Re: [PATCH 3/4] drm/tiny: add simple-dbi driver

Hi

Am 02.08.21 um 08:35 schrieb Icenowy Zheng:

Add a driver for generic MIPI DBI panels initialized with MIPI DCS commands.

Currently a ST7789V-based panel is added to it. This panel has its configuration pre-programmed into the controller, so no vendor-specific configuration is needed.

Signed-off-by: Icenowy Zheng icenowy@sipeed.com

drivers/gpu/drm/tiny/Kconfig | 12 ++ drivers/gpu/drm/tiny/Makefile | 1 + drivers/gpu/drm/tiny/simple-dbi.c | 244 ++++++++++++++++++++++++++++++ 3 files changed, 257 insertions(+) create mode 100644 drivers/gpu/drm/tiny/simple-dbi.c

diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig index d31be274a2bd..6cfc57b68a46 100644 --- a/drivers/gpu/drm/tiny/Kconfig +++ b/drivers/gpu/drm/tiny/Kconfig @@ -144,6 +144,18 @@ config TINYDRM_REPAPER

 If M is selected the module will be called repaper.

+config TINYDRM_SIMPLE_DBI

• tristate "DRM support for generic MIPI DBI panels"
• depends on DRM && SPI
• select DRM_KMS_HELPER
• select DRM_KMS_CMA_HELPER
• select DRM_MIPI_DBI
• help

•  DRM driver for generic DBI panels that are MIPI DCS compatible
  

•  and needs no vendor-specific setup commands.
  

•  If M is selected the module will be called simple-dbi.
  

• config TINYDRM_ST7586 tristate "DRM support for Sitronix ST7586 display panels" depends on DRM && SPI

diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile index e09942895c77..2553de651aa3 100644 --- a/drivers/gpu/drm/tiny/Makefile +++ b/drivers/gpu/drm/tiny/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o obj-$(CONFIG_TINYDRM_ST7586) += st7586.o obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o +obj-$(CONFIG_TINYDRM_SIMPLE_DBI) += simple-dbi.o diff --git a/drivers/gpu/drm/tiny/simple-dbi.c b/drivers/gpu/drm/tiny/simple-dbi.c new file mode 100644 index 000000000000..2b207e43d500 --- /dev/null +++ b/drivers/gpu/drm/tiny/simple-dbi.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • DRM driver for display panels with configuration preset and needs only
• • standard MIPI DCS commands to bring up.
• • Copyright (C) 2021 Sipeed
• */

+#include <linux/backlight.h> +#include <linux/delay.h> +#include <linux/dma-buf.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/spi/spi.h> +#include <video/mipi_display.h>

+#include <drm/drm_atomic_helper.h> +#include <drm/drm_drv.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_gem_atomic_helper.h> +#include <drm/drm_gem_cma_helper.h> +#include <drm/drm_managed.h> +#include <drm/drm_mipi_dbi.h>

+#define MIPI_DCS_ADDRESS_MODE_BGR BIT(3) +#define MIPI_DCS_ADDRESS_MODE_REVERSE BIT(5) +#define MIPI_DCS_ADDRESS_MODE_RTL BIT(6) +#define MIPI_DCS_ADDRESS_MODE_BTT BIT(7)

+struct simple_dbi_cfg {

• const struct drm_display_mode mode;
• unsigned int left_offset;
• unsigned int top_offset;
• bool inverted;
• bool write_only;
• bool bgr;
• bool right_to_left;
• bool bottom_to_top;

+};

+struct simple_dbi_priv {

• struct mipi_dbi_dev dbidev; /* Must be first for .release() */

Which release?

• const struct simple_dbi_cfg *cfg;

+};

+static void simple_dbi_pipe_enable(struct drm_simple_display_pipe *pipe,

• 		struct drm_crtc_state *crtc_state,
  

• 		struct drm_plane_state *plane_state)
  

+{

• struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
• struct simple_dbi_priv *priv = container_of(dbidev,

• 				    struct simple_dbi_priv,
  

• 				    dbidev);
  

• struct mipi_dbi *dbi = &dbidev->dbi;
• int ret, idx;
• u8 addr_mode = 0x00;
• if (!drm_dev_enter(pipe->crtc.dev, &idx))

• return;
  

• DRM_DEBUG_KMS("\n");

I'm not a friend of such debugging statements. If you absolutely want to keep it, rather use drm_dbg_kms().

