Re: [OSS-Tools] [PATCH platsch 2/3] platsch: split into platsch and libplatsch

[Marco Felsch <m.felsch@pengutronix.de>]

On 24-06-12, LI Qingwu wrote:
> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> ---
>  cairo.c                   |   4 +-

Please make sure that your patches are based on the upstream status.

Regards,
  Marco

>  libplatsch.c              | 614 ++++++++++++++++++++++++++++++++++++++
>  platsch.h => libplatsch.h |  45 ++-
>  meson.build               |  21 +-
>  platsch.c                 | 534 +--------------------------------
>  5 files changed, 677 insertions(+), 541 deletions(-)
>  create mode 100644 libplatsch.c
>  rename platsch.h => libplatsch.h (51%)
> 
> diff --git a/cairo.c b/cairo.c
> index 8ced3b2..d651b7a 100644
> --- a/cairo.c
> +++ b/cairo.c
> @@ -25,7 +25,7 @@
>  #include <drm_fourcc.h>
>  #include <cairo.h>
>  
> -#include "platsch.h"
> +#include "libplatsch.h"
>  
>  static struct cairo_ctx {
>  	struct modeset_dev *dev;
> @@ -255,7 +255,7 @@ static uint32_t convert_to_cairo_format(uint32_t format)
>  	return CAIRO_FORMAT_INVALID;
>  }
>  
> -static cairo_t *cairo_init(struct modeset_dev *dev, const char *dir, const char *base)
> +cairo_t *cairo_init(struct modeset_dev *dev, const char *dir, const char *base)
>  {
>  	cairo_surface_t *surface;
>  	cairo_status_t status;
> diff --git a/libplatsch.c b/libplatsch.c
> new file mode 100644
> index 0000000..9fceda4
> --- /dev/null
> +++ b/libplatsch.c
> @@ -0,0 +1,614 @@
> +/*
> + * Copyright (C) 2019 Pengutronix, Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> + *
> + * Permission to use, copy, modify, and/or distribute this software
> + * for any purpose with or without fee is hereby granted.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
> + * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
> + * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
> + * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
> + * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
> + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
> + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + *
> + * Some code parts base on example code written in 2012 by David Herrmann
> + * <dh.herrmann@googlemail.com> and dedicated to the Public Domain. It was found
> + * in 2019 on
> + * https://raw.githubusercontent.com/dvdhrm/docs/master/drm-howto/modeset.c
> + */
> +
> +#include <assert.h>
> +#include <ctype.h>
> +#include <errno.h>
> +#include <getopt.h>
> +#include <libgen.h>
> +#include <stdarg.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/mman.h>
> +#include <fcntl.h>
> +
> +#include <xf86drm.h>
> +#include <xf86drmMode.h>
> +#include <drm_fourcc.h>
> +#include "libplatsch.h"
> +
> +
> +static const struct platsch_format platsch_formats[] = {
> +	{ DRM_FORMAT_RGB565, 16, "RGB565" }, /* default */
> +	{ DRM_FORMAT_XRGB8888, 32, "XRGB8888" },
> +};
> +
> +
> +ssize_t readfull(int fd, void *buf, size_t count)
> +{
> +	ssize_t ret = 0, err;
> +
> +	while (count > 0) {
> +		err = read(fd, buf, count);
> +		if (err < 0)
> +			return err;
> +		else if (err > 0) {
> +			buf += err;
> +			count -= err;
> +			ret += err;
> +		} else {
> +			return ret;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int draw_buffer(struct modeset_dev *dev, const char *dir, const char *base)
> +{
> +	int fd_src;
> +	char filename[128];
> +	ssize_t size;
> +	int ret;
> +
> +	/* Try cairo draw first and fall back in case of failure. */
> +	ret = cairo_draw_buffer(dev, dir, base);
> +	if (ret == 0)
> +		return ret;
> +
> +	/*
> +	 * make it easy and load a raw file in the right format instead of
> +	 * opening an (say) PNG and convert the image data to the right format.
> +	 */
> +	ret = snprintf(filename, sizeof(filename),
> +		       "%s/%s-%ux%u-%s.bin",
> +		       dir, base, dev->width, dev->height, dev->format->name);
> +	if (ret >= sizeof(filename)) {
> +		error("Failed to fit filename into buffer\n");
> +		return -EINVAL;
> +	}
> +
> +	fd_src = open(filename, O_RDONLY | O_CLOEXEC);
> +	if (fd_src < 0) {
> +		error("Failed to open %s: %m\n", filename);
> +		return -ENOENT;
> +	}
> +
> +	size = readfull(fd_src, dev->map, dev->size);
> +	if (size < dev->size) {
> +		if (size < 0)
> +			error("Failed to read from %s: %m\n", filename);
> +		else
> +			error("Could only read %zd/%u bytes from %s\n",
> +			      size, dev->size, filename);
> +		return -EIO;
> +	}
> +
> +	ret = close(fd_src);
> +	if (ret < 0) {
> +		/* Nothing we can do about this, so just warn */
> +		error("Failed to close image file\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static struct modeset_dev *modeset_list = NULL;
