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