1 /*
2  * Copyright (C) 2012 Texas Instruments
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/pinctrl/pinmux.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/backlight.h>
21 #include <linux/gpio/consumer.h>
22 #include <video/display_timing.h>
23 #include <video/of_display_timing.h>
24 #include <video/videomode.h>
25 #include <drm/drm_atomic_helper.h>
26 
27 #include "tilcdc_drv.h"
28 #include "tilcdc_panel.h"
29 
30 struct panel_module {
31 	struct tilcdc_module base;
32 	struct tilcdc_panel_info *info;
33 	struct display_timings *timings;
34 	struct backlight_device *backlight;
35 	struct gpio_desc *enable_gpio;
36 };
37 #define to_panel_module(x) container_of(x, struct panel_module, base)
38 
39 
40 /*
41  * Encoder:
42  */
43 
44 struct panel_encoder {
45 	struct drm_encoder base;
46 	struct panel_module *mod;
47 };
48 #define to_panel_encoder(x) container_of(x, struct panel_encoder, base)
49 
50 static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
51 {
52 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
53 	struct backlight_device *backlight = panel_encoder->mod->backlight;
54 	struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;
55 
56 	if (backlight) {
57 		backlight->props.power = mode == DRM_MODE_DPMS_ON ?
58 					 FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
59 		backlight_update_status(backlight);
60 	}
61 
62 	if (gpio)
63 		gpiod_set_value_cansleep(gpio,
64 					 mode == DRM_MODE_DPMS_ON ? 1 : 0);
65 }
66 
67 static void panel_encoder_prepare(struct drm_encoder *encoder)
68 {
69 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
70 }
71 
72 static void panel_encoder_commit(struct drm_encoder *encoder)
73 {
74 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
75 }
76 
77 static void panel_encoder_mode_set(struct drm_encoder *encoder,
78 		struct drm_display_mode *mode,
79 		struct drm_display_mode *adjusted_mode)
80 {
81 	/* nothing needed */
82 }
83 
84 static const struct drm_encoder_funcs panel_encoder_funcs = {
85 		.destroy        = drm_encoder_cleanup,
86 };
87 
88 static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
89 		.dpms           = panel_encoder_dpms,
90 		.prepare        = panel_encoder_prepare,
91 		.commit         = panel_encoder_commit,
92 		.mode_set       = panel_encoder_mode_set,
93 };
94 
95 static struct drm_encoder *panel_encoder_create(struct drm_device *dev,
96 		struct panel_module *mod)
97 {
98 	struct panel_encoder *panel_encoder;
99 	struct drm_encoder *encoder;
100 	int ret;
101 
102 	panel_encoder = devm_kzalloc(dev->dev, sizeof(*panel_encoder),
103 				     GFP_KERNEL);
104 	if (!panel_encoder) {
105 		dev_err(dev->dev, "allocation failed\n");
106 		return NULL;
107 	}
108 
109 	panel_encoder->mod = mod;
110 
111 	encoder = &panel_encoder->base;
112 	encoder->possible_crtcs = 1;
113 
114 	ret = drm_encoder_init(dev, encoder, &panel_encoder_funcs,
115 			DRM_MODE_ENCODER_LVDS, NULL);
116 	if (ret < 0)
117 		goto fail;
118 
119 	drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);
120 
121 	return encoder;
122 
123 fail:
124 	drm_encoder_cleanup(encoder);
125 	return NULL;
126 }
127 
128 /*
129  * Connector:
130  */
131 
132 struct panel_connector {
133 	struct drm_connector base;
134 
135 	struct drm_encoder *encoder;  /* our connected encoder */
136 	struct panel_module *mod;
137 };
138 #define to_panel_connector(x) container_of(x, struct panel_connector, base)
139 
140 
141 static void panel_connector_destroy(struct drm_connector *connector)
142 {
143 	drm_connector_unregister(connector);
144 	drm_connector_cleanup(connector);
145 }
146 
147 static int panel_connector_get_modes(struct drm_connector *connector)
148 {
149 	struct drm_device *dev = connector->dev;
150 	struct panel_connector *panel_connector = to_panel_connector(connector);
151 	struct display_timings *timings = panel_connector->mod->timings;
152 	int i;
153 
154 	for (i = 0; i < timings->num_timings; i++) {
155 		struct drm_display_mode *mode = drm_mode_create(dev);
156 		struct videomode vm;
157 
158 		if (videomode_from_timings(timings, &vm, i))
