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 
26 #include "tilcdc_drv.h"
27 
28 struct panel_module {
29 	struct tilcdc_module base;
30 	struct tilcdc_panel_info *info;
31 	struct display_timings *timings;
32 	struct backlight_device *backlight;
33 	struct gpio_desc *enable_gpio;
34 };
35 #define to_panel_module(x) container_of(x, struct panel_module, base)
36 
37 
38 /*
39  * Encoder:
40  */
41 
42 struct panel_encoder {
43 	struct drm_encoder base;
44 	struct panel_module *mod;
45 };
46 #define to_panel_encoder(x) container_of(x, struct panel_encoder, base)
47 
48 static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
49 {
50 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
51 	struct backlight_device *backlight = panel_encoder->mod->backlight;
52 	struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;
53 
54 	if (backlight) {
55 		backlight->props.power = mode == DRM_MODE_DPMS_ON ?
56 					 FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
57 		backlight_update_status(backlight);
58 	}
59 
60 	if (gpio)
61 		gpiod_set_value_cansleep(gpio,
62 					 mode == DRM_MODE_DPMS_ON ? 1 : 0);
63 }
64 
65 static void panel_encoder_prepare(struct drm_encoder *encoder)
66 {
67 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
68 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
69 	tilcdc_crtc_set_panel_info(encoder->crtc, panel_encoder->mod->info);
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 enum drm_connector_status panel_connector_detect(
148 		struct drm_connector *connector,
149 		bool force)
150 {
151 	return connector_status_connected;
152 }
153 
154 static int panel_connector_get_modes(struct drm_connector *connector)
155 {
156 	struct drm_device *dev = connector->dev;
157 	struct panel_connector *panel_connector = to_panel_connector(connector);
158 	struct display_timings *timings = panel_connector->mod->timings;
159 	int i;
160 
161 	for (i = 0; i < timings->num_timings; i++) {
162 		struct drm_display_mode *mode = drm_mode_create(dev);
163 		struct videomode vm;
164 
165 		if (videomode_from_timings(timings, &vm, i))
166 			break;
167 
168 		drm_display_mode_from_videomode(&vm, mode);
169 
170 		mode->type = DRM_MODE_TYPE_DRIVER;
171 
172 		if (timings->native_mode == i)
173 			mode->type |= DRM_MODE_TYPE_PREFERRED;
174 
175 		drm_mode_set_name(mode);
176 		drm_mode_probed_add(connector, mode);
177 	}
178 
179 	return i;
180 }
181 
182 static int panel_connector_mode_valid(struct drm_connector *connector,
183 		  struct drm_display_mode *mode)
184 {
185 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
186 	/* our only constraints are what the crtc can generate: */
187 	return tilcdc_crtc_mode_valid(priv->crtc, mode);
188 }
189 
190 static struct drm_encoder *panel_connector_best_encoder(
191 		struct drm_connector *connector)
192 {
193 	struct panel_connector *panel_connector = to_panel_connector(connector);
194 	return panel_connector->encoder;
195 }
196 
197 static const struct drm_connector_funcs panel_connector_funcs = {
198 	.destroy            = panel_connector_destroy,
199 	.dpms               = drm_helper_connector_dpms,
200 	.detect             = panel_connector_detect,
201 	.fill_modes         = drm_helper_probe_single_connector_modes,
202 };
203 
204 static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
205 	.get_modes          = panel_connector_get_modes,
206 	.mode_valid         = panel_connector_mode_valid,
207 	.best_encoder       = panel_connector_best_encoder,
208 };
209 
210 static struct drm_connector *panel_connector_create(struct drm_device *dev,
211 		struct panel_module *mod, struct drm_encoder *encoder)
212 {
213 	struct panel_connector *panel_connector;
214 	struct drm_connector *connector;
215 	int ret;
216 
217 	panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
218 				       GFP_KERNEL);
219 	if (!panel_connector) {
220 		dev_err(dev->dev, "allocation failed\n");
221 		return NULL;
222 	}
223 
224 	panel_connector->encoder = encoder;
225 	panel_connector->mod = mod;
226 
227 	connector = &panel_connector->base;
228 
229 	drm_connector_init(dev, connector, &panel_connector_funcs,
230 			DRM_MODE_CONNECTOR_LVDS);
231 	drm_connector_helper_add(connector, &panel_connector_helper_funcs);
232 
233 	connector->interlace_allowed = 0;
234 	connector->doublescan_allowed = 0;
235 
236 	ret = drm_mode_connector_attach_encoder(connector, encoder);
237 	if (ret)
238 		goto fail;
239 
240 	drm_connector_register(connector);
241 
242 	return connector;
243 
244 fail:
245 	panel_connector_destroy(connector);
246 	return NULL;
247 }
248 
249 /*
250  * Module:
251  */
252 
253 static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
254 {
255 	struct panel_module *panel_mod = to_panel_module(mod);
256 	struct tilcdc_drm_private *priv = dev->dev_private;
257 	struct drm_encoder *encoder;
258 	struct drm_connector *connector;
259 
260 	encoder = panel_encoder_create(dev, panel_mod);
261 	if (!encoder)
262 		return -ENOMEM;
263 
264 	connector = panel_connector_create(dev, panel_mod, encoder);
265 	if (!connector)
266 		return -ENOMEM;
