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Date:   Sat, 28 Aug 2021 15:12:19 +0100
From:   Paul Cercueil <paul@crapouillou.net>
Subject: Re: [PATCH 2/2] drm/panel: Add driver for the AUO A030JTN01 TFT LCD
To:     Kari Argillander <kari.argillander@gmail.com>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Rob Herring <robh+dt@kernel.org>,
        Christophe Branchereau <cbranchereau@gmail.com>,
        list@opendingux.net, dri-devel@lists.freedesktop.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Message-Id: <JGZJYQ.UFG8C3UEXPVS1@crapouillou.net>
In-Reply-To: <20210828140139.vwhgcjmgnas4fh7w@kari-VirtualBox>
References: <20210828112640.7248-1-paul@crapouillou.net>
        <20210828112640.7248-2-paul@crapouillou.net>
        <20210828140139.vwhgcjmgnas4fh7w@kari-VirtualBox>
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Hi,

Le sam., ao?t 28 2021 at 17:01:39 +0300, Kari Argillander 
<kari.argillander@gmail.com> a ?crit :
> On Sat, Aug 28, 2021 at 12:26:40PM +0100, Paul Cercueil wrote:
>>  From: Christophe Branchereau <cbranchereau@gmail.com>
>> 
>>  Add driver for the AUO A030JTN01 panel, which is a 320x480 3.0" 4:3
>>  24-bit TFT LCD with non-square pixels and a delta-RGB 8-bit 
>> interface.
>> 
>>  Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
>>  Signed-off-by: Paul Cercueil <paul@crapouillou.net>
>>  ---
>>   drivers/gpu/drm/panel/Kconfig               |   8 +
>>   drivers/gpu/drm/panel/Makefile              |   1 +
>>   drivers/gpu/drm/panel/panel-auo-a030jtn01.c | 297 
>> ++++++++++++++++++++
>>   3 files changed, 306 insertions(+)
>>   create mode 100644 drivers/gpu/drm/panel/panel-auo-a030jtn01.c
>> 
>>  diff --git a/drivers/gpu/drm/panel/Kconfig 
>> b/drivers/gpu/drm/panel/Kconfig
>>  index 0b3784941312..42d42f999266 100644
>>  --- a/drivers/gpu/drm/panel/Kconfig
>>  +++ b/drivers/gpu/drm/panel/Kconfig
>>  @@ -8,6 +8,14 @@ config DRM_PANEL
>>   menu "Display Panels"
>>   	depends on DRM && DRM_PANEL
>> 
>>  +config DRM_PANEL_AUO_A030JTN01
>>  +	tristate "AUO A030JTN01"
>>  +	depends on OF && SPI
>>  +	select REGMAP_SPI
>>  +	help
>>  +	  Say Y here to enable support for the AUO A030JTN01 320x480 3.0" 
>> panel
>>  +	  as found in the YLM RS-97 handheld gaming console.
>>  +
> 
> It seems that these should be alphabetical order.

You're totally right, sorry about that.

>>   config DRM_PANEL_ABT_Y030XX067A
>>   	tristate "ABT Y030XX067A 320x480 LCD panel"
>>   	depends on OF && SPI
>>  diff --git a/drivers/gpu/drm/panel/Makefile 
>> b/drivers/gpu/drm/panel/Makefile
>>  index 60c0149fc54a..edf62866e4af 100644
>>  --- a/drivers/gpu/drm/panel/Makefile
>>  +++ b/drivers/gpu/drm/panel/Makefile
>>  @@ -1,4 +1,5 @@
>>   # SPDX-License-Identifier: GPL-2.0
>>  +obj-$(CONFIG_DRM_PANEL_AUO_A030JTN01) += panel-auo-a030jtn01.o
>>   obj-$(CONFIG_DRM_PANEL_ABT_Y030XX067A) += panel-abt-y030xx067a.o
>>   obj-$(CONFIG_DRM_PANEL_ARM_VERSATILE) += panel-arm-versatile.o
>>   obj-$(CONFIG_DRM_PANEL_ASUS_Z00T_TM5P5_NT35596) += 
>> panel-asus-z00t-tm5p5-n35596.o
>>  diff --git a/drivers/gpu/drm/panel/panel-auo-a030jtn01.c 
>> b/drivers/gpu/drm/panel/panel-auo-a030jtn01.c
>>  new file mode 100644
>>  index 000000000000..804567a59d19
>>  --- /dev/null
>>  +++ b/drivers/gpu/drm/panel/panel-auo-a030jtn01.c
>>  @@ -0,0 +1,297 @@
>>  +// SPDX-License-Identifier: GPL-2.0
>>  +/*
>>  + * AU Optronics A030JTN01.0 TFT LCD panel driver
>>  + *
>>  + * Copyright (C) 2020, Paul Cercueil <paul@crapouillou.net>
>>  + * Copyright (C) 2020, Christophe Branchereau 
>> <cbranchereau@gmail.com>
> 
> Should these be 2021?