> +
> +static int drmprepare_crtc(int fd, drmModeRes *res, drmModeConnector *conn,
> +			   struct modeset_dev *dev)
> +{
> +	drmModeEncoder *enc;
> +	unsigned int i, j;
> +	int32_t crtc_id;
> +	struct modeset_dev *iter;
> +
> +	/* first try the currently connected encoder+crtc */
> +	if (conn->encoder_id) {
> +		debug("connector #%d uses encoder #%d\n", conn->connector_id,
> +		      conn->encoder_id);
> +		enc = drmModeGetEncoder(fd, conn->encoder_id);
> +		assert(enc);
> +		assert(enc->encoder_id == conn->encoder_id);
> +	} else {
> +		debug("connector #%d has no active encoder\n",
> +		      conn->connector_id);
> +		enc = NULL;
> +		dev->setmode = 1;
> +	}
> +
> +	if (enc) {
> +		if (enc->crtc_id) {
> +			crtc_id = enc->crtc_id;
> +			assert(crtc_id >= 0);
> +
> +			for (iter = modeset_list; iter; iter = iter->next) {
> +				if (iter->crtc_id == crtc_id) {
> +					crtc_id = -1;
> +					break;
> +				}
> +			}
> +
> +			if (crtc_id > 0) {
> +				debug("encoder #%d uses crtc #%d\n",
> +				      enc->encoder_id, enc->crtc_id);
> +				drmModeFreeEncoder(enc);
> +				dev->crtc_id = crtc_id;
> +				return 0;
> +			} else {
> +				debug("encoder #%d used crtc #%d, but that's in use\n",
> +				      enc->encoder_id, iter->crtc_id);
> +			}
> +		} else {
> +			debug("encoder #%d doesn't have an active crtc\n",
> +			      enc->encoder_id);
> +		}
> +
> +		drmModeFreeEncoder(enc);
> +	}
> +
> +	/* If the connector is not currently bound to an encoder or if the
> +	 * encoder+crtc is already used by another connector (actually unlikely
> +	 * but let's be safe), iterate all other available encoders to find a
> +	 * matching CRTC. */
> +	for (i = 0; i < conn->count_encoders; ++i) {
> +		enc = drmModeGetEncoder(fd, conn->encoders[i]);
> +		if (!enc) {
> +			error("Cannot retrieve encoder %u: %m\n",
> +			      conn->encoders[i]);
> +			continue;
> +		}
> +		assert(enc->encoder_id == conn->encoders[i]);
> +
> +		/* iterate all global CRTCs */
> +		for (j = 0; j < res->count_crtcs; ++j) {
> +			/* check whether this CRTC works with the encoder */
> +			if (!(enc->possible_crtcs & (1 << j)))
> +				continue;
> +
> +			/* check that no other device already uses this CRTC */
> +			crtc_id = res->crtcs[j];
> +			for (iter = modeset_list; iter; iter = iter->next) {
> +				if (iter->crtc_id == crtc_id) {
> +					crtc_id = -1;
> +					break;
> +				}
> +			}
> +
> +			/* we have found a CRTC, so save it and return */
> +			if (crtc_id >= 0) {
> +				debug("encoder #%d will use crtc #%d\n",
> +				      enc->encoder_id, crtc_id);
> +				drmModeFreeEncoder(enc);
> +				dev->crtc_id = crtc_id;
> +				return 0;
> +			}
> +
> +		}
> +		drmModeFreeEncoder(enc);
> +	}
> +
> +	error("Cannot find suitable CRTC for connector #%u\n",
> +	      conn->connector_id);
> +	return -ENOENT;
> +}
> +
> +static int modeset_create_fb(int fd, struct modeset_dev *dev)
> +{
> +	struct drm_mode_create_dumb creq;
> +	struct drm_mode_destroy_dumb dreq;
> +	struct drm_mode_map_dumb mreq;
> +	int ret;
> +
> +	/* create dumb buffer */
> +	memset(&creq, 0, sizeof(creq));
> +	creq.width = dev->width;
> +	creq.height = dev->height;
> +	creq.bpp = dev->format->bpp;
> +	ret = drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &creq);
> +	if (ret < 0) {
> +		error("Cannot create dumb buffer: %m\n");
> +		return -errno;
> +	}
> +	dev->stride = creq.pitch;
> +	dev->size = creq.size;
> +	dev->handle = creq.handle;
> +
> +	/* create framebuffer object for the dumb-buffer */
> +	ret = drmModeAddFB2(fd, dev->width, dev->height,
> +			    dev->format->format,
> +			    (uint32_t[4]){ dev->handle, },
> +			    (uint32_t[4]){ dev->stride, },
> +			    (uint32_t[4]){ 0, },
> +			    &dev->fb_id, 0);
> +	if (ret) {
> +		ret = -errno;
> +		error("Cannot create framebuffer: %m\n");
> +		goto err_destroy;
> +	}
> +
> +	/* prepare buffer for memory mapping */
> +	memset(&mreq, 0, sizeof(mreq));
> +	mreq.handle = dev->handle;
> +	ret = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq);
> +	if (ret) {
> +		ret = -errno;
> +		error("Cannot get mmap offset: %m\n");
> +		goto err_fb;
> +	}
> +
> +	/* perform actual memory mapping */
> +	dev->map = mmap(0, dev->size, PROT_READ | PROT_WRITE, MAP_SHARED,
> +			fd, mreq.offset);
> +	if (dev->map == MAP_FAILED) {
> +		ret = -errno;
> +		error("Cannot mmap dumb buffer: %m\n");
> +		goto err_fb;
> +	}
> +
> +	/*
> +	 * Clear the framebuffer. Normally it's overwritten later with some
> +	 * image data, but in case this fails, initialize to all-black.
