Merge drm/drm-fixes into drm-misc-fixes

Let's start the 5.18 fixes cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

26 files changed, 727 insertions, 563 deletions

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 9989a316fe88..ddf5f38e8731 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -294,6 +294,18 @@ config DRM_PANEL_NOVATEK_NT35510
 	  around the Novatek NT35510 display controller, such as some
 	  Hydis panels.
 
+config DRM_PANEL_NOVATEK_NT35560
+	tristate "Novatek NT35560 DSI command mode panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	select VIDEOMODE_HELPERS
+	help
+	  Say Y here if you want to enable the Novatek NT35560 display
+	  controller. This panel supports DSI in both command and video
+	  mode. This supports several panels such as Sony ACX424AKM and
+	  ACX424AKP.
+
 config DRM_PANEL_NOVATEK_NT35950
 	tristate "Novatek NT35950 DSI panel"
 	depends on OF
@@ -594,17 +606,6 @@ config DRM_PANEL_SITRONIX_ST7789V
 	  Say Y here if you want to enable support for the Sitronix
 	  ST7789V controller for 240x320 LCD panels
 
-config DRM_PANEL_SONY_ACX424AKP
-	tristate "Sony ACX424AKP DSI command mode panel"
-	depends on OF
-	depends on DRM_MIPI_DSI
-	depends on BACKLIGHT_CLASS_DEVICE
-	select VIDEOMODE_HELPERS
-	help
-	  Say Y here if you want to enable the Sony ACX424 display
-	  panel. This panel supports DSI in both command and video
-	  mode.
-
 config DRM_PANEL_SONY_ACX565AKM
 	tristate "Sony ACX565AKM panel"
 	depends on GPIOLIB && OF && SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index d99fbbce49d1..5740911f637c 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.o
+obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35560) += panel-novatek-nt35560.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35950) += panel-novatek-nt35950.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
@@ -60,7 +61,6 @@ obj-$(CONFIG_DRM_PANEL_SHARP_LS060T1SX01) += panel-sharp-ls060t1sx01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7703) += panel-sitronix-st7703.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
-obj-$(CONFIG_DRM_PANEL_SONY_ACX424AKP) += panel-sony-acx424akp.o
 obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
 obj-$(CONFIG_DRM_PANEL_SONY_TULIP_TRULY_NT35521) += panel-sony-tulip-truly-nt35521.o
 obj-$(CONFIG_DRM_PANEL_TDO_TL070WSH30) += panel-tdo-tl070wsh30.o
diff --git a/drivers/gpu/drm/panel/panel-abt-y030xx067a.c b/drivers/gpu/drm/panel/panel-abt-y030xx067a.c
index f043b484055b..ed626fdc08e8 100644
--- a/drivers/gpu/drm/panel/panel-abt-y030xx067a.c
+++ b/drivers/gpu/drm/panel/panel-abt-y030xx067a.c
@@ -293,15 +293,13 @@ static int y030xx067a_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int y030xx067a_remove(struct spi_device *spi)
+static void y030xx067a_remove(struct spi_device *spi)
 {
 	struct y030xx067a *priv = spi_get_drvdata(spi);
 
 	drm_panel_remove(&priv->panel);
 	drm_panel_disable(&priv->panel);
 	drm_panel_unprepare(&priv->panel);
-
-	return 0;
 }
 
 static const struct drm_display_mode y030xx067a_modes[] = {
diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
index 5fcbde789ddb..1be150ac758f 100644
--- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
+++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
@@ -86,7 +86,7 @@ static const struct panel_init_cmd boe_tv110c9m_init_cmd[] = {
 	_INIT_DCS_CMD(0x0F, 0x73),
 	_INIT_DCS_CMD(0x95, 0xE6),
 	_INIT_DCS_CMD(0x96, 0xF0),
-	_INIT_DCS_CMD(0x30, 0x11),
+	_INIT_DCS_CMD(0x30, 0x00),
 	_INIT_DCS_CMD(0x6D, 0x66),
 	_INIT_DCS_CMD(0x75, 0xA2),
 	_INIT_DCS_CMD(0x77, 0x3B),
@@ -112,17 +112,17 @@ static const struct panel_init_cmd boe_tv110c9m_init_cmd[] = {
 	_INIT_DCS_CMD(0xB1, 0x00, 0xD2, 0x01, 0x0B, 0x01, 0x34, 0x01, 0x76, 0x01, 0xA3, 0x01, 0xEF, 0x02, 0x27, 0x02, 0x29),
 	_INIT_DCS_CMD(0xB2, 0x02, 0x5F, 0x02, 0x9E, 0x02, 0xC9, 0x03, 0x00, 0x03, 0x26, 0x03, 0x53, 0x03, 0x63, 0x03, 0x73),
 
-	_INIT_DCS_CMD(0xB3, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xA7, 0x03, 0xCF, 0x03, 0xDE, 0x03, 0xE0),
+	_INIT_DCS_CMD(0xB3, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xAF, 0x03, 0xDF, 0x03, 0xF5, 0x03, 0xE0),
 	_INIT_DCS_CMD(0xB4, 0x00, 0x00, 0x00, 0x1B, 0x00, 0x45, 0x00, 0x65, 0x00, 0x81, 0x00, 0x99, 0x00, 0xAE, 0x00, 0xC1),
 	_INIT_DCS_CMD(0xB5, 0x00, 0xD2, 0x01, 0x0B, 0x01, 0x34, 0x01, 0x76, 0x01, 0xA3, 0x01, 0xEF, 0x02, 0x27, 0x02, 0x29),
 	_INIT_DCS_CMD(0xB6, 0x02, 0x5F, 0x02, 0x9E, 0x02, 0xC9, 0x03, 0x00, 0x03, 0x26, 0x03, 0x53, 0x03, 0x63, 0x03, 0x73),
-	_INIT_DCS_CMD(0xB7, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xA7, 0x03, 0xCF, 0x03, 0xDE, 0x03, 0xE0),
+	_INIT_DCS_CMD(0xB7, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xAF, 0x03, 0xDF, 0x03, 0xF5, 0x03, 0xE0),
 
 	_INIT_DCS_CMD(0xB8, 0x00, 0x00, 0x00, 0x1B, 0x00, 0x45, 0x00, 0x65, 0x00, 0x81, 0x00, 0x99, 0x00, 0xAE, 0x00, 0xC1),
 	_INIT_DCS_CMD(0xB9, 0x00, 0xD2, 0x01, 0x0B, 0x01, 0x34, 0x01, 0x76, 0x01, 0xA3, 0x01, 0xEF, 0x02, 0x27, 0x02, 0x29),
 	_INIT_DCS_CMD(0xBA, 0x02, 0x5F, 0x02, 0x9E, 0x02, 0xC9, 0x03, 0x00, 0x03, 0x26, 0x03, 0x53, 0x03, 0x63, 0x03, 0x73),
 
-	_INIT_DCS_CMD(0xBB, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xA7, 0x03, 0xCF, 0x03, 0xDE, 0x03, 0xE0),
+	_INIT_DCS_CMD(0xBB, 0x03, 0x86, 0x03, 0x9A, 0x03, 0xAF, 0x03, 0xDF, 0x03, 0xF5, 0x03, 0xE0),
 	_INIT_DCS_CMD(0xFF, 0x24),
 	_INIT_DCS_CMD(0xFB, 0x01),
 
diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 176ef0c3cc1d..f7bfcf63d48e 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -21,6 +21,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/iopoll.h>
@@ -36,8 +37,8 @@
 
 #include <drm/drm_crtc.h>
 #include <drm/drm_device.h>
-#include <drm/drm_dp_aux_bus.h>
-#include <drm/drm_dp_helper.h>
+#include <drm/dp/drm_dp_aux_bus.h>
+#include <drm/dp/drm_dp_helper.h>
 #include <drm/drm_panel.h>
 
 /**
@@ -222,6 +223,8 @@ struct panel_edp {
 	struct gpio_desc *enable_gpio;
 	struct gpio_desc *hpd_gpio;
 
