xref: /openbmc/linux/drivers/gpu/drm/sti/sti_dvo.c (revision 72d25643)
1 /*
2  * Copyright (C) STMicroelectronics SA 2014
3  * Author: Vincent Abriou <vincent.abriou@st.com> for STMicroelectronics.
4  * License terms:  GNU General Public License (GPL), version 2
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/component.h>
9 #include <linux/debugfs.h>
10 #include <linux/module.h>
11 #include <linux/of_gpio.h>
12 #include <linux/platform_device.h>
13 
14 #include <drm/drmP.h>
15 #include <drm/drm_atomic_helper.h>
16 #include <drm/drm_crtc_helper.h>
17 #include <drm/drm_panel.h>
18 
19 #include "sti_awg_utils.h"
20 #include "sti_mixer.h"
21 
22 /* DVO registers */
23 #define DVO_AWG_DIGSYNC_CTRL      0x0000
24 #define DVO_DOF_CFG               0x0004
25 #define DVO_LUT_PROG_LOW          0x0008
26 #define DVO_LUT_PROG_MID          0x000C
27 #define DVO_LUT_PROG_HIGH         0x0010
28 #define DVO_DIGSYNC_INSTR_I       0x0100
29 
30 #define DVO_AWG_CTRL_EN           BIT(0)
31 #define DVO_AWG_FRAME_BASED_SYNC  BIT(2)
32 
33 #define DVO_DOF_EN_LOWBYTE        BIT(0)
34 #define DVO_DOF_EN_MIDBYTE        BIT(1)
35 #define DVO_DOF_EN_HIGHBYTE       BIT(2)
36 #define DVO_DOF_EN                BIT(6)
37 #define DVO_DOF_MOD_COUNT_SHIFT   8
38 
39 #define DVO_LUT_ZERO              0
40 #define DVO_LUT_Y_G               1
41 #define DVO_LUT_Y_G_DEL           2
42 #define DVO_LUT_CB_B              3
43 #define DVO_LUT_CB_B_DEL          4
44 #define DVO_LUT_CR_R              5
45 #define DVO_LUT_CR_R_DEL          6
46 #define DVO_LUT_HOLD              7
47 
48 struct dvo_config {
49 	u32 flags;
50 	u32 lowbyte;
51 	u32 midbyte;
52 	u32 highbyte;
53 	int (*awg_fwgen_fct)(
54 			struct awg_code_generation_params *fw_gen_params,
55 			struct awg_timing *timing);
56 };
57 
58 static struct dvo_config rgb_24bit_de_cfg = {
59 	.flags         = (0L << DVO_DOF_MOD_COUNT_SHIFT),
60 	.lowbyte       = DVO_LUT_CR_R,
61 	.midbyte       = DVO_LUT_Y_G,
62 	.highbyte      = DVO_LUT_CB_B,
63 	.awg_fwgen_fct = sti_awg_generate_code_data_enable_mode,
64 };
65 
66 /**
67  * STI digital video output structure
68  *
69  * @dev: driver device
70  * @drm_dev: pointer to drm device
71  * @mode: current display mode selected
72  * @regs: dvo registers
73  * @clk_pix: pixel clock for dvo
74  * @clk: clock for dvo
75  * @clk_main_parent: dvo parent clock if main path used
76  * @clk_aux_parent: dvo parent clock if aux path used
77  * @panel_node: panel node reference from device tree
78  * @panel: reference to the panel connected to the dvo
79  * @enabled: true if dvo is enabled else false
80  * @encoder: drm_encoder it is bound
81  */
82 struct sti_dvo {
83 	struct device dev;
84 	struct drm_device *drm_dev;
85 	struct drm_display_mode mode;
86 	void __iomem *regs;
87 	struct clk *clk_pix;
88 	struct clk *clk;
89 	struct clk *clk_main_parent;
90 	struct clk *clk_aux_parent;
91 	struct device_node *panel_node;
92 	struct drm_panel *panel;
93 	struct dvo_config *config;
94 	bool enabled;
95 	struct drm_encoder *encoder;
96 	struct drm_bridge *bridge;
97 };
98 
99 struct sti_dvo_connector {
100 	struct drm_connector drm_connector;
101 	struct drm_encoder *encoder;
102 	struct sti_dvo *dvo;
103 };
104 
105 #define to_sti_dvo_connector(x) \
106 	container_of(x, struct sti_dvo_connector, drm_connector)
107 
108 #define BLANKING_LEVEL 16
109 int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
110 {
111 	struct drm_display_mode *mode = &dvo->mode;
112 	struct dvo_config *config = dvo->config;
113 	struct awg_code_generation_params fw_gen_params;
114 	struct awg_timing timing;
115 