> +	 */
> +	memset(dev->map, 0x0, dev->size);
> +
> +	return 0;
> +
> +err_fb:
> +	drmModeRmFB(fd, dev->fb_id);
> +err_destroy:
> +	memset(&dreq, 0, sizeof(dreq));
> +	dreq.handle = dev->handle;
> +	drmIoctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &dreq);
> +	return ret;
> +}
> +
> +/* Returns lowercase connector type names with '_' for '-' */
> +static char *get_normalized_conn_type_name(uint32_t connector_type)
> +{
> +	int i;
> +	const char *connector_name;
> +	char *normalized_name;
> +
> +	connector_name = drmModeGetConnectorTypeName(connector_type);
> +	if (!connector_name)
> +		return NULL;
> +
> +	normalized_name = strdup(connector_name);
> +
> +	for (i = 0; normalized_name[i]; i++) {
> +		normalized_name[i] = tolower(normalized_name[i]);
> +		if (normalized_name[i] == '-')
> +			normalized_name[i] = '_';
> +	}
> +
> +	return normalized_name;
> +}
> +
> +static const struct platsch_format *platsch_format_find(const char *name)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(platsch_formats); i++)
> +		if (!strcmp(platsch_formats[i].name, name))
> +			return &platsch_formats[i];
> +
> +	return NULL;
> +}
> +
> +static int set_env_connector_mode(drmModeConnector *conn,
> +				  struct modeset_dev *dev)
> +{
> +	int ret, i = 0;
> +	u_int32_t width = 0, height = 0;
> +	const char *mode;
> +	char *connector_type_name, mode_env_name[32], fmt_specifier[32] = "";
> +	const struct platsch_format *format = NULL;
> +
> +	connector_type_name = get_normalized_conn_type_name(conn->connector_type);
> +	if (!connector_type_name) {
> +		error("could not look up name for connector type %u\n",
> +		      conn->connector_type);
> +		goto fallback;
> +	}
> +
> +	ret = snprintf(mode_env_name, sizeof(mode_env_name), "platsch_%s%u_mode",
> +		       connector_type_name, conn->connector_type_id);
> +	free(connector_type_name);
> +	if (ret >= sizeof(mode_env_name)) {
> +		error("failed to fit platsch env mode variable name into buffer\n");
> +		return -EFAULT;
> +	}
> +
> +	/* check for connector mode configuration in environment */
> +	debug("looking up %s env variable\n", mode_env_name);
> +	mode = getenv(mode_env_name);
> +	if (!mode)
> +		goto fallback;
> +
> +	/* format suffix is optional */
> +	ret = sscanf(mode, "%ux%u@%s", &width, &height, fmt_specifier);
> +	if (ret < 2) {
> +		error("error while scanning %s for mode\n", mode_env_name);
> +		return -EFAULT;
> +	}
> +
> +	/* use first mode matching given resolution */
> +	for (i = 0; i < conn->count_modes; i++) {
> +		drmModeModeInfo mode = conn->modes[i];
> +		if (mode.hdisplay == width && mode.vdisplay == height) {
> +			memcpy(&dev->mode, &mode, sizeof(dev->mode));
> +			dev->width = width;
> +			dev->height = height;
> +			break;
> +		}
> +	}
> +
> +	if (i == conn->count_modes) {
> +		error("no mode available matching %ux%u\n", width, height);
> +		return -ENOENT;
> +	}
> +
> +	format = platsch_format_find(fmt_specifier);
> +	if (!format) {
> +		if (strlen(fmt_specifier))
> +			error("unknown format specifier %s\n", fmt_specifier);
> +		goto fallback_format;
> +	}
> +
> +	dev->format = format;
> +
> +	return 0;
> +
> +fallback:
> +	memcpy(&dev->mode, &conn->modes[0], sizeof(dev->mode));
> +	dev->width = conn->modes[0].hdisplay;
> +	dev->height = conn->modes[0].vdisplay;
> +	debug("using default mode for connector #%u\n", conn->connector_id);
> +
> +fallback_format:
> +	dev->format = &platsch_formats[0];
> +	debug("using default format %s for connector #%u\n", dev->format->name,
> +	      conn->connector_id);
> +
> +	return 0;
> +}
> +
> +static int drmprepare_connector(int fd, drmModeRes *res, drmModeConnector *conn,
> +				struct modeset_dev *dev)
> +{
> +	int ret;
> +
> +	/* check if a monitor is connected */
> +	if (conn->connection != DRM_MODE_CONNECTED) {
> +		error("Ignoring unused connector #%u\n", conn->connector_id);
> +		return -ENOENT;
> +	}
> +
> +	/* check if there is at least one valid mode */
> +	if (conn->count_modes == 0) {
> +		error("no valid mode for connector #%u\n", conn->connector_id);
> +		return -EFAULT;
> +	}
> +
> +	/* configure mode information in our device structure */
> +	ret = set_env_connector_mode(conn, dev);
> +	if (ret) {
> +		error("no valid mode for connector #%u\n", conn->connector_id);
> +		return ret;
> +	}
> +	debug("mode for connector #%u is %ux%u@%s\n",
> +	      conn->connector_id, dev->width, dev->height, dev->format->name);
> +
> +	/* find a crtc for this connector */
> +	ret = drmprepare_crtc(fd, res, conn, dev);
> +	if (ret) {
> +		error("no valid crtc for connector #%u\n", conn->connector_id);
> +		return ret;
> +	}
> +
> +	/* create a framebuffer for this CRTC */
> +	ret = modeset_create_fb(fd, dev);
> +	if (ret) {
> +		error("cannot create framebuffer for connector #%u\n",
> +		      conn->connector_id);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int drmprepare(int fd)
> +{
> +	drmModeRes *res;
> +	drmModeConnector *conn;
> +	unsigned int i;
> +	struct modeset_dev *dev;
> +	int ret;
> +
> +	/* retrieve resources */
> +	res = drmModeGetResources(fd);
> +	if (!res) {
> +		error("cannot retrieve DRM resources: %m\n");
> +		return -errno;
> +	}
> +
> +	debug("Found %d connectors\n", res->count_connectors);
> +
> +	/* iterate all connectors */
> +	for (i = 0; i < res->count_connectors; ++i) {
> +		/* get information for each connector */
> +		conn = drmModeGetConnector(fd, res->connectors[i]);
> +		if (!conn) {
> +			error("Cannot retrieve DRM connector #%u: %m\n",
> +				res->connectors[i]);
> +			continue;
> +		}
> +		assert(conn->connector_id == res->connectors[i]);
> +
> +		debug("Connector #%u has type %s\n", conn->connector_id,
> +		      drmModeGetConnectorTypeName(conn->connector_type));
> +
> +		/* create a device structure */
> +		dev = malloc(sizeof(*dev));
> +		if (!dev) {
> +			error("Cannot allocate memory for connector #%u: %m\n",
> +			      res->connectors[i]);
> +			continue;
> +		}
> +		memset(dev, 0, sizeof(*dev));
> +		dev->conn_id = conn->connector_id;
> +
> +		ret = drmprepare_connector(fd, res, conn, dev);
> +		if (ret) {
> +			if (ret != -ENOENT) {
> +				error("Cannot setup device for connector #%u: %m\n",
> +				      res->connectors[i]);
> +			}
> +			free(dev);
> +			drmModeFreeConnector(conn);
> +			continue;
> +		}
> +
> +		/* free connector data and link device into global list */
> +		drmModeFreeConnector(conn);
> +		dev->next = modeset_list;
> +		modeset_list = dev;
> +	}
> +
> +	/* free resources again */
> +	drmModeFreeResources(res);
> +	return 0;
> +}
> +
> +
> +static int drmfd;
> +
> +struct modeset_dev *init(void) 
> +{
> +	static char drmdev[128];
> +	int ret = 0, i;
> +
> +	for (i = 0; i < 64; i++) {
> +		struct drm_mode_card_res res = {0};
> +
> +		/*
> +		 * XXX: Maybe use drmOpen instead?