+	const struct edp_panel_entry *detected_panel;
+
 	struct edid *edid;
 
 	struct drm_display_mode override_mode;
@@ -606,6 +609,28 @@ static int panel_edp_get_timings(struct drm_panel *panel,
 	return p->desc->num_timings;
 }
 
+static int detected_panel_show(struct seq_file *s, void *data)
+{
+	struct drm_panel *panel = s->private;
+	struct panel_edp *p = to_panel_edp(panel);
+
+	if (IS_ERR(p->detected_panel))
+		seq_puts(s, "UNKNOWN\n");
+	else if (!p->detected_panel)
+		seq_puts(s, "HARDCODED\n");
+	else
+		seq_printf(s, "%s\n", p->detected_panel->name);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(detected_panel);
+
+static void panel_edp_debugfs_init(struct drm_panel *panel, struct dentry *root)
+{
+	debugfs_create_file("detected_panel", 0600, root, panel, &detected_panel_fops);
+}
+
 static const struct drm_panel_funcs panel_edp_funcs = {
 	.disable = panel_edp_disable,
 	.unprepare = panel_edp_unprepare,
@@ -613,6 +638,7 @@ static const struct drm_panel_funcs panel_edp_funcs = {
 	.enable = panel_edp_enable,
 	.get_modes = panel_edp_get_modes,
 	.get_timings = panel_edp_get_timings,
+	.debugfs_init = panel_edp_debugfs_init,
 };
 
 #define PANEL_EDP_BOUNDS_CHECK(to_check, bounds, field) \
@@ -666,7 +692,6 @@ static const struct edp_panel_entry *find_edp_panel(u32 panel_id);
 
 static int generic_edp_panel_probe(struct device *dev, struct panel_edp *panel)
 {
-	const struct edp_panel_entry *edp_panel;
 	struct panel_desc *desc;
 	u32 panel_id;
 	char vend[4];
@@ -705,14 +730,14 @@ static int generic_edp_panel_probe(struct device *dev, struct panel_edp *panel)
 	}
 	drm_edid_decode_panel_id(panel_id, vend, &product_id);
 
-	edp_panel = find_edp_panel(panel_id);
+	panel->detected_panel = find_edp_panel(panel_id);
 
 	/*
 	 * We're using non-optimized timings and want it really obvious that
 	 * someone needs to add an entry to the table, so we'll do a WARN_ON
 	 * splat.
 	 */
-	if (WARN_ON(!edp_panel)) {
+	if (WARN_ON(!panel->detected_panel)) {
 		dev_warn(dev,
 			 "Unknown panel %s %#06x, using conservative timings\n",
 			 vend, product_id);
@@ -734,12 +759,14 @@ static int generic_edp_panel_probe(struct device *dev, struct panel_edp *panel)
 		 */
 		desc->delay.unprepare = 2000;
 		desc->delay.enable = 200;
+
+		panel->detected_panel = ERR_PTR(-EINVAL);
 	} else {
 		dev_info(dev, "Detected %s %s (%#06x)\n",
-			 vend, edp_panel->name, product_id);
+			 vend, panel->detected_panel->name, product_id);
 
 		/* Update the delay; everything else comes from EDID */
-		desc->delay = *edp_panel->delay;
+		desc->delay = *panel->detected_panel->delay;
 	}
 
 	ret = 0;
@@ -1605,6 +1632,47 @@ static const struct panel_desc sharp_lq123p1jx31 = {
 	},
 };
 
+static const struct drm_display_mode sharp_lq140m1jw46_mode[] = {
+	{
+		.clock = 346500,
+		.hdisplay = 1920,
+		.hsync_start = 1920 + 48,
+		.hsync_end = 1920 + 48 + 32,
+		.htotal = 1920 + 48 + 32 + 80,
+		.vdisplay = 1080,
+		.vsync_start = 1080 + 3,
+		.vsync_end = 1080 + 3 + 5,
+		.vtotal = 1080 + 3 + 5 + 69,
+		.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+	}, {
+		.clock = 144370,
+		.hdisplay = 1920,
+		.hsync_start = 1920 + 48,
+		.hsync_end = 1920 + 48 + 32,
+		.htotal = 1920 + 48 + 32 + 80,
+		.vdisplay = 1080,
+		.vsync_start = 1080 + 3,
+		.vsync_end = 1080 + 3 + 5,
+		.vtotal = 1080 + 3 + 5 + 69,
+		.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+	},
+};
+
+static const struct panel_desc sharp_lq140m1jw46 = {
+	.modes = sharp_lq140m1jw46_mode,
+	.num_modes = ARRAY_SIZE(sharp_lq140m1jw46_mode),
+	.bpc = 8,
+	.size = {
+		.width = 309,
+		.height = 174,
+	},
+	.delay = {
+		.hpd_absent = 80,
+		.enable = 50,
+		.unprepare = 500,
+	},
+};
+
 static const struct drm_display_mode starry_kr122ea0sra_mode = {
 	.clock = 147000,
 	.hdisplay = 1920,
@@ -1719,6 +1787,9 @@ static const struct of_device_id platform_of_match[] = {
 		.compatible = "sharp,lq123p1jx31",
 		.data = &sharp_lq123p1jx31,
 	}, {
+		.compatible = "sharp,lq140m1jw46",
+		.data = &sharp_lq140m1jw46,
+	}, {
 		.compatible = "starry,kr122ea0sra",
 		.data = &starry_kr122ea0sra,
 	}, {
@@ -1745,6 +1816,19 @@ static const struct panel_delay delay_200_500_e50 = {
 	.enable = 50,
 };
 
+static const struct panel_delay delay_200_500_e80_d50 = {
+	.hpd_absent = 200,
+	.unprepare = 500,
+	.enable = 80,
+	.disable = 50,
+};
+
+static const struct panel_delay delay_100_500_e200 = {
+	.hpd_absent = 100,
+	.unprepare = 500,
+	.enable = 200,
+};
+
 #define EDP_PANEL_ENTRY(vend_chr_0, vend_chr_1, vend_chr_2, product_id, _delay, _name) \
 { \
 	.name = _name, \
@@ -1768,13 +1852,17 @@ static const struct edp_panel_entry edp_panels[] = {
 	EDP_PANEL_ENTRY('B', 'O', 'E', 0x07d1, &boe_nv133fhm_n61.delay, "NV133FHM-N61"),
 	EDP_PANEL_ENTRY('B', 'O', 'E', 0x082d, &boe_nv133fhm_n61.delay, "NV133FHM-N62"),
 	EDP_PANEL_ENTRY('B', 'O', 'E', 0x098d, &boe_nv110wtm_n61.delay, "NV110WTM-N61"),
+	EDP_PANEL_ENTRY('B', 'O', 'E', 0x0a5d, &delay_200_500_e50, "NV116WHM-N45"),
 
 	EDP_PANEL_ENTRY('C', 'M', 'N', 0x114c, &innolux_n116bca_ea1.delay, "N116BCA-EA1"),
 
 	EDP_PANEL_ENTRY('K', 'D', 'B', 0x0624, &kingdisplay_kd116n21_30nv_a010.delay, "116N21-30NV-A010"),
+	EDP_PANEL_ENTRY('K', 'D', 'B', 0x1120, &delay_200_500_e80_d50, "116N29-30NK-C007"),
 
 	EDP_PANEL_ENTRY('S', 'H', 'P', 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"),
 
+	EDP_PANEL_ENTRY('S', 'T', 'A', 0x0100, &delay_100_500_e200, "2081116HHD028001-51D"),
+
 	{ /* sentinal */ }
 };
 
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9322.c b/drivers/gpu/drm/panel/panel-ilitek-ili9322.c
index 8e84df9a0033..3dfafa585127 100644
--- a/drivers/gpu/drm/panel/panel-ilitek-ili9322.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9322.c
@@ -896,14 +896,12 @@ static int ili9322_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int ili9322_remove(struct spi_device *spi)
+static void ili9322_remove(struct spi_device *spi)
 {
 	struct ili9322 *ili = spi_get_drvdata(spi);
 
 	ili9322_power_off(ili);
 	drm_panel_remove(&ili->panel);
-
-	return 0;
 }
 
 /*
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
index e1542451ef9d..6826f4d4826a 100644
--- a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
@@ -730,7 +730,7 @@ static int ili9341_probe(struct spi_device *spi)
 	return -1;
 }
 