116 	fw_gen_params.ram_code = ram_code;
117 	fw_gen_params.instruction_offset = 0;
118 
119 	timing.total_lines = mode->vtotal;
120 	timing.active_lines = mode->vdisplay;
121 	timing.blanking_lines = mode->vsync_start - mode->vdisplay;
122 	timing.trailing_lines = mode->vtotal - mode->vsync_start;
123 	timing.total_pixels = mode->htotal;
124 	timing.active_pixels = mode->hdisplay;
125 	timing.blanking_pixels = mode->hsync_start - mode->hdisplay;
126 	timing.trailing_pixels = mode->htotal - mode->hsync_start;
127 	timing.blanking_level = BLANKING_LEVEL;
128 
129 	if (config->awg_fwgen_fct(&fw_gen_params, &timing)) {
130 		DRM_ERROR("AWG firmware not properly generated\n");
131 		return -EINVAL;
132 	}
133 
134 	*ram_size = fw_gen_params.instruction_offset;
135 
136 	return 0;
137 }
138 
139 /* Configure AWG, writing instructions
140  *
141  * @dvo: pointer to DVO structure
142  * @awg_ram_code: pointer to AWG instructions table
143  * @nb: nb of AWG instructions
144  */
145 static void dvo_awg_configure(struct sti_dvo *dvo, u32 *awg_ram_code, int nb)
146 {
147 	int i;
148 
149 	DRM_DEBUG_DRIVER("\n");
150 
151 	for (i = 0; i < nb; i++)
152 		writel(awg_ram_code[i],
153 		       dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
154 	for (i = nb; i < AWG_MAX_INST; i++)
155 		writel(0, dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
156 
157 	writel(DVO_AWG_CTRL_EN, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
158 }
159 
160 #define DBGFS_DUMP(reg) seq_printf(s, "\n  %-25s 0x%08X", #reg, \
161 				   readl(dvo->regs + reg))
162 
163 static void dvo_dbg_awg_microcode(struct seq_file *s, void __iomem *reg)
164 {
165 	unsigned int i;
166 
167 	seq_puts(s, "\n\n");
168 	seq_puts(s, "  DVO AWG microcode:");
169 	for (i = 0; i < AWG_MAX_INST; i++) {
170 		if (i % 8 == 0)
171 			seq_printf(s, "\n  %04X:", i);
172 		seq_printf(s, " %04X", readl(reg + i * 4));
173 	}
174 }
175 
176 static int dvo_dbg_show(struct seq_file *s, void *data)
177 {
178 	struct drm_info_node *node = s->private;
179 	struct sti_dvo *dvo = (struct sti_dvo *)node->info_ent->data;
180 
181 	seq_printf(s, "DVO: (vaddr = 0x%p)", dvo->regs);
182 	DBGFS_DUMP(DVO_AWG_DIGSYNC_CTRL);
183 	DBGFS_DUMP(DVO_DOF_CFG);
184 	DBGFS_DUMP(DVO_LUT_PROG_LOW);
185 	DBGFS_DUMP(DVO_LUT_PROG_MID);
186 	DBGFS_DUMP(DVO_LUT_PROG_HIGH);
187 	dvo_dbg_awg_microcode(s, dvo->regs + DVO_DIGSYNC_INSTR_I);
188 	seq_puts(s, "\n");
189 
190 	return 0;
191 }
192 
193 static struct drm_info_list dvo_debugfs_files[] = {
194 	{ "dvo", dvo_dbg_show, 0, NULL },
195 };
196 
197 static void dvo_debugfs_exit(struct sti_dvo *dvo, struct drm_minor *minor)
198 {
199 	drm_debugfs_remove_files(dvo_debugfs_files,
200 				 ARRAY_SIZE(dvo_debugfs_files),
201 				 minor);
202 }
203 
204 static int dvo_debugfs_init(struct sti_dvo *dvo, struct drm_minor *minor)
205 {
206 	unsigned int i;
207 
208 	for (i = 0; i < ARRAY_SIZE(dvo_debugfs_files); i++)
209 		dvo_debugfs_files[i].data = dvo;
210 
211 	return drm_debugfs_create_files(dvo_debugfs_files,
212 					ARRAY_SIZE(dvo_debugfs_files),
213 					minor->debugfs_root, minor);
214 }
215 
216 static void sti_dvo_disable(struct drm_bridge *bridge)
217 {
218 	struct sti_dvo *dvo = bridge->driver_private;
219 
220 	if (!dvo->enabled)
221 		return;
222 
223 	DRM_DEBUG_DRIVER("\n");
224 
225 	if (dvo->config->awg_fwgen_fct)
226 		writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
227 
228 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
229 
230 	if (dvo->panel)
231 		dvo->panel->funcs->disable(dvo->panel);
232 
233 	/* Disable/unprepare dvo clock */
234 	clk_disable_unprepare(dvo->clk_pix);