> +		 * (Where should name/busid come from?)
> +		 * XXX: Loop through drm devices to find one with connectors.
> +		 */
> +		ret = snprintf(drmdev, sizeof(drmdev), DRM_DEV_NAME, DRM_DIR_NAME, i);
> +		if (ret >= sizeof(drmdev)) {
> +			error("Huh, device name overflowed buffer\n");
> +			goto execinit;
> +		}
> +
> +		drmfd = open(drmdev, O_RDWR | O_CLOEXEC, 0);
> +		if (drmfd < 0) {
> +			error("Failed to open drm device: %m\n");
> +			goto execinit;
> +		}
> +
> +		ret = drmIoctl(drmfd, DRM_IOCTL_MODE_GETRESOURCES, &res);
> +		if (ret < 0) {
> +			close(drmfd);
> +			continue;
> +		} else {
> +			/* Device found */
> +			break;
> +		}
> +	}
> +
> +	if (i == 64) {
> +		error("No suitable DRM device found\n");
> +		goto execinit;
> +	}
> +
> +	ret = drmprepare(drmfd);
> +	if (ret) {
> +		error("Failed to prepare DRM device\n");
> +		goto execinit;
> +	}
> +
> +	return modeset_list;
> +
> +execinit:
> +	return NULL;
> +}
> +
> +
> +int update_display(struct modeset_dev *dev) {
> +	int ret = 0;
> +
> +	if (dev->setmode) {
> +		ret = drmModeSetCrtc(drmfd, dev->crtc_id, dev->fb_id, 0, 0, &dev->conn_id, 1, &dev->mode);
> +		if (ret) {
> +			error("Cannot set CRTC for connector #%u: %m\n", dev->conn_id);
> +		}
> +		dev->setmode = 0;
> +	} else {
> +		ret = drmModePageFlip(drmfd, dev->crtc_id, dev->fb_id, 0, NULL);
> +		if (ret) {
> +			error("Page flip failed on connector #%u: %m\n", dev->conn_id);
> +		}
> +	}
> +	return ret;
> +}
> +
> +int draw(struct modeset_dev *dev, const char *dir, const char *base)
> +{
> +	int ret = 0;
> +	ret = draw_buffer(dev, dir, base);
> +	if (ret) {
> +		error("Failed to draw buffer\n");
> +		return ret;
> +	}
> +	return update_display(dev);
> +}
> +
> +int finish(void) {
> +	int ret = drmDropMaster(drmfd);
> +	if (ret) {
> +		error("Failed to drop master on DRM device\n");
> +	}
> +
> +	return ret;
> +}
> +
> +void deinit(void) {
> +	struct modeset_dev *iter;
> +
> +	for (iter = modeset_list; iter; iter = iter->next) {
> +		if (iter->map) {
> +			munmap(iter->map, iter->size);
> +		}
> +		if (iter->fb_id) {
> +			drmModeRmFB(drmfd, iter->fb_id);
> +		}
> +		free(iter);
> +	}
> +}
> diff --git a/platsch.h b/libplatsch.h
> similarity index 51%
> rename from platsch.h
> rename to libplatsch.h
> index dee22eb..87f6ef5 100644
> --- a/platsch.h
> +++ b/libplatsch.h
> @@ -1,8 +1,27 @@
> -#ifndef __PLATSCH_H__
> -#define __PLATSCH_H__
> +#ifndef __LIBPLATSCH_H__
> +#define __LIBPLATSCH_H__
>  
> -#include <stdint.h>
> +#include <assert.h>
> +#include <ctype.h>
> +#include <errno.h>
> +#include <getopt.h>
> +#include <libgen.h>
> +#include <stdarg.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/mman.h>
> +#include <fcntl.h>
> +
> +#include <xf86drm.h>
>  #include <xf86drmMode.h>
> +#include <drm_fourcc.h>
> +#include "libplatsch.h"
> +
>  
>  #define debug(fmt, ...) printf("%s:%d: " fmt, __func__, __LINE__, ##__VA_ARGS__)
>  #define error(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
> @@ -17,7 +36,6 @@ struct platsch_format {
>  
>  struct modeset_dev {
>  	struct modeset_dev *next;
> -
>  	uint32_t width;
>  	uint32_t height;
>  	uint32_t stride;
> @@ -25,7 +43,6 @@ struct modeset_dev {
>  	const struct platsch_format *format;
>  	uint32_t handle;
>  	void *map;
> -
>  	bool setmode;
>  	drmModeModeInfo mode;
>  	uint32_t fb_id;
> @@ -34,14 +51,24 @@ struct modeset_dev {
>  };
>  
>  ssize_t readfull(int fd, void *buf, size_t count);