-static int ili9341_remove(struct spi_device *spi)
+static void ili9341_remove(struct spi_device *spi)
 {
 	const struct spi_device_id *id = spi_get_device_id(spi);
 	struct ili9341 *ili = spi_get_drvdata(spi);
@@ -743,7 +743,6 @@ static int ili9341_remove(struct spi_device *spi)
 		drm_dev_unplug(drm);
 		drm_atomic_helper_shutdown(drm);
 	}
-	return 0;
 }
 
 static void ili9341_shutdown(struct spi_device *spi)
diff --git a/drivers/gpu/drm/panel/panel-innolux-ej030na.c b/drivers/gpu/drm/panel/panel-innolux-ej030na.c
index c558de3f99be..e3b1daa0cb72 100644
--- a/drivers/gpu/drm/panel/panel-innolux-ej030na.c
+++ b/drivers/gpu/drm/panel/panel-innolux-ej030na.c
@@ -219,15 +219,13 @@ static int ej030na_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int ej030na_remove(struct spi_device *spi)
+static void ej030na_remove(struct spi_device *spi)
 {
 	struct ej030na *priv = spi_get_drvdata(spi);
 
 	drm_panel_remove(&priv->panel);
 	drm_panel_disable(&priv->panel);
 	drm_panel_unprepare(&priv->panel);
-
-	return 0;
 }
 
 static const struct drm_display_mode ej030na_modes[] = {
diff --git a/drivers/gpu/drm/panel/panel-lg-lb035q02.c b/drivers/gpu/drm/panel/panel-lg-lb035q02.c
index f3183b68704f..9d0d4faa3f58 100644
--- a/drivers/gpu/drm/panel/panel-lg-lb035q02.c
+++ b/drivers/gpu/drm/panel/panel-lg-lb035q02.c
@@ -203,14 +203,12 @@ static int lb035q02_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int lb035q02_remove(struct spi_device *spi)
+static void lb035q02_remove(struct spi_device *spi)
 {
 	struct lb035q02_device *lcd = spi_get_drvdata(spi);
 
 	drm_panel_remove(&lcd->panel);
 	drm_panel_disable(&lcd->panel);
-
-	return 0;
 }
 
 static const struct of_device_id lb035q02_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-lg-lg4573.c b/drivers/gpu/drm/panel/panel-lg-lg4573.c
index 8e5160af1de5..cf246d15b7b6 100644
--- a/drivers/gpu/drm/panel/panel-lg-lg4573.c
+++ b/drivers/gpu/drm/panel/panel-lg-lg4573.c
@@ -266,14 +266,12 @@ static int lg4573_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int lg4573_remove(struct spi_device *spi)
+static void lg4573_remove(struct spi_device *spi)
 {
 	struct lg4573 *ctx = spi_get_drvdata(spi);
 
 	lg4573_display_off(ctx);
 	drm_panel_remove(&ctx->panel);
-
-	return 0;
 }
 
 static const struct of_device_id lg4573_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c b/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
index 6e5ab1debc8b..81c5c541a351 100644
--- a/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
+++ b/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
@@ -212,15 +212,13 @@ static int nl8048_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int nl8048_remove(struct spi_device *spi)
+static void nl8048_remove(struct spi_device *spi)
 {
 	struct nl8048_panel *lcd = spi_get_drvdata(spi);
 
 	drm_panel_remove(&lcd->panel);
 	drm_panel_disable(&lcd->panel);
 	drm_panel_unprepare(&lcd->panel);
-
-	return 0;
 }
 
