1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Texas Instruments
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include <linux/pinctrl/pinmux.h>
8 #include <linux/pinctrl/consumer.h>
9 #include <linux/backlight.h>
10 #include <linux/gpio/consumer.h>
11 #include <video/display_timing.h>
12 #include <video/of_display_timing.h>
13 #include <video/videomode.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_probe_helper.h>
16 
17 #include "tilcdc_drv.h"
18 #include "tilcdc_panel.h"
19 
20 struct panel_module {
21 	struct tilcdc_module base;
22 	struct tilcdc_panel_info *info;
23 	struct display_timings *timings;
24 	struct backlight_device *backlight;
25 	struct gpio_desc *enable_gpio;
26 };
27 #define to_panel_module(x) container_of(x, struct panel_module, base)
28 
29 
30 /*
31  * Encoder:
32  */
33 
34 struct panel_encoder {
35 	struct drm_encoder base;
36 	struct panel_module *mod;
37 };
38 #define to_panel_encoder(x) container_of(x, struct panel_encoder, base)
39 
40 static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
41 {
42 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
43 	struct backlight_device *backlight = panel_encoder->mod->backlight;
44 	struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;
45 
46 	if (backlight) {
47 		backlight->props.power = mode == DRM_MODE_DPMS_ON ?
48 					 FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
49 		backlight_update_status(backlight);
50 	}
51 
52 	if (gpio)
53 		gpiod_set_value_cansleep(gpio,
54 					 mode == DRM_MODE_DPMS_ON ? 1 : 0);
55 }
56 
57 static void panel_encoder_prepare(struct drm_encoder *encoder)
58 {
59 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
60 }
61 
62 static void panel_encoder_commit(struct drm_encoder *encoder)
63 {
64 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
65 }
66 
67 static void panel_encoder_mode_set(struct drm_encoder *encoder,
68 		struct drm_display_mode *mode,
69 		struct drm_display_mode *adjusted_mode)
70 {
71 	/* nothing needed */
72 }
73 
74 static const struct drm_encoder_funcs panel_encoder_funcs = {
75 		.destroy        = drm_encoder_cleanup,
76 };
77 
78 static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
79 		.dpms           = panel_encoder_dpms,
80 		.prepare        = panel_encoder_prepare,
81 		.commit         = panel_encoder_commit,
82 		.mode_set       = panel_encoder_mode_set,
83 };
84 
85 static struct drm_encoder *panel_encoder_create(struct drm_device *dev,
86 		struct panel_module *mod)
87 {
88 	struct panel_encoder *panel_encoder;
89 	struct drm_encoder *encoder;
90 	int ret;
91 
92 	panel_encoder = devm_kzalloc(dev->dev, sizeof(*panel_encoder),
93 				     GFP_KERNEL);
94 	if (!panel_encoder)
95 		return NULL;
96 
97 	panel_encoder->mod = mod;
98 
99 	encoder = &panel_encoder->base;
100 	encoder->possible_crtcs = 1;
101 
102 	ret = drm_encoder_init(dev, encoder, &panel_encoder_funcs,
103 			DRM_MODE_ENCODER_LVDS, NULL);
104 	if (ret < 0)
105 		goto fail;
106 
107 	drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);
108 
109 	return encoder;
110 
111 fail:
112 	drm_encoder_cleanup(encoder);
113 	return NULL;
114 }
115 
116 /*
117  * Connector:
118  */
119 
120 struct panel_connector {
121 	struct drm_connector base;
122 
123 	struct drm_encoder *encoder;  /* our connected encoder */
124 	struct panel_module *mod;
125 };
126 #define to_panel_connector(x) container_of(x, struct panel_connector, base)
127 
128 
129 static void panel_connector_destroy(struct drm_connector *connector)
130 {
131 	drm_connector_unregister(connector);
132 	drm_connector_cleanup(connector);
133 }
134 
135 static int panel_connector_get_modes(struct drm_connector *connector)
136 {
137 	struct drm_device *dev = connector->dev;
138 	struct panel_connector *panel_connector = to_panel_connector(connector);
139 	struct display_timings *timings = panel_connector->mod->timings;
140 	int i;
141 
142 	for (i = 0; i < timings->num_timings; i++) {
143 		struct drm_display_mode *mode = drm_mode_create(dev);
144 		struct videomode vm;