> +struct modeset_dev * init(void);
>  
> -#ifdef HAVE_CAIRO
> -int cairo_draw_buffer(struct modeset_dev *dev, const char *dir, const char *base);
> -#else
> +int draw(struct modeset_dev *dev, const char *dir, const char *base);
> +int finish(void);
> +int update_display(struct modeset_dev *dev);
> +
> +#ifndef HAVE_CAIRO
>  static inline int cairo_draw_buffer(struct modeset_dev *dev, const char *dir, const char *base)
>  {
> +	printf("cairo_draw_buffer do nothing %s %s\n", dir, base);
>  	return -ENOTSUP;
>  }
> +#else
> +
> +#include <cairo.h>
> +int cairo_draw_buffer(struct modeset_dev *dev, const char *dir, const char *base);
> +cairo_t *cairo_init(struct modeset_dev *dev, const char *dir, const char *base);
> +
>  #endif /* HAVE_CAIRO */
>  
> -#endif /* __PLATSCH_H__ */
> +#endif /* __LIBPLATSCH_H__ */
> diff --git a/meson.build b/meson.build
> index e7e8e80..8c15fb9 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1,26 +1,35 @@
>  project('platsch', 'c')
>  
> +have_cairo = get_option('HAVE_CAIRO')
> +
>  # Define dependencies conditionally based on the HAVE_CAIRO option
>  platsch_dep = [dependency('libdrm', required: true)]
> -sources = ['platsch.c']
> +sources = ['libplatsch.c']
>  args = []
>  
> -have_cairo = get_option('HAVE_CAIRO')
> -
>  if have_cairo
>      platsch_dep += dependency('cairo', required: true)
>      sources += 'cairo.c'
>      args += ['-DHAVE_CAIRO']
>  endif
>  
> +# Create a static library from libplatsch.c and optionally cairo.c
> +libplatsch = static_library('libplatsch',
> +    sources,
> +    dependencies: platsch_dep,
> +    c_args: args,
> +    install: true
> +)
> +
>  # Define the headers
> -headers = ['platsch.h']
> +headers = ['libplatsch.h', 'platsch.h']
>  
> -# Create the platsch executable
> +# Create the platsch executable, linking it statically with libplatsch
>  executable('platsch',
> -    sources,
> +    'platsch.c',
>      dependencies: platsch_dep,
>      c_args: args,
> +    link_with: libplatsch,
>      install: true,
>      include_directories: include_directories('.')
>  )
> diff --git a/platsch.c b/platsch.c
> index a7e82a6..92123d8 100644
> --- a/platsch.c
> +++ b/platsch.c
> @@ -35,16 +35,7 @@
>  #include <sys/mman.h>
>  #include <fcntl.h>
>  
> -#include <xf86drm.h>
> -#include <xf86drmMode.h>
> -#include <drm_fourcc.h>
> -
> -#include "platsch.h"
> -
> -static const struct platsch_format platsch_formats[] = {
> -	{ DRM_FORMAT_RGB565, 16, "RGB565" }, /* default */
> -	{ DRM_FORMAT_XRGB8888, 32, "XRGB8888" },
> -};
> +#include "libplatsch.h"
>  
>  void redirect_stdfd(void)
>  {
> @@ -64,461 +55,6 @@ void redirect_stdfd(void)
>  	close(devnull);
>  }
>  
> -ssize_t readfull(int fd, void *buf, size_t count)
> -{
> -	ssize_t ret = 0, err;
> -
> -	while (count > 0) {
> -		err = read(fd, buf, count);
> -		if (err < 0)
> -			return err;
> -		else if (err > 0) {
> -			buf += err;
> -			count -= err;
> -			ret += err;
> -		} else {
> -			return ret;
> -		}
> -	}
> -
> -	return ret;
> -}
> -
> -void draw_buffer(struct modeset_dev *dev, const char *dir, const char *base)
> -{
> -	int fd_src;
> -	char filename[128];
> -	ssize_t size;
> -	int ret;
> -
> -	/* Try cairo draw first and fall back in case of failure. */
> -	ret = cairo_draw_buffer(dev, dir, base);
> -	if (ret == 0)
> -		return;
> -
> -	/*
> -	 * make it easy and load a raw file in the right format instead of
> -	 * opening an (say) PNG and convert the image data to the right format.
