OMAPDSS: Add N800 panel driver

This is a driver for N800's display, ported from the old omapfb. This is
a slightly lighter version of the driver as not all features of the old
driver can be ported without big changes to DSS2, and also because some
of the HW features used in the old driver are unclear (e.g. the power
management part).

That said, the new driver works fine for basic use.

Architecturally the driver is not as neat as it could be. N800's display
HW consists of a display buffer chip and a panel, and ideally they would
be represented by separate, independent drivers. This is not currently
possible, and this driver contains both buffer chip and panel driver.

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

1 files changed, 747 insertions, 0 deletions

diff --git a/drivers/video/omap2/displays/panel-n8x0.c b/drivers/video/omap2/displays/panel-n8x0.c
new file mode 100644
index 000000000000..150e8bae35a1
--- /dev/null
+++ b/drivers/video/omap2/displays/panel-n8x0.c
@@ -0,0 +1,747 @@
+/* #define DEBUG */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
+
+#include <video/omapdss.h>
+#include <video/omap-panel-n8x0.h>
+
+#define BLIZZARD_REV_CODE                      0x00
+#define BLIZZARD_CONFIG                        0x02
+#define BLIZZARD_PLL_DIV                       0x04
+#define BLIZZARD_PLL_LOCK_RANGE                0x06
+#define BLIZZARD_PLL_CLOCK_SYNTH_0             0x08
+#define BLIZZARD_PLL_CLOCK_SYNTH_1             0x0a
+#define BLIZZARD_PLL_MODE                      0x0c
+#define BLIZZARD_CLK_SRC                       0x0e
+#define BLIZZARD_MEM_BANK0_ACTIVATE            0x10
+#define BLIZZARD_MEM_BANK0_STATUS              0x14
+#define BLIZZARD_PANEL_CONFIGURATION           0x28
+#define BLIZZARD_HDISP                         0x2a
+#define BLIZZARD_HNDP                          0x2c
+#define BLIZZARD_VDISP0                        0x2e
+#define BLIZZARD_VDISP1                        0x30
+#define BLIZZARD_VNDP                          0x32
+#define BLIZZARD_HSW                           0x34
+#define BLIZZARD_VSW                           0x38
+#define BLIZZARD_DISPLAY_MODE                  0x68
+#define BLIZZARD_INPUT_WIN_X_START_0           0x6c
+#define BLIZZARD_DATA_SOURCE_SELECT            0x8e
+#define BLIZZARD_DISP_MEM_DATA_PORT            0x90
+#define BLIZZARD_DISP_MEM_READ_ADDR0           0x92
+#define BLIZZARD_POWER_SAVE                    0xE6
+#define BLIZZARD_NDISP_CTRL_STATUS             0xE8
+
+/* Data source select */
+/* For S1D13745 */
+#define BLIZZARD_SRC_WRITE_LCD_BACKGROUND	0x00
+#define BLIZZARD_SRC_WRITE_LCD_DESTRUCTIVE	0x01
+#define BLIZZARD_SRC_WRITE_OVERLAY_ENABLE	0x04
+#define BLIZZARD_SRC_DISABLE_OVERLAY		0x05
+/* For S1D13744 */
+#define BLIZZARD_SRC_WRITE_LCD			0x00
+#define BLIZZARD_SRC_BLT_LCD			0x06
+
+#define BLIZZARD_COLOR_RGB565			0x01
+#define BLIZZARD_COLOR_YUV420			0x09
+
+#define BLIZZARD_VERSION_S1D13745		0x01	/* Hailstorm */
