omapfb: lcd_ams_delta: add support for contrast control
authorJanusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Fri, 11 Dec 2009 13:21:46 +0000 (13:21 +0000)
committerTomi Valkeinen <tomi.valkeinen@nokia.com>
Fri, 12 Feb 2010 10:46:07 +0000 (12:46 +0200)
The patch extends the Amstrad Delta LCD panel driver with optional support for
changing contrast using standard LCD class device API instead of setting it
silently to a default value at panel enable. It also allows for lowering power
consumption by turning off OMAP_PWL_CLK_ENABLE via lcd_ops.set_power callback.

Created and tested against linux-omap for-next,
commit 155a75d9725e66e5ec8a383822957dee52427057.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
drivers/video/omap/lcd_ams_delta.c

index 567db6ac32c80ea0d80f6a7b5f398c82dc96ea7f..6978ae4ef83aedf90a560f1d166a890a413ad25e 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/delay.h>
+#include <linux/lcd.h>
 
 #include <plat/board-ams-delta.h>
 #include <mach/hardware.h>
 
 #define AMS_DELTA_DEFAULT_CONTRAST     112
 
+#define AMS_DELTA_MAX_CONTRAST         0x00FF
+#define AMS_DELTA_LCD_POWER            0x0100
+
+
+/* LCD class device section */
+
+static int ams_delta_lcd;
+
+static int ams_delta_lcd_set_power(struct lcd_device *dev, int power)
+{
+       if (power == FB_BLANK_UNBLANK) {
+               if (!(ams_delta_lcd & AMS_DELTA_LCD_POWER)) {
+                       omap_writeb(ams_delta_lcd & AMS_DELTA_MAX_CONTRAST,
+                                       OMAP_PWL_ENABLE);
+                       omap_writeb(1, OMAP_PWL_CLK_ENABLE);
+                       ams_delta_lcd |= AMS_DELTA_LCD_POWER;
+               }
+       } else {
+               if (ams_delta_lcd & AMS_DELTA_LCD_POWER) {
+                       omap_writeb(0, OMAP_PWL_ENABLE);
+                       omap_writeb(0, OMAP_PWL_CLK_ENABLE);
+                       ams_delta_lcd &= ~AMS_DELTA_LCD_POWER;
+               }
+       }
+       return 0;
+}
+
+static int ams_delta_lcd_set_contrast(struct lcd_device *dev, int value)
+{
+       if ((value >= 0) && (value <= AMS_DELTA_MAX_CONTRAST)) {
+               omap_writeb(value, OMAP_PWL_ENABLE);
+               ams_delta_lcd &= ~AMS_DELTA_MAX_CONTRAST;
+               ams_delta_lcd |= value;
+       }
+       return 0;
+}
+
+#ifdef CONFIG_LCD_CLASS_DEVICE
+static int ams_delta_lcd_get_power(struct lcd_device *dev)
+{
+       if (ams_delta_lcd & AMS_DELTA_LCD_POWER)
+               return FB_BLANK_UNBLANK;
+       else
+               return FB_BLANK_POWERDOWN;
+}
+
+static int ams_delta_lcd_get_contrast(struct lcd_device *dev)
+{
+       if (!(ams_delta_lcd & AMS_DELTA_LCD_POWER))
+               return 0;
+
+       return ams_delta_lcd & AMS_DELTA_MAX_CONTRAST;
+}
+
+static struct lcd_ops ams_delta_lcd_ops = {
+       .get_power = ams_delta_lcd_get_power,
+       .set_power = ams_delta_lcd_set_power,
+       .get_contrast = ams_delta_lcd_get_contrast,
+       .set_contrast = ams_delta_lcd_set_contrast,
+};
+#endif
+
+
+/* omapfb panel section */
+
 static int ams_delta_panel_init(struct lcd_panel *panel,
                struct omapfb_device *fbdev)
 {
@@ -48,10 +114,6 @@ static int ams_delta_panel_enable(struct lcd_panel *panel)
                        AMS_DELTA_LATCH2_LCD_NDISP);
        ams_delta_latch2_write(AMS_DELTA_LATCH2_LCD_VBLEN,
                        AMS_DELTA_LATCH2_LCD_VBLEN);
-
-       omap_writeb(1, OMAP_PWL_CLK_ENABLE);
-       omap_writeb(AMS_DELTA_DEFAULT_CONTRAST, OMAP_PWL_ENABLE);
-
        return 0;
 }
 
@@ -91,8 +153,31 @@ static struct lcd_panel ams_delta_panel = {
        .get_caps       = ams_delta_panel_get_caps,
 };
 
+
+/* platform driver section */
+
 static int ams_delta_panel_probe(struct platform_device *pdev)
 {
+       struct lcd_device *lcd_device = NULL;
+#ifdef CONFIG_LCD_CLASS_DEVICE
+       int ret;
+
+       lcd_device = lcd_device_register("omapfb", &pdev->dev, NULL,
+                                               &ams_delta_lcd_ops);
+
+       if (IS_ERR(lcd_device)) {
+               ret = PTR_ERR(lcd_device);
+               dev_err(&pdev->dev, "failed to register device\n");
+               return ret;
+       }
+
+       platform_set_drvdata(pdev, lcd_device);
+       lcd_device->props.max_contrast = AMS_DELTA_MAX_CONTRAST;
+#endif
+
+       ams_delta_lcd_set_contrast(lcd_device, AMS_DELTA_DEFAULT_CONTRAST);
+       ams_delta_lcd_set_power(lcd_device, FB_BLANK_UNBLANK);
+
        omapfb_register_panel(&ams_delta_panel);
        return 0;
 }