> -	 */
> -	ret = snprintf(filename, sizeof(filename),
> -		       "%s/%s-%ux%u-%s.bin",
> -		       dir, base, dev->width, dev->height, dev->format->name);
> -	if (ret >= sizeof(filename)) {
> -		error("Failed to fit filename into buffer\n");
> -		return;
> -	}
> -
> -	fd_src = open(filename, O_RDONLY | O_CLOEXEC);
> -	if (fd_src < 0) {
> -		error("Failed to open %s: %m\n", filename);
> -		return;
> -	}
> -
> -	size = readfull(fd_src, dev->map, dev->size);
> -	if (size < dev->size) {
> -		if (size < 0)
> -			error("Failed to read from %s: %m\n", filename);
> -		else
> -			error("Could only read %zd/%u bytes from %s\n",
> -			      size, dev->size, filename);
> -	}
> -
> -	ret = close(fd_src);
> -	if (ret < 0) {
> -		/* Nothing we can do about this, so just warn */
> -		error("Failed to close image file\n");
> -	}
> -
> -	return;
> -}
> -
> -static struct modeset_dev *modeset_list = NULL;
> -
> -static int drmprepare_crtc(int fd, drmModeRes *res, drmModeConnector *conn,
> -			   struct modeset_dev *dev)
> -{
> -	drmModeEncoder *enc;
> -	unsigned int i, j;
> -	int32_t crtc_id;
> -	struct modeset_dev *iter;
> -
> -	/* first try the currently connected encoder+crtc */
> -	if (conn->encoder_id) {
> -		debug("connector #%d uses encoder #%d\n", conn->connector_id,
> -		      conn->encoder_id);
> -		enc = drmModeGetEncoder(fd, conn->encoder_id);
> -		assert(enc);
> -		assert(enc->encoder_id == conn->encoder_id);
> -	} else {
> -		debug("connector #%d has no active encoder\n",
> -		      conn->connector_id);
> -		enc = NULL;
> -		dev->setmode = 1;
> -	}
> -
> -	if (enc) {
> -		if (enc->crtc_id) {
> -			crtc_id = enc->crtc_id;
> -			assert(crtc_id >= 0);
> -
> -			for (iter = modeset_list; iter; iter = iter->next) {
> -				if (iter->crtc_id == crtc_id) {
> -					crtc_id = -1;
> -					break;
> -				}
> -			}
> -
> -			if (crtc_id > 0) {
> -				debug("encoder #%d uses crtc #%d\n",
> -				      enc->encoder_id, enc->crtc_id);
> -				drmModeFreeEncoder(enc);
> -				dev->crtc_id = crtc_id;
> -				return 0;
> -			} else {
> -				debug("encoder #%d used crtc #%d, but that's in use\n",
> -				      enc->encoder_id, iter->crtc_id);
> -			}
> -		} else {
> -			debug("encoder #%d doesn't have an active crtc\n",
> -			      enc->encoder_id);
> -		}
> -
> -		drmModeFreeEncoder(enc);
> -	}
> -
> -	/* If the connector is not currently bound to an encoder or if the
> -	 * encoder+crtc is already used by another connector (actually unlikely
> -	 * but let's be safe), iterate all other available encoders to find a
> -	 * matching CRTC. */
> -	for (i = 0; i < conn->count_encoders; ++i) {
> -		enc = drmModeGetEncoder(fd, conn->encoders[i]);
> -		if (!enc) {
> -			error("Cannot retrieve encoder %u: %m\n",
> -			      conn->encoders[i]);
> -			continue;
> -		}
> -		assert(enc->encoder_id == conn->encoders[i]);
> -
> -		/* iterate all global CRTCs */
> -		for (j = 0; j < res->count_crtcs; ++j) {
> -			/* check whether this CRTC works with the encoder */
> -			if (!(enc->possible_crtcs & (1 << j)))
> -				continue;
> -
> -			/* check that no other device already uses this CRTC */
> -			crtc_id = res->crtcs[j];
> -			for (iter = modeset_list; iter; iter = iter->next) {
> -				if (iter->crtc_id == crtc_id) {
> -					crtc_id = -1;
> -					break;
> -				}
> -			}
> -
> -			/* we have found a CRTC, so save it and return */
> -			if (crtc_id >= 0) {
> -				debug("encoder #%d will use crtc #%d\n",
> -				      enc->encoder_id, crtc_id);
> -				drmModeFreeEncoder(enc);
> -				dev->crtc_id = crtc_id;
> -				return 0;
> -			}
> -
> -		}
> -		drmModeFreeEncoder(enc);
> -	}
> -
> -	error("Cannot find suitable CRTC for connector #%u\n",
> -	      conn->connector_id);
> -	return -ENOENT;
> -}
> -
> -static int modeset_create_fb(int fd, struct modeset_dev *dev)
> -{
> -	struct drm_mode_create_dumb creq;
> -	struct drm_mode_destroy_dumb dreq;
> -	struct drm_mode_map_dumb mreq;
> -	int ret;
> -
> -	/* create dumb buffer */
> -	memset(&creq, 0, sizeof(creq));
> -	creq.width = dev->width;
> -	creq.height = dev->height;
> -	creq.bpp = dev->format->bpp;
> -	ret = drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &creq);
> -	if (ret < 0) {
> -		error("Cannot create dumb buffer: %m\n");
> -		return -errno;
> -	}
> -	dev->stride = creq.pitch;
> -	dev->size = creq.size;
> -	dev->handle = creq.handle;
> -
> -	/* create framebuffer object for the dumb-buffer */
> -	ret = drmModeAddFB2(fd, dev->width, dev->height,
> -			    dev->format->format,
> -			    (uint32_t[4]){ dev->handle, },
> -			    (uint32_t[4]){ dev->stride, },
> -			    (uint32_t[4]){ 0, },
> -			    &dev->fb_id, 0);
> -	if (ret) {
> -		ret = -errno;
> -		error("Cannot create framebuffer: %m\n");
> -		goto err_destroy;
> -	}
> -
> -	/* prepare buffer for memory mapping */
> -	memset(&mreq, 0, sizeof(mreq));
> -	mreq.handle = dev->handle;
> -	ret = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq);
> -	if (ret) {
> -		ret = -errno;
> -		error("Cannot get mmap offset: %m\n");
> -		goto err_fb;
> -	}
> -
> -	/* perform actual memory mapping */
> -	dev->map = mmap(0, dev->size, PROT_READ | PROT_WRITE, MAP_SHARED,
> -			fd, mreq.offset);
> -	if (dev->map == MAP_FAILED) {
> -		ret = -errno;
> -		error("Cannot mmap dumb buffer: %m\n");
> -		goto err_fb;
> -	}
> -
> -	/*
> -	 * Clear the framebuffer. Normally it's overwritten later with some
> -	 * image data, but in case this fails, initialize to all-black.