+#define BLIZZARD_VERSION_S1D13744		0x02	/* Blizzard */
+
+#define MIPID_CMD_READ_DISP_ID		0x04
+#define MIPID_CMD_READ_RED		0x06
+#define MIPID_CMD_READ_GREEN		0x07
+#define MIPID_CMD_READ_BLUE		0x08
+#define MIPID_CMD_READ_DISP_STATUS	0x09
+#define MIPID_CMD_RDDSDR		0x0F
+#define MIPID_CMD_SLEEP_IN		0x10
+#define MIPID_CMD_SLEEP_OUT		0x11
+#define MIPID_CMD_DISP_OFF		0x28
+#define MIPID_CMD_DISP_ON		0x29
+
+static struct panel_drv_data {
+	struct mutex lock;
+
+	struct omap_dss_device *dssdev;
+	struct spi_device *spidev;
+	struct backlight_device *bldev;
+
+	int blizzard_ver;
+} s_drv_data;
+
+
+static inline
+struct panel_n8x0_data *get_board_data(const struct omap_dss_device *dssdev)
+{
+	return dssdev->data;
+}
+
+static inline
+struct panel_drv_data *get_drv_data(const struct omap_dss_device *dssdev)
+{
+	return &s_drv_data;
+}
+
+
+static inline void blizzard_cmd(u8 cmd)
+{
+	omap_rfbi_write_command(&cmd, 1);
+}
+
+static inline void blizzard_write(u8 cmd, const u8 *buf, int len)
+{
+	omap_rfbi_write_command(&cmd, 1);
+	omap_rfbi_write_data(buf, len);
+}
+
+static inline void blizzard_read(u8 cmd, u8 *buf, int len)
+{
+	omap_rfbi_write_command(&cmd, 1);
+	omap_rfbi_read_data(buf, len);
+}
+
+static u8 blizzard_read_reg(u8 cmd)
+{
+	u8 data;
+	blizzard_read(cmd, &data, 1);
+	return data;
+}
+
+static void blizzard_ctrl_setup_update(struct omap_dss_device *dssdev,
+		int x, int y, int w, int h)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	u8 tmp[18];
+	int x_end, y_end;
+
+	x_end = x + w - 1;
+	y_end = y + h - 1;
+
+	tmp[0] = x;
+	tmp[1] = x >> 8;
+	tmp[2] = y;
+	tmp[3] = y >> 8;
+	tmp[4] = x_end;
+	tmp[5] = x_end >> 8;
+	tmp[6] = y_end;
+	tmp[7] = y_end >> 8;
+
+	/* scaling? */
+	tmp[8] = x;
+	tmp[9] = x >> 8;
+	tmp[10] = y;
+	tmp[11] = y >> 8;
+	tmp[12] = x_end;
+	tmp[13] = x_end >> 8;
+	tmp[14] = y_end;
+	tmp[15] = y_end >> 8;
+
+	tmp[16] = BLIZZARD_COLOR_RGB565;
+
+	if (ddata->blizzard_ver == BLIZZARD_VERSION_S1D13745)
+		tmp[17] = BLIZZARD_SRC_WRITE_LCD_BACKGROUND;
+	else
+		tmp[17] = ddata->blizzard_ver == BLIZZARD_VERSION_S1D13744 ?
+			BLIZZARD_SRC_WRITE_LCD :
+			BLIZZARD_SRC_WRITE_LCD_DESTRUCTIVE;
+
+	omap_rfbi_configure(dssdev, 16, 8);
+
+	blizzard_write(BLIZZARD_INPUT_WIN_X_START_0, tmp, 18);
+
+	omap_rfbi_configure(dssdev, 16, 16);
+}
+
+static void mipid_transfer(struct spi_device *spi, int cmd, const u8 *wbuf,
+		int wlen, u8 *rbuf, int rlen)
+{
+	struct spi_message	m;
+	struct spi_transfer	*x, xfer[4];
+	u16			w;
+	int			r;
+
+	spi_message_init(&m);
+
+	memset(xfer, 0, sizeof(xfer));
+	x = &xfer[0];
+
+	cmd &=  0xff;
+	x->tx_buf		= &cmd;
+	x->bits_per_word	= 9;
+	x->len			= 2;
+	spi_message_add_tail(x, &m);
+
+	if (wlen) {
+		x++;
+		x->tx_buf		= wbuf;
+		x->len			= wlen;
+		x->bits_per_word	= 9;
+		spi_message_add_tail(x, &m);
+	}
+
+	if (rlen) {
+		x++;
+		x->rx_buf	= &w;
+		x->len		= 1;
+		spi_message_add_tail(x, &m);
+
+		if (rlen > 1) {
+			/* Arrange for the extra clock before the first
+			 * data bit.
