1 // SPDX-License-Identifier: GPL-2.0-only
4 #include <linux/of_clk.h>
5 #include <linux/platform_data/simplefb.h>
6 #include <linux/platform_device.h>
7 #include <linux/regulator/consumer.h>
9 #include <drm/drm_aperture.h>
10 #include <drm/drm_atomic_state_helper.h>
11 #include <drm/drm_connector.h>
12 #include <drm/drm_damage_helper.h>
13 #include <drm/drm_device.h>
14 #include <drm/drm_drv.h>
15 #include <drm/drm_fb_helper.h>
16 #include <drm/drm_format_helper.h>
17 #include <drm/drm_gem_atomic_helper.h>
18 #include <drm/drm_gem_framebuffer_helper.h>
19 #include <drm/drm_gem_shmem_helper.h>
20 #include <drm/drm_managed.h>
21 #include <drm/drm_modeset_helper_vtables.h>
22 #include <drm/drm_probe_helper.h>
23 #include <drm/drm_simple_kms_helper.h>
25 #define DRIVER_NAME "simpledrm"
26 #define DRIVER_DESC "DRM driver for simple-framebuffer platform devices"
27 #define DRIVER_DATE "20200625"
28 #define DRIVER_MAJOR 1
29 #define DRIVER_MINOR 0
32 * Assume a monitor resolution of 96 dpi to
33 * get a somewhat reasonable screen size.
36 (((d) * 254ul) / (96ul * 10ul))
38 #define SIMPLEDRM_MODE(hd, vd) \
39 DRM_SIMPLE_MODE(hd, vd, RES_MM(hd), RES_MM(vd))
42 * Helpers for simplefb
46 simplefb_get_validated_int(struct drm_device *dev, const char *name,
49 if (value > INT_MAX) {
50 drm_err(dev, "simplefb: invalid framebuffer %s of %u\n",
58 simplefb_get_validated_int0(struct drm_device *dev, const char *name,
62 drm_err(dev, "simplefb: invalid framebuffer %s of %u\n",
66 return simplefb_get_validated_int(dev, name, value);
69 static const struct drm_format_info *
70 simplefb_get_validated_format(struct drm_device *dev, const char *format_name)
72 static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
73 const struct simplefb_format *fmt = formats;
74 const struct simplefb_format *end = fmt + ARRAY_SIZE(formats);
75 const struct drm_format_info *info;
78 drm_err(dev, "simplefb: missing framebuffer format\n");
79 return ERR_PTR(-EINVAL);
83 if (!strcmp(format_name, fmt->name)) {
84 info = drm_format_info(fmt->fourcc);
86 return ERR_PTR(-EINVAL);
92 drm_err(dev, "simplefb: unknown framebuffer format %s\n",
95 return ERR_PTR(-EINVAL);
99 simplefb_get_width_pd(struct drm_device *dev,
100 const struct simplefb_platform_data *pd)
102 return simplefb_get_validated_int0(dev, "width", pd->width);
106 simplefb_get_height_pd(struct drm_device *dev,
107 const struct simplefb_platform_data *pd)
109 return simplefb_get_validated_int0(dev, "height", pd->height);
113 simplefb_get_stride_pd(struct drm_device *dev,
114 const struct simplefb_platform_data *pd)
116 return simplefb_get_validated_int(dev, "stride", pd->stride);
119 static const struct drm_format_info *
120 simplefb_get_format_pd(struct drm_device *dev,
121 const struct simplefb_platform_data *pd)
123 return simplefb_get_validated_format(dev, pd->format);
127 simplefb_read_u32_of(struct drm_device *dev, struct device_node *of_node,
128 const char *name, u32 *value)
130 int ret = of_property_read_u32(of_node, name, value);
133 drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
139 simplefb_read_string_of(struct drm_device *dev, struct device_node *of_node,
140 const char *name, const char **value)
142 int ret = of_property_read_string(of_node, name, value);
145 drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
151 simplefb_get_width_of(struct drm_device *dev, struct device_node *of_node)
154 int ret = simplefb_read_u32_of(dev, of_node, "width", &width);
158 return simplefb_get_validated_int0(dev, "width", width);
162 simplefb_get_height_of(struct drm_device *dev, struct device_node *of_node)
165 int ret = simplefb_read_u32_of(dev, of_node, "height", &height);
169 return simplefb_get_validated_int0(dev, "height", height);
173 simplefb_get_stride_of(struct drm_device *dev, struct device_node *of_node)
176 int ret = simplefb_read_u32_of(dev, of_node, "stride", &stride);
180 return simplefb_get_validated_int(dev, "stride", stride);
183 static const struct drm_format_info *