• ret = mipi_dbi_poweron_reset(dbidev);
• if (ret)

• goto out_exit;
  

• mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
• msleep(5);
• /* Currently tinydrm supports 16bit only now */
• mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,

• 	 MIPI_DCS_PIXEL_FMT_16BIT);
  

• if (priv->cfg->inverted)

• mipi_dbi_command(dbi, MIPI_DCS_ENTER_INVERT_MODE);
  

• else

• mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
  

• if (priv->cfg->bgr)

• addr_mode |= MIPI_DCS_ADDRESS_MODE_BGR;
  

• if (priv->cfg->right_to_left)

• addr_mode |= MIPI_DCS_ADDRESS_MODE_RTL;
  

• if (priv->cfg->bottom_to_top)

• addr_mode |= MIPI_DCS_ADDRESS_MODE_BTT;
  

• switch (dbidev->rotation) {
• default:

• break;
  

• case 90:

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;
  

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;
  

• break;
  

• case 180:

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;
  

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;
  

• break;
  

• case 270:

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;
  

• addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;
  

• break;
  

• }
• mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
• mipi_dbi_command(dbi, MIPI_DCS_ENTER_NORMAL_MODE);
• mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
• mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);

+out_exit:

• drm_dev_exit(idx);

+}

+static const struct drm_simple_display_pipe_funcs simple_dbi_pipe_funcs = {

• .enable = simple_dbi_pipe_enable,
• .disable = mipi_dbi_pipe_disable,
• .update = mipi_dbi_pipe_update,
• .prepare_fb = drm_gem_simple_display_pipe_prepare_fb,

+};

+static const struct simple_dbi_cfg zsx154_b1206_cfg = {

• .mode = { DRM_SIMPLE_MODE(240, 240, 28, 28) },
• .inverted = true,
• .write_only = true,

+};

+DEFINE_DRM_GEM_CMA_FOPS(simple_dbi_fops);

+static const struct drm_driver simple_dbi_driver = {

• .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
• .fops = &simple_dbi_fops,
• DRM_GEM_CMA_DRIVER_OPS_VMAP,
• .debugfs_init = mipi_dbi_debugfs_init,
• .name = "simple-dbi",
• .desc = "Generic MIPI-DCS compatible DBI panel",
• .date = "20210723",
• .major = 1,
• .minor = 0,

+};

+static const struct of_device_id simple_dbi_of_match[] = {

• { .compatible = "zsx,zsx154-b1206", .data = &zsx154_b1206_cfg },
• { },

+} +MODULE_DEVICE_TABLE(of, simple_dbi_of_match);

+static int simple_dbi_probe(struct spi_device *spi) +{

• struct device *dev = &spi->dev;
• const struct simple_dbi_cfg *cfg;
• struct mipi_dbi_dev *dbidev;
• struct simple_dbi_priv *priv;
• struct drm_device *drm;
• struct mipi_dbi *dbi;
• struct gpio_desc *dc;
• u32 rotation = 0;
• int ret;
• cfg = device_get_match_data(&spi->dev);
• if (!cfg)

• cfg = (void *)spi_get_device_id(spi)->driver_data;
  

• priv = devm_drm_dev_alloc(dev, &simple_dbi_driver,

• 		  struct simple_dbi_priv, dbidev.drm);
  

• if (IS_ERR(priv))

• return PTR_ERR(priv);
  

• dbidev = &priv->dbidev;
• priv->cfg = cfg;
• dbi = &dbidev->dbi;
• drm = &dbidev->drm;
• dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
• if (IS_ERR(dbi->reset))

• return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get reset GPIO\n");
  

• dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
• if (IS_ERR(dc))

• return dev_err_probe(dev, PTR_ERR(dc), "Failed to get D/C GPIO\n");
  

• dbidev->backlight = devm_of_find_backlight(dev);
• if (IS_ERR(dbidev->backlight))

• return PTR_ERR(dbidev->backlight);
  

• device_property_read_u32(dev, "rotation", &rotation);
• ret = mipi_dbi_spi_init(spi, dbi, dc);
• if (ret)

• return ret;
  

• if (cfg->write_only)

• dbi->read_commands = NULL;
  

• ret = mipi_dbi_dev_init(dbidev, &simple_dbi_pipe_funcs, &cfg->mode,

• 		rotation);
  

• if (ret)

• return ret;
  

• drm_mode_config_reset(drm);
• ret = drm_dev_register(drm, 0);
• if (ret)

• return ret;
  

• spi_set_drvdata(spi, drm);

AFAIK dev files are being created during drm_dev_register(). It's probably safer to set the drvdata before.

• drm_fbdev_generic_setup(drm, 0);
• return 0;

+}

+static int simple_dbi_remove(struct spi_device *spi) +{

• struct drm_device *drm = spi_get_drvdata(spi);
• drm_dev_unplug(drm);
• drm_atomic_helper_shutdown(drm);
• return 0;

+}

+static void simple_dbi_shutdown(struct spi_device *spi) +{

• drm_atomic_helper_shutdown(spi_get_drvdata(spi));

+}

+static struct spi_driver simple_dbi_spi_driver = {

• .driver = {

• .name = "simple-dbi",
  

• .of_match_table = simple_dbi_of_match,
  

• },
• .probe = simple_dbi_probe,
• .remove = simple_dbi_remove,
• .shutdown = simple_dbi_shutdown,

+}; +module_spi_driver(simple_dbi_spi_driver);

+MODULE_DESCRIPTION("Simple DBI panel DRM driver"); +MODULE_AUTHOR("Icenowy Zheng icenowy@aosc.io"); +MODULE_LICENSE("GPL");

Trailing blank line. (?)

Best regards Thomas