Re: [PATCH v4 4/6] drm/solomon: Add SSD130x OLED displays I2C support

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, Feb 11, 2022 at 10:19:25AM +0100, Javier Martinez Canillas wrote:
> 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.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
> 
> 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
> 

-- 
With Best Regards,
Andy Shevchenko