184 simplefb_get_format_of(struct drm_device *dev, struct device_node *of_node)
187 int ret = simplefb_read_string_of(dev, of_node, "format", &format);
191 return simplefb_get_validated_format(dev, format);
195 * Simple Framebuffer device
198 struct simpledrm_device {
199 struct drm_device dev;
200 struct platform_device *pdev;
203 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
204 unsigned int clk_count;
208 #if defined CONFIG_OF && defined CONFIG_REGULATOR
209 unsigned int regulator_count;
210 struct regulator **regulators;
213 /* simplefb settings */
214 struct drm_display_mode mode;
215 const struct drm_format_info *format;
218 /* memory management */
219 struct resource *mem;
220 void __iomem *screen_base;
225 struct drm_connector connector;
226 struct drm_simple_display_pipe pipe;
229 static struct simpledrm_device *simpledrm_device_of_dev(struct drm_device *dev)
231 return container_of(dev, struct simpledrm_device, dev);
238 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
240 * Clock handling code.
242 * Here we handle the clocks property of our "simple-framebuffer" dt node.
243 * This is necessary so that we can make sure that any clocks needed by
244 * the display engine that the bootloader set up for us (and for which it
245 * provided a simplefb dt node), stay up, for the life of the simplefb
248 * When the driver unloads, we cleanly disable, and then release the clocks.
250 * We only complain about errors here, no action is taken as the most likely
251 * error can only happen due to a mismatch between the bootloader which set
252 * up simplefb, and the clock definitions in the device tree. Chances are
253 * that there are no adverse effects, and if there are, a clean teardown of
254 * the fb probe will not help us much either. So just complain and carry on,
255 * and hope that the user actually gets a working fb at the end of things.
258 static void simpledrm_device_release_clocks(void *res)
260 struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
263 for (i = 0; i < sdev->clk_count; ++i) {
265 clk_disable_unprepare(sdev->clks[i]);
266 clk_put(sdev->clks[i]);
271 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
273 struct drm_device *dev = &sdev->dev;
274 struct platform_device *pdev = sdev->pdev;
275 struct device_node *of_node = pdev->dev.of_node;
280 if (dev_get_platdata(&pdev->dev) || !of_node)
283 sdev->clk_count = of_clk_get_parent_count(of_node);
284 if (!sdev->clk_count)
287 sdev->clks = drmm_kzalloc(dev, sdev->clk_count * sizeof(sdev->clks[0]),
292 for (i = 0; i < sdev->clk_count; ++i) {
293 clock = of_clk_get(of_node, i);
295 ret = PTR_ERR(clock);
296 if (ret == -EPROBE_DEFER)
298 drm_err(dev, "clock %u not found: %d\n", i, ret);
301 ret = clk_prepare_enable(clock);
303 drm_err(dev, "failed to enable clock %u: %d\n",
308 sdev->clks[i] = clock;
311 return devm_add_action_or_reset(&pdev->dev,
312 simpledrm_device_release_clocks,
319 clk_disable_unprepare(sdev->clks[i]);
320 clk_put(sdev->clks[i]);
326 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
332 #if defined CONFIG_OF && defined CONFIG_REGULATOR
334 #define SUPPLY_SUFFIX "-supply"
337 * Regulator handling code.
339 * Here we handle the num-supplies and vin*-supply properties of our
340 * "simple-framebuffer" dt node. This is necessary so that we can make sure
341 * that any regulators needed by the display hardware that the bootloader
342 * set up for us (and for which it provided a simplefb dt node), stay up,
343 * for the life of the simplefb driver.
345 * When the driver unloads, we cleanly disable, and then release the
348 * We only complain about errors here, no action is taken as the most likely
349 * error can only happen due to a mismatch between the bootloader which set
350 * up simplefb, and the regulator definitions in the device tree. Chances are
351 * that there are no adverse effects, and if there are, a clean teardown of
352 * the fb probe will not help us much either. So just complain and carry on,
353 * and hope that the user actually gets a working fb at the end of things.
