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);
77 drm_err(dev, "simplefb: missing framebuffer format\n");
78 return ERR_PTR(-EINVAL);
82 if (!strcmp(format_name, fmt->name))
83 return drm_format_info(fmt->fourcc);
87 drm_err(dev, "simplefb: unknown framebuffer format %s\n",
90 return ERR_PTR(-EINVAL);
94 simplefb_get_width_pd(struct drm_device *dev,
95 const struct simplefb_platform_data *pd)
97 return simplefb_get_validated_int0(dev, "width", pd->width);
101 simplefb_get_height_pd(struct drm_device *dev,
102 const struct simplefb_platform_data *pd)
104 return simplefb_get_validated_int0(dev, "height", pd->height);
108 simplefb_get_stride_pd(struct drm_device *dev,
109 const struct simplefb_platform_data *pd)
111 return simplefb_get_validated_int(dev, "stride", pd->stride);
114 static const struct drm_format_info *
115 simplefb_get_format_pd(struct drm_device *dev,
116 const struct simplefb_platform_data *pd)
118 return simplefb_get_validated_format(dev, pd->format);
122 simplefb_read_u32_of(struct drm_device *dev, struct device_node *of_node,
123 const char *name, u32 *value)
125 int ret = of_property_read_u32(of_node, name, value);
128 drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
134 simplefb_read_string_of(struct drm_device *dev, struct device_node *of_node,
135 const char *name, const char **value)
137 int ret = of_property_read_string(of_node, name, value);
140 drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
146 simplefb_get_width_of(struct drm_device *dev, struct device_node *of_node)
149 int ret = simplefb_read_u32_of(dev, of_node, "width", &width);
153 return simplefb_get_validated_int0(dev, "width", width);
157 simplefb_get_height_of(struct drm_device *dev, struct device_node *of_node)
160 int ret = simplefb_read_u32_of(dev, of_node, "height", &height);
164 return simplefb_get_validated_int0(dev, "height", height);
168 simplefb_get_stride_of(struct drm_device *dev, struct device_node *of_node)
171 int ret = simplefb_read_u32_of(dev, of_node, "stride", &stride);
175 return simplefb_get_validated_int(dev, "stride", stride);
178 static const struct drm_format_info *
179 simplefb_get_format_of(struct drm_device *dev, struct device_node *of_node)
182 int ret = simplefb_read_string_of(dev, of_node, "format", &format);
186 return simplefb_get_validated_format(dev, format);
190 * Simple Framebuffer device
193 struct simpledrm_device {
194 struct drm_device dev;
195 struct platform_device *pdev;
198 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
199 unsigned int clk_count;
203 #if defined CONFIG_OF && defined CONFIG_REGULATOR
204 unsigned int regulator_count;
205 struct regulator **regulators;
208 /* simplefb settings */
209 struct drm_display_mode mode;
210 const struct drm_format_info *format;
213 /* memory management */
214 struct resource *mem;
215 void __iomem *screen_base;
220 struct drm_connector connector;
221 struct drm_simple_display_pipe pipe;
224 static struct simpledrm_device *simpledrm_device_of_dev(struct drm_device *dev)
226 return container_of(dev, struct simpledrm_device, dev);
233 #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
235 * Clock handling code.
237 * Here we handle the clocks property of our "simple-framebuffer" dt node.
238 * This is necessary so that we can make sure that any clocks needed by
239 * the display engine that the bootloader set up for us (and for which it
240 * provided a simplefb dt node), stay up, for the life of the simplefb
243 * When the driver unloads, we cleanly disable, and then release the clocks.
245 * We only complain about errors here, no action is taken as the most likely
246 * error can only happen due to a mismatch between the bootloader which set
247 * up simplefb, and the clock definitions in the device tree. Chances are
248 * that there are no adverse effects, and if there are, a clean teardown of
249 * the fb probe will not help us much either. So just complain and carry on,
250 * and hope that the user actually gets a working fb at the end of things.
253 static void simpledrm_device_release_clocks(void *res)
255 struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
258 for (i = 0; i < sdev->clk_count; ++i) {
260 clk_disable_unprepare(sdev->clks[i]);
261 clk_put(sdev->clks[i]);
266 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
268 struct drm_device *dev = &sdev->dev;
269 struct platform_device *pdev = sdev->pdev;
270 struct device_node *of_node = pdev->dev.of_node;
275 if (dev_get_platdata(&pdev->dev) || !of_node)
278 sdev->clk_count = of_clk_get_parent_count(of_node);
279 if (!sdev->clk_count)
282 sdev->clks = drmm_kzalloc(dev, sdev->clk_count * sizeof(sdev->clks[0]),
287 for (i = 0; i < sdev->clk_count; ++i) {
288 clock = of_clk_get(of_node, i);
290 ret = PTR_ERR(clock);
291 if (ret == -EPROBE_DEFER)
293 drm_err(dev, "clock %u not found: %d\n", i, ret);
296 ret = clk_prepare_enable(clock);
298 drm_err(dev, "failed to enable clock %u: %d\n",
302 sdev->clks[i] = clock;
305 return devm_add_action_or_reset(&pdev->dev,
306 simpledrm_device_release_clocks,
313 clk_disable_unprepare(sdev->clks[i]);
314 clk_put(sdev->clks[i]);
320 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
326 #if defined CONFIG_OF && defined CONFIG_REGULATOR
328 #define SUPPLY_SUFFIX "-supply"
331 * Regulator handling code.