> -	 */
> -	memset(dev->map, 0x0, dev->size);
> -
> -	return 0;
> -
> -err_fb:
> -	drmModeRmFB(fd, dev->fb_id);
> -err_destroy:
> -	memset(&dreq, 0, sizeof(dreq));
> -	dreq.handle = dev->handle;
> -	drmIoctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &dreq);
> -	return ret;
> -}
> -
> -/* Returns lowercase connector type names with '_' for '-' */
> -static char *get_normalized_conn_type_name(uint32_t connector_type)
> -{
> -	int i;
> -	const char *connector_name;
> -	char *normalized_name;
> -
> -	connector_name = drmModeGetConnectorTypeName(connector_type);
> -	if (!connector_name)
> -		return NULL;
> -
> -	normalized_name = strdup(connector_name);
> -
> -	for (i = 0; normalized_name[i]; i++) {
> -		normalized_name[i] = tolower(normalized_name[i]);
> -		if (normalized_name[i] == '-')
> -			normalized_name[i] = '_';
> -	}
> -
> -	return normalized_name;
> -}
> -
> -static const struct platsch_format *platsch_format_find(const char *name)
> -{
> -	int i;
> -
> -	for (i = 0; i < ARRAY_SIZE(platsch_formats); i++)
> -		if (!strcmp(platsch_formats[i].name, name))
> -			return &platsch_formats[i];
> -
> -	return NULL;
> -}
> -
> -static int set_env_connector_mode(drmModeConnector *conn,
> -				  struct modeset_dev *dev)
> -{
> -	int ret, i = 0;
> -	u_int32_t width = 0, height = 0;
> -	const char *mode;
> -	char *connector_type_name, mode_env_name[32], fmt_specifier[32] = "";
> -	const struct platsch_format *format = NULL;
> -
> -	connector_type_name = get_normalized_conn_type_name(conn->connector_type);
> -	if (!connector_type_name) {
> -		error("could not look up name for connector type %u\n",
> -		      conn->connector_type);
> -		goto fallback;
> -	}
> -
> -	ret = snprintf(mode_env_name, sizeof(mode_env_name), "platsch_%s%u_mode",
> -		       connector_type_name, conn->connector_type_id);
> -	free(connector_type_name);
> -	if (ret >= sizeof(mode_env_name)) {
> -		error("failed to fit platsch env mode variable name into buffer\n");
> -		return -EFAULT;
> -	}
> -
> -	/* check for connector mode configuration in environment */
> -	debug("looking up %s env variable\n", mode_env_name);
> -	mode = getenv(mode_env_name);
> -	if (!mode)
> -		goto fallback;
> -
> -	/* format suffix is optional */
> -	ret = sscanf(mode, "%ux%u@%s", &width, &height, fmt_specifier);
> -	if (ret < 2) {
> -		error("error while scanning %s for mode\n", mode_env_name);
> -		return -EFAULT;
> -	}
> -
> -	/* use first mode matching given resolution */
> -	for (i = 0; i < conn->count_modes; i++) {
> -		drmModeModeInfo mode = conn->modes[i];
> -		if (mode.hdisplay == width && mode.vdisplay == height) {
> -			memcpy(&dev->mode, &mode, sizeof(dev->mode));
> -			dev->width = width;
> -			dev->height = height;
> -			break;
> -		}
> -	}
> -
> -	if (i == conn->count_modes) {
> -		error("no mode available matching %ux%u\n", width, height);
> -		return -ENOENT;
> -	}
> -
> -	format = platsch_format_find(fmt_specifier);
> -	if (!format) {
> -		if (strlen(fmt_specifier))
> -			error("unknown format specifier %s\n", fmt_specifier);
> -		goto fallback_format;
> -	}
> -
> -	dev->format = format;
> -
> -	return 0;
> -
> -fallback:
> -	memcpy(&dev->mode, &conn->modes[0], sizeof(dev->mode));
> -	dev->width = conn->modes[0].hdisplay;
> -	dev->height = conn->modes[0].vdisplay;
> -	debug("using default mode for connector #%u\n", conn->connector_id);
> -
> -fallback_format:
> -	dev->format = &platsch_formats[0];
> -	debug("using default format %s for connector #%u\n", dev->format->name,
> -	      conn->connector_id);
> -
> -	return 0;
> -}
> -
> -static int drmprepare_connector(int fd, drmModeRes *res, drmModeConnector *conn,
> -				struct modeset_dev *dev)
> -{
> -	int ret;
> -
> -	/* check if a monitor is connected */
> -	if (conn->connection != DRM_MODE_CONNECTED) {
> -		error("Ignoring unused connector #%u\n", conn->connector_id);
> -		return -ENOENT;
> -	}
> -
> -	/* check if there is at least one valid mode */
> -	if (conn->count_modes == 0) {
> -		error("no valid mode for connector #%u\n", conn->connector_id);
> -		return -EFAULT;
> -	}
> -
> -	/* configure mode information in our device structure */
> -	ret = set_env_connector_mode(conn, dev);
> -	if (ret) {
> -		error("no valid mode for connector #%u\n", conn->connector_id);
> -		return ret;
> -	}
> -	debug("mode for connector #%u is %ux%u@%s\n",
> -	      conn->connector_id, dev->width, dev->height, dev->format->name);
> -
> -	/* find a crtc for this connector */
> -	ret = drmprepare_crtc(fd, res, conn, dev);
