drm/panel: Add driver for the Toppoly TD028TTEC1 panel

This panel is used on the OpenMoko Neo FreeRunner and Neo 1973.

The code is based on the omapdrm-specific panel-tpo-td028ttec1 driver.

v2:
- fix checkpatch warnings:
  o (lcd == NULL) => (!lcd) (sam)
  o (1 << X) => BIT(X) (sam)
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190813201101.30980-9-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/panel/Kconfig

@@ -324,6 +324,14 @@ config DRM_PANEL_SONY_ACX565AKM
 	  Say Y here if you want to enable support for the Sony ACX565AKM
 	  800x600 3.5" panel (found on the Nokia N900).
 
+config DRM_PANEL_TPO_TD028TTEC1
+	tristate "Toppoly (TPO) TD028TTEC1 panel driver"
+	depends on OF && SPI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for TPO TD028TTEC1 480x640
+	  2.8" panel (found on the OpenMoko Neo FreeRunner and Neo 1973).
+
 config DRM_PANEL_TPO_TPG110
 	tristate "TPO TPG 800x400 panel"
 	depends on OF && SPI && GPIOLIB

drivers/gpu/drm/panel/Makefile

@@ -34,5 +34,6 @@ obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
 obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
+obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
 obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o

drivers/gpu/drm/panel/panel-sony-acx565akm.c

@@ -31,10 +31,10 @@
 #include <drm/drm_modes.h>
 #include <drm/drm_panel.h>
 
-#define CTRL_DISP_BRIGHTNESS_CTRL_ON		(1 << 5)
-#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON		(1 << 4)
-#define CTRL_DISP_BACKLIGHT_ON			(1 << 2)
-#define CTRL_DISP_AUTO_BRIGHTNESS_ON		(1 << 1)
+#define CTRL_DISP_BRIGHTNESS_CTRL_ON		BIT(5)
+#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON		BIT(4)
+#define CTRL_DISP_BACKLIGHT_ON			BIT(2)
+#define CTRL_DISP_AUTO_BRIGHTNESS_ON		BIT(1)
 
 #define MIPID_CMD_WRITE_CABC		0x55
 #define MIPID_CMD_READ_CABC		0x56
@@ -621,7 +621,7 @@ static int acx565akm_probe(struct spi_device *spi)
 	int ret;
 
 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
-	if (lcd == NULL)
+	if (!lcd)
 		return -ENOMEM;
 
 	spi_set_drvdata(spi, lcd);