Hi Paul & Christophe,
On Sat, Aug 28, 2021 at 12:26:40PM +0100, Paul Cercueil wrote:
> From: Christophe Branchereau <cbranchereau@xxxxxxxxx>
>
> 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.
I had expected a:
Co-developed-by: Christophe Branchereau <cbranchereau@xxxxxxxxx>
?
>
> Signed-off-by: Christophe Branchereau <cbranchereau@xxxxxxxxx>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
The driver is prepared for more panels with the nice panel_info
structure. If you really consider this can be used for additional panels
maybe the driver should have a more generic name?
I like how a regmap is used for the spi stuff!
A few nits below.
Sam
> ---
> 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@xxxxxxxxxxxxxxx>
> + * Copyright (C) 2020, Christophe Branchereau <cbranchereau@xxxxxxxxx>
> + */
> +
> +#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;
drm_display_mode already have width_mm, and height_mm.
I think it would be better to utilize those.
But I also see why not as the same physical panel can have different
modes - shrug.
> + 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);
If there is any chance to get the register names, then that would hep
rather than the hardcoded numbers here.
Same goes in other places.
> +
> + /* 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;
I would put right after devm_kzalloc() and if it fails write soemthing
to the log - as it really is not supposed to happen.
Probe should not be called unless we know the compatible and have
panel_info for it.
> +
> + 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@xxxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Christophe Branchereau <cbranchereau@xxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> --
> 2.33.0
