				break;
+			}
+			dev_p++;
+		}
+	}
+	memset(dev, 0, sizeof(*dev));
+	dev->platform_data = saved_pdata;
+}
+
+
+static void omap_dss_dev_release(struct device *dev)
+{
+	reset_device(dev, 0);
+}
+
+int omap_dss_register_device(struct omap_dss_device *dssdev)
+{
+	static int dev_num;
+	static int panel_num;
+	int r;
+
+	WARN_ON(!dssdev->driver_name);
+
+	reset_device(&dssdev->dev, 1);
+	dssdev->dev.bus = &dss_bus_type;
+	dssdev->dev.parent = &dss_bus;
+	dssdev->dev.release = omap_dss_dev_release;
+	dev_set_name(&dssdev->dev, "display%d", dev_num++);
+	r = device_register(&dssdev->dev);
+	if (r)
+		return r;
+
+	if (dssdev->ctrl.panel) {
+		struct omap_dss_device *panel = dssdev->ctrl.panel;
+
+		panel->panel.ctrl = dssdev;
+
+		reset_device(&panel->dev, 1);
+		panel->dev.bus = &dss_bus_type;
+		panel->dev.parent = &dssdev->dev;
+		panel->dev.release = omap_dss_dev_release;
+		dev_set_name(&panel->dev, "panel%d", panel_num++);
+		r = device_register(&panel->dev);
+		if (r)
+			return r;
+	}
+
+	return 0;
+}
+
+void omap_dss_unregister_device(struct omap_dss_device *dssdev)
+{
+	device_unregister(&dssdev->dev);
+
+	if (dssdev->ctrl.panel) {
+		struct omap_dss_device *panel = dssdev->ctrl.panel;
+		device_unregister(&panel->dev);
+	}
+}
+
+/* BUS */
+static int omap_dss_bus_register(void)
+{
+	int r;
+
+	r = bus_register(&dss_bus_type);
+	if (r) {
+		DSSERR("bus register failed\n");
+		return r;
+	}
+
+	dev_set_name(&dss_bus, "omapdss");
+	r = device_register(&dss_bus);
+	if (r) {
+		DSSERR("bus driver register failed\n");
+		bus_unregister(&dss_bus_type);
+		return r;
+	}
+
+	return 0;
+}
+
+/* INIT */
+
+#ifdef CONFIG_OMAP2_DSS_MODULE
+static void omap_dss_bus_unregister(void)
+{
+	device_unregister(&dss_bus);
+
+	bus_unregister(&dss_bus_type);
+}
+
+static int __init omap_dss_init(void)
+{
+	int r;
+
+	r = omap_dss_bus_register();
+	if (r)
+		return r;
+
+	r = platform_driver_register(&omap_dss_driver);
+	if (r) {
+		omap_dss_bus_unregister();
+		return r;
+	}
+
+	return 0;
+}
+
+static void __exit omap_dss_exit(void)
+{
+	platform_driver_unregister(&omap_dss_driver);
+
+	omap_dss_bus_unregister();
+}
+
+module_init(omap_dss_init);
+module_exit(omap_dss_exit);
+#else
+static int __init omap_dss_init(void)
+{
+	return omap_dss_bus_register();
+}
+
+static int __init omap_dss_init2(void)
+{
+	return platform_driver_register(&omap_dss_driver);
+}
+
+core_initcall(omap_dss_init);
+device_initcall(omap_dss_init2);
+#endif
+
+MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@nokia.com>");
+MODULE_DESCRIPTION("OMAP2/3 Display Subsystem");
+MODULE_LICENSE("GPL v2");
+