+			 */
+			x->bits_per_word = 9;
+			x->len		 = 2;
+
+			x++;
+			x->rx_buf	 = &rbuf[1];
+			x->len		 = rlen - 1;
+			spi_message_add_tail(x, &m);
+		}
+	}
+
+	r = spi_sync(spi, &m);
+	if (r < 0)
+		dev_dbg(&spi->dev, "spi_sync %d\n", r);
+
+	if (rlen)
+		rbuf[0] = w & 0xff;
+}
+
+static inline void mipid_cmd(struct spi_device *spi, int cmd)
+{
+	mipid_transfer(spi, cmd, NULL, 0, NULL, 0);
+}
+
+static inline void mipid_write(struct spi_device *spi,
+		int reg, const u8 *buf, int len)
+{
+	mipid_transfer(spi, reg, buf, len, NULL, 0);
+}
+
+static inline void mipid_read(struct spi_device *spi,
+		int reg, u8 *buf, int len)
+{
+	mipid_transfer(spi, reg, NULL, 0, buf, len);
+}
+
+static void set_data_lines(struct spi_device *spi, int data_lines)
+{
+	u16 par;
+
+	switch (data_lines) {
+	case 16:
+		par = 0x150;
+		break;
+	case 18:
+		par = 0x160;
+		break;
+	case 24:
+		par = 0x170;
+		break;
+	}
+
+	mipid_write(spi, 0x3a, (u8 *)&par, 2);
+}
+
+static void send_init_string(struct spi_device *spi)
+{
+	u16 initpar[] = { 0x0102, 0x0100, 0x0100 };
+	mipid_write(spi, 0xc2, (u8 *)initpar, sizeof(initpar));
+}
+
+static void send_display_on(struct spi_device *spi)
+{
+	mipid_cmd(spi, MIPID_CMD_DISP_ON);
+}
+
+static void send_display_off(struct spi_device *spi)
+{
+	mipid_cmd(spi, MIPID_CMD_DISP_OFF);
+}
+
+static void send_sleep_out(struct spi_device *spi)
+{
+	mipid_cmd(spi, MIPID_CMD_SLEEP_OUT);
+	msleep(120);
+}
+
+static void send_sleep_in(struct spi_device *spi)
+{
+	mipid_cmd(spi, MIPID_CMD_SLEEP_IN);
+	msleep(50);
+}
+
+static int n8x0_panel_power_on(struct omap_dss_device *dssdev)
+{
+	int r;
+	struct panel_n8x0_data *bdata = get_board_data(dssdev);
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	struct spi_device *spi = ddata->spidev;
+	u8 rev, conf;
+	u8 display_id[3];
+	const char *panel_name;
+
+	if (dssdev->state == OMAP_DSS_DISPLAY_ACTIVE)
+		return 0;
+
+	gpio_direction_output(bdata->ctrl_pwrdown, 1);
+
+	if (bdata->platform_enable) {
+		r = bdata->platform_enable(dssdev);
+		if (r)
+			goto err_plat_en;
+	}
+
+	r = omapdss_rfbi_display_enable(dssdev);
+	if (r)
+		goto err_rfbi_en;
+
+	rev = blizzard_read_reg(BLIZZARD_REV_CODE);
+	conf = blizzard_read_reg(BLIZZARD_CONFIG);
+
+	switch (rev & 0xfc) {
+	case 0x9c:
+		ddata->blizzard_ver = BLIZZARD_VERSION_S1D13744;
+		dev_info(&dssdev->dev, "s1d13744 LCD controller rev %d "
+			"initialized (CNF pins %x)\n", rev & 0x03, conf & 0x07);
+		break;
+	case 0xa4:
+		ddata->blizzard_ver = BLIZZARD_VERSION_S1D13745;
+		dev_info(&dssdev->dev, "s1d13745 LCD controller rev %d "
+			"initialized (CNF pins %x)\n", rev & 0x03, conf & 0x07);
+		break;
+	default:
+		dev_err(&dssdev->dev, "invalid s1d1374x revision %02x\n", rev);
+		r = -ENODEV;
+		goto err_inv_chip;
+	}
+
+	/* panel */
+
+	gpio_direction_output(bdata->panel_reset, 1);
+
+	mipid_read(spi, MIPID_CMD_READ_DISP_ID, display_id, 3);
+	dev_dbg(&spi->dev, "MIPI display ID: %02x%02x%02x\n",
