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",
303 sdev->clks[i] = clock;
306 return devm_add_action_or_reset(&pdev->dev,
307 simpledrm_device_release_clocks,
314 clk_disable_unprepare(sdev->clks[i]);
315 clk_put(sdev->clks[i]);
321 static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
327 #if defined CONFIG_OF && defined CONFIG_REGULATOR
329 #define SUPPLY_SUFFIX "-supply"
332 * Regulator handling code.
334 * Here we handle the num-supplies and vin*-supply properties of our
335 * "simple-framebuffer" dt node. This is necessary so that we can make sure
336 * that any regulators needed by the display hardware that the bootloader
337 * set up for us (and for which it provided a simplefb dt node), stay up,
338 * for the life of the simplefb driver.
340 * When the driver unloads, we cleanly disable, and then release the
343 * We only complain about errors here, no action is taken as the most likely
344 * error can only happen due to a mismatch between the bootloader which set
345 * up simplefb, and the regulator definitions in the device tree. Chances are
346 * that there are no adverse effects, and if there are, a clean teardown of
347 * the fb probe will not help us much either. So just complain and carry on,
348 * and hope that the user actually gets a working fb at the end of things.
351 static void simpledrm_device_release_regulators(void *res)
353 struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
356 for (i = 0; i < sdev->regulator_count; ++i) {
357 if (sdev->regulators[i]) {
358 regulator_disable(sdev->regulators[i]);
359 regulator_put(sdev->regulators[i]);
364 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
366 struct drm_device *dev = &sdev->dev;
367 struct platform_device *pdev = sdev->pdev;
368 struct device_node *of_node = pdev->dev.of_node;
369 struct property *prop;
370 struct regulator *regulator;
372 unsigned int count = 0, i = 0;
375 if (dev_get_platdata(&pdev->dev) || !of_node)
378 /* Count the number of regulator supplies */
379 for_each_property_of_node(of_node, prop) {
380 p = strstr(prop->name, SUPPLY_SUFFIX);
381 if (p && p != prop->name)
388 sdev->regulators = drmm_kzalloc(dev,
389 count * sizeof(sdev->regulators[0]),
391 if (!sdev->regulators)
394 for_each_property_of_node(of_node, prop) {
395 char name[32]; /* 32 is max size of property name */
398 p = strstr(prop->name, SUPPLY_SUFFIX);
399 if (!p || p == prop->name)
401 len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1;
402 strscpy(name, prop->name, min(sizeof(name), len));
404 regulator = regulator_get_optional(&pdev->dev, name);
405 if (IS_ERR(regulator)) {
406 ret = PTR_ERR(regulator);
407 if (ret == -EPROBE_DEFER)
409 drm_err(dev, "regulator %s not found: %d\n",
414 ret = regulator_enable(regulator);
416 drm_err(dev, "failed to enable regulator %u: %d\n",
418 regulator_put(regulator);
422 sdev->regulators[i++] = regulator;
424 sdev->regulator_count = i;
426 return devm_add_action_or_reset(&pdev->dev,
427 simpledrm_device_release_regulators,
433 if (sdev->regulators[i]) {
434 regulator_disable(sdev->regulators[i]);
435 regulator_put(sdev->regulators[i]);
441 static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
451 static struct drm_display_mode simpledrm_mode(unsigned int width,
454 struct drm_display_mode mode = { SIMPLEDRM_MODE(width, height) };
456 mode.clock = 60 /* Hz */ * mode.hdisplay * mode.vdisplay;
457 drm_mode_set_name(&mode);
462 static int simpledrm_device_init_fb(struct simpledrm_device *sdev)
464 int width, height, stride;
465 const struct drm_format_info *format;
466 struct drm_format_name_buf buf;
467 struct drm_device *dev = &sdev->dev;
468 struct platform_device *pdev = sdev->pdev;
469 const struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
470 struct device_node *of_node = pdev->dev.of_node;
473 width = simplefb_get_width_pd(dev, pd);
476 height = simplefb_get_height_pd(dev, pd);
479 stride = simplefb_get_stride_pd(dev, pd);
482 format = simplefb_get_format_pd(dev, pd);
484 return PTR_ERR(format);
485 } else if (of_node) {
486 width = simplefb_get_width_of(dev, of_node);
489 height = simplefb_get_height_of(dev, of_node);
492 stride = simplefb_get_stride_of(dev, of_node);
495 format = simplefb_get_format_of(dev, of_node);
497 return PTR_ERR(format);
499 drm_err(dev, "no simplefb configuration found\n");
503 sdev->mode = simpledrm_mode(width, height);
504 sdev->format = format;
505 sdev->pitch = stride;
507 drm_dbg_kms(dev, "display mode={" DRM_MODE_FMT "}\n",
508 DRM_MODE_ARG(&sdev->mode));
510 "framebuffer format=\"%s\", size=%dx%d, stride=%d byte\n",
511 drm_get_format_name(format->format, &buf), width,
521 static int simpledrm_device_init_mm(struct simpledrm_device *sdev)
523 struct drm_device *dev = &sdev->dev;
524 struct platform_device *pdev = sdev->pdev;
525 struct resource *mem;
526 void __iomem *screen_base;
529 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
533 ret = devm_aperture_acquire_from_firmware(dev, mem->start, resource_size(mem));
535 drm_err(dev, "could not acquire memory range %pr: error %d\n",
540 screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
546 sdev->screen_base = screen_base;
556 * Support all formats of simplefb and maybe more; in order
557 * of preference. The display's update function will do any
558 * conversion necessary.
