drm/solomon: Add SSD130x OLED displays I2C support

The ssd130x driver only provides the core support for these devices but it
does not have any bus transport logic. Add a driver to interface over I2C.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-5-javierm@redhat.com

diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig
index 7720a70..5861c3a 100644 (file)
--- a/drivers/gpu/drm/solomon/Kconfig
+++ b/drivers/gpu/drm/solomon/Kconfig
@@ -10,3 +10,12 @@ config DRM_SSD130X
          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)"
+       depends on DRM_SSD130X && I2C
+       select REGMAP_I2C
+       help
+         Say Y here if the SSD130x OLED display is connected via I2C bus.
+
+         If M is selected the module will be called ssd130x-i2c.

diff --git a/drivers/gpu/drm/solomon/Makefile b/drivers/gpu/drm/solomon/Makefile
index f685add..4bfc5ac 100644 (file)
--- a/drivers/gpu/drm/solomon/Makefile
+++ b/drivers/gpu/drm/solomon/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_DRM_SSD130X)      += ssd130x.o
+obj-$(CONFIG_DRM_SSD130X_I2C)  += ssd130x-i2c.o

diff --git a/drivers/gpu/drm/solomon/ssd130x-i2c.c b/drivers/gpu/drm/solomon/ssd130x-i2c.c
new file mode 100644 (file)
index 0000000..3126aed
--- /dev/null
+++ b/drivers/gpu/drm/solomon/ssd130x-i2c.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DRM driver for Solomon SSD130x OLED displays (I2C bus)
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Author: Javier Martinez Canillas <javierm@redhat.com>
+ *
+ * Based on drivers/video/fbdev/ssd1307fb.c
+ * Copyright 2012 Free Electrons
+ */
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "ssd130x.h"
+
+#define DRIVER_NAME    "ssd130x-i2c"
+#define DRIVER_DESC    "DRM driver for Solomon SSD130x OLED displays (I2C)"
+
+static const struct regmap_config ssd130x_i2c_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+};
+
+static int ssd130x_i2c_probe(struct i2c_client *client)
+{
+       struct ssd130x_device *ssd130x;
+       struct regmap *regmap;
+
+       regmap = devm_regmap_init_i2c(client, &ssd130x_i2c_regmap_config);
+       if (IS_ERR(regmap))
+               return PTR_ERR(regmap);
+
+       ssd130x = ssd130x_probe(&client->dev, regmap);
+       if (IS_ERR(ssd130x))
+               return PTR_ERR(ssd130x);
+
+       i2c_set_clientdata(client, ssd130x);
+
+       return 0;
+}
+
+static int ssd130x_i2c_remove(struct i2c_client *client)
+{
+       struct ssd130x_device *ssd130x = i2c_get_clientdata(client);
+
+       return ssd130x_remove(ssd130x);
+}
+
+static void ssd130x_i2c_shutdown(struct i2c_client *client)
+{
+       struct ssd130x_device *ssd130x = i2c_get_clientdata(client);
+
+       ssd130x_shutdown(ssd130x);
+}
+
+static struct ssd130x_deviceinfo ssd130x_ssd1305_deviceinfo = {
+       .default_vcomh = 0x34,
+       .default_dclk_div = 1,
+       .default_dclk_frq = 7,
+};
+
+static struct ssd130x_deviceinfo ssd130x_ssd1306_deviceinfo = {
+       .default_vcomh = 0x20,
+       .default_dclk_div = 1,
+       .default_dclk_frq = 8,
+       .need_chargepump = 1,
+};
+
+static struct ssd130x_deviceinfo ssd130x_ssd1307_deviceinfo = {
+       .default_vcomh = 0x20,
+       .default_dclk_div = 2,
+       .default_dclk_frq = 12,
+       .need_pwm = 1,
+};
+
+static struct ssd130x_deviceinfo ssd130x_ssd1309_deviceinfo = {
+       .default_vcomh = 0x34,
+       .default_dclk_div = 1,
+       .default_dclk_frq = 10,
+};
+
+static const struct of_device_id ssd130x_of_match[] = {
+       {
+               .compatible = "solomon,ssd1305fb-i2c",
+               .data = &ssd130x_ssd1305_deviceinfo,
+       },
+       {
+               .compatible = "solomon,ssd1306fb-i2c",
+               .data = &ssd130x_ssd1306_deviceinfo,
+       },
+       {
+               .compatible = "solomon,ssd1307fb-i2c",
+               .data = &ssd130x_ssd1307_deviceinfo,
+       },
+       {
+               .compatible = "solomon,ssd1309fb-i2c",
+               .data = &ssd130x_ssd1309_deviceinfo,
+       },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ssd130x_of_match);
+
+static struct i2c_driver ssd130x_i2c_driver = {
+       .driver = {
+               .name = DRIVER_NAME,
+               .of_match_table = ssd130x_of_match,
+       },
+       .probe_new = ssd130x_i2c_probe,
+       .remove = ssd130x_i2c_remove,
+       .shutdown = ssd130x_i2c_shutdown,
+};
+module_i2c_driver(ssd130x_i2c_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
+MODULE_LICENSE("GPL v2");