+			display_id[0], display_id[1], display_id[2]);
+
+	switch (display_id[0]) {
+	case 0x45:
+		panel_name = "lph8923";
+		break;
+	case 0x83:
+		panel_name = "ls041y3";
+		break;
+	default:
+		dev_err(&dssdev->dev, "invalid display ID 0x%x\n",
+				display_id[0]);
+		r = -ENODEV;
+		goto err_inv_panel;
+	}
+
+	dev_info(&dssdev->dev, "%s rev %02x LCD detected\n",
+			panel_name, display_id[1]);
+
+	send_sleep_out(spi);
+	send_init_string(spi);
+	set_data_lines(spi, 24);
+	send_display_on(spi);
+
+	return 0;
+
+err_inv_panel:
+	/*
+	 * HACK: we should turn off the panel here, but there is some problem
+	 * with the initialization sequence, and we fail to init the panel if we
+	 * have turned it off
+	 */
+	/* gpio_direction_output(bdata->panel_reset, 0); */
+err_inv_chip:
+	omapdss_rfbi_display_disable(dssdev);
+err_rfbi_en:
+	if (bdata->platform_disable)
+		bdata->platform_disable(dssdev);
+err_plat_en:
+	gpio_direction_output(bdata->ctrl_pwrdown, 0);
+	return r;
+}
+
+static void n8x0_panel_power_off(struct omap_dss_device *dssdev)
+{
+	struct panel_n8x0_data *bdata = get_board_data(dssdev);
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	struct spi_device *spi = ddata->spidev;
+
+	if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
+		return;
+
+	send_display_off(spi);
+	send_sleep_in(spi);
+
+	if (bdata->platform_disable)
+		bdata->platform_disable(dssdev);
+
+	/*
+	 * HACK: we should turn off the panel here, but there is some problem
+	 * with the initialization sequence, and we fail to init the panel if we
+	 * have turned it off
+	 */
+	/* gpio_direction_output(bdata->panel_reset, 0); */
+	gpio_direction_output(bdata->ctrl_pwrdown, 0);
+	omapdss_rfbi_display_disable(dssdev);
+}
+
+static const struct rfbi_timings n8x0_panel_timings = {
+	.cs_on_time     = 0,
+
+	.we_on_time     = 9000,
+	.we_off_time    = 18000,
+	.we_cycle_time  = 36000,
+
+	.re_on_time     = 9000,
+	.re_off_time    = 27000,
+	.re_cycle_time  = 36000,
+
+	.access_time    = 27000,
+	.cs_off_time    = 36000,
+
+	.cs_pulse_width = 0,
+};
+
+static int n8x0_bl_update_status(struct backlight_device *dev)
+{
+	struct omap_dss_device *dssdev = dev_get_drvdata(&dev->dev);
+	struct panel_n8x0_data *bdata = get_board_data(dssdev);
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	int r;
+	int level;
+
+	mutex_lock(&ddata->lock);
+
+	if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
+			dev->props.power == FB_BLANK_UNBLANK)
+		level = dev->props.brightness;
+	else
+		level = 0;
+
+	dev_dbg(&dssdev->dev, "update brightness to %d\n", level);
+
+	if (!bdata->set_backlight)
+		r = -EINVAL;
+	else
+		r = bdata->set_backlight(dssdev, level);
+
+	mutex_unlock(&ddata->lock);
+
+	return r;
+}
+
+static int n8x0_bl_get_intensity(struct backlight_device *dev)
+{
+	if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
+			dev->props.power == FB_BLANK_UNBLANK)
+		return dev->props.brightness;
+
+	return 0;
+}
+