145 
146 		if (videomode_from_timings(timings, &vm, i))
147 			break;
148 
149 		drm_display_mode_from_videomode(&vm, mode);
150 
151 		mode->type = DRM_MODE_TYPE_DRIVER;
152 
153 		if (timings->native_mode == i)
154 			mode->type |= DRM_MODE_TYPE_PREFERRED;
155 
156 		drm_mode_set_name(mode);
157 		drm_mode_probed_add(connector, mode);
158 	}
159 
160 	return i;
161 }
162 
163 static int panel_connector_mode_valid(struct drm_connector *connector,
164 		  struct drm_display_mode *mode)
165 {
166 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
167 	/* our only constraints are what the crtc can generate: */
168 	return tilcdc_crtc_mode_valid(priv->crtc, mode);
169 }
170 
171 static struct drm_encoder *panel_connector_best_encoder(
172 		struct drm_connector *connector)
173 {
174 	struct panel_connector *panel_connector = to_panel_connector(connector);
175 	return panel_connector->encoder;
176 }
177 
178 static const struct drm_connector_funcs panel_connector_funcs = {
179 	.destroy            = panel_connector_destroy,
180 	.fill_modes         = drm_helper_probe_single_connector_modes,
181 	.reset              = drm_atomic_helper_connector_reset,
182 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
183 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
184 };
185 
186 static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
187 	.get_modes          = panel_connector_get_modes,
188 	.mode_valid         = panel_connector_mode_valid,
189 	.best_encoder       = panel_connector_best_encoder,
190 };
191 
192 static struct drm_connector *panel_connector_create(struct drm_device *dev,
193 		struct panel_module *mod, struct drm_encoder *encoder)
194 {
195 	struct panel_connector *panel_connector;
196 	struct drm_connector *connector;
197 	int ret;
198 
199 	panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
200 				       GFP_KERNEL);
201 	if (!panel_connector)
202 		return NULL;
203 
204 	panel_connector->encoder = encoder;
205 	panel_connector->mod = mod;
206 
207 	connector = &panel_connector->base;
208 
209 	drm_connector_init(dev, connector, &panel_connector_funcs,
210 			DRM_MODE_CONNECTOR_LVDS);
211 	drm_connector_helper_add(connector, &panel_connector_helper_funcs);
212 
213 	connector->interlace_allowed = 0;
214 	connector->doublescan_allowed = 0;
215 
216 	ret = drm_connector_attach_encoder(connector, encoder);
217 	if (ret)
218 		goto fail;
219 
220 	return connector;
221 
222 fail:
223 	panel_connector_destroy(connector);
224 	return NULL;
225 }
226 
227 /*
228  * Module:
229  */
230 
231 static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
232 {
233 	struct panel_module *panel_mod = to_panel_module(mod);
234 	struct tilcdc_drm_private *priv = dev->dev_private;
235 	struct drm_encoder *encoder;
236 	struct drm_connector *connector;
237 
238 	encoder = panel_encoder_create(dev, panel_mod);
239 	if (!encoder)
240 		return -ENOMEM;
241 
242 	connector = panel_connector_create(dev, panel_mod, encoder);
243 	if (!connector)
244 		return -ENOMEM;
245 
246 	priv->encoders[priv->num_encoders++] = encoder;
247 	priv->connectors[priv->num_connectors++] = connector;
248 
249 	tilcdc_crtc_set_panel_info(priv->crtc,
250 				   to_panel_encoder(encoder)->mod->info);
251 
252 	return 0;
253 }
254 
255 static const struct tilcdc_module_ops panel_module_ops = {
256 		.modeset_init = panel_modeset_init,
257 };
258 
259 /*
260  * Device:
261  */
262 
263 /* maybe move this somewhere common if it is needed by other outputs? */
264 static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
265 {
266 	struct device_node *info_np;
267 	struct tilcdc_panel_info *info;
268 	int ret = 0;
269 
270 	if (!np) {
271 		pr_err("%s: no devicenode given\n", __func__);
272 		return NULL;
273 	}
274 
275 	info_np = of_get_child_by_name(np, "panel-info");
276 	if (!info_np) {
277 		pr_err("%s: could not find panel-info node\n", __func__);
278 		return NULL;
279 	}
280 
281 	info = kzalloc(sizeof(*info), GFP_KERNEL);
282 	if (!info)
283 		goto put_node;
284 