333 * Here we handle the num-supplies and vin*-supply properties of our
334 * "simple-framebuffer" dt node. This is necessary so that we can make sure
335 * that any regulators needed by the display hardware that the bootloader
336 * set up for us (and for which it provided a simplefb dt node), stay up,
337 * for the life of the simplefb driver.
339 * When the driver unloads, we cleanly disable, and then release the
342 * We only complain about errors here, no action is taken as the most likely
343 * error can only happen due to a mismatch between the bootloader which set
344 * up simplefb, and the regulator definitions in the device tree. Chances are
345 * that there are no adverse effects, and if there are, a clean teardown of
346 * the fb probe will not help us much either. So just complain and carry on,
347 * and hope that the user actually gets a working fb at the end of things.
350 static void simpledrm_device_release_regulators(void *res)
352 struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
355 for (i = 0; i < sdev->regulator_count; ++i) {
356 if (sdev->regulators[i]) {
357 regulator_disable(sdev->regulators[i]);
358 regulator_put(sdev->regulators[i]);
363 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
365 struct drm_device *dev = &sdev->dev;
366 struct platform_device *pdev = sdev->pdev;
367 struct device_node *of_node = pdev->dev.of_node;
368 struct property *prop;
369 struct regulator *regulator;
371 unsigned int count = 0, i = 0;
374 if (dev_get_platdata(&pdev->dev) || !of_node)
377 /* Count the number of regulator supplies */
378 for_each_property_of_node(of_node, prop) {
379 p = strstr(prop->name, SUPPLY_SUFFIX);
380 if (p && p != prop->name)
387 sdev->regulators = drmm_kzalloc(dev,
388 count * sizeof(sdev->regulators[0]),
390 if (!sdev->regulators)
393 for_each_property_of_node(of_node, prop) {
394 char name[32]; /* 32 is max size of property name */
397 p = strstr(prop->name, SUPPLY_SUFFIX);
398 if (!p || p == prop->name)
400 len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1;
401 strscpy(name, prop->name, min(sizeof(name), len));
403 regulator = regulator_get_optional(&pdev->dev, name);
404 if (IS_ERR(regulator)) {
405 ret = PTR_ERR(regulator);
406 if (ret == -EPROBE_DEFER)
408 drm_err(dev, "regulator %s not found: %d\n",
413 ret = regulator_enable(regulator);
415 drm_err(dev, "failed to enable regulator %u: %d\n",
417 regulator_put(regulator);
420 sdev->regulators[i++] = regulator;
422 sdev->regulator_count = i;
424 return devm_add_action_or_reset(&pdev->dev,
425 simpledrm_device_release_regulators,
431 if (sdev->regulators[i]) {
432 regulator_disable(sdev->regulators[i]);
433 regulator_put(sdev->regulators[i]);
439 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
449 static struct drm_display_mode simpledrm_mode(unsigned int width,
452 struct drm_display_mode mode = { SIMPLEDRM_MODE(width, height) };
454 mode.clock = 60 /* Hz */ * mode.hdisplay * mode.vdisplay;
455 drm_mode_set_name(&mode);
460 static int simpledrm_device_init_fb(struct simpledrm_device *sdev)
462 int width, height, stride;
463 const struct drm_format_info *format;
464 struct drm_format_name_buf buf;
465 struct drm_device *dev = &sdev->dev;
466 struct platform_device *pdev = sdev->pdev;
467 const struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
468 struct device_node *of_node = pdev->dev.of_node;
471 width = simplefb_get_width_pd(dev, pd);
474 height = simplefb_get_height_pd(dev, pd);
477 stride = simplefb_get_stride_pd(dev, pd);
480 format = simplefb_get_format_pd(dev, pd);
482 return PTR_ERR(format);
483 } else if (of_node) {
484 width = simplefb_get_width_of(dev, of_node);
487 height = simplefb_get_height_of(dev, of_node);
490 stride = simplefb_get_stride_of(dev, of_node);
493 format = simplefb_get_format_of(dev, of_node);
495 return PTR_ERR(format);
497 drm_err(dev, "no simplefb configuration found\n");
501 sdev->mode = simpledrm_mode(width, height);
502 sdev->format = format;
503 sdev->pitch = stride;
505 drm_dbg_kms(dev, "display mode={" DRM_MODE_FMT "}\n",
506 DRM_MODE_ARG(&sdev->mode));
508 "framebuffer format=\"%s\", size=%dx%d, stride=%d byte\n",
509 drm_get_format_name(format->format, &buf), width,
519 static int simpledrm_device_init_mm(struct simpledrm_device *sdev)
521 struct drm_device *dev = &sdev->dev;
522 struct platform_device *pdev = sdev->pdev;
523 struct resource *mem;
524 void __iomem *screen_base;
527 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
531 ret = devm_aperture_acquire_from_firmware(dev, mem->start, resource_size(mem));
533 drm_err(dev, "could not acquire memory range %pr: error %d\n",
538 screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
544 sdev->screen_base = screen_base;
554 * Support all formats of simplefb and maybe more; in order
555 * of preference. The display's update function will do any
556 * conversion necessary.
