[PATCH 2/3] video: fbdev: ssd1307fb: Support to pixel inversion

From: Rodrigo Rolim Mendes de Alencar
Date: Tue May 12 2020 - 16:53:20 EST


Pixel inversion in hardware is performed by issuing the
command 0xa7. This patch adds a boolean property to control
color inversion.

Signed-off-by: Rodrigo Alencar <455.rodrigo.alencar@xxxxxxxxx>
---
.../devicetree/bindings/display/ssd1307fb.txt | 1 +
drivers/video/fbdev/ssd1307fb.c | 11 ++++++++++-
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/ssd1307fb.txt b/Documentation/devicetree/bindings/display/ssd1307fb.txt
index 74a7b228bcef..3076b71ede68 100644
--- a/Documentation/devicetree/bindings/display/ssd1307fb.txt
+++ b/Documentation/devicetree/bindings/display/ssd1307fb.txt
@@ -22,6 +22,7 @@ Optional properties:
- solomon,com-seq: Display uses sequential COM pin configuration
- solomon,com-lrremap: Display uses left-right COM pin remap
- solomon,com-invdir: Display uses inverted COM pin scan direction
+ - solomon,color-inv: Set Inverse display mode (invert pixel color)
- solomon,com-offset: Number of the COM pin wired to the first display line
- solomon,col-offset: Offset of columns (SEG) that the screen is mapped to.
- solomon,prechargep1: Length of deselect period (phase 1) in clock cycles.
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index ac88bbe174b6..748c21c0567b 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -31,8 +31,9 @@
#define SSD1307FB_SET_LOOKUP_TABLE 0x91
#define SSD1307FB_CHARGE_PUMP 0x8d
#define SSD1307FB_SEG_REMAP_ON 0xa1
-#define SSD1307FB_DISPLAY_OFF 0xae
+#define SSD1307FB_DISPLAY_NORMAL 0xa6
#define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8
+#define SSD1307FB_DISPLAY_OFF 0xae
#define SSD1307FB_DISPLAY_ON 0xaf
#define SSD1307FB_START_PAGE_ADDRESS 0xb0
#define SSD1307FB_SET_DISPLAY_OFFSET 0xd3
@@ -62,6 +63,7 @@ struct ssd1307fb_deviceinfo {
struct ssd1307fb_par {
unsigned area_color_enable : 1;
unsigned com_invdir : 1;
+ unsigned color_inv : 1;
unsigned com_lrremap : 1;
unsigned com_seq : 1;
unsigned lookup_table_set : 1;
@@ -492,6 +494,12 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
if (ret < 0)
return ret;

+ /* Set normal or inverse */
+ ret = ssd1307fb_write_cmd(par->client,
+ SSD1307FB_DISPLAY_NORMAL | (par->color_inv & 0x1));
+ if (ret < 0)
+ return ret;
+
/* Clear the screen */
ssd1307fb_update_display(par);

@@ -666,6 +674,7 @@ static int ssd1307fb_probe(struct i2c_client *client,
par->com_seq = of_property_read_bool(node, "solomon,com-seq");
par->com_lrremap = of_property_read_bool(node, "solomon,com-lrremap");
par->com_invdir = of_property_read_bool(node, "solomon,com-invdir");
+ par->color_inv = of_property_read_bool(node, "solomon,color-inv");
par->area_color_enable =
of_property_read_bool(node, "solomon,area-color-enable");
par->low_power = of_property_read_bool(node, "solomon,low-power");
--
2.23.0.rc1