235 	clk_disable_unprepare(dvo->clk);
236 
237 	dvo->enabled = false;
238 }
239 
240 static void sti_dvo_pre_enable(struct drm_bridge *bridge)
241 {
242 	struct sti_dvo *dvo = bridge->driver_private;
243 	struct dvo_config *config = dvo->config;
244 	u32 val;
245 
246 	DRM_DEBUG_DRIVER("\n");
247 
248 	if (dvo->enabled)
249 		return;
250 
251 	/* Make sure DVO is disabled */
252 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
253 	writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
254 
255 	if (config->awg_fwgen_fct) {
256 		u8 nb_instr;
257 		u32 awg_ram_code[AWG_MAX_INST];
258 		/* Configure AWG */
259 		if (!dvo_awg_generate_code(dvo, &nb_instr, awg_ram_code))
260 			dvo_awg_configure(dvo, awg_ram_code, nb_instr);
261 		else
262 			return;
263 	}
264 
265 	/* Prepare/enable clocks */
266 	if (clk_prepare_enable(dvo->clk_pix))
267 		DRM_ERROR("Failed to prepare/enable dvo_pix clk\n");
268 	if (clk_prepare_enable(dvo->clk))
269 		DRM_ERROR("Failed to prepare/enable dvo clk\n");
270 
271 	if (dvo->panel)
272 		dvo->panel->funcs->enable(dvo->panel);
273 
274 	/* Set LUT */
275 	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
276 	writel(config->midbyte,  dvo->regs + DVO_LUT_PROG_MID);
277 	writel(config->highbyte, dvo->regs + DVO_LUT_PROG_HIGH);
278 
279 	/* Digital output formatter config */
280 	val = (config->flags | DVO_DOF_EN);
281 	writel(val, dvo->regs + DVO_DOF_CFG);
282 
283 	dvo->enabled = true;
284 }
285 
286 static void sti_dvo_set_mode(struct drm_bridge *bridge,
287 			     struct drm_display_mode *mode,
288 			     struct drm_display_mode *adjusted_mode)
289 {
290 	struct sti_dvo *dvo = bridge->driver_private;
291 	struct sti_mixer *mixer = to_sti_mixer(dvo->encoder->crtc);
292 	int rate = mode->clock * 1000;
293 	struct clk *clkp;
294 	int ret;
295 
296 	DRM_DEBUG_DRIVER("\n");
297 
298 	memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
299 
300 	/* According to the path used (main or aux), the dvo clocks should
301 	 * have a different parent clock. */
302 	if (mixer->id == STI_MIXER_MAIN)
303 		clkp = dvo->clk_main_parent;
304 	else
305 		clkp = dvo->clk_aux_parent;
306 
307 	if (clkp) {
308 		clk_set_parent(dvo->clk_pix, clkp);
309 		clk_set_parent(dvo->clk, clkp);
310 	}
311 
312 	/* DVO clocks = compositor clock */
313 	ret = clk_set_rate(dvo->clk_pix, rate);
314 	if (ret < 0) {
315 		DRM_ERROR("Cannot set rate (%dHz) for dvo_pix clk\n", rate);
316 		return;
317 	}
318 
319 	ret = clk_set_rate(dvo->clk, rate);
320 	if (ret < 0) {
321 		DRM_ERROR("Cannot set rate (%dHz) for dvo clk\n", rate);
322 		return;
323 	}
324 
325 	/* For now, we only support 24bit data enable (DE) synchro format */
326 	dvo->config = &rgb_24bit_de_cfg;
327 }
328 
329 static void sti_dvo_bridge_nope(struct drm_bridge *bridge)
330 {
331 	/* do nothing */
332 }
333 
334 static const struct drm_bridge_funcs sti_dvo_bridge_funcs = {
335 	.pre_enable = sti_dvo_pre_enable,
336 	.enable = sti_dvo_bridge_nope,
337 	.disable = sti_dvo_disable,
338 	.post_disable = sti_dvo_bridge_nope,
339 	.mode_set = sti_dvo_set_mode,
340 };
341 
342 static int sti_dvo_connector_get_modes(struct drm_connector *connector)
343 {
344 	struct sti_dvo_connector *dvo_connector
345 		= to_sti_dvo_connector(connector);
346 	struct sti_dvo *dvo = dvo_connector->dvo;
347 
348 	if (dvo->panel)
349 		return dvo->panel->funcs->get_modes(dvo->panel);
350 
351 	return 0;
352 }
353 
354 #define CLK_TOLERANCE_HZ 50
355 
356 static int sti_dvo_connector_mode_valid(struct drm_connector *connector,
357 					struct drm_display_mode *mode)
358 {
359 	int target = mode->clock * 1000;