285 	ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
286 	ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
287 	ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
288 	ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
289 	ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
290 	ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
291 	ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
292 	ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
293 	ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);
294 
295 	/* optional: */
296 	info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
297 	info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");
298 
299 	if (ret) {
300 		pr_err("%s: error reading panel-info properties\n", __func__);
301 		kfree(info);
302 		info = NULL;
303 	}
304 
305 put_node:
306 	of_node_put(info_np);
307 	return info;
308 }
309 
310 static int panel_probe(struct platform_device *pdev)
311 {
312 	struct device_node *bl_node, *node = pdev->dev.of_node;
313 	struct panel_module *panel_mod;
314 	struct tilcdc_module *mod;
315 	struct pinctrl *pinctrl;
316 	int ret;
317 
318 	/* bail out early if no DT data: */
319 	if (!node) {
320 		dev_err(&pdev->dev, "device-tree data is missing\n");
321 		return -ENXIO;
322 	}
323 
324 	panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
325 	if (!panel_mod)
326 		return -ENOMEM;
327 
328 	bl_node = of_parse_phandle(node, "backlight", 0);
329 	if (bl_node) {
330 		panel_mod->backlight = of_find_backlight_by_node(bl_node);
331 		of_node_put(bl_node);
332 
333 		if (!panel_mod->backlight)
334 			return -EPROBE_DEFER;
335 
336 		dev_info(&pdev->dev, "found backlight\n");
337 	}
338 
339 	panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
340 							 GPIOD_OUT_LOW);
341 	if (IS_ERR(panel_mod->enable_gpio)) {
342 		ret = PTR_ERR(panel_mod->enable_gpio);
343 		dev_err(&pdev->dev, "failed to request enable GPIO\n");
344 		goto fail_backlight;
345 	}
346 
347 	if (panel_mod->enable_gpio)
348 		dev_info(&pdev->dev, "found enable GPIO\n");
349 
350 	mod = &panel_mod->base;
351 	pdev->dev.platform_data = mod;
352 
353 	tilcdc_module_init(mod, "panel", &panel_module_ops);
354 
355 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
356 	if (IS_ERR(pinctrl))
357 		dev_warn(&pdev->dev, "pins are not configured\n");
358 
359 	panel_mod->timings = of_get_display_timings(node);
360 	if (!panel_mod->timings) {
361 		dev_err(&pdev->dev, "could not get panel timings\n");
362 		ret = -EINVAL;
363 		goto fail_free;
364 	}
365 
366 	panel_mod->info = of_get_panel_info(node);
367 	if (!panel_mod->info) {
368 		dev_err(&pdev->dev, "could not get panel info\n");
369 		ret = -EINVAL;
370 		goto fail_timings;
371 	}
372 
373 	return 0;
374 
375 fail_timings:
376 	display_timings_release(panel_mod->timings);
377 
378 fail_free:
379 	tilcdc_module_cleanup(mod);
380 
381 fail_backlight:
382 	if (panel_mod->backlight)
383 		put_device(&panel_mod->backlight->dev);
384 	return ret;
385 }
386 
387 static int panel_remove(struct platform_device *pdev)
388 {
389 	struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
390 	struct panel_module *panel_mod = to_panel_module(mod);
391 	struct backlight_device *backlight = panel_mod->backlight;
392 
393 	if (backlight)
394 		put_device(&backlight->dev);
395 
396 	display_timings_release(panel_mod->timings);
397 
398 	tilcdc_module_cleanup(mod);
399 	kfree(panel_mod->info);
400 
401 	return 0;
402 }
403 
404 static const struct of_device_id panel_of_match[] = {
405 		{ .compatible = "ti,tilcdc,panel", },
406 		{ },
407 };
408 
409 struct platform_driver panel_driver = {
410 	.probe = panel_probe,
411 	.remove = panel_remove,
412 	.driver = {
413 		.owner = THIS_MODULE,
414 		.name = "tilcdc-panel",
415 		.of_match_table = panel_of_match,
416 	},
417 };
418 
419 int __init tilcdc_panel_init(void)
420 {
421 	return platform_driver_register(&panel_driver);
422 }
423 
424 void __exit tilcdc_panel_fini(void)
425 {
426 	platform_driver_unregister(&panel_driver);
427 }
428