356 static void simpledrm_device_release_regulators(void *res)
358 struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
361 for (i = 0; i < sdev->regulator_count; ++i) {
362 if (sdev->regulators[i]) {
363 regulator_disable(sdev->regulators[i]);
364 regulator_put(sdev->regulators[i]);
369 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
371 struct drm_device *dev = &sdev->dev;
372 struct platform_device *pdev = sdev->pdev;
373 struct device_node *of_node = pdev->dev.of_node;
374 struct property *prop;
375 struct regulator *regulator;
377 unsigned int count = 0, i = 0;
380 if (dev_get_platdata(&pdev->dev) || !of_node)
383 /* Count the number of regulator supplies */
384 for_each_property_of_node(of_node, prop) {
385 p = strstr(prop->name, SUPPLY_SUFFIX);
386 if (p && p != prop->name)
393 sdev->regulators = drmm_kzalloc(dev,
394 count * sizeof(sdev->regulators[0]),
396 if (!sdev->regulators)
399 for_each_property_of_node(of_node, prop) {
400 char name[32]; /* 32 is max size of property name */
403 p = strstr(prop->name, SUPPLY_SUFFIX);
404 if (!p || p == prop->name)
406 len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1;
407 strscpy(name, prop->name, min(sizeof(name), len));
409 regulator = regulator_get_optional(&pdev->dev, name);
410 if (IS_ERR(regulator)) {
411 ret = PTR_ERR(regulator);
412 if (ret == -EPROBE_DEFER)
414 drm_err(dev, "regulator %s not found: %d\n",
419 ret = regulator_enable(regulator);
421 drm_err(dev, "failed to enable regulator %u: %d\n",
423 regulator_put(regulator);
427 sdev->regulators[i++] = regulator;
429 sdev->regulator_count = i;
431 return devm_add_action_or_reset(&pdev->dev,
432 simpledrm_device_release_regulators,
438 if (sdev->regulators[i]) {
439 regulator_disable(sdev->regulators[i]);
440 regulator_put(sdev->regulators[i]);
446 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
456 static struct drm_display_mode simpledrm_mode(unsigned int width,
459 struct drm_display_mode mode = { SIMPLEDRM_MODE(width, height) };
461 mode.clock = 60 /* Hz */ * mode.hdisplay * mode.vdisplay;
462 drm_mode_set_name(&mode);
467 static int simpledrm_device_init_fb(struct simpledrm_device *sdev)
469 int width, height, stride;
470 const struct drm_format_info *format;
471 struct drm_format_name_buf buf;
472 struct drm_device *dev = &sdev->dev;
473 struct platform_device *pdev = sdev->pdev;
474 const struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
475 struct device_node *of_node = pdev->dev.of_node;
478 width = simplefb_get_width_pd(dev, pd);
481 height = simplefb_get_height_pd(dev, pd);
484 stride = simplefb_get_stride_pd(dev, pd);
487 format = simplefb_get_format_pd(dev, pd);
489 return PTR_ERR(format);
490 } else if (of_node) {
491 width = simplefb_get_width_of(dev, of_node);
494 height = simplefb_get_height_of(dev, of_node);
497 stride = simplefb_get_stride_of(dev, of_node);
500 format = simplefb_get_format_of(dev, of_node);
502 return PTR_ERR(format);
504 drm_err(dev, "no simplefb configuration found\n");
508 sdev->mode = simpledrm_mode(width, height);
509 sdev->format = format;
510 sdev->pitch = stride;
512 drm_dbg_kms(dev, "display mode={" DRM_MODE_FMT "}\n",
513 DRM_MODE_ARG(&sdev->mode));
515 "framebuffer format=\"%s\", size=%dx%d, stride=%d byte\n",
516 drm_get_format_name(format->format, &buf), width,
526 static int simpledrm_device_init_mm(struct simpledrm_device *sdev)
528 struct drm_device *dev = &sdev->dev;
529 struct platform_device *pdev = sdev->pdev;
530 struct resource *mem;
531 void __iomem *screen_base;
534 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
538 ret = devm_aperture_acquire_from_firmware(dev, mem->start, resource_size(mem));
540 drm_err(dev, "could not acquire memory range %pr: error %d\n",
545 screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
551 sdev->screen_base = screen_base;
561 * Support all formats of simplefb and maybe more; in order
562 * of preference. The display's update function will do any
563 * conversion necessary.