The commits were written in 2021, but I guess I can update the date, 
yes.

Cheers,
-Paul

>     Argillander
> 
>>  + */
>>  +
>>  +#include <linux/delay.h>
>>  +#include <linux/device.h>
>>  +#include <linux/gpio/consumer.h>
>>  +#include <linux/media-bus-format.h>
>>  +#include <linux/module.h>
>>  +#include <linux/of_device.h>
>>  +#include <linux/regmap.h>
>>  +#include <linux/regulator/consumer.h>
>>  +#include <linux/spi/spi.h>
>>  +
>>  +#include <drm/drm_modes.h>
>>  +#include <drm/drm_panel.h>
>>  +
>>  +struct a030jtn01_info {
>>  +	const struct drm_display_mode *display_modes;
>>  +	unsigned int num_modes;
>>  +	u16 width_mm, height_mm;
>>  +	u32 bus_format, bus_flags;
>>  +};
>>  +
>>  +struct a030jtn01 {
>>  +	struct drm_panel panel;
>>  +	struct spi_device *spi;
>>  +	struct regmap *map;
>>  +
>>  +	const struct a030jtn01_info *panel_info;
>>  +
>>  +	struct regulator *supply;
>>  +	struct gpio_desc *reset_gpio;
>>  +};
>>  +
>>  +static inline struct a030jtn01 *to_a030jtn01(struct drm_panel 
>> *panel)
>>  +{
>>  +	return container_of(panel, struct a030jtn01, panel);
>>  +}
>>  +
>>  +static int a030jtn01_prepare(struct drm_panel *panel)
>>  +{
>>  +	struct a030jtn01 *priv = to_a030jtn01(panel);
>>  +	struct device *dev = &priv->spi->dev;
>>  +	int err;
>>  +
>>  +	err = regulator_enable(priv->supply);
>>  +	if (err) {
>>  +		dev_err(dev, "Failed to enable power supply: %d\n", err);
>>  +		return err;
>>  +	}
>>  +
>>  +	usleep_range(1000, 8000);
>>  +
>>  +	/* Reset the chip */
>>  +	gpiod_set_value_cansleep(priv->reset_gpio, 1);
>>  +	usleep_range(100, 8000);
>>  +	gpiod_set_value_cansleep(priv->reset_gpio, 0);
>>  +	usleep_range(2000, 8000);
>>  +
>>  +	/*
>>  +	 * No idea why two writes are needed. If this write is commented,
>>  +	 * the colors are wrong. Doesn't seem to be timing-related, since
>>  +	 * a msleep(200) doesn't fix it.