159 			break;
160 
161 		drm_display_mode_from_videomode(&vm, mode);
162 
163 		mode->type = DRM_MODE_TYPE_DRIVER;
164 
165 		if (timings->native_mode == i)
166 			mode->type |= DRM_MODE_TYPE_PREFERRED;
167 
168 		drm_mode_set_name(mode);
169 		drm_mode_probed_add(connector, mode);
170 	}
171 
172 	return i;
173 }
174 
175 static int panel_connector_mode_valid(struct drm_connector *connector,
176 		  struct drm_display_mode *mode)
177 {
178 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
179 	/* our only constraints are what the crtc can generate: */
180 	return tilcdc_crtc_mode_valid(priv->crtc, mode);
181 }
182 
183 static struct drm_encoder *panel_connector_best_encoder(
184 		struct drm_connector *connector)
185 {
186 	struct panel_connector *panel_connector = to_panel_connector(connector);
187 	return panel_connector->encoder;
188 }
189 
190 static const struct drm_connector_funcs panel_connector_funcs = {
191 	.destroy            = panel_connector_destroy,
192 	.fill_modes         = drm_helper_probe_single_connector_modes,
193 	.reset              = drm_atomic_helper_connector_reset,
194 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
195 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
196 };
197 
198 static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
199 	.get_modes          = panel_connector_get_modes,
200 	.mode_valid         = panel_connector_mode_valid,
201 	.best_encoder       = panel_connector_best_encoder,
202 };
203 
204 static struct drm_connector *panel_connector_create(struct drm_device *dev,
205 		struct panel_module *mod, struct drm_encoder *encoder)
206 {
207 	struct panel_connector *panel_connector;
208 	struct drm_connector *connector;
209 	int ret;
210 
211 	panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
212 				       GFP_KERNEL);
213 	if (!panel_connector) {
214 		dev_err(dev->dev, "allocation failed\n");
215 		return NULL;
216 	}
217 
218 	panel_connector->encoder = encoder;
219 	panel_connector->mod = mod;
220 
221 	connector = &panel_connector->base;
222 
223 	drm_connector_init(dev, connector, &panel_connector_funcs,
224 			DRM_MODE_CONNECTOR_LVDS);
225 	drm_connector_helper_add(connector, &panel_connector_helper_funcs);
226 
227 	connector->interlace_allowed = 0;
228 	connector->doublescan_allowed = 0;
229 
230 	ret = drm_mode_connector_attach_encoder(connector, encoder);
231 	if (ret)
232 		goto fail;
233 
234 	return connector;
235 
236 fail:
237 	panel_connector_destroy(connector);
238 	return NULL;
239 }
240 
241 /*
242  * Module:
243  */
244 
245 static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
246 {
247 	struct panel_module *panel_mod = to_panel_module(mod);
248 	struct tilcdc_drm_private *priv = dev->dev_private;
249 	struct drm_encoder *encoder;
250 	struct drm_connector *connector;
251 
252 	encoder = panel_encoder_create(dev, panel_mod);
253 	if (!encoder)
254 		return -ENOMEM;
255 
256 	connector = panel_connector_create(dev, panel_mod, encoder);
257 	if (!connector)
258 		return -ENOMEM;
259 
260 	priv->encoders[priv->num_encoders++] = encoder;
261 	priv->connectors[priv->num_connectors++] = connector;
262 
263 	tilcdc_crtc_set_panel_info(priv->crtc,
264 				   to_panel_encoder(encoder)->mod->info);
265 
266 	return 0;
267 }
268 
269 static const struct tilcdc_module_ops panel_module_ops = {
270 		.modeset_init = panel_modeset_init,
271 };
272 
273 /*
274  * Device:
275  */
276 
277 /* maybe move this somewhere common if it is needed by other outputs? */
278 static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
279 {
280 	struct device_node *info_np;
281 	struct tilcdc_panel_info *info;
282 	int ret = 0;
283 
284 	if (!np) {
285 		pr_err("%s: no devicenode given\n", __func__);
286 		return NULL;
287 	}
288 
289 	info_np = of_get_child_by_name(np, "panel-info");
290 	if (!info_np) {
291 		pr_err("%s: could not find panel-info node\n", __func__);
292 		return NULL;
293 	}
294 
295 	info = kzalloc(sizeof(*info), GFP_KERNEL);
296 	if (!info) {
297 		pr_err("%s: allocation failed\n", __func__);
298 		of_node_put(info_np);