267 
268 	priv->encoders[priv->num_encoders++] = encoder;
269 	priv->connectors[priv->num_connectors++] = connector;
270 
271 	return 0;
272 }
273 
274 static const struct tilcdc_module_ops panel_module_ops = {
275 		.modeset_init = panel_modeset_init,
276 };
277 
278 /*
279  * Device:
280  */
281 
282 /* maybe move this somewhere common if it is needed by other outputs? */
283 static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
284 {
285 	struct device_node *info_np;
286 	struct tilcdc_panel_info *info;
287 	int ret = 0;
288 
289 	if (!np) {
290 		pr_err("%s: no devicenode given\n", __func__);
291 		return NULL;
292 	}
293 
294 	info_np = of_get_child_by_name(np, "panel-info");
295 	if (!info_np) {
296 		pr_err("%s: could not find panel-info node\n", __func__);
297 		return NULL;
298 	}
299 
300 	info = kzalloc(sizeof(*info), GFP_KERNEL);
301 	if (!info) {
302 		pr_err("%s: allocation failed\n", __func__);
303 		of_node_put(info_np);
304 		return NULL;
305 	}
306 
307 	ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
308 	ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
309 	ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
310 	ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
311 	ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
312 	ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
313 	ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
314 	ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
315 	ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);
316 
317 	/* optional: */
318 	info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
319 	info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");
320 
321 	if (ret) {
322 		pr_err("%s: error reading panel-info properties\n", __func__);
323 		kfree(info);
324 		of_node_put(info_np);
325 		return NULL;
326 	}
327 	of_node_put(info_np);
328 
329 	return info;
330 }
331 
332 static int panel_probe(struct platform_device *pdev)
333 {
334 	struct device_node *bl_node, *node = pdev->dev.of_node;
335 	struct panel_module *panel_mod;
336 	struct tilcdc_module *mod;
337 	struct pinctrl *pinctrl;
338 	int ret;
339 
340 	/* bail out early if no DT data: */
341 	if (!node) {
342 		dev_err(&pdev->dev, "device-tree data is missing\n");
343 		return -ENXIO;
344 	}
345 
346 	panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
347 	if (!panel_mod)
348 		return -ENOMEM;
349 
350 	bl_node = of_parse_phandle(node, "backlight", 0);
351 	if (bl_node) {
352 		panel_mod->backlight = of_find_backlight_by_node(bl_node);
353 		of_node_put(bl_node);
354 
355 		if (!panel_mod->backlight)
356 			return -EPROBE_DEFER;
357 
358 		dev_info(&pdev->dev, "found backlight\n");
359 	}
360 
361 	panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
362 							 GPIOD_OUT_LOW);
363 	if (IS_ERR(panel_mod->enable_gpio)) {
364 		ret = PTR_ERR(panel_mod->enable_gpio);
365 		dev_err(&pdev->dev, "failed to request enable GPIO\n");
366 		goto fail_backlight;
367 	}
368 
369 	if (panel_mod->enable_gpio)
370 		dev_info(&pdev->dev, "found enable GPIO\n");
371 
372 	mod = &panel_mod->base;
373 	pdev->dev.platform_data = mod;
374 
375 	tilcdc_module_init(mod, "panel", &panel_module_ops);
376 
377 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
378 	if (IS_ERR(pinctrl))
379 		dev_warn(&pdev->dev, "pins are not configured\n");
380 
381 	panel_mod->timings = of_get_display_timings(node);
382 	if (!panel_mod->timings) {
383 		dev_err(&pdev->dev, "could not get panel timings\n");
384 		ret = -EINVAL;
385 		goto fail_free;
386 	}
387 
388 	panel_mod->info = of_get_panel_info(node);
389 	if (!panel_mod->info) {
390 		dev_err(&pdev->dev, "could not get panel info\n");
391 		ret = -EINVAL;
392 		goto fail_timings;
393 	}
394 
395 	mod->preferred_bpp = panel_mod->info->bpp;
396 
397 	return 0;
398 
399 fail_timings:
400 	display_timings_release(panel_mod->timings);
401 
402 fail_free:
403 	tilcdc_module_cleanup(mod);
404 
405 fail_backlight:
406 	if (panel_mod->backlight)
407 		put_device(&panel_mod->backlight->dev);
408 	return ret;
409 }
410 
411 static int panel_remove(struct platform_device *pdev)
412 {
413 	struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
414 	struct panel_module *panel_mod = to_panel_module(mod);
415 	struct backlight_device *backlight = panel_mod->backlight;
416 
417 	if (backlight)
418 		put_device(&backlight->dev);
419 
420 	display_timings_release(panel_mod->timings);
421 
422 	tilcdc_module_cleanup(mod);
423 	kfree(panel_mod->info);
424 
425 	return 0;
426 }
427 
428 static struct of_device_id panel_of_match[] = {
429 		{ .compatible = "ti,tilcdc,panel", },
430 		{ },
431 };
432 
433 struct platform_driver panel_driver = {
434 	.probe = panel_probe,
435 	.remove = panel_remove,
436 	.driver = {
437 		.owner = THIS_MODULE,
438 		.name = "panel",
439 		.of_match_table = panel_of_match,
440 	},
441 };
442 
443 int __init tilcdc_panel_init(void)
444 {
445 	return platform_driver_register(&panel_driver);
446 }
447 
448 void __exit tilcdc_panel_fini(void)
449 {
450 	platform_driver_unregister(&panel_driver);
451 }
452