>>  +	 */
>>  +	regmap_write(priv->map, 0x06, 0x00);
>>  +
>>  +	/* Use (24 + 6) == 0x1e as the vertical back porch */
>>  +	err = regmap_write(priv->map, 0x06, 0x1e);
>>  +	if (err)
>>  +		goto err_disable_regulator;
>>  +
>>  +	/* Use (42 + 30) * 3 == 0xd8 as the horizontal back porch */
>>  +	err = regmap_write(priv->map, 0x07, 0xd8);
>>  +	if (err)
>>  +		goto err_disable_regulator;
>>  +
>>  +	regmap_write(priv->map, 0x05, 0x74);
>>  +
>>  +	return 0;
>>  +
>>  +err_disable_regulator:
>>  +	gpiod_set_value_cansleep(priv->reset_gpio, 1);
>>  +	regulator_disable(priv->supply);
>>  +	return err;
>>  +}
>>  +
>>  +static int a030jtn01_unprepare(struct drm_panel *panel)
>>  +{
>>  +	struct a030jtn01 *priv = to_a030jtn01(panel);
>>  +
>>  +	gpiod_set_value_cansleep(priv->reset_gpio, 1);
>>  +	regulator_disable(priv->supply);
>>  +
>>  +	return 0;
>>  +}
>>  +
>>  +static int a030jtn01_enable(struct drm_panel *panel)
>>  +{
>>  +	struct a030jtn01 *priv = to_a030jtn01(panel);
>>  +	int ret;
>>  +
>>  +	ret = regmap_write(priv->map, 0x05, 0x75);
>>  +	if (ret)
>>  +		return ret;
>>  +
>>  +	/* Wait for the picture to be stable */
>>  +	if (panel->backlight)
>>  +		msleep(100);
>>  +
>>  +	return 0;
>>  +}
>>  +
>>  +static int a030jtn01_disable(struct drm_panel *panel)
>>  +{
>>  +	struct a030jtn01 *priv = to_a030jtn01(panel);
>>  +
>>  +	return regmap_write(priv->map, 0x05, 0x74);
>>  +}
>>  +
>>  +static int a030jtn01_get_modes(struct drm_panel *panel,
>>  +				struct drm_connector *connector)
>>  +{
>>  +	struct a030jtn01 *priv = to_a030jtn01(panel);
>>  +	const struct a030jtn01_info *panel_info = priv->panel_info;
>>  +	struct drm_display_mode *mode;
>>  +	unsigned int i;
>>  +
>>  +	for (i = 0; i < panel_info->num_modes; i++) {
>>  +		mode = drm_mode_duplicate(connector->dev,
>>  +					  &panel_info->display_modes[i]);
>>  +		if (!mode)
>>  +			return -ENOMEM;
>>  +
>>  +		drm_mode_set_name(mode);
>>  +
>>  +		mode->type = DRM_MODE_TYPE_DRIVER;
>>  +		if (panel_info->num_modes == 1)
>>  +			mode->type |= DRM_MODE_TYPE_PREFERRED;
>>  +
>>  +		drm_mode_probed_add(connector, mode);
>>  +	}
>>  +
>>  +	connector->display_info.bpc = 8;
>>  +	connector->display_info.width_mm = panel_info->width_mm;
>>  +	connector->display_info.height_mm = panel_info->height_mm;
>>  +
>>  +	drm_display_info_set_bus_formats(&connector->display_info,
>>  +					 &panel_info->bus_format, 1);
>>  +	connector->display_info.bus_flags = panel_info->bus_flags;
>>  +
>>  +	return panel_info->num_modes;
>>  +}
>>  +
>>  +static const struct drm_panel_funcs a030jtn01_funcs = {
>>  +	.prepare	= a030jtn01_prepare,
>>  +	.unprepare	= a030jtn01_unprepare,
>>  +	.enable		= a030jtn01_enable,
>>  +	.disable	= a030jtn01_disable,
>>  +	.get_modes	= a030jtn01_get_modes,
>>  +};
>>  +
>>  +static bool a030jtn01_has_reg(struct device *dev, unsigned int reg)
>>  +{
>>  +	static const u32 a030jtn01_regs_mask = 0x001823f1fb;
>>  +
>>  +	return a030jtn01_regs_mask & BIT(reg);
>>  +};
>>  +
>>  +static const struct regmap_config a030jtn01_regmap_config = {
>>  +	.reg_bits = 8,
>>  +	.val_bits = 8,
>>  +	.read_flag_mask = 0x40,
>>  +	.max_register = 0x1c,
>>  +	.readable_reg = a030jtn01_has_reg,
>>  +	.writeable_reg = a030jtn01_has_reg,
>>  +};
>>  +
>>  +static int a030jtn01_probe(struct spi_device *spi)
>>  +{