> -	if (ret) {
> -		error("no valid crtc for connector #%u\n", conn->connector_id);
> -		return ret;
> -	}
> -
> -	/* create a framebuffer for this CRTC */
> -	ret = modeset_create_fb(fd, dev);
> -	if (ret) {
> -		error("cannot create framebuffer for connector #%u\n",
> -		      conn->connector_id);
> -		return ret;
> -	}
> -
> -	return 0;
> -}
> -
> -static int drmprepare(int fd)
> -{
> -	drmModeRes *res;
> -	drmModeConnector *conn;
> -	unsigned int i;
> -	struct modeset_dev *dev;
> -	int ret;
> -
> -	/* retrieve resources */
> -	res = drmModeGetResources(fd);
> -	if (!res) {
> -		error("cannot retrieve DRM resources: %m\n");
> -		return -errno;
> -	}
> -
> -	debug("Found %d connectors\n", res->count_connectors);
> -
> -	/* iterate all connectors */
> -	for (i = 0; i < res->count_connectors; ++i) {
> -		/* get information for each connector */
> -		conn = drmModeGetConnector(fd, res->connectors[i]);
> -		if (!conn) {
> -			error("Cannot retrieve DRM connector #%u: %m\n",
> -				res->connectors[i]);
> -			continue;
> -		}
> -		assert(conn->connector_id == res->connectors[i]);
> -
> -		debug("Connector #%u has type %s\n", conn->connector_id,
> -		      drmModeGetConnectorTypeName(conn->connector_type));
> -
> -		/* create a device structure */
> -		dev = malloc(sizeof(*dev));
> -		if (!dev) {
> -			error("Cannot allocate memory for connector #%u: %m\n",
> -			      res->connectors[i]);
> -			continue;
> -		}
> -		memset(dev, 0, sizeof(*dev));
> -		dev->conn_id = conn->connector_id;
> -
> -		ret = drmprepare_connector(fd, res, conn, dev);
> -		if (ret) {
> -			if (ret != -ENOENT) {
> -				error("Cannot setup device for connector #%u: %m\n",
> -				      res->connectors[i]);
> -			}
> -			free(dev);
> -			drmModeFreeConnector(conn);
> -			continue;
> -		}
> -
> -		/* free connector data and link device into global list */
> -		drmModeFreeConnector(conn);
> -		dev->next = modeset_list;
> -		modeset_list = dev;
> -	}
> -
> -	/* free resources again */
> -	drmModeFreeResources(res);
> -	return 0;
> -}
>  
>  static struct option longopts[] =
>  {
> @@ -539,14 +75,14 @@ static void usage(const char *prog)
>  int main(int argc, char *argv[])
>  {
>  	char **initsargv;
> -	int drmfd;
> -	char drmdev[128];
> +	//int drmfd;
> +	//char drmdev[128];
>  	struct modeset_dev *iter;
>  	bool pid1 = getpid() == 1;
>  	const char *dir = "/usr/share/platsch";
>  	const char *base = "splash";
>  	const char *env;
> -	int ret = 0, c, i;
> +	int ret = 0, c;
>  
>  	env = getenv("platsch_directory");
>  	if (env)
> @@ -582,67 +118,17 @@ int main(int argc, char *argv[])
>  		}
>  	}
>  
> -	for (i = 0; i < 64; i++) {
> -		struct drm_mode_card_res res = {0};
> -
> -		/*
> -		 * XXX: Maybe use drmOpen instead?
> -		 * (Where should name/busid come from?)
> -		 * XXX: Loop through drm devices to find one with connectors.
> -		 */
> -		ret = snprintf(drmdev, sizeof(drmdev), DRM_DEV_NAME, DRM_DIR_NAME, i);
> -		if (ret >= sizeof(drmdev)) {
> -			error("Huh, device name overflowed buffer\n");
> -			goto execinit;
> -		}
> -
> -		drmfd = open(drmdev, O_RDWR | O_CLOEXEC, 0);
> -		if (drmfd < 0) {
> -			error("Failed to open drm device: %m\n");
> -			goto execinit;
> -		}
> -
> -		ret = drmIoctl(drmfd, DRM_IOCTL_MODE_GETRESOURCES, &res);
> -		if (ret < 0) {
> -			close(drmfd);
> -			continue;
> -		} else {
> -			/* Device found */
> -			break;
> -		}
> +	struct modeset_dev *modeset_list = init();
> +	if (!modeset_list) {
> +		error("Failed to initialize modeset\n");
> +		return EXIT_FAILURE;
>  	}
> -
> -	ret = drmprepare(drmfd);
> -	assert(!ret);
> -
>  	for (iter = modeset_list; iter; iter = iter->next) {
> -
> -		/* draw first then set the mode */
> -		draw_buffer(iter, dir, base);
> -
> -		if (iter->setmode) {
> -			debug("set crtc\n");
> -
> -			ret = drmModeSetCrtc(drmfd, iter->crtc_id, iter->fb_id,
> -					     0, 0, &iter->conn_id, 1, &iter->mode);
> -			if (ret)
> -				error("Cannot set CRTC for connector #%u: %m\n",
> -				      iter->conn_id);
> -		} else {
> -			debug("page flip\n");
> -			ret = drmModePageFlip(drmfd, iter->crtc_id, iter->fb_id,
> -					      0, NULL);
> -			if (ret)
> -				error("Page flip failed on connector #%u: %m\n",
> -				      iter->conn_id);
> -		}
> +		draw(iter,dir,base);
>  	}
>  
> -	ret = drmDropMaster(drmfd);
> -	if (ret)
> -		error("Failed to drop master on drm device\n");
> +	finish();
>  
> -execinit:
>  	if (pid1) {
>  		ret = fork();
>  		if (ret < 0) {
> -- 
> 2.34.1
> 
>