560 * TODO: Add blit helpers for remaining formats and uncomment
563 static const uint32_t simpledrm_default_formats[] = {
567 //DRM_FORMAT_XRGB1555,
568 //DRM_FORMAT_ARGB1555,
570 //DRM_FORMAT_XRGB2101010,
571 //DRM_FORMAT_ARGB2101010,
574 static const uint64_t simpledrm_format_modifiers[] = {
575 DRM_FORMAT_MOD_LINEAR,
576 DRM_FORMAT_MOD_INVALID
579 static int simpledrm_connector_helper_get_modes(struct drm_connector *connector)
581 struct simpledrm_device *sdev = simpledrm_device_of_dev(connector->dev);
582 struct drm_display_mode *mode;
584 mode = drm_mode_duplicate(connector->dev, &sdev->mode);
588 if (mode->name[0] == '\0')
589 drm_mode_set_name(mode);
591 mode->type |= DRM_MODE_TYPE_PREFERRED;
592 drm_mode_probed_add(connector, mode);
595 connector->display_info.width_mm = mode->width_mm;
597 connector->display_info.height_mm = mode->height_mm;
602 static const struct drm_connector_helper_funcs simpledrm_connector_helper_funcs = {
603 .get_modes = simpledrm_connector_helper_get_modes,
606 static const struct drm_connector_funcs simpledrm_connector_funcs = {
607 .reset = drm_atomic_helper_connector_reset,
608 .fill_modes = drm_helper_probe_single_connector_modes,
609 .destroy = drm_connector_cleanup,
610 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
611 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
615 simpledrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
616 const struct drm_display_mode *mode)
618 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
620 if (mode->hdisplay != sdev->mode.hdisplay &&
621 mode->vdisplay != sdev->mode.vdisplay)
622 return MODE_ONE_SIZE;
623 else if (mode->hdisplay != sdev->mode.hdisplay)
624 return MODE_ONE_WIDTH;
625 else if (mode->vdisplay != sdev->mode.vdisplay)
626 return MODE_ONE_HEIGHT;
632 simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
633 struct drm_crtc_state *crtc_state,
634 struct drm_plane_state *plane_state)
636 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
637 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
638 struct drm_framebuffer *fb = plane_state->fb;
639 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
640 struct drm_device *dev = &sdev->dev;
646 if (!drm_dev_enter(dev, &idx))
649 drm_fb_blit_dstclip(sdev->screen_base, sdev->pitch,
650 sdev->format->format, vmap, fb);
655 simpledrm_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
657 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
658 struct drm_device *dev = &sdev->dev;
661 if (!drm_dev_enter(dev, &idx))
664 /* Clear screen to black if disabled */
665 memset_io(sdev->screen_base, 0, sdev->pitch * sdev->mode.vdisplay);
671 simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
672 struct drm_plane_state *old_plane_state)
674 struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
675 struct drm_plane_state *plane_state = pipe->plane.state;
676 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
677 void *vmap = shadow_plane_state->map[0].vaddr; /* TODO: Use mapping abstraction properly */
678 struct drm_framebuffer *fb = plane_state->fb;
679 struct drm_device *dev = &sdev->dev;
680 struct drm_rect clip;
686 if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &clip))
689 if (!drm_dev_enter(dev, &idx))
692 drm_fb_blit_rect_dstclip(sdev->screen_base, sdev->pitch,
693 sdev->format->format, vmap, fb, &clip);
698 static const struct drm_simple_display_pipe_funcs
699 simpledrm_simple_display_pipe_funcs = {
700 .mode_valid = simpledrm_simple_display_pipe_mode_valid,
701 .enable = simpledrm_simple_display_pipe_enable,
702 .disable = simpledrm_simple_display_pipe_disable,
703 .update = simpledrm_simple_display_pipe_update,
704 DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
707 static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
708 .fb_create = drm_gem_fb_create_with_dirty,
709 .atomic_check = drm_atomic_helper_check,
710 .atomic_commit = drm_atomic_helper_commit,
713 static const uint32_t *simpledrm_device_formats(struct simpledrm_device *sdev,
714 size_t *nformats_out)
716 struct drm_device *dev = &sdev->dev;
720 goto out; /* don't rebuild list on recurring calls */
722 /* native format goes first */
723 sdev->formats[0] = sdev->format->format;
726 /* default formats go second */
727 for (i = 0; i < ARRAY_SIZE(simpledrm_default_formats); ++i) {
728 if (simpledrm_default_formats[i] == sdev->format->format)
729 continue; /* native format already went first */
730 sdev->formats[sdev->nformats] = simpledrm_default_formats[i];
735 * TODO: The simpledrm driver converts framebuffers to the native
736 * format when copying them to device memory. If there are more
737 * formats listed than supported by the driver, the native format
738 * is not supported by the conversion helpers. Therefore *only*
739 * support the native format and add a conversion helper ASAP.