558 * TODO: Add blit helpers for remaining formats and uncomment
561 static const uint32_t simpledrm_default_formats[] = {
565 //DRM_FORMAT_XRGB1555,
566 //DRM_FORMAT_ARGB1555,
568 //DRM_FORMAT_XRGB2101010,
569 //DRM_FORMAT_ARGB2101010,
572 static const uint64_t simpledrm_format_modifiers[] = {
573 DRM_FORMAT_MOD_LINEAR,
574 DRM_FORMAT_MOD_INVALID
577 static int simpledrm_connector_helper_get_modes(struct drm_connector *connector)
579 struct simpledrm_device *sdev = simpledrm_device_of_dev(connector->dev);
580 struct drm_display_mode *mode;
582 mode = drm_mode_duplicate(connector->dev, &sdev->mode);
586 if (mode->name[0] == '\0')
587 drm_mode_set_name(mode);
589 mode->type |= DRM_MODE_TYPE_PREFERRED;
590 drm_mode_probed_add(connector, mode);
593 connector->display_info.width_mm = mode->width_mm;
595 connector->display_info.height_mm = mode->height_mm;
600 static const struct drm_connector_helper_funcs simpledrm_connector_helper_funcs = {
601 .get_modes = simpledrm_connector_helper_get_modes,
604 static const struct drm_connector_funcs simpledrm_connector_funcs = {
605 .reset = drm_atomic_helper_connector_reset,
606 .fill_modes = drm_helper_probe_single_connector_modes,
607 .destroy = drm_connector_cleanup,
608 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
609 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
613 simpledrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
614 const struct drm_display_mode *mode)
616 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
618 if (mode->hdisplay != sdev->mode.hdisplay &&
619 mode->vdisplay != sdev->mode.vdisplay)
620 return MODE_ONE_SIZE;
621 else if (mode->hdisplay != sdev->mode.hdisplay)
622 return MODE_ONE_WIDTH;
623 else if (mode->vdisplay != sdev->mode.vdisplay)
624 return MODE_ONE_HEIGHT;
630 simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
631 struct drm_crtc_state *crtc_state,
632 struct drm_plane_state *plane_state)
634 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
635 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
636 struct drm_framebuffer *fb = plane_state->fb;
637 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
638 struct drm_device *dev = &sdev->dev;
644 if (!drm_dev_enter(dev, &idx))
647 drm_fb_blit_dstclip(sdev->screen_base, sdev->pitch,
648 sdev->format->format, vmap, fb);
653 simpledrm_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
655 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
656 struct drm_device *dev = &sdev->dev;
659 if (!drm_dev_enter(dev, &idx))
662 /* Clear screen to black if disabled */
663 memset_io(sdev->screen_base, 0, sdev->pitch * sdev->mode.vdisplay);
669 simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
670 struct drm_plane_state *old_plane_state)
672 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
673 struct drm_plane_state *plane_state = pipe->plane.state;
674 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
675 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
676 struct drm_framebuffer *fb = plane_state->fb;
677 struct drm_device *dev = &sdev->dev;
678 struct drm_rect clip;
684 if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &clip))
687 if (!drm_dev_enter(dev, &idx))
690 drm_fb_blit_rect_dstclip(sdev->screen_base, sdev->pitch,
691 sdev->format->format, vmap, fb, &clip);
696 static const struct drm_simple_display_pipe_funcs
697 simpledrm_simple_display_pipe_funcs = {
698 .mode_valid = simpledrm_simple_display_pipe_mode_valid,
699 .enable = simpledrm_simple_display_pipe_enable,
700 .disable = simpledrm_simple_display_pipe_disable,
701 .update = simpledrm_simple_display_pipe_update,
702 DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
705 static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
706 .fb_create = drm_gem_fb_create_with_dirty,
707 .atomic_check = drm_atomic_helper_check,
708 .atomic_commit = drm_atomic_helper_commit,
711 static const uint32_t *simpledrm_device_formats(struct simpledrm_device *sdev,
712 size_t *nformats_out)
714 struct drm_device *dev = &sdev->dev;
718 goto out; /* don't rebuild list on recurring calls */
720 /* native format goes first */
721 sdev->formats[0] = sdev->format->format;
724 /* default formats go second */
725 for (i = 0; i < ARRAY_SIZE(simpledrm_default_formats); ++i) {
726 if (simpledrm_default_formats[i] == sdev->format->format)
727 continue; /* native format already went first */
728 sdev->formats[sdev->nformats] = simpledrm_default_formats[i];
733 * TODO: The simpledrm driver converts framebuffers to the native
734 * format when copying them to device memory. If there are more
735 * formats listed than supported by the driver, the native format
736 * is not supported by the conversion helpers. Therefore *only*
737 * support the native format and add a conversion helper ASAP.