360 	int target_min = target - CLK_TOLERANCE_HZ;
361 	int target_max = target + CLK_TOLERANCE_HZ;
362 	int result;
363 	struct sti_dvo_connector *dvo_connector
364 		= to_sti_dvo_connector(connector);
365 	struct sti_dvo *dvo = dvo_connector->dvo;
366 
367 	result = clk_round_rate(dvo->clk_pix, target);
368 
369 	DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
370 			 target, result);
371 
372 	if ((result < target_min) || (result > target_max)) {
373 		DRM_DEBUG_DRIVER("dvo pixclk=%d not supported\n", target);
374 		return MODE_BAD;
375 	}
376 
377 	return MODE_OK;
378 }
379 
380 static const
381 struct drm_connector_helper_funcs sti_dvo_connector_helper_funcs = {
382 	.get_modes = sti_dvo_connector_get_modes,
383 	.mode_valid = sti_dvo_connector_mode_valid,
384 };
385 
386 static enum drm_connector_status
387 sti_dvo_connector_detect(struct drm_connector *connector, bool force)
388 {
389 	struct sti_dvo_connector *dvo_connector
390 		= to_sti_dvo_connector(connector);
391 	struct sti_dvo *dvo = dvo_connector->dvo;
392 
393 	DRM_DEBUG_DRIVER("\n");
394 
395 	if (!dvo->panel) {
396 		dvo->panel = of_drm_find_panel(dvo->panel_node);
397 		if (dvo->panel)
398 			drm_panel_attach(dvo->panel, connector);
399 	}
400 
401 	if (dvo->panel)
402 		return connector_status_connected;
403 
404 	return connector_status_disconnected;
405 }
406 
407 static int sti_dvo_late_register(struct drm_connector *connector)
408 {
409 	struct sti_dvo_connector *dvo_connector
410 		= to_sti_dvo_connector(connector);
411 	struct sti_dvo *dvo = dvo_connector->dvo;
412 
413 	if (dvo_debugfs_init(dvo, dvo->drm_dev->primary)) {
414 		DRM_ERROR("DVO debugfs setup failed\n");
415 		return -EINVAL;
416 	}
417 
418 	return 0;
419 }
420 
421 static const struct drm_connector_funcs sti_dvo_connector_funcs = {
422 	.dpms = drm_atomic_helper_connector_dpms,
423 	.fill_modes = drm_helper_probe_single_connector_modes,
424 	.detect = sti_dvo_connector_detect,
425 	.destroy = drm_connector_cleanup,
426 	.reset = drm_atomic_helper_connector_reset,
427 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
428 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
429 	.late_register = sti_dvo_late_register,
430 };
431 
432 static struct drm_encoder *sti_dvo_find_encoder(struct drm_device *dev)
433 {
434 	struct drm_encoder *encoder;
435 
436 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
437 		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
438 			return encoder;
439 	}
440 
441 	return NULL;
442 }
443 
444 static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
445 {
446 	struct sti_dvo *dvo = dev_get_drvdata(dev);
447 	struct drm_device *drm_dev = data;
448 	struct drm_encoder *encoder;
449 	struct sti_dvo_connector *connector;
450 	struct drm_connector *drm_connector;
451 	struct drm_bridge *bridge;
452 	int err;
453 
454 	/* Set the drm device handle */
455 	dvo->drm_dev = drm_dev;
456 
457 	encoder = sti_dvo_find_encoder(drm_dev);
458 	if (!encoder)
459 		return -ENOMEM;
460 
461 	connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
462 	if (!connector)
463 		return -ENOMEM;
464 
465 	connector->dvo = dvo;
466 
467 	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
468 	if (!bridge)
469 		return -ENOMEM;
470 
471 	bridge->driver_private = dvo;
472 	bridge->funcs = &sti_dvo_bridge_funcs;
473 	bridge->of_node = dvo->dev.of_node;
474 	err = drm_bridge_add(bridge);
475 	if (err) {
476 		DRM_ERROR("Failed to add bridge\n");
477 		return err;
478 	}
479 
480 	err = drm_bridge_attach(drm_dev, bridge);
481 	if (err) {
482 		DRM_ERROR("Failed to attach bridge\n");
483 		return err;