 static const struct of_device_id nl8048_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35560.c b/drivers/gpu/drm/panel/panel-novatek-nt35560.c
new file mode 100644
index 000000000000..1b6042321ea1
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-novatek-nt35560.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MIPI-DSI Novatek NT35560-based panel controller.
+ *
+ * Supported panels include:
+ * Sony ACX424AKM - a 480x854 AMOLED DSI panel
+ * Sony ACX424AKP - a 480x864 AMOLED DSI panel
+ *
+ * Copyright (C) Linaro Ltd. 2019-2021
+ * Author: Linus Walleij
+ * Based on code and know-how from Marcus Lorentzon
+ * Copyright (C) ST-Ericsson SA 2010
+ * Based on code and know-how from Johan Olson and Joakim Wesslen
+ * Copyright (C) Sony Ericsson Mobile Communications 2010
+ */
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#define NT35560_DCS_READ_ID1		0xDA
+#define NT35560_DCS_READ_ID2		0xDB
+#define NT35560_DCS_READ_ID3		0xDC
+#define NT35560_DCS_SET_MDDI		0xAE
+
+/*
+ * Sony seems to use vendor ID 0x81
+ */
+#define DISPLAY_SONY_ACX424AKP_ID1	0x8103
+#define DISPLAY_SONY_ACX424AKP_ID2	0x811a
+#define DISPLAY_SONY_ACX424AKP_ID3	0x811b
+/*
+ * The fourth ID looks like a bug, vendor IDs begin at 0x80
+ * and panel 00 ... seems like default values.
+ */
+#define DISPLAY_SONY_ACX424AKP_ID4	0x8000
+
+struct nt35560_config {
+	const struct drm_display_mode *vid_mode;
+	const struct drm_display_mode *cmd_mode;
+};
+
+struct nt35560 {
+	const struct nt35560_config *conf;
+	struct drm_panel panel;
+	struct device *dev;
+	struct regulator *supply;
+	struct gpio_desc *reset_gpio;
+	bool video_mode;
+};
+
+static const struct drm_display_mode sony_acx424akp_vid_mode = {
+	.clock = 27234,
+	.hdisplay = 480,
+	.hsync_start = 480 + 15,
+	.hsync_end = 480 + 15 + 0,
+	.htotal = 480 + 15 + 0 + 15,
+	.vdisplay = 864,
+	.vsync_start = 864 + 14,
+	.vsync_end = 864 + 14 + 1,
+	.vtotal = 864 + 14 + 1 + 11,
+	.width_mm = 48,
+	.height_mm = 84,
+	.flags = DRM_MODE_FLAG_PVSYNC,
+};
+
+/*
+ * The timings are not very helpful as the display is used in
+ * command mode using the maximum HS frequency.
+ */
+static const struct drm_display_mode sony_acx424akp_cmd_mode = {
+	.clock = 35478,
+	.hdisplay = 480,
+	.hsync_start = 480 + 154,
+	.hsync_end = 480 + 154 + 16,
+	.htotal = 480 + 154 + 16 + 32,
+	.vdisplay = 864,
+	.vsync_start = 864 + 1,
+	.vsync_end = 864 + 1 + 1,
+	.vtotal = 864 + 1 + 1 + 1,
+	/*
+	 * Some desired refresh rate, experiments at the maximum "pixel"
+	 * clock speed (HS clock 420 MHz) yields around 117Hz.
+	 */
+	.width_mm = 48,
+	.height_mm = 84,
+};
+
+static const struct nt35560_config sony_acx424akp_data = {
+	.vid_mode = &sony_acx424akp_vid_mode,
+	.cmd_mode = &sony_acx424akp_cmd_mode,
+};
+
+static const struct drm_display_mode sony_acx424akm_vid_mode = {
+	.clock = 27234,
+	.hdisplay = 480,
+	.hsync_start = 480 + 15,
+	.hsync_end = 480 + 15 + 0,
+	.htotal = 480 + 15 + 0 + 15,
+	.vdisplay = 854,
+	.vsync_start = 854 + 14,
+	.vsync_end = 854 + 14 + 1,
+	.vtotal = 854 + 14 + 1 + 11,
+	.width_mm = 46,
+	.height_mm = 82,
+	.flags = DRM_MODE_FLAG_PVSYNC,
+};
+
+/*
+ * The timings are not very helpful as the display is used in
+ * command mode using the maximum HS frequency.
+ */
+static const struct drm_display_mode sony_acx424akm_cmd_mode = {
+	.clock = 35478,
+	.hdisplay = 480,
+	.hsync_start = 480 + 154,
+	.hsync_end = 480 + 154 + 16,
+	.htotal = 480 + 154 + 16 + 32,
+	.vdisplay = 854,
+	.vsync_start = 854 + 1,
+	.vsync_end = 854 + 1 + 1,
+	.vtotal = 854 + 1 + 1 + 1,
+	.width_mm = 46,
+	.height_mm = 82,
+};
+
+static const struct nt35560_config sony_acx424akm_data = {
+	.vid_mode = &sony_acx424akm_vid_mode,
+	.cmd_mode = &sony_acx424akm_cmd_mode,
+};
+
+static inline struct nt35560 *panel_to_nt35560(struct drm_panel *panel)
+{
+	return container_of(panel, struct nt35560, panel);
+}
+
+#define FOSC			20 /* 20Mhz */
+#define SCALE_FACTOR_NS_DIV_MHZ	1000
+
+static int nt35560_set_brightness(struct backlight_device *bl)
+{
+	struct nt35560 *nt = bl_get_data(bl);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);
+	int period_ns = 1023;
+	int duty_ns = bl->props.brightness;
+	u8 pwm_ratio;
+	u8 pwm_div;
+	u8 par;
+	int ret;
+
+	if (backlight_is_blank(bl)) {
+		/* Disable backlight */
+		par = 0x00;
+		ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+					 &par, 1);
+		if (ret) {
+			dev_err(nt->dev, "failed to disable display backlight (%d)\n", ret);
+			return ret;
+		}
+		return 0;
+	}
+
+	/* Calculate the PWM duty cycle in n/256's */
+	pwm_ratio = max(((duty_ns * 256) / period_ns) - 1, 1);
+	pwm_div = max(1,
+		      ((FOSC * period_ns) / 256) /
+		      SCALE_FACTOR_NS_DIV_MHZ);
+
+	/* Set up PWM dutycycle ONE byte (differs from the standard) */
+	dev_dbg(nt->dev, "calculated duty cycle %02x\n", pwm_ratio);
+	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
+				 &pwm_ratio, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to set display PWM ratio (%d)\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Sequence to write PWMDIV:
+	 *	address		data
+	 *	0xF3		0xAA   CMD2 Unlock
+	 *	0x00		0x01   Enter CMD2 page 0
+	 *	0X7D		0x01   No reload MTP of CMD2 P1
+	 *	0x22		PWMDIV
+	 *	0x7F		0xAA   CMD2 page 1 lock
+	 */
+	par = 0xaa;
+	ret = mipi_dsi_dcs_write(dsi, 0xf3, &par, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to unlock CMD 2 (%d)\n", ret);
+		return ret;
+	}
+	par = 0x01;
+	ret = mipi_dsi_dcs_write(dsi, 0x00, &par, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to enter page 1 (%d)\n", ret);
+		return ret;
+	}
+	par = 0x01;
+	ret = mipi_dsi_dcs_write(dsi, 0x7d, &par, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to disable MTP reload (%d)\n", ret);
+		return ret;
+	}
+	ret = mipi_dsi_dcs_write(dsi, 0x22, &pwm_div, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to set PWM divisor (%d)\n", ret);
+		return ret;
+	}
+	par = 0xaa;
+	ret = mipi_dsi_dcs_write(dsi, 0x7f, &par, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to lock CMD 2 (%d)\n", ret);
+		return ret;
+	}
+
+	/* Enable backlight */
+	par = 0x24;
+	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				 &par, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to enable display backlight (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct backlight_ops nt35560_bl_ops = {
+	.update_status = nt35560_set_brightness,
+};
+
+static const struct backlight_properties nt35560_bl_props = {
+	.type = BACKLIGHT_RAW,
+	.brightness = 512,
+	.max_brightness = 1023,
+};
+
+static int nt35560_read_id(struct nt35560 *nt)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);
+	u8 vendor, version, panel;
+	u16 val;
+	int ret;
+
+	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID1, &vendor, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "could not vendor ID byte\n");
+		return ret;
+	}
+	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID2, &version, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "could not read device version byte\n");
+		return ret;
+	}
+	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID3, &panel, 1);
+	if (ret < 0) {
+		dev_err(nt->dev, "could not read panel ID byte\n");
+		return ret;
+	}
+
+	if (vendor == 0x00) {
+		dev_err(nt->dev, "device vendor ID is zero\n");
+		return -ENODEV;
+	}
+
+	val = (vendor << 8) | panel;
+	switch (val) {
+	case DISPLAY_SONY_ACX424AKP_ID1:
+	case DISPLAY_SONY_ACX424AKP_ID2:
+	case DISPLAY_SONY_ACX424AKP_ID3:
+	case DISPLAY_SONY_ACX424AKP_ID4:
+		dev_info(nt->dev, "MTP vendor: %02x, version: %02x, panel: %02x\n",
+			 vendor, version, panel);
+		break;
+	default:
+		dev_info(nt->dev, "unknown vendor: %02x, version: %02x, panel: %02x\n",
+			 vendor, version, panel);
+		break;
+	}
+
+	return 0;
+}
+
+static int nt35560_power_on(struct nt35560 *nt)
+{
+	int ret;
+
+	ret = regulator_enable(nt->supply);
+	if (ret) {
+		dev_err(nt->dev, "failed to enable supply (%d)\n", ret);
+		return ret;
+	}
+
+	/* Assert RESET */
+	gpiod_set_value_cansleep(nt->reset_gpio, 1);
+	udelay(20);
+	/* De-assert RESET */
+	gpiod_set_value_cansleep(nt->reset_gpio, 0);
+	usleep_range(11000, 20000);
+
+	return 0;
+}
+
+static void nt35560_power_off(struct nt35560 *nt)
+{
+	/* Assert RESET */
+	gpiod_set_value_cansleep(nt->reset_gpio, 1);
+	usleep_range(11000, 20000);
+
+	regulator_disable(nt->supply);
+}
+
+static int nt35560_prepare(struct drm_panel *panel)
+{
+	struct nt35560 *nt = panel_to_nt35560(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);
+	const u8 mddi = 3;
+	int ret;
+
+	ret = nt35560_power_on(nt);
+	if (ret)
+		return ret;
+
+	ret = nt35560_read_id(nt);
+	if (ret) {
+		dev_err(nt->dev, "failed to read panel ID (%d)\n", ret);
+		goto err_power_off;
+	}
+
+	/* Enabe tearing mode: send TE (tearing effect) at VBLANK */
+	ret = mipi_dsi_dcs_set_tear_on(dsi,
+				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
+	if (ret) {
+		dev_err(nt->dev, "failed to enable vblank TE (%d)\n", ret);
+		goto err_power_off;
+	}
+
+	/*
+	 * Set MDDI
+	 *
+	 * This presumably deactivates the Qualcomm MDDI interface and
+	 * selects DSI, similar code is found in other drivers such as the
+	 * Sharp LS043T1LE01 which makes us suspect that this panel may be
+	 * using a Novatek NT35565 or similar display driver chip that shares
+	 * this command. Due to the lack of documentation we cannot know for
+	 * sure.
+	 */
+	ret = mipi_dsi_dcs_write(dsi, NT35560_DCS_SET_MDDI,
+				 &mddi, sizeof(mddi));
+	if (ret < 0) {
+		dev_err(nt->dev, "failed to set MDDI (%d)\n", ret);
+		goto err_power_off;
+	}
+
+	/* Exit sleep mode */
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret) {
+		dev_err(nt->dev, "failed to exit sleep mode (%d)\n", ret);
+		goto err_power_off;
+	}
+	msleep(140);
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret) {
+		dev_err(nt->dev, "failed to turn display on (%d)\n", ret);
+		goto err_power_off;
+	}
+	if (nt->video_mode) {
+		/* In video mode turn peripheral on */
+		ret = mipi_dsi_turn_on_peripheral(dsi);
+		if (ret) {
+			dev_err(nt->dev, "failed to turn on peripheral\n");
+			goto err_power_off;
+		}
+	}
+
+	return 0;
+
+err_power_off:
+	nt35560_power_off(nt);
+	return ret;
+}
+
+static int nt35560_unprepare(struct drm_panel *panel)
+{
+	struct nt35560 *nt = panel_to_nt35560(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);
+	int ret;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret) {
+		dev_err(nt->dev, "failed to turn display off (%d)\n", ret);
+		return ret;
+	}
+
+	/* Enter sleep mode */
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret) {
+		dev_err(nt->dev, "failed to enter sleep mode (%d)\n", ret);
+		return ret;
+	}
+	msleep(85);
+
+	nt35560_power_off(nt);
+
+	return 0;
+}
+
+
+static int nt35560_get_modes(struct drm_panel *panel,
+			     struct drm_connector *connector)
+{
+	struct nt35560 *nt = panel_to_nt35560(panel);
+	const struct nt35560_config *conf = nt->conf;
+	struct drm_display_mode *mode;
+
+	if (nt->video_mode)
+		mode = drm_mode_duplicate(connector->dev,
+					  conf->vid_mode);
+	else
+		mode = drm_mode_duplicate(connector->dev,
+					  conf->cmd_mode);
+	if (!mode) {
+		dev_err(panel->dev, "bad mode or failed to add mode\n");
+		return -EINVAL;
+	}
+	drm_mode_set_name(mode);
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+
+	drm_mode_probed_add(connector, mode);
+
+	return 1; /* Number of modes */
+}
+
+static const struct drm_panel_funcs nt35560_drm_funcs = {
+	.unprepare = nt35560_unprepare,
+	.prepare = nt35560_prepare,
+	.get_modes = nt35560_get_modes,
+};
+
+static int nt35560_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct nt35560 *nt;
+	int ret;
+
+	nt = devm_kzalloc(dev, sizeof(struct nt35560), GFP_KERNEL);
+	if (!nt)
+		return -ENOMEM;
+	nt->video_mode = of_property_read_bool(dev->of_node,
+						"enforce-video-mode");
+
+	mipi_dsi_set_drvdata(dsi, nt);
+	nt->dev = dev;
+
+	nt->conf = of_device_get_match_data(dev);
+	if (!nt->conf) {
+		dev_err(dev, "missing device configuration\n");
+		return -ENODEV;
+	}
+
+	dsi->lanes = 2;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	/*
+	 * FIXME: these come from the ST-Ericsson vendor driver for the
+	 * HREF520 and seems to reflect limitations in the PLLs on that
+	 * platform, if you have the datasheet, please cross-check the
+	 * actual max rates.
+	 */
+	dsi->lp_rate = 19200000;
+	dsi->hs_rate = 420160000;
+
+	if (nt->video_mode)
+		/* Burst mode using event for sync */
+		dsi->mode_flags =
+			MIPI_DSI_MODE_VIDEO |
+			MIPI_DSI_MODE_VIDEO_BURST;
+	else
+		dsi->mode_flags =
+			MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+	nt->supply = devm_regulator_get(dev, "vddi");
+	if (IS_ERR(nt->supply))
+		return PTR_ERR(nt->supply);
+
+	/* This asserts RESET by default */
+	nt->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(nt->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(nt->reset_gpio),
+				     "failed to request GPIO\n");
+
+	drm_panel_init(&nt->panel, dev, &nt35560_drm_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	nt->panel.backlight = devm_backlight_device_register(dev, "nt35560", dev, nt,
+					&nt35560_bl_ops, &nt35560_bl_props);
+	if (IS_ERR(nt->panel.backlight))
+		return dev_err_probe(dev, PTR_ERR(nt->panel.backlight),
+				     "failed to register backlight device\n");
+
+	drm_panel_add(&nt->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		drm_panel_remove(&nt->panel);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int nt35560_remove(struct mipi_dsi_device *dsi)
+{
+	struct nt35560 *nt = mipi_dsi_get_drvdata(dsi);
+
+	mipi_dsi_detach(dsi);
+	drm_panel_remove(&nt->panel);
+
+	return 0;
+}
+
+static const struct of_device_id nt35560_of_match[] = {
+	{
+		.compatible = "sony,acx424akp",
+		.data = &sony_acx424akp_data,
+	},
+	{
+		.compatible = "sony,acx424akm",
+		.data = &sony_acx424akm_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, nt35560_of_match);
+
+static struct mipi_dsi_driver nt35560_driver = {
+	.probe = nt35560_probe,
+	.remove = nt35560_remove,
+	.driver = {
+		.name = "panel-novatek-nt35560",
+		.of_match_table = nt35560_of_match,
+	},
+};
+module_mipi_dsi_driver(nt35560_driver);
+
+MODULE_AUTHOR("Linus Wallei <linus.walleij@linaro.org>");
+MODULE_DESCRIPTION("MIPI-DSI Novatek NT35560 Panel Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/panel/panel-novatek-nt39016.c b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
index d036853db865..f58cfb10b58a 100644
--- a/drivers/gpu/drm/panel/panel-novatek-nt39016.c
+++ b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
@@ -292,7 +292,7 @@ static int nt39016_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int nt39016_remove(struct spi_device *spi)
+static void nt39016_remove(struct spi_device *spi)
 {
 	struct nt39016 *panel = spi_get_drvdata(spi);
 