739 if (drm_WARN_ONCE(dev, i != sdev->nformats,
740 "format conversion helpers required for %p4cc",
741 &sdev->format->format)) {
746 *nformats_out = sdev->nformats;
747 return sdev->formats;
750 static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
752 struct drm_device *dev = &sdev->dev;
753 struct drm_display_mode *mode = &sdev->mode;
754 struct drm_connector *connector = &sdev->connector;
755 struct drm_simple_display_pipe *pipe = &sdev->pipe;
756 const uint32_t *formats;
760 ret = drmm_mode_config_init(dev);
764 dev->mode_config.min_width = mode->hdisplay;
765 dev->mode_config.max_width = mode->hdisplay;
766 dev->mode_config.min_height = mode->vdisplay;
767 dev->mode_config.max_height = mode->vdisplay;
768 dev->mode_config.prefer_shadow_fbdev = true;
769 dev->mode_config.preferred_depth = sdev->format->cpp[0] * 8;
770 dev->mode_config.funcs = &simpledrm_mode_config_funcs;
772 ret = drm_connector_init(dev, connector, &simpledrm_connector_funcs,
773 DRM_MODE_CONNECTOR_Unknown);
776 drm_connector_helper_add(connector, &simpledrm_connector_helper_funcs);
778 formats = simpledrm_device_formats(sdev, &nformats);
780 ret = drm_simple_display_pipe_init(dev, pipe, &simpledrm_simple_display_pipe_funcs,
781 formats, nformats, simpledrm_format_modifiers,
786 drm_mode_config_reset(dev);
795 static struct simpledrm_device *
796 simpledrm_device_create(struct drm_driver *drv, struct platform_device *pdev)
798 struct simpledrm_device *sdev;
801 sdev = devm_drm_dev_alloc(&pdev->dev, drv, struct simpledrm_device,
804 return ERR_CAST(sdev);
806 platform_set_drvdata(pdev, sdev);
808 ret = simpledrm_device_init_clocks(sdev);
811 ret = simpledrm_device_init_regulators(sdev);
814 ret = simpledrm_device_init_fb(sdev);
817 ret = simpledrm_device_init_mm(sdev);
820 ret = simpledrm_device_init_modeset(sdev);
831 DEFINE_DRM_GEM_FOPS(simpledrm_fops);
833 static struct drm_driver simpledrm_driver = {
834 DRM_GEM_SHMEM_DRIVER_OPS,
838 .major = DRIVER_MAJOR,
839 .minor = DRIVER_MINOR,
840 .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
841 .fops = &simpledrm_fops,
848 static int simpledrm_probe(struct platform_device *pdev)
850 struct simpledrm_device *sdev;
851 struct drm_device *dev;
854 sdev = simpledrm_device_create(&simpledrm_driver, pdev);
856 return PTR_ERR(sdev);
859 ret = drm_dev_register(dev, 0);
863 drm_fbdev_generic_setup(dev, 0);
868 static int simpledrm_remove(struct platform_device *pdev)
870 struct simpledrm_device *sdev = platform_get_drvdata(pdev);
871 struct drm_device *dev = &sdev->dev;
878 static const struct of_device_id simpledrm_of_match_table[] = {
879 { .compatible = "simple-framebuffer", },
882 MODULE_DEVICE_TABLE(of, simpledrm_of_match_table);
884 static struct platform_driver simpledrm_platform_driver = {
886 .name = "simple-framebuffer", /* connect to sysfb */
887 .of_match_table = simpledrm_of_match_table,
889 .probe = simpledrm_probe,
890 .remove = simpledrm_remove,
893 module_platform_driver(simpledrm_platform_driver);
895 MODULE_DESCRIPTION(DRIVER_DESC);
896 MODULE_LICENSE("GPL v2");