[PATCH v3 1/2] drm/panel: Add driver for the AUO A030JTN01 TFT LCD

Paul Cercueil paul at crapouillou.net
Tue Jan 17 12:12:38 UTC 2023


Hi Christophe,

Le mardi 20 décembre 2022 à 13:01 +0100, Christophe Branchereau a
écrit :
> Add driver for the AUO A030JTN01 panel, which is a 320x480 3.0" 4:3
> 24-bit TFT LCD panel with non-square pixels and a delta-RGB 8-bit
> interface.
> 
> Signed-off-by: Christophe Branchereau <cbranchereau at gmail.com>
> Signed-off-by: Paul Cercueil <paul at crapouillou.net>
> ---
>  drivers/gpu/drm/panel/Kconfig               |   8 +
>  drivers/gpu/drm/panel/Makefile              |   1 +
>  drivers/gpu/drm/panel/panel-auo-a030jtn01.c | 307
> ++++++++++++++++++++
>  3 files changed, 316 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 737edcdf9eef..23cf0f4ba2e6 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 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.
> +
>  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 f8f9d9f6a307..af88658abcab 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..b9fc64f9e49c
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-auo-a030jtn01.c
> @@ -0,0 +1,307 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AU Optronics A030JTN01.0 TFT LCD panel driver
> + *
> + * Copyright (C) 2020, Paul Cercueil <paul at crapouillou.net>
> + * Copyright (C) 2020, Christophe Branchereau
> <cbranchereau at gmail.com>
> + */
> +
> +#include <linux/bits.h>
> +#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>
> +
> +#define REG05          0x05
> +#define REG05_STDBY    BIT(0)
> +
> +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);

Do we have register names for these? It would be better with macros
than hardcoded addresses, e.g. AUO_REG_VPORCH and AUO_REG_HPORCH, with
AUO_REG_CTRL as a "generic" name for REG05.

(Besides, you actually have 'REG05' defined above and didn't use it
here)

> +
> +       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_set_bits(priv->map, REG05, REG05_STDBY);
> +       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_clear_bits(priv->map, REG05, REG05_STDBY);
> +}
> +
> +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)
> +{
> +       const struct spi_device_id *id = spi_get_device_id(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);

return dev_err_probe(dev, PTR_ERR(priv->map), "Unable to init regmap");

> +       }
> +
> +       priv->panel_info = (const struct a030jtn01_info *) id-
> >driver_data;

priv->panel_info = spi_get_device_match_data(spi);

Then you don't even need the 'id' variable.

> +       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);

use dev_err_probe() here too.

> +       }
> +
> +       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);

And here.

The rest of the driver looks good to me overall.

Cheers,
-Paul

> +       }
> +
> +       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 void 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);
> +}
> +
> +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 spi_device_id a030jtn01_id[] = {
> +       { "a030jtn01", (kernel_ulong_t) &a030jtn01_info },
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(spi, a030jtn01_id);
> +
> +static const struct of_device_id a030jtn01_of_match[] = {
> +       { .compatible = "auo,a030jtn01" },
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, a030jtn01_of_match);
> +
> +static struct spi_driver a030jtn01_driver = {
> +       .driver = {
> +               .name = "auo-a030jtn01",
> +               .of_match_table = a030jtn01_of_match,
> +       },
> +       .id_table = a030jtn01_id,
> +       .probe = a030jtn01_probe,
> +       .remove = a030jtn01_remove,
> +};
> +module_spi_driver(a030jtn01_driver);
> +
> +MODULE_AUTHOR("Paul Cercueil <paul at crapouillou.net>");
> +MODULE_AUTHOR("Christophe Branchereau <cbranchereau at gmail.com>");
> +MODULE_LICENSE("GPL v2");



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