565 * TODO: Add blit helpers for remaining formats and uncomment
568 static const uint32_t simpledrm_default_formats[] = {
572 //DRM_FORMAT_XRGB1555,
573 //DRM_FORMAT_ARGB1555,
575 //DRM_FORMAT_XRGB2101010,
576 //DRM_FORMAT_ARGB2101010,
579 static const uint64_t simpledrm_format_modifiers[] = {
580 DRM_FORMAT_MOD_LINEAR,
581 DRM_FORMAT_MOD_INVALID
584 static int simpledrm_connector_helper_get_modes(struct drm_connector *connector)
586 struct simpledrm_device *sdev = simpledrm_device_of_dev(connector->dev);
587 struct drm_display_mode *mode;
589 mode = drm_mode_duplicate(connector->dev, &sdev->mode);
593 if (mode->name[0] == '\0')
594 drm_mode_set_name(mode);
596 mode->type |= DRM_MODE_TYPE_PREFERRED;
597 drm_mode_probed_add(connector, mode);
600 connector->display_info.width_mm = mode->width_mm;
602 connector->display_info.height_mm = mode->height_mm;
607 static const struct drm_connector_helper_funcs simpledrm_connector_helper_funcs = {
608 .get_modes = simpledrm_connector_helper_get_modes,
611 static const struct drm_connector_funcs simpledrm_connector_funcs = {
612 .reset = drm_atomic_helper_connector_reset,
613 .fill_modes = drm_helper_probe_single_connector_modes,
614 .destroy = drm_connector_cleanup,
615 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
616 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
620 simpledrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
621 const struct drm_display_mode *mode)
623 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
625 if (mode->hdisplay != sdev->mode.hdisplay &&
626 mode->vdisplay != sdev->mode.vdisplay)
627 return MODE_ONE_SIZE;
628 else if (mode->hdisplay != sdev->mode.hdisplay)
629 return MODE_ONE_WIDTH;
630 else if (mode->vdisplay != sdev->mode.vdisplay)
631 return MODE_ONE_HEIGHT;
637 simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
638 struct drm_crtc_state *crtc_state,
639 struct drm_plane_state *plane_state)
641 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
642 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
643 struct drm_framebuffer *fb = plane_state->fb;
644 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
645 struct drm_device *dev = &sdev->dev;
651 if (!drm_dev_enter(dev, &idx))
654 drm_fb_blit_dstclip(sdev->screen_base, sdev->pitch,
655 sdev->format->format, vmap, fb);
660 simpledrm_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
662 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
663 struct drm_device *dev = &sdev->dev;
666 if (!drm_dev_enter(dev, &idx))
669 /* Clear screen to black if disabled */
670 memset_io(sdev->screen_base, 0, sdev->pitch * sdev->mode.vdisplay);
676 simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
677 struct drm_plane_state *old_plane_state)
679 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
680 struct drm_plane_state *plane_state = pipe->plane.state;
681 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
682 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
683 struct drm_framebuffer *fb = plane_state->fb;
684 struct drm_device *dev = &sdev->dev;
685 struct drm_rect clip;
691 if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &clip))
694 if (!drm_dev_enter(dev, &idx))
697 drm_fb_blit_rect_dstclip(sdev->screen_base, sdev->pitch,
698 sdev->format->format, vmap, fb, &clip);
703 static const struct drm_simple_display_pipe_funcs
704 simpledrm_simple_display_pipe_funcs = {
705 .mode_valid = simpledrm_simple_display_pipe_mode_valid,
706 .enable = simpledrm_simple_display_pipe_enable,
707 .disable = simpledrm_simple_display_pipe_disable,
708 .update = simpledrm_simple_display_pipe_update,
709 DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
712 static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
713 .fb_create = drm_gem_fb_create_with_dirty,
714 .atomic_check = drm_atomic_helper_check,
715 .atomic_commit = drm_atomic_helper_commit,
718 static const uint32_t *simpledrm_device_formats(struct simpledrm_device *sdev,
719 size_t *nformats_out)
721 struct drm_device *dev = &sdev->dev;
725 goto out; /* don't rebuild list on recurring calls */
727 /* native format goes first */
728 sdev->formats[0] = sdev->format->format;
731 /* default formats go second */
732 for (i = 0; i < ARRAY_SIZE(simpledrm_default_formats); ++i) {
733 if (simpledrm_default_formats[i] == sdev->format->format)
734 continue; /* native format already went first */
735 sdev->formats[sdev->nformats] = simpledrm_default_formats[i];
740 * TODO: The simpledrm driver converts framebuffers to the native
741 * format when copying them to device memory. If there are more
742 * formats listed than supported by the driver, the native format
743 * is not supported by the conversion helpers. Therefore *only*
744 * support the native format and add a conversion helper ASAP.
