drm/ssd130x: Add support for the SSD132x OLED controller family

The Solomon SSD132x controllers (such as the SSD1322, SSD1325 and SSD1327)
are used by 16 grayscale dot matrix OLED panels, extend the driver to also
support this chip family.

Instead adding an indirection level to allow the same modesetting pipeline
to be used by both controller families, add another pipeline for SSD132x.

This leads to some code duplication but it makes the driver easier to read
and reason about. Once other controller families are added (e.g: SSD133x),
some common code can be factored out in driver helpers to be shared by the
different families. But that can be done later once these patterns emerge.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231014071520.1342189-5-javierm@redhat.com

drivers/gpu/drm/solomon/Kconfig

 config DRM_SSD130X
-	tristate "DRM support for Solomon SSD130x OLED displays"
+	tristate "DRM support for Solomon SSD13xx OLED displays"
 	depends on DRM && MMU
 	select BACKLIGHT_CLASS_DEVICE
 	select DRM_GEM_SHMEM_HELPER
 	select DRM_KMS_HELPER
 	help
-	  DRM driver for the SSD130x Solomon and SINO WEALTH SH110x OLED
+	  DRM driver for the SSD13xx Solomon and SINO WEALTH SH110x OLED
 	  controllers. This is only for the core driver, a driver for the
 	  appropriate bus transport in your chip also must be selected.
 
 	  If M is selected the module will be called ssd130x.
 
 config DRM_SSD130X_I2C
-	tristate "DRM support for Solomon SSD130x OLED displays (I2C bus)"
+	tristate "DRM support for Solomon SSD13xx OLED displays (I2C bus)"
 	depends on DRM_SSD130X && I2C
 	select REGMAP_I2C
 	help
-	  Say Y here if the SSD130x or SH110x OLED display is connected via
+	  Say Y here if the SSD13xx or SH110x OLED display is connected via
 	  I2C bus.
 
 	  If M is selected the module will be called ssd130x-i2c.
 
 config DRM_SSD130X_SPI
-	tristate "DRM support for Solomon SSD130X OLED displays (SPI bus)"
+	tristate "DRM support for Solomon SSD13xx OLED displays (SPI bus)"
 	depends on DRM_SSD130X && SPI
 	select REGMAP
 	help
-	  Say Y here if the SSD130x OLED display is connected via SPI bus.
+	  Say Y here if the SSD13xx OLED display is connected via SPI bus.
 
 	  If M is selected the module will be called ssd130x-spi.

drivers/gpu/drm/solomon/ssd130x-i2c.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * DRM driver for Solomon SSD130x OLED displays (I2C bus)
+ * DRM driver for Solomon SSD13xx OLED displays (I2C bus)
  *
  * Copyright 2022 Red Hat Inc.
  * Author: Javier Martinez Canillas <javierm@redhat.com>
@@ -14,7 +14,7 @@
 #include "ssd130x.h"
 
 #define DRIVER_NAME	"ssd130x-i2c"
-#define DRIVER_DESC	"DRM driver for Solomon SSD130x OLED displays (I2C)"
+#define DRIVER_DESC	"DRM driver for Solomon SSD13xx OLED displays (I2C)"
 
 static const struct regmap_config ssd130x_i2c_regmap_config = {
 	.reg_bits = 8,
@@ -92,6 +92,19 @@ static const struct of_device_id ssd130x_of_match[] = {
 		.compatible = "solomon,ssd1309fb-i2c",
 		.data = &ssd130x_variants[SSD1309_ID],
 	},
+	/* ssd132x family */
+	{
+		.compatible = "solomon,ssd1322",
+		.data = &ssd130x_variants[SSD1322_ID],
+	},
+	{
+		.compatible = "solomon,ssd1325",
+		.data = &ssd130x_variants[SSD1325_ID],
+	},
+	{
+		.compatible = "solomon,ssd1327",
+		.data = &ssd130x_variants[SSD1327_ID],
+	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, ssd130x_of_match);

drivers/gpu/drm/solomon/ssd130x-spi.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * DRM driver for Solomon SSD130X OLED displays (SPI bus)
+ * DRM driver for Solomon SSD13xx OLED displays (SPI bus)
  *
  * Copyright 2022 Red Hat Inc.
  * Authors: Javier Martinez Canillas <javierm@redhat.com>
@@ -11,7 +11,7 @@
 #include "ssd130x.h"
 
 #define DRIVER_NAME	"ssd130x-spi"
-#define DRIVER_DESC	"DRM driver for Solomon SSD130X OLED displays (SPI)"
+#define DRIVER_DESC	"DRM driver for Solomon SSD13xx OLED displays (SPI)"
 
 struct ssd130x_spi_transport {
 	struct spi_device *spi;
@@ -129,6 +129,19 @@ static const struct of_device_id ssd130x_of_match[] = {
 		.compatible = "solomon,ssd1309",
 		.data = &ssd130x_variants[SSD1309_ID],
 	},
+	/* ssd132x family */
+	{
+		.compatible = "solomon,ssd1322",
+		.data = &ssd130x_variants[SSD1322_ID],
+	},
+	{
+		.compatible = "solomon,ssd1325",
+		.data = &ssd130x_variants[SSD1325_ID],
+	},
+	{
+		.compatible = "solomon,ssd1327",
+		.data = &ssd130x_variants[SSD1327_ID],
+	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, ssd130x_of_match);
@@ -149,6 +162,10 @@ static const struct spi_device_id ssd130x_spi_table[] = {
 	{ "ssd1306", SSD1306_ID },
 	{ "ssd1307", SSD1307_ID },
 	{ "ssd1309", SSD1309_ID },
+	/* ssd132x family */
+	{ "ssd1322", SSD1322_ID },
+	{ "ssd1325", SSD1325_ID },
+	{ "ssd1327", SSD1327_ID },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(spi, ssd130x_spi_table);

drivers/gpu/drm/solomon/ssd130x.h

@@ -25,7 +25,8 @@
 #define SSD13XX_COMMAND				0x80
 
 enum ssd130x_family_ids {
-	SSD130X_FAMILY
+	SSD130X_FAMILY,
+	SSD132X_FAMILY
 };
 
 enum ssd130x_variants {
@@ -35,6 +36,10 @@ enum ssd130x_variants {
 	SSD1306_ID,
 	SSD1307_ID,
 	SSD1309_ID,
+	/* ssd132x family */
+	SSD1322_ID,
+	SSD1325_ID,
+	SSD1327_ID,
 	NR_SSD130X_VARIANTS
 };