@@ -300,8 +300,6 @@ static int nt39016_remove(struct spi_device *spi)
 
 	nt39016_disable(&panel->drm_panel);
 	nt39016_unprepare(&panel->drm_panel);
-
-	return 0;
 }
 
 static const struct drm_display_mode kd035g6_display_modes[] = {
diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
index 221db6512859..20666b6217e7 100644
--- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
+++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
@@ -14,8 +14,8 @@
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 
-#include <drm/drm_dp_aux_bus.h>
-#include <drm/drm_dp_helper.h>
+#include <drm/dp/drm_dp_aux_bus.h>
+#include <drm/dp/drm_dp_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_panel.h>
 
diff --git a/drivers/gpu/drm/panel/panel-samsung-db7430.c b/drivers/gpu/drm/panel/panel-samsung-db7430.c
index ead479719f00..04640c5256a8 100644
--- a/drivers/gpu/drm/panel/panel-samsung-db7430.c
+++ b/drivers/gpu/drm/panel/panel-samsung-db7430.c
@@ -314,12 +314,11 @@ static int db7430_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int db7430_remove(struct spi_device *spi)
+static void db7430_remove(struct spi_device *spi)
 {
 	struct db7430 *db = spi_get_drvdata(spi);
 
 	drm_panel_remove(&db->panel);
-	return 0;
 }
 
 /*
diff --git a/drivers/gpu/drm/panel/panel-samsung-ld9040.c b/drivers/gpu/drm/panel/panel-samsung-ld9040.c
index c4b388850a13..01eb211f32f7 100644
--- a/drivers/gpu/drm/panel/panel-samsung-ld9040.c
+++ b/drivers/gpu/drm/panel/panel-samsung-ld9040.c
@@ -358,14 +358,12 @@ static int ld9040_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int ld9040_remove(struct spi_device *spi)
+static void ld9040_remove(struct spi_device *spi)
 {
 	struct ld9040 *ctx = spi_get_drvdata(spi);
 
 	ld9040_power_off(ctx);
 	drm_panel_remove(&ctx->panel);
-
-	return 0;
 }
 
 static const struct of_device_id ld9040_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-samsung-s6d27a1.c b/drivers/gpu/drm/panel/panel-samsung-s6d27a1.c
index 1696ceb36aa0..2adb223a895c 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6d27a1.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6d27a1.c
@@ -291,12 +291,11 @@ static int s6d27a1_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int s6d27a1_remove(struct spi_device *spi)
+static void s6d27a1_remove(struct spi_device *spi)
 {
 	struct s6d27a1 *ctx = spi_get_drvdata(spi);
 
 	drm_panel_remove(&ctx->panel);
-	return 0;
 }
 
 static const struct of_device_id s6d27a1_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c b/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
index c178d962b0d5..d99afcc672ca 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
@@ -62,10 +62,9 @@ static int s6e63m0_spi_probe(struct spi_device *spi)
 			     s6e63m0_spi_dcs_write, false);
 }
 
