[PATCH v5 4/6] drm/solomon: Add SSD130x OLED displays I2C support

Javier Martinez Canillas
2022-02-11T14:34:24Z

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>
---

Changes in v5:
- Add Andy Shevchenko's Reviewed-by tag to patch #4.

Changes in v4:
- Remove unnecessary casting (Geert Uytterhoeven)
- Remove redundant blank lines (Andy Shevchenko)
- Remove comma after of_device_id table terminator (Andy Shevchenko)

Changes in v3:
- Add a separate driver for SSD130X chips I2C support (Andy Shevchenko)

drivers/gpu/drm/solomon/Kconfig | 9 ++
drivers/gpu/drm/solomon/Makefile | 1 +
drivers/gpu/drm/solomon/ssd130x-i2c.c | 116 ++++++++++++++++++++++++++
3 files changed, 126 insertions(+)
create mode 100644 drivers/gpu/drm/solomon/ssd130x-i2c.c

diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig
index 7720a7039e8d..5861c3ab7c45 100644
--- 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 f685addb19fe..4bfc5acb0447 100644
--- 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
index 000000000000..3126aeda4ced
--- /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");
--
2.34.1