drivers: display: Add gamma table setting to ssd1327

This adds the ability to send gamma settings to the controller

Signed-off-by: Camille BAUD <[email protected]>

Author: VynDragon

drivers/display/ssd1327.c

@@ -47,6 +47,7 @@ struct ssd1327_config {
 	uint8_t function_selection_b;
 	uint8_t precharge_voltage;
 	uint8_t vcomh_voltage;
+	uint8_t *greyscale_table;
 	bool color_inversion;
 	uint8_t *conversion_buf;
 	size_t conversion_buf_size;
@@ -119,6 +120,13 @@ static inline int ssd1327_set_timing_setting(const struct device *dev)
 	if (err < 0) {
 		return err;
 	}
+	if (config->greyscale_table != NULL) {
+		err = config->write_cmd(dev, SSD1327_SET_LUT, config->greyscale_table,
+					SSD1327_SET_LUT_COUNT);
+		if (err < 0) {
+			return err;
+		}
+	}
 	err = config->write_cmd(dev, SSD1327_SET_PRECHARGE_VOLTAGE, &config->precharge_voltage, 1);
 	if (err < 0) {
 		return err;
@@ -452,9 +460,16 @@ static DEVICE_API(display, ssd1327_driver_api) = {
 #define SSD1327_CONV_BUFFER_SIZE(node_id)                                                          \
 	DIV_ROUND_UP(DT_PROP(node_id, width) * CONFIG_SSD1327_CONV_BUFFER_LINES, 2)
 
+#define SSD1327_GREYSCALE_TABLE(node_id)                                                           \
+	.greyscale_table = COND_CODE_1(DT_NODE_HAS_PROP(node_id, greyscale_table),                 \
+	(ssd1327_greyscale_table_##node_id), (NULL))
+
 #define SSD1327_DEFINE_I2C(node_id)                                                                \
 	static uint8_t conversion_buf##node_id[SSD1327_CONV_BUFFER_SIZE(node_id)];                 \
 	static struct ssd1327_data data##node_id;                                                  \
+	COND_CODE_1(DT_NODE_HAS_PROP(node_id, greyscale_table), (                                  \
+	static uint8_t ssd1327_greyscale_table_##node_id[SSD1327_SET_LUT_COUNT] =                  \
+	DT_PROP(node_id, greyscale_table);), ())                                                   \
 	static const struct ssd1327_config config##node_id = {                                     \
 		.i2c = I2C_DT_SPEC_GET(node_id),                                                   \
 		.height = DT_PROP(node_id, height),                                                \
@@ -470,6 +485,7 @@ static DEVICE_API(display, ssd1327_driver_api) = {
 		.function_selection_b = DT_PROP(node_id, function_selection_b),                    \
 		.precharge_voltage = DT_PROP(node_id, precharge_voltage),                          \
 		.vcomh_voltage = DT_PROP(node_id, vcomh_voltage),                                  \
+		SSD1327_GREYSCALE_TABLE(node_id),                                                  \
 		.write_cmd = ssd1327_write_bus_cmd_i2c,                                            \
 		.write_pixels = ssd1327_write_pixels_i2c,                                          \
 		.conversion_buf = conversion_buf##node_id,                                         \
@@ -482,6 +498,9 @@ static DEVICE_API(display, ssd1327_driver_api) = {
 #define SSD1327_DEFINE_MIPI(node_id)                                                               \
 	static uint8_t conversion_buf##node_id[SSD1327_CONV_BUFFER_SIZE(node_id)];                 \
 	static struct ssd1327_data data##node_id;                                                  \
+	COND_CODE_1(DT_NODE_HAS_PROP(node_id, greyscale_table), (                                  \
+	static uint8_t ssd1327_greyscale_table_##node_id[SSD1327_SET_LUT_COUNT] =                  \
+	DT_PROP(node_id, greyscale_table);), ())                                                   \
 	static const struct ssd1327_config config##node_id = {                                     \
 		.mipi_dev = DEVICE_DT_GET(DT_PARENT(node_id)),                                     \
 		.dbi_config = MIPI_DBI_CONFIG_DT(                                                  \
@@ -499,6 +518,7 @@ static DEVICE_API(display, ssd1327_driver_api) = {
 		.function_selection_b = DT_PROP(node_id, function_selection_b),                    \
 		.precharge_voltage = DT_PROP(node_id, precharge_voltage),                          \
 		.vcomh_voltage = DT_PROP(node_id, vcomh_voltage),                                  \
+		SSD1327_GREYSCALE_TABLE(node_id),                                                  \
 		.write_cmd = ssd1327_write_bus_cmd_mipi,                                           \
 		.write_pixels = ssd1327_write_pixels_mipi,                                         \
 		.conversion_buf = conversion_buf##node_id,                                         \

drivers/display/ssd1327_regs.h

@@ -34,6 +34,8 @@
 #define SSD1327_SET_PRECHARGE_PERIOD		0xb6
 #define SSD1327_FUNCTION_SELECTION_B		0xd5
 
+#define SSD1327_SET_LUT				0xb8
+#define SSD1327_SET_LUT_COUNT			15
 #define SSD1327_LINEAR_LUT			0xb9
 
 #define SSD1327_SET_PRECHARGE_VOLTAGE		0xbc

dts/bindings/display/solomon,ssd1327fb-common.yaml

@@ -76,3 +76,7 @@ properties:
   inversion-on:
     type: boolean
     description: Turn on display color inverting
+
+  greyscale-table:
+    type: uint8-array
+    description: 15 elements array defines gamma settings for each brightness levels.