-static int s6e63m0_spi_remove(struct spi_device *spi)
+static void s6e63m0_spi_remove(struct spi_device *spi)
 {
 	s6e63m0_remove(&spi->dev);
-	return 0;
 }
 
 static const struct of_device_id s6e63m0_spi_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index b42c1d816e79..a34f4198a534 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -2526,6 +2526,36 @@ static const struct panel_desc mitsubishi_aa070mc01 = {
 	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 };
 
+static const struct display_timing multi_inno_mi0700s4t_6_timing = {
+	.pixelclock = { 29000000, 33000000, 38000000 },
+	.hactive = { 800, 800, 800 },
+	.hfront_porch = { 180, 210, 240 },
+	.hback_porch = { 16, 16, 16 },
+	.hsync_len = { 30, 30, 30 },
+	.vactive = { 480, 480, 480 },
+	.vfront_porch = { 12, 22, 32 },
+	.vback_porch = { 10, 10, 10 },
+	.vsync_len = { 13, 13, 13 },
+	.flags = DISPLAY_FLAGS_HSYNC_LOW | DISPLAY_FLAGS_VSYNC_LOW |
+		 DISPLAY_FLAGS_DE_HIGH | DISPLAY_FLAGS_PIXDATA_POSEDGE |
+		 DISPLAY_FLAGS_SYNC_POSEDGE,
+};
+
+static const struct panel_desc multi_inno_mi0700s4t_6 = {
+	.timings = &multi_inno_mi0700s4t_6_timing,
+	.num_timings = 1,
+	.bpc = 8,
+	.size = {
+		.width = 154,
+		.height = 86,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH |
+		     DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
+		     DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE,
+	.connector_type = DRM_MODE_CONNECTOR_DPI,
+};
+
 static const struct display_timing multi_inno_mi1010ait_1cp_timing = {
 	.pixelclock = { 68900000, 70000000, 73400000 },
 	.hactive = { 1280, 1280, 1280 },
@@ -3028,6 +3058,7 @@ static const struct drm_display_mode rocktech_rk101ii01d_ct_mode = {
 
 static const struct panel_desc rocktech_rk101ii01d_ct = {
 	.modes = &rocktech_rk101ii01d_ct_mode,
+	.bpc = 8,
 	.num_modes = 1,
 	.size = {
 		.width = 217,
@@ -3873,6 +3904,9 @@ static const struct of_device_id platform_of_match[] = {
 		.compatible = "mitsubishi,aa070mc01-ca1",
 		.data = &mitsubishi_aa070mc01,
 	}, {
+		.compatible = "multi-inno,mi0700s4t-6",
+		.data = &multi_inno_mi0700s4t_6,
+	}, {
 		.compatible = "multi-inno,mi1010ait-1cp",
 		.data = &multi_inno_mi1010ait_1cp,
 	}, {
diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
index 61e565524542..bbc4569cbcdc 100644
--- a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
@@ -387,13 +387,11 @@ static int st7789v_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int st7789v_remove(struct spi_device *spi)
+static void st7789v_remove(struct spi_device *spi)
 {
 	struct st7789v *ctx = spi_get_drvdata(spi);
 