746 if (drm_WARN_ONCE(dev, i != sdev->nformats,
747 "format conversion helpers required for %p4cc",
748 &sdev->format->format)) {
753 *nformats_out = sdev->nformats;
754 return sdev->formats;
757 static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
759 struct drm_device *dev = &sdev->dev;
760 struct drm_display_mode *mode = &sdev->mode;
761 struct drm_connector *connector = &sdev->connector;
762 struct drm_simple_display_pipe *pipe = &sdev->pipe;
763 const uint32_t *formats;
767 ret = drmm_mode_config_init(dev);
771 dev->mode_config.min_width = mode->hdisplay;
772 dev->mode_config.max_width = mode->hdisplay;
773 dev->mode_config.min_height = mode->vdisplay;
774 dev->mode_config.max_height = mode->vdisplay;
775 dev->mode_config.prefer_shadow_fbdev = true;
776 dev->mode_config.preferred_depth = sdev->format->cpp[0] * 8;
777 dev->mode_config.funcs = &simpledrm_mode_config_funcs;
779 ret = drm_connector_init(dev, connector, &simpledrm_connector_funcs,
780 DRM_MODE_CONNECTOR_Unknown);
783 drm_connector_helper_add(connector, &simpledrm_connector_helper_funcs);
785 formats = simpledrm_device_formats(sdev, &nformats);
787 ret = drm_simple_display_pipe_init(dev, pipe, &simpledrm_simple_display_pipe_funcs,
788 formats, nformats, simpledrm_format_modifiers,
793 drm_mode_config_reset(dev);
802 static struct simpledrm_device *
803 simpledrm_device_create(struct drm_driver *drv, struct platform_device *pdev)
805 struct simpledrm_device *sdev;
808 sdev = devm_drm_dev_alloc(&pdev->dev, drv, struct simpledrm_device,
811 return ERR_CAST(sdev);
813 platform_set_drvdata(pdev, sdev);
815 ret = simpledrm_device_init_clocks(sdev);
818 ret = simpledrm_device_init_regulators(sdev);
821 ret = simpledrm_device_init_fb(sdev);
824 ret = simpledrm_device_init_mm(sdev);
827 ret = simpledrm_device_init_modeset(sdev);
838 DEFINE_DRM_GEM_FOPS(simpledrm_fops);
840 static struct drm_driver simpledrm_driver = {
841 DRM_GEM_SHMEM_DRIVER_OPS,
845 .major = DRIVER_MAJOR,
846 .minor = DRIVER_MINOR,
847 .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
848 .fops = &simpledrm_fops,
855 static int simpledrm_probe(struct platform_device *pdev)
857 struct simpledrm_device *sdev;
858 struct drm_device *dev;
861 sdev = simpledrm_device_create(&simpledrm_driver, pdev);
863 return PTR_ERR(sdev);
866 ret = drm_dev_register(dev, 0);
870 drm_fbdev_generic_setup(dev, 0);
875 static int simpledrm_remove(struct platform_device *pdev)
877 struct simpledrm_device *sdev = platform_get_drvdata(pdev);
878 struct drm_device *dev = &sdev->dev;
885 static const struct of_device_id simpledrm_of_match_table[] = {
886 { .compatible = "simple-framebuffer", },
889 MODULE_DEVICE_TABLE(of, simpledrm_of_match_table);
891 static struct platform_driver simpledrm_platform_driver = {
893 .name = "simple-framebuffer", /* connect to sysfb */
894 .of_match_table = simpledrm_of_match_table,
896 .probe = simpledrm_probe,
897 .remove = simpledrm_remove,
900 module_platform_driver(simpledrm_platform_driver);
902 MODULE_DESCRIPTION(DRIVER_DESC);
903 MODULE_LICENSE("GPL v2");