741 if (drm_WARN_ONCE(dev, i != sdev->nformats,
742 "format conversion helpers required for %p4cc",
743 &sdev->format->format)) {
748 *nformats_out = sdev->nformats;
749 return sdev->formats;
752 static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
754 struct drm_device *dev = &sdev->dev;
755 struct drm_display_mode *mode = &sdev->mode;
756 struct drm_connector *connector = &sdev->connector;
757 struct drm_simple_display_pipe *pipe = &sdev->pipe;
758 const uint32_t *formats;
762 ret = drmm_mode_config_init(dev);
766 dev->mode_config.min_width = mode->hdisplay;
767 dev->mode_config.max_width = mode->hdisplay;
768 dev->mode_config.min_height = mode->vdisplay;
769 dev->mode_config.max_height = mode->vdisplay;
770 dev->mode_config.prefer_shadow_fbdev = true;
771 dev->mode_config.preferred_depth = sdev->format->cpp[0] * 8;
772 dev->mode_config.funcs = &simpledrm_mode_config_funcs;
774 ret = drm_connector_init(dev, connector, &simpledrm_connector_funcs,
775 DRM_MODE_CONNECTOR_Unknown);
778 drm_connector_helper_add(connector, &simpledrm_connector_helper_funcs);
780 formats = simpledrm_device_formats(sdev, &nformats);
782 ret = drm_simple_display_pipe_init(dev, pipe, &simpledrm_simple_display_pipe_funcs,
783 formats, nformats, simpledrm_format_modifiers,
788 drm_mode_config_reset(dev);
797 static struct simpledrm_device *
798 simpledrm_device_create(struct drm_driver *drv, struct platform_device *pdev)
800 struct simpledrm_device *sdev;
803 sdev = devm_drm_dev_alloc(&pdev->dev, drv, struct simpledrm_device,
806 return ERR_CAST(sdev);
808 platform_set_drvdata(pdev, sdev);
810 ret = simpledrm_device_init_clocks(sdev);
813 ret = simpledrm_device_init_regulators(sdev);
816 ret = simpledrm_device_init_fb(sdev);
819 ret = simpledrm_device_init_mm(sdev);
822 ret = simpledrm_device_init_modeset(sdev);
833 DEFINE_DRM_GEM_FOPS(simpledrm_fops);
835 static struct drm_driver simpledrm_driver = {
836 DRM_GEM_SHMEM_DRIVER_OPS,
840 .major = DRIVER_MAJOR,
841 .minor = DRIVER_MINOR,
842 .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
843 .fops = &simpledrm_fops,
850 static int simpledrm_probe(struct platform_device *pdev)
852 struct simpledrm_device *sdev;
853 struct drm_device *dev;
856 sdev = simpledrm_device_create(&simpledrm_driver, pdev);
858 return PTR_ERR(sdev);
861 ret = drm_dev_register(dev, 0);
865 drm_fbdev_generic_setup(dev, 0);
870 static int simpledrm_remove(struct platform_device *pdev)
872 struct simpledrm_device *sdev = platform_get_drvdata(pdev);
873 struct drm_device *dev = &sdev->dev;
880 static const struct of_device_id simpledrm_of_match_table[] = {
881 { .compatible = "simple-framebuffer", },
884 MODULE_DEVICE_TABLE(of, simpledrm_of_match_table);
886 static struct platform_driver simpledrm_platform_driver = {
888 .name = "simple-framebuffer", /* connect to sysfb */
889 .of_match_table = simpledrm_of_match_table,
891 .probe = simpledrm_probe,
892 .remove = simpledrm_remove,
895 module_platform_driver(simpledrm_platform_driver);
897 MODULE_DESCRIPTION(DRIVER_DESC);
898 MODULE_LICENSE("GPL v2");