 	drm_panel_remove(&ctx->panel);
-
-	return 0;
 }
 
 static const struct of_device_id st7789v_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-sony-acx424akp.c b/drivers/gpu/drm/panel/panel-sony-acx424akp.c
deleted file mode 100644
index 9536d56a94a5..000000000000
--- a/drivers/gpu/drm/panel/panel-sony-acx424akp.c
+++ /dev/null
@@ -1,490 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * MIPI-DSI Sony ACX424AKP panel driver. This is a 480x864
- * AMOLED panel with a command-only DSI interface.
- *
- * Copyright (C) Linaro Ltd. 2019
- * Author: Linus Walleij
- * Based on code and know-how from Marcus Lorentzon
- * Copyright (C) ST-Ericsson SA 2010
- */
-#include <linux/backlight.h>
-#include <linux/delay.h>
-#include <linux/gpio/consumer.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/regulator/consumer.h>
-
-#include <video/mipi_display.h>
-
-#include <drm/drm_mipi_dsi.h>
-#include <drm/drm_modes.h>
-#include <drm/drm_panel.h>
-
-#define ACX424_DCS_READ_ID1		0xDA
-#define ACX424_DCS_READ_ID2		0xDB
-#define ACX424_DCS_READ_ID3		0xDC
-#define ACX424_DCS_SET_MDDI		0xAE
-
-/*
- * Sony seems to use vendor ID 0x81
- */
-#define DISPLAY_SONY_ACX424AKP_ID1	0x811b
-#define DISPLAY_SONY_ACX424AKP_ID2	0x811a
-/*
- * The third ID looks like a bug, vendor IDs begin at 0x80
- * and panel 00 ... seems like default values.
- */
-#define DISPLAY_SONY_ACX424AKP_ID3	0x8000
-
-struct acx424akp {
-	struct drm_panel panel;
-	struct device *dev;
-	struct regulator *supply;
-	struct gpio_desc *reset_gpio;
-	bool video_mode;
-};
-
-static const struct drm_display_mode sony_acx424akp_vid_mode = {
-	.clock = 27234,
-	.hdisplay = 480,
-	.hsync_start = 480 + 15,
-	.hsync_end = 480 + 15 + 0,
-	.htotal = 480 + 15 + 0 + 15,
-	.vdisplay = 864,
-	.vsync_start = 864 + 14,
-	.vsync_end = 864 + 14 + 1,
-	.vtotal = 864 + 14 + 1 + 11,
-	.width_mm = 48,
-	.height_mm = 84,
-	.flags = DRM_MODE_FLAG_PVSYNC,
-};
-
-/*
- * The timings are not very helpful as the display is used in
- * command mode using the maximum HS frequency.
- */
-static const struct drm_display_mode sony_acx424akp_cmd_mode = {
-	.clock = 35478,
-	.hdisplay = 480,
-	.hsync_start = 480 + 154,
-	.hsync_end = 480 + 154 + 16,
-	.htotal = 480 + 154 + 16 + 32,
-	.vdisplay = 864,
-	.vsync_start = 864 + 1,
-	.vsync_end = 864 + 1 + 1,
-	.vtotal = 864 + 1 + 1 + 1,
-	/*
-	 * Some desired refresh rate, experiments at the maximum "pixel"
-	 * clock speed (HS clock 420 MHz) yields around 117Hz.
-	 */
-	.width_mm = 48,
-	.height_mm = 84,
-};
-
-static inline struct acx424akp *panel_to_acx424akp(struct drm_panel *panel)
-{
-	return container_of(panel, struct acx424akp, panel);
-}
-
-#define FOSC			20 /* 20Mhz */
-#define SCALE_FACTOR_NS_DIV_MHZ	1000
-
-static int acx424akp_set_brightness(struct backlight_device *bl)
-{
-	struct acx424akp *acx = bl_get_data(bl);
-	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);
-	int period_ns = 1023;
-	int duty_ns = bl->props.brightness;
-	u8 pwm_ratio;
-	u8 pwm_div;
-	u8 par;
-	int ret;
-
-	if (backlight_is_blank(bl)) {
-		/* Disable backlight */
-		par = 0x00;
-		ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
-					 &par, 1);
-		if (ret) {
-			dev_err(acx->dev, "failed to disable display backlight (%d)\n", ret);
-			return ret;
-		}
-		return 0;
-	}
-
-	/* Calculate the PWM duty cycle in n/256's */
-	pwm_ratio = max(((duty_ns * 256) / period_ns) - 1, 1);
-	pwm_div = max(1,
-		      ((FOSC * period_ns) / 256) /
-		      SCALE_FACTOR_NS_DIV_MHZ);
-
-	/* Set up PWM dutycycle ONE byte (differs from the standard) */
-	dev_dbg(acx->dev, "calculated duty cycle %02x\n", pwm_ratio);
-	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
-				 &pwm_ratio, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to set display PWM ratio (%d)\n", ret);
-		return ret;
-	}
-
-	/*
-	 * Sequence to write PWMDIV:
-	 *	address		data
-	 *	0xF3		0xAA   CMD2 Unlock
-	 *	0x00		0x01   Enter CMD2 page 0
-	 *	0X7D		0x01   No reload MTP of CMD2 P1
-	 *	0x22		PWMDIV
-	 *	0x7F		0xAA   CMD2 page 1 lock
-	 */
-	par = 0xaa;
-	ret = mipi_dsi_dcs_write(dsi, 0xf3, &par, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to unlock CMD 2 (%d)\n", ret);
-		return ret;
-	}
-	par = 0x01;
-	ret = mipi_dsi_dcs_write(dsi, 0x00, &par, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to enter page 1 (%d)\n", ret);
-		return ret;
-	}
-	par = 0x01;
-	ret = mipi_dsi_dcs_write(dsi, 0x7d, &par, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to disable MTP reload (%d)\n", ret);
-		return ret;
-	}
-	ret = mipi_dsi_dcs_write(dsi, 0x22, &pwm_div, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to set PWM divisor (%d)\n", ret);
-		return ret;
-	}
-	par = 0xaa;
-	ret = mipi_dsi_dcs_write(dsi, 0x7f, &par, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to lock CMD 2 (%d)\n", ret);
-		return ret;
-	}
-
-	/* Enable backlight */
-	par = 0x24;
-	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
-				 &par, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to enable display backlight (%d)\n", ret);
-		return ret;
-	}
-
-	return 0;
-}
-
-static const struct backlight_ops acx424akp_bl_ops = {
-	.update_status = acx424akp_set_brightness,
-};
-
-static const struct backlight_properties acx424akp_bl_props = {
-	.type = BACKLIGHT_RAW,
-	.brightness = 512,
-	.max_brightness = 1023,
-};
-
-static int acx424akp_read_id(struct acx424akp *acx)
-{
-	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);
-	u8 vendor, version, panel;
-	u16 val;
-	int ret;
-
-	ret = mipi_dsi_dcs_read(dsi, ACX424_DCS_READ_ID1, &vendor, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "could not vendor ID byte\n");
-		return ret;
-	}
-	ret = mipi_dsi_dcs_read(dsi, ACX424_DCS_READ_ID2, &version, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "could not read device version byte\n");
-		return ret;
-	}
-	ret = mipi_dsi_dcs_read(dsi, ACX424_DCS_READ_ID3, &panel, 1);
-	if (ret < 0) {
-		dev_err(acx->dev, "could not read panel ID byte\n");
-		return ret;
-	}
-
-	if (vendor == 0x00) {
-		dev_err(acx->dev, "device vendor ID is zero\n");
-		return -ENODEV;
-	}
-
-	val = (vendor << 8) | panel;
-	switch (val) {
-	case DISPLAY_SONY_ACX424AKP_ID1:
-	case DISPLAY_SONY_ACX424AKP_ID2:
-	case DISPLAY_SONY_ACX424AKP_ID3:
-		dev_info(acx->dev, "MTP vendor: %02x, version: %02x, panel: %02x\n",
-			 vendor, version, panel);
-		break;
-	default:
-		dev_info(acx->dev, "unknown vendor: %02x, version: %02x, panel: %02x\n",
-			 vendor, version, panel);
-		break;
-	}
-
-	return 0;
-}
-
-static int acx424akp_power_on(struct acx424akp *acx)
-{
-	int ret;
-
-	ret = regulator_enable(acx->supply);
-	if (ret) {
-		dev_err(acx->dev, "failed to enable supply (%d)\n", ret);
-		return ret;
-	}
-
-	/* Assert RESET */
-	gpiod_set_value_cansleep(acx->reset_gpio, 1);
-	udelay(20);
-	/* De-assert RESET */
-	gpiod_set_value_cansleep(acx->reset_gpio, 0);
-	usleep_range(11000, 20000);
-
-	return 0;
-}
-
-static void acx424akp_power_off(struct acx424akp *acx)
-{
-	/* Assert RESET */
-	gpiod_set_value_cansleep(acx->reset_gpio, 1);
-	usleep_range(11000, 20000);
-
-	regulator_disable(acx->supply);
-}
-
-static int acx424akp_prepare(struct drm_panel *panel)
-{
-	struct acx424akp *acx = panel_to_acx424akp(panel);
-	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);
-	const u8 mddi = 3;
-	int ret;
-
-	ret = acx424akp_power_on(acx);
-	if (ret)
-		return ret;
-
-	ret = acx424akp_read_id(acx);
-	if (ret) {
-		dev_err(acx->dev, "failed to read panel ID (%d)\n", ret);
-		goto err_power_off;
-	}
-
-	/* Enabe tearing mode: send TE (tearing effect) at VBLANK */
-	ret = mipi_dsi_dcs_set_tear_on(dsi,
-				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
-	if (ret) {
-		dev_err(acx->dev, "failed to enable vblank TE (%d)\n", ret);
-		goto err_power_off;
-	}
-
-	/*
-	 * Set MDDI
-	 *
-	 * This presumably deactivates the Qualcomm MDDI interface and
-	 * selects DSI, similar code is found in other drivers such as the
-	 * Sharp LS043T1LE01 which makes us suspect that this panel may be
-	 * using a Novatek NT35565 or similar display driver chip that shares
-	 * this command. Due to the lack of documentation we cannot know for
-	 * sure.
-	 */
-	ret = mipi_dsi_dcs_write(dsi, ACX424_DCS_SET_MDDI,
-				 &mddi, sizeof(mddi));
-	if (ret < 0) {
-		dev_err(acx->dev, "failed to set MDDI (%d)\n", ret);
-		goto err_power_off;
-	}
-
-	/* Exit sleep mode */
-	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
-	if (ret) {
-		dev_err(acx->dev, "failed to exit sleep mode (%d)\n", ret);
-		goto err_power_off;
-	}
-	msleep(140);
-
-	ret = mipi_dsi_dcs_set_display_on(dsi);
-	if (ret) {
-		dev_err(acx->dev, "failed to turn display on (%d)\n", ret);
-		goto err_power_off;
-	}
-	if (acx->video_mode) {
-		/* In video mode turn peripheral on */
-		ret = mipi_dsi_turn_on_peripheral(dsi);
-		if (ret) {
-			dev_err(acx->dev, "failed to turn on peripheral\n");
-			goto err_power_off;
-		}
-	}
-
-	return 0;
-
-err_power_off:
-	acx424akp_power_off(acx);
-	return ret;
-}
-
-static int acx424akp_unprepare(struct drm_panel *panel)
-{
-	struct acx424akp *acx = panel_to_acx424akp(panel);
-	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);
-	int ret;
-
-	ret = mipi_dsi_dcs_set_display_off(dsi);
-	if (ret) {
-		dev_err(acx->dev, "failed to turn display off (%d)\n", ret);
-		return ret;
-	}
-
-	/* Enter sleep mode */
-	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
-	if (ret) {
-		dev_err(acx->dev, "failed to enter sleep mode (%d)\n", ret);
-		return ret;
-	}
-	msleep(85);
-
-	acx424akp_power_off(acx);
-
-	return 0;
-}
-
-
-static int acx424akp_get_modes(struct drm_panel *panel,
-			       struct drm_connector *connector)
-{
-	struct acx424akp *acx = panel_to_acx424akp(panel);
-	struct drm_display_mode *mode;
-
-	if (acx->video_mode)
-		mode = drm_mode_duplicate(connector->dev,
-					  &sony_acx424akp_vid_mode);
-	else
-		mode = drm_mode_duplicate(connector->dev,
-					  &sony_acx424akp_cmd_mode);
-	if (!mode) {
-		dev_err(panel->dev, "bad mode or failed to add mode\n");
-		return -EINVAL;
-	}
-	drm_mode_set_name(mode);
-	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
-
-	connector->display_info.width_mm = mode->width_mm;
-	connector->display_info.height_mm = mode->height_mm;
-
-	drm_mode_probed_add(connector, mode);
-
-	return 1; /* Number of modes */
-}
-
-static const struct drm_panel_funcs acx424akp_drm_funcs = {
-	.unprepare = acx424akp_unprepare,
-	.prepare = acx424akp_prepare,
-	.get_modes = acx424akp_get_modes,
-};
-
-static int acx424akp_probe(struct mipi_dsi_device *dsi)
-{
-	struct device *dev = &dsi->dev;
-	struct acx424akp *acx;
-	int ret;
-
-	acx = devm_kzalloc(dev, sizeof(struct acx424akp), GFP_KERNEL);
-	if (!acx)
-		return -ENOMEM;
-	acx->video_mode = of_property_read_bool(dev->of_node,
-						"enforce-video-mode");
-
-	mipi_dsi_set_drvdata(dsi, acx);
-	acx->dev = dev;
-
-	dsi->lanes = 2;
-	dsi->format = MIPI_DSI_FMT_RGB888;
-	/*
-	 * FIXME: these come from the ST-Ericsson vendor driver for the
-	 * HREF520 and seems to reflect limitations in the PLLs on that
-	 * platform, if you have the datasheet, please cross-check the
-	 * actual max rates.
-	 */
-	dsi->lp_rate = 19200000;
-	dsi->hs_rate = 420160000;
-
-	if (acx->video_mode)
-		/* Burst mode using event for sync */
-		dsi->mode_flags =
-			MIPI_DSI_MODE_VIDEO |
-			MIPI_DSI_MODE_VIDEO_BURST;
-	else
-		dsi->mode_flags =
-			MIPI_DSI_CLOCK_NON_CONTINUOUS;
-
-	acx->supply = devm_regulator_get(dev, "vddi");
-	if (IS_ERR(acx->supply))
-		return PTR_ERR(acx->supply);
-
-	/* This asserts RESET by default */
-	acx->reset_gpio = devm_gpiod_get_optional(dev, "reset",
-						  GPIOD_OUT_HIGH);
-	if (IS_ERR(acx->reset_gpio))
-		return dev_err_probe(dev, PTR_ERR(acx->reset_gpio),
-				     "failed to request GPIO\n");
-
-	drm_panel_init(&acx->panel, dev, &acx424akp_drm_funcs,
-		       DRM_MODE_CONNECTOR_DSI);
-
-	acx->panel.backlight = devm_backlight_device_register(dev, "acx424akp", dev, acx,
-					&acx424akp_bl_ops, &acx424akp_bl_props);
-	if (IS_ERR(acx->panel.backlight))
-		return dev_err_probe(dev, PTR_ERR(acx->panel.backlight),
-				     "failed to register backlight device\n");
-
-	drm_panel_add(&acx->panel);
-
-	ret = mipi_dsi_attach(dsi);
-	if (ret < 0) {
-		drm_panel_remove(&acx->panel);
-		return ret;
-	}
-
-	return 0;
-}
-
-static int acx424akp_remove(struct mipi_dsi_device *dsi)
-{
-	struct acx424akp *acx = mipi_dsi_get_drvdata(dsi);
-
-	mipi_dsi_detach(dsi);
-	drm_panel_remove(&acx->panel);
-
-	return 0;
-}
-
-static const struct of_device_id acx424akp_of_match[] = {
-	{ .compatible = "sony,acx424akp" },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, acx424akp_of_match);
-
-static struct mipi_dsi_driver acx424akp_driver = {
-	.probe = acx424akp_probe,
-	.remove = acx424akp_remove,
-	.driver = {
-		.name = "panel-sony-acx424akp",
-		.of_match_table = acx424akp_of_match,
-	},
-};
-module_mipi_dsi_driver(acx424akp_driver);
-
-MODULE_AUTHOR("Linus Wallei <linus.walleij@linaro.org>");
-MODULE_DESCRIPTION("MIPI-DSI Sony acx424akp Panel Driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/panel/panel-sony-acx565akm.c b/drivers/gpu/drm/panel/panel-sony-acx565akm.c
index ba0b3ead150f..0d7541a33f87 100644
--- a/drivers/gpu/drm/panel/panel-sony-acx565akm.c
+++ b/drivers/gpu/drm/panel/panel-sony-acx565akm.c
@@ -655,7 +655,7 @@ static int acx565akm_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int acx565akm_remove(struct spi_device *spi)
+static void acx565akm_remove(struct spi_device *spi)
 {
 	struct acx565akm_panel *lcd = spi_get_drvdata(spi);
 