+static const struct backlight_ops n8x0_bl_ops = {
+	.get_brightness = n8x0_bl_get_intensity,
+	.update_status  = n8x0_bl_update_status,
+};
+
+static int n8x0_panel_probe(struct omap_dss_device *dssdev)
+{
+	struct panel_n8x0_data *bdata = get_board_data(dssdev);
+	struct panel_drv_data *ddata;
+	struct backlight_device *bldev;
+	struct backlight_properties props;
+	int r;
+
+	dev_dbg(&dssdev->dev, "probe\n");
+
+	if (!bdata)
+		return -EINVAL;
+
+	s_drv_data.dssdev = dssdev;
+
+	ddata = &s_drv_data;
+
+	mutex_init(&ddata->lock);
+
+	dssdev->panel.config = OMAP_DSS_LCD_TFT;
+	dssdev->panel.timings.x_res = 800;
+	dssdev->panel.timings.y_res = 480;
+	dssdev->ctrl.pixel_size = 16;
+	dssdev->ctrl.rfbi_timings = n8x0_panel_timings;
+
+	memset(&props, 0, sizeof(props));
+	props.max_brightness = 127;
+	props.type = BACKLIGHT_PLATFORM;
+	bldev = backlight_device_register(dev_name(&dssdev->dev), &dssdev->dev,
+			dssdev, &n8x0_bl_ops, &props);
+	if (IS_ERR(bldev)) {
+		r = PTR_ERR(bldev);
+		dev_err(&dssdev->dev, "register backlight failed\n");
+		return r;
+	}
+
+	ddata->bldev = bldev;
+
+	bldev->props.fb_blank = FB_BLANK_UNBLANK;
+	bldev->props.power = FB_BLANK_UNBLANK;
+	bldev->props.brightness = 127;
+
+	n8x0_bl_update_status(bldev);
+
+	return 0;
+}
+
+static void n8x0_panel_remove(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	struct backlight_device *bldev;
+
+	dev_dbg(&dssdev->dev, "remove\n");
+
+	bldev = ddata->bldev;
+	bldev->props.power = FB_BLANK_POWERDOWN;
+	n8x0_bl_update_status(bldev);
+	backlight_device_unregister(bldev);
+
+	dev_set_drvdata(&dssdev->dev, NULL);
+}
+
+static int n8x0_panel_enable(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	int r;
+
+	dev_dbg(&dssdev->dev, "enable\n");
+
+	mutex_lock(&ddata->lock);
+
+	rfbi_bus_lock();
+
+	r = n8x0_panel_power_on(dssdev);
+
+	rfbi_bus_unlock();
+
+	if (r) {
+		mutex_unlock(&ddata->lock);
+		return r;
+	}
+
+	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
+
+	mutex_unlock(&ddata->lock);
+
+	return 0;
+}
+
+static void n8x0_panel_disable(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+
+	dev_dbg(&dssdev->dev, "disable\n");
+
+	mutex_lock(&ddata->lock);
+
+	rfbi_bus_lock();
+
+	n8x0_panel_power_off(dssdev);
+
+	rfbi_bus_unlock();
+
+	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
+
+	mutex_unlock(&ddata->lock);
+}
+
+static int n8x0_panel_suspend(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+
+	dev_dbg(&dssdev->dev, "suspend\n");
+
+	mutex_lock(&ddata->lock);
+
+	rfbi_bus_lock();
+
+	n8x0_panel_power_off(dssdev);
+
+	rfbi_bus_unlock();
+
+	dssdev->state = OMAP_DSS_DISPLAY_SUSPENDED;
+
+	mutex_unlock(&ddata->lock);
+
+	return 0;
+}
+
+static int n8x0_panel_resume(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+	int r;
+
+	dev_dbg(&dssdev->dev, "resume\n");
+
+	mutex_lock(&ddata->lock);
+
+	rfbi_bus_lock();
+
+	r = n8x0_panel_power_on(dssdev);
+
+	rfbi_bus_unlock();
+
+	if (r) {
+		mutex_unlock(&ddata->lock);