299 		return NULL;
300 	}
301 
302 	ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
303 	ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
304 	ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
305 	ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
306 	ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
307 	ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
308 	ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
309 	ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
310 	ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);
311 
312 	/* optional: */
313 	info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
314 	info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");
315 
316 	if (ret) {
317 		pr_err("%s: error reading panel-info properties\n", __func__);
318 		kfree(info);
319 		of_node_put(info_np);
320 		return NULL;
321 	}
322 	of_node_put(info_np);
323 
324 	return info;
325 }
326 
327 static int panel_probe(struct platform_device *pdev)
328 {
329 	struct device_node *bl_node, *node = pdev->dev.of_node;
330 	struct panel_module *panel_mod;
331 	struct tilcdc_module *mod;
332 	struct pinctrl *pinctrl;
333 	int ret;
334 
335 	/* bail out early if no DT data: */
336 	if (!node) {
337 		dev_err(&pdev->dev, "device-tree data is missing\n");
338 		return -ENXIO;
339 	}
340 
341 	panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
342 	if (!panel_mod)
343 		return -ENOMEM;
344 
345 	bl_node = of_parse_phandle(node, "backlight", 0);
346 	if (bl_node) {
347 		panel_mod->backlight = of_find_backlight_by_node(bl_node);
348 		of_node_put(bl_node);
349 
350 		if (!panel_mod->backlight)
351 			return -EPROBE_DEFER;
352 
353 		dev_info(&pdev->dev, "found backlight\n");
354 	}
355 
356 	panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
357 							 GPIOD_OUT_LOW);
358 	if (IS_ERR(panel_mod->enable_gpio)) {
359 		ret = PTR_ERR(panel_mod->enable_gpio);
360 		dev_err(&pdev->dev, "failed to request enable GPIO\n");
361 		goto fail_backlight;
362 	}
363 
364 	if (panel_mod->enable_gpio)
365 		dev_info(&pdev->dev, "found enable GPIO\n");
366 
367 	mod = &panel_mod->base;
368 	pdev->dev.platform_data = mod;
369 
370 	tilcdc_module_init(mod, "panel", &panel_module_ops);
371 
372 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
373 	if (IS_ERR(pinctrl))
374 		dev_warn(&pdev->dev, "pins are not configured\n");
375 
376 	panel_mod->timings = of_get_display_timings(node);
377 	if (!panel_mod->timings) {
378 		dev_err(&pdev->dev, "could not get panel timings\n");
379 		ret = -EINVAL;
380 		goto fail_free;
381 	}
382 
383 	panel_mod->info = of_get_panel_info(node);
384 	if (!panel_mod->info) {
385 		dev_err(&pdev->dev, "could not get panel info\n");
386 		ret = -EINVAL;
387 		goto fail_timings;
388 	}
389 
390 	return 0;
391 
392 fail_timings:
393 	display_timings_release(panel_mod->timings);
394 
395 fail_free:
396 	tilcdc_module_cleanup(mod);
397 
398 fail_backlight:
399 	if (panel_mod->backlight)
400 		put_device(&panel_mod->backlight->dev);
401 	return ret;
402 }
403 
404 static int panel_remove(struct platform_device *pdev)
405 {
406 	struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
407 	struct panel_module *panel_mod = to_panel_module(mod);
408 	struct backlight_device *backlight = panel_mod->backlight;
409 
410 	if (backlight)
411 		put_device(&backlight->dev);
412 
413 	display_timings_release(panel_mod->timings);
414 
415 	tilcdc_module_cleanup(mod);
416 	kfree(panel_mod->info);
417 
418 	return 0;
419 }
420 
421 static const struct of_device_id panel_of_match[] = {
422 		{ .compatible = "ti,tilcdc,panel", },
423 		{ },
424 };
425 
426 struct platform_driver panel_driver = {
427 	.probe = panel_probe,
428 	.remove = panel_remove,
429 	.driver = {
430 		.owner = THIS_MODULE,
431 		.name = "panel",
432 		.of_match_table = panel_of_match,
433 	},
434 };
435 
436 int __init tilcdc_panel_init(void)
437 {
438 	return platform_driver_register(&panel_driver);
439 }
440 
441 void __exit tilcdc_panel_fini(void)
442 {
443 	platform_driver_unregister(&panel_driver);
444 }
445