@@ -666,8 +666,6 @@ static int acx565akm_remove(struct spi_device *spi)
 
 	drm_panel_disable(&lcd->panel);
 	drm_panel_unprepare(&lcd->panel);
-
-	return 0;
 }
 
 static const struct of_device_id acx565akm_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-tpo-td028ttec1.c b/drivers/gpu/drm/panel/panel-tpo-td028ttec1.c
index ba0c00d1a001..4dbf8b88f264 100644
--- a/drivers/gpu/drm/panel/panel-tpo-td028ttec1.c
+++ b/drivers/gpu/drm/panel/panel-tpo-td028ttec1.c
@@ -350,15 +350,13 @@ static int td028ttec1_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int td028ttec1_remove(struct spi_device *spi)
+static void td028ttec1_remove(struct spi_device *spi)
 {
 	struct td028ttec1_panel *lcd = spi_get_drvdata(spi);
 
 	drm_panel_remove(&lcd->panel);
 	drm_panel_disable(&lcd->panel);
 	drm_panel_unprepare(&lcd->panel);
-
-	return 0;
 }
 
 static const struct of_device_id td028ttec1_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
index 1866cdb8f9c1..cf4609bb9b1d 100644
--- a/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
+++ b/drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
@@ -463,7 +463,7 @@ static int td043mtea1_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int td043mtea1_remove(struct spi_device *spi)
+static void td043mtea1_remove(struct spi_device *spi)
 {
 	struct td043mtea1_panel *lcd = spi_get_drvdata(spi);
 
@@ -472,8 +472,6 @@ static int td043mtea1_remove(struct spi_device *spi)
 	drm_panel_unprepare(&lcd->panel);
 
 	sysfs_remove_group(&spi->dev.kobj, &td043mtea1_attr_group);
-
-	return 0;
 }
 
 static const struct of_device_id td043mtea1_of_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-tpo-tpg110.c b/drivers/gpu/drm/panel/panel-tpo-tpg110.c
index e3791dad6830..0b1f5a11a055 100644
--- a/drivers/gpu/drm/panel/panel-tpo-tpg110.c
+++ b/drivers/gpu/drm/panel/panel-tpo-tpg110.c
@@ -450,12 +450,11 @@ static int tpg110_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int tpg110_remove(struct spi_device *spi)
+static void tpg110_remove(struct spi_device *spi)
 {
 	struct tpg110 *tpg = spi_get_drvdata(spi);
 
 	drm_panel_remove(&tpg->panel);
-	return 0;
 }
 
 static const struct of_device_id tpg110_match[] = {
diff --git a/drivers/gpu/drm/panel/panel-widechips-ws2401.c b/drivers/gpu/drm/panel/panel-widechips-ws2401.c
index 8bc976f54b80..236f3cb2b594 100644
--- a/drivers/gpu/drm/panel/panel-widechips-ws2401.c
+++ b/drivers/gpu/drm/panel/panel-widechips-ws2401.c
@@ -407,12 +407,11 @@ static int ws2401_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int ws2401_remove(struct spi_device *spi)
+static void ws2401_remove(struct spi_device *spi)
 {
 	struct ws2401 *ws = spi_get_drvdata(spi);
 
 	drm_panel_remove(&ws->panel);
-	return 0;
 }
 
 /*