+		return r;
+	}
+
+	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
+
+	mutex_unlock(&ddata->lock);
+
+	return 0;
+}
+
+static void n8x0_panel_get_timings(struct omap_dss_device *dssdev,
+		struct omap_video_timings *timings)
+{
+	*timings = dssdev->panel.timings;
+}
+
+static void n8x0_panel_get_resolution(struct omap_dss_device *dssdev,
+		u16 *xres, u16 *yres)
+{
+	*xres = dssdev->panel.timings.x_res;
+	*yres = dssdev->panel.timings.y_res;
+}
+
+static void update_done(void *data)
+{
+	rfbi_bus_unlock();
+}
+
+static int n8x0_panel_update(struct omap_dss_device *dssdev,
+		u16 x, u16 y, u16 w, u16 h)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+
+	dev_dbg(&dssdev->dev, "update\n");
+
+	mutex_lock(&ddata->lock);
+	rfbi_bus_lock();
+
+	omap_rfbi_prepare_update(dssdev, &x, &y, &w, &h);
+
+	blizzard_ctrl_setup_update(dssdev, x, y, w, h);
+
+	omap_rfbi_update(dssdev, x, y, w, h, update_done, NULL);
+
+	mutex_unlock(&ddata->lock);
+
+	return 0;
+}
+
+static int n8x0_panel_sync(struct omap_dss_device *dssdev)
+{
+	struct panel_drv_data *ddata = get_drv_data(dssdev);
+
+	dev_dbg(&dssdev->dev, "sync\n");
+
+	mutex_lock(&ddata->lock);
+	rfbi_bus_lock();
+	rfbi_bus_unlock();
+	mutex_unlock(&ddata->lock);
+
+	return 0;
+}
+
+static struct omap_dss_driver n8x0_panel_driver = {
+	.probe		= n8x0_panel_probe,
+	.remove		= n8x0_panel_remove,
+
+	.enable		= n8x0_panel_enable,
+	.disable	= n8x0_panel_disable,
+	.suspend	= n8x0_panel_suspend,
+	.resume		= n8x0_panel_resume,
+
+	.update		= n8x0_panel_update,
+	.sync		= n8x0_panel_sync,
+
+	.get_resolution	= n8x0_panel_get_resolution,
+	.get_recommended_bpp = omapdss_default_get_recommended_bpp,
+
+	.get_timings	= n8x0_panel_get_timings,
+
+	.driver         = {
+		.name   = "n8x0_panel",
+		.owner  = THIS_MODULE,
+	},
+};
+
+/* PANEL */
+
+static int mipid_spi_probe(struct spi_device *spi)
+{
+	dev_dbg(&spi->dev, "mipid_spi_probe\n");
+
+	spi->mode = SPI_MODE_0;
+
+	s_drv_data.spidev = spi;
+
+	return 0;
+}
+
+static int mipid_spi_remove(struct spi_device *spi)
+{
+	dev_dbg(&spi->dev, "mipid_spi_remove\n");
+	return 0;
+}
+
+static struct spi_driver mipid_spi_driver = {
+	.driver = {
+		.name	= "lcd_mipid",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe	= mipid_spi_probe,
+	.remove	= __devexit_p(mipid_spi_remove),
+};
+
+static int __init n8x0_panel_drv_init(void)
+{
+	int r;
+
+	r = spi_register_driver(&mipid_spi_driver);
+	if (r) {
+		pr_err("n8x0_panel: spi driver registration failed\n");
+		return r;
+	}
+
+	r = omap_dss_register_driver(&n8x0_panel_driver);
+	if (r) {
+		pr_err("n8x0_panel: dss driver registration failed\n");
+		spi_unregister_driver(&mipid_spi_driver);
+		return r;
+	}
+
+	return 0;
+}
+
+static void __exit n8x0_panel_drv_exit(void)
+{
+	spi_unregister_driver(&mipid_spi_driver);
+
+	omap_dss_unregister_driver(&n8x0_panel_driver);
+}
+
+module_init(n8x0_panel_drv_init);
+module_exit(n8x0_panel_drv_exit);
+MODULE_LICENSE("GPL");