484 	}
485 
486 	dvo->bridge = bridge;
487 	encoder->bridge = bridge;
488 	connector->encoder = encoder;
489 	dvo->encoder = encoder;
490 
491 	drm_connector = (struct drm_connector *)connector;
492 
493 	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
494 
495 	drm_connector_init(drm_dev, drm_connector,
496 			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
497 	drm_connector_helper_add(drm_connector,
498 				 &sti_dvo_connector_helper_funcs);
499 
500 	err = drm_mode_connector_attach_encoder(drm_connector, encoder);
501 	if (err) {
502 		DRM_ERROR("Failed to attach a connector to a encoder\n");
503 		goto err_sysfs;
504 	}
505 
506 	return 0;
507 
508 err_sysfs:
509 	drm_bridge_remove(bridge);
510 	return -EINVAL;
511 }
512 
513 static void sti_dvo_unbind(struct device *dev,
514 			   struct device *master, void *data)
515 {
516 	struct sti_dvo *dvo = dev_get_drvdata(dev);
517 	struct drm_device *drm_dev = data;
518 
519 	dvo_debugfs_exit(dvo, drm_dev->primary);
520 
521 	drm_bridge_remove(dvo->bridge);
522 }
523 
524 static const struct component_ops sti_dvo_ops = {
525 	.bind = sti_dvo_bind,
526 	.unbind = sti_dvo_unbind,
527 };
528 
529 static int sti_dvo_probe(struct platform_device *pdev)
530 {
531 	struct device *dev = &pdev->dev;
532 	struct sti_dvo *dvo;
533 	struct resource *res;
534 	struct device_node *np = dev->of_node;
535 
536 	DRM_INFO("%s\n", __func__);
537 
538 	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
539 	if (!dvo) {
540 		DRM_ERROR("Failed to allocate memory for DVO\n");
541 		return -ENOMEM;
542 	}
543 
544 	dvo->dev = pdev->dev;
545 
546 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
547 	if (!res) {
548 		DRM_ERROR("Invalid dvo resource\n");
549 		return -ENOMEM;
550 	}
551 	dvo->regs = devm_ioremap_nocache(dev, res->start,
552 			resource_size(res));
553 	if (!dvo->regs)
554 		return -ENOMEM;
555 
556 	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
557 	if (IS_ERR(dvo->clk_pix)) {
558 		DRM_ERROR("Cannot get dvo_pix clock\n");
559 		return PTR_ERR(dvo->clk_pix);
560 	}
561 
562 	dvo->clk = devm_clk_get(dev, "dvo");
563 	if (IS_ERR(dvo->clk)) {
564 		DRM_ERROR("Cannot get dvo clock\n");
565 		return PTR_ERR(dvo->clk);
566 	}
567 
568 	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
569 	if (IS_ERR(dvo->clk_main_parent)) {
570 		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
571 		dvo->clk_main_parent = NULL;
572 	}
573 
574 	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
575 	if (IS_ERR(dvo->clk_aux_parent)) {
576 		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
577 		dvo->clk_aux_parent = NULL;
578 	}
579 
580 	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
581 	if (!dvo->panel_node)
582 		DRM_ERROR("No panel associated to the dvo output\n");
583 	of_node_put(dvo->panel_node);
584 
585 	platform_set_drvdata(pdev, dvo);
586 
587 	return component_add(&pdev->dev, &sti_dvo_ops);
588 }
589 
590 static int sti_dvo_remove(struct platform_device *pdev)
591 {
592 	component_del(&pdev->dev, &sti_dvo_ops);
593 	return 0;
594 }
595 
596 static struct of_device_id dvo_of_match[] = {
597 	{ .compatible = "st,stih407-dvo", },
598 	{ /* end node */ }
599 };
600 MODULE_DEVICE_TABLE(of, dvo_of_match);
601 
602 struct platform_driver sti_dvo_driver = {
603 	.driver = {
604 		.name = "sti-dvo",
605 		.owner = THIS_MODULE,
606 		.of_match_table = dvo_of_match,
607 	},
608 	.probe = sti_dvo_probe,
609 	.remove = sti_dvo_remove,
610 };
611 
612 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
613 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
614 MODULE_LICENSE("GPL");
615