The new API function mipi_dsi_maybe_register_tiny_driver() is supposed to be called by DSI/DBI panel drivers at the end of their probe.
If it is detected that the panel is not connected to any controller, because it has no port #0 node in Device Tree that points back to it, then a TinyDRM driver is registered with it.
This TinyDRM driver expects that a DCS-compliant protocol is used by the DSI/DBI panel and can only be used with these.
Signed-off-by: Paul Cercueil paul@crapouillou.net --- drivers/gpu/drm/tiny/Kconfig | 8 + drivers/gpu/drm/tiny/Makefile | 1 + drivers/gpu/drm/tiny/tiny-dsi.c | 266 ++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 19 +++ 4 files changed, 294 insertions(+) create mode 100644 drivers/gpu/drm/tiny/tiny-dsi.c
diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig index 2b6414f0fa75..b62427b88dfe 100644 --- a/drivers/gpu/drm/tiny/Kconfig +++ b/drivers/gpu/drm/tiny/Kconfig @@ -28,6 +28,14 @@ config DRM_GM12U320 This is a KMS driver for projectors which use the GM12U320 chipset for video transfer over USB2/3, such as the Acer C120 mini projector.
+config TINYDRM_DSI + tristate "DRM support for generic DBI/DSI display panels" + depends on DRM && DRM_MIPI_DSI + select DRM_MIPI_DBI + select DRM_KMS_CMA_HELPER + help + DRM driver for generic DBI/DSI display panels + config TINYDRM_HX8357D tristate "DRM support for HX8357D display panels" depends on DRM && SPI diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile index 6ae4e9e5a35f..2bfee13347a5 100644 --- a/drivers/gpu/drm/tiny/Makefile +++ b/drivers/gpu/drm/tiny/Makefile @@ -2,6 +2,7 @@
obj-$(CONFIG_DRM_CIRRUS_QEMU) += cirrus.o obj-$(CONFIG_DRM_GM12U320) += gm12u320.o +obj-$(CONFIG_TINYDRM_DSI) += tiny-dsi.o obj-$(CONFIG_TINYDRM_HX8357D) += hx8357d.o obj-$(CONFIG_TINYDRM_ILI9225) += ili9225.o obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o diff --git a/drivers/gpu/drm/tiny/tiny-dsi.c b/drivers/gpu/drm/tiny/tiny-dsi.c new file mode 100644 index 000000000000..b24d49836125 --- /dev/null +++ b/drivers/gpu/drm/tiny/tiny-dsi.c @@ -0,0 +1,266 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TinyDRM driver for standard DSI/DBI panels + * + * Copyright 2020 Paul Cercueil paul@crapouillou.net + */ + +#include <linux/dma-mapping.h> +#include <linux/module.h> + +#include <drm/drm_atomic_helper.h> +#include <drm/drm_damage_helper.h> +#include <drm/drm_drv.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_fourcc.h> +#include <drm/drm_gem_cma_helper.h> +#include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_mipi_dbi.h> +#include <drm/drm_mipi_dsi.h> +#include <drm/drm_modeset_helper.h> +#include <drm/drm_panel.h> +#include <drm/drm_probe_helper.h> + +#include <video/mipi_display.h> + +struct tiny_dsi { + struct drm_device drm; + struct drm_connector connector; + struct drm_simple_display_pipe pipe; + + struct mipi_dsi_device *dsi; + struct drm_panel *panel; +}; + +#define mipi_dcs_command(dsi, cmd, seq...) \ +({ \ + u8 d[] = { seq }; \ + mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d)); \ +}) + +static inline struct tiny_dsi *drm_to_tiny_dsi(struct drm_device *drm) +{ + return container_of(drm, struct tiny_dsi, drm); +} + +static void tiny_dsi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) +{ + struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0); + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem); + struct tiny_dsi *priv = drm_to_tiny_dsi(fb->dev); + unsigned int height = rect->y2 - rect->y1; + unsigned int width = rect->x2 - rect->x1; + bool fb_convert; + int idx, ret; + void *tr; + + if (!drm_dev_enter(fb->dev, &idx)) + return; + + DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); + + fb_convert = width != fb->width || height != fb->height + || fb->format->format == DRM_FORMAT_XRGB8888; + if (fb_convert) { + tr = kzalloc(width * height * 2, GFP_KERNEL); + + /* TODO: swap pixels if needed */ + ret = mipi_dbi_buf_copy(tr, fb, rect, false); + if (ret) + goto err_msg; + } else { + tr = cma_obj->vaddr; + } + + mipi_dcs_command(priv->dsi, MIPI_DCS_SET_COLUMN_ADDRESS, + (rect->x1 >> 8) & 0xff, rect->x1 & 0xff, + (rect->x2 >> 8) & 0xff, rect->x2 & 0xff); + mipi_dcs_command(priv->dsi, MIPI_DCS_SET_PAGE_ADDRESS, + (rect->y1 >> 8) & 0xff, rect->y1 & 0xff, + (rect->y2 >> 8) & 0xff, rect->y2 & 0xff); + + ret = mipi_dsi_dcs_write(priv->dsi, MIPI_DCS_WRITE_MEMORY_START, + tr, width * height * 2); +err_msg: + if (ret) + dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); + + if (fb_convert) + kfree(tr); + drm_dev_exit(idx); +} + +static void tiny_dsi_enable(struct drm_simple_display_pipe *pipe, + struct drm_crtc_state *crtc_state, + struct drm_plane_state *plane_state) +{ + struct tiny_dsi *priv = drm_to_tiny_dsi(pipe->crtc.dev); + + drm_panel_enable(priv->panel); +} + +static void tiny_dsi_disable(struct drm_simple_display_pipe *pipe) +{ + struct tiny_dsi *priv = drm_to_tiny_dsi(pipe->crtc.dev); + + drm_panel_disable(priv->panel); +} + +static void tiny_dsi_update(struct drm_simple_display_pipe *pipe, + struct drm_plane_state *old_state) +{ + struct drm_plane_state *state = pipe->plane.state; + struct drm_rect rect; + + if (drm_atomic_helper_damage_merged(old_state, state, &rect)) + tiny_dsi_fb_dirty(state->fb, &rect); +} + +static const struct drm_simple_display_pipe_funcs tiny_dsi_pipe_funcs = { + .enable = tiny_dsi_enable, + .disable = tiny_dsi_disable, + .update = tiny_dsi_update, + .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, +}; + +static int tiny_dsi_connector_get_modes(struct drm_connector *connector) +{ + struct tiny_dsi *priv = drm_to_tiny_dsi(connector->dev); + + return drm_panel_get_modes(priv->panel, connector); +} + +static const struct drm_connector_helper_funcs tiny_dsi_connector_hfuncs = { + .get_modes = tiny_dsi_connector_get_modes, +}; + +static const struct drm_connector_funcs tiny_dsi_connector_funcs = { + .reset = drm_atomic_helper_connector_reset, + .fill_modes = drm_helper_probe_single_connector_modes, + .destroy = drm_connector_cleanup, + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, +}; + +static const uint32_t tiny_dsi_formats[] = { + DRM_FORMAT_RGB565, + DRM_FORMAT_XRGB8888, +}; + +static const struct drm_mode_config_funcs tiny_dsi_mode_config_funcs = { + .fb_create = drm_gem_fb_create_with_dirty, + .atomic_check = drm_atomic_helper_check, + .atomic_commit = drm_atomic_helper_commit, +}; + +DEFINE_DRM_GEM_CMA_FOPS(tiny_dsi_fops); + +static struct drm_driver tiny_dsi_driver = { + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, + .name = "tiny-dsi", + .desc = "Tiny DSI", + .date = "20200605", + .major = 1, + .minor = 0, + + .fops = &tiny_dsi_fops, + DRM_GEM_CMA_DRIVER_OPS, +}; + +static void tiny_dsi_remove(void *drm) +{ + drm_dev_unplug(drm); + drm_atomic_helper_shutdown(drm); +} + +int mipi_dsi_register_tiny_driver(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + struct drm_device *drm; + struct tiny_dsi *priv; + static const uint64_t modifiers[] = { + DRM_FORMAT_MOD_LINEAR, + DRM_FORMAT_MOD_INVALID + }; + int ret; + + /* + * Even though it's not the SPI device that does DMA (the master does), + * the dma mask is necessary for the dma_alloc_wc() in + * drm_gem_cma_create(). The dma_addr returned will be a physical + * address which might be different from the bus address, but this is + * not a problem since the address will not be used. + * The virtual address is used in the transfer and the SPI core + * re-maps it on the SPI master device using the DMA streaming API + * (spi_map_buf()). + */ + if (!dev->coherent_dma_mask) { + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); + if (ret) { + dev_warn(dev, "Failed to set dma mask %d\n", ret); + return ret; + } + } + + priv = devm_drm_dev_alloc(dev, &tiny_dsi_driver, struct tiny_dsi, drm); + if (!priv) + return ret; + + priv->dsi = dsi; + drm = &priv->drm; + + priv->panel = of_drm_find_panel(dev->of_node); + if (IS_ERR(priv->panel)) { + dev_err(dev, "Unable to find panel\n"); + return PTR_ERR(priv->panel); + } + + drm_mode_config_init(drm); + + drm->mode_config.preferred_depth = 16; + + drm->mode_config.funcs = &tiny_dsi_mode_config_funcs; + drm->mode_config.min_width = 0; + drm->mode_config.min_height = 0; + drm->mode_config.max_width = 4096; + drm->mode_config.max_height = 4096; + + drm_connector_helper_add(&priv->connector, &tiny_dsi_connector_hfuncs); + ret = drm_connector_init(drm, &priv->connector, &tiny_dsi_connector_funcs, + DRM_MODE_CONNECTOR_DSI); + if (ret) { + dev_err(dev, "Unable to init connector\n"); + return ret; + } + + ret = drm_simple_display_pipe_init(drm, &priv->pipe, &tiny_dsi_pipe_funcs, + tiny_dsi_formats, ARRAY_SIZE(tiny_dsi_formats), + modifiers, &priv->connector); + if (ret) { + dev_err(dev, "Unable to init display pipe\n"); + return ret; + } + + drm_plane_enable_fb_damage_clips(&priv->pipe.plane); + + drm_mode_config_reset(drm); + + ret = drm_dev_register(drm, 0); + if (ret) { + dev_err(dev, "Failed to register DRM driver\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, tiny_dsi_remove, drm); + if (ret) + return ret; + + drm_fbdev_generic_setup(drm, 0); + + return 0; +} +EXPORT_SYMBOL_GPL(mipi_dsi_register_tiny_driver); + +MODULE_DESCRIPTION("DSI/DBI TinyDRM driver"); +MODULE_AUTHOR("Paul Cercueil paul@crapouillou.net"); +MODULE_LICENSE("GPL"); diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 65d2961fc054..0c2589a55df6 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -10,6 +10,7 @@ #define __DRM_MIPI_DSI_H__
#include <linux/device.h> +#include <linux/of_graph.h>
struct mipi_dsi_host; struct mipi_dsi_device; @@ -337,4 +338,22 @@ void mipi_dsi_driver_unregister(struct mipi_dsi_driver *driver); module_driver(__mipi_dsi_driver, mipi_dsi_driver_register, \ mipi_dsi_driver_unregister)
+#if IS_ENABLED(CONFIG_TINYDRM_DSI) +int mipi_dsi_register_tiny_driver(struct mipi_dsi_device *dsi); +#else +static inline int mipi_dsi_register_tiny_driver(struct mipi_dsi_device *dsi) +{ + return 0; +} +#endif + +static inline int mipi_dsi_maybe_register_tiny_driver(struct mipi_dsi_device *dsi) +{ + /* Register the TinyDRM DSI/DBI driver if the panel has no controller */ + if (!of_graph_get_port_by_id(dsi->dev.of_node, 0)) + return mipi_dsi_register_tiny_driver(dsi); + + return 0; +} + #endif /* __DRM_MIPI_DSI__ */