>>  +	struct device *dev = &spi->dev;
>>  +	struct a030jtn01 *priv;
>>  +	int err;
>>  +
>>  +	spi->mode |= SPI_MODE_3 | SPI_3WIRE;
>>  +
>>  +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>  +	if (!priv)
>>  +		return -ENOMEM;
>>  +
>>  +	priv->spi = spi;
>>  +	spi_set_drvdata(spi, priv);
>>  +
>>  +	priv->map = devm_regmap_init_spi(spi, &a030jtn01_regmap_config);
>>  +	if (IS_ERR(priv->map)) {
>>  +		dev_err(dev, "Unable to init regmap\n");
>>  +		return PTR_ERR(priv->map);
>>  +	}
>>  +
>>  +	priv->panel_info = of_device_get_match_data(dev);
>>  +	if (!priv->panel_info)
>>  +		return -EINVAL;
>>  +
>>  +	priv->supply = devm_regulator_get(dev, "power");
>>  +	if (IS_ERR(priv->supply)) {
>>  +		dev_err(dev, "Failed to get power supply\n");
>>  +		return PTR_ERR(priv->supply);
>>  +	}
>>  +
>>  +	priv->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
>>  +	if (IS_ERR(priv->reset_gpio)) {
>>  +		dev_err(dev, "Failed to get reset GPIO\n");
>>  +		return PTR_ERR(priv->reset_gpio);
>>  +	}
>>  +
>>  +	drm_panel_init(&priv->panel, dev, &a030jtn01_funcs,
>>  +		       DRM_MODE_CONNECTOR_DPI);
>>  +
>>  +	err = drm_panel_of_backlight(&priv->panel);
>>  +	if (err)
>>  +		return err;
>>  +
>>  +	drm_panel_add(&priv->panel);
>>  +
>>  +	return 0;
>>  +}
>>  +
>>  +static int a030jtn01_remove(struct spi_device *spi)
>>  +{
>>  +	struct a030jtn01 *priv = spi_get_drvdata(spi);
>>  +
>>  +	drm_panel_remove(&priv->panel);
>>  +	drm_panel_disable(&priv->panel);
>>  +	drm_panel_unprepare(&priv->panel);
>>  +
>>  +	return 0;
>>  +}
>>  +
>>  +static const struct drm_display_mode a030jtn01_modes[] = {
>>  +	{ /* 60 Hz */
>>  +		.clock = 14400,
>>  +		.hdisplay = 320,
>>  +		.hsync_start = 320 + 8,
>>  +		.hsync_end = 320 + 8 + 42,
>>  +		.htotal = 320 + 8 + 42 + 30,
>>  +		.vdisplay = 480,
>>  +		.vsync_start = 480 + 90,
>>  +		.vsync_end = 480 + 90 + 24,
>>  +		.vtotal = 480 + 90 + 24 + 6,
>>  +		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
>>  +	},
>>  +	{ /* 50 Hz */
>>  +		.clock = 12000,
>>  +		.hdisplay = 320,
>>  +		.hsync_start = 320 + 8,
>>  +		.hsync_end = 320 + 8 + 42,
>>  +		.htotal = 320 + 8 + 42 + 30,
>>  +		.vdisplay = 480,
>>  +		.vsync_start = 480 + 90,
>>  +		.vsync_end = 480 + 90 + 24,
>>  +		.vtotal = 480 + 90 + 24 + 6,
>>  +		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
>>  +	},
>>  +};
>>  +
>>  +static const struct a030jtn01_info a030jtn01_info = {
>>  +	.display_modes = a030jtn01_modes,
>>  +	.num_modes = ARRAY_SIZE(a030jtn01_modes),
>>  +	.width_mm = 70,
>>  +	.height_mm = 51,
>>  +	.bus_format = MEDIA_BUS_FMT_RGB888_3X8_DELTA,
>>  +	.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
>>  +};
>>  +
>>  +static const struct of_device_id a030jtn01_of_match[] = {
>>  +	{ .compatible = "auo,a030jtn01", .data = &a030jtn01_info },
>>  +	{ /* sentinel */ }
>>  +};
>>  +MODULE_DEVICE_TABLE(of, a030jtn01_of_match);
>>  +
>>  +static struct spi_driver a030jtn01_driver = {
>>  +	.driver = {
>>  +		.name = "auo-a030jtn01",
>>  +		.of_match_table = a030jtn01_of_match,
>>  +	},
>>  +	.probe = a030jtn01_probe,
>>  +	.remove = a030jtn01_remove,
>>  +};
>>  +module_spi_driver(a030jtn01_driver);
>>  +
>>  +MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
>>  +MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
>>  +MODULE_LICENSE("GPL v2");
>>  --
>>  2.33.0
>>