xref: /openbmc/linux/drivers/gpu/drm/sti/sti_dvo.c (revision e5f586c763a079349398e2b0c7c271386193ac34)
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_drv.h"
21 #include "sti_mixer.h"
22 
23 /* DVO registers */
24 #define DVO_AWG_DIGSYNC_CTRL      0x0000
25 #define DVO_DOF_CFG               0x0004
26 #define DVO_LUT_PROG_LOW          0x0008
27 #define DVO_LUT_PROG_MID          0x000C
28 #define DVO_LUT_PROG_HIGH         0x0010
29 #define DVO_DIGSYNC_INSTR_I       0x0100
30 
31 #define DVO_AWG_CTRL_EN           BIT(0)
32 #define DVO_AWG_FRAME_BASED_SYNC  BIT(2)
33 
34 #define DVO_DOF_EN_LOWBYTE        BIT(0)
35 #define DVO_DOF_EN_MIDBYTE        BIT(1)
36 #define DVO_DOF_EN_HIGHBYTE       BIT(2)
37 #define DVO_DOF_EN                BIT(6)
38 #define DVO_DOF_MOD_COUNT_SHIFT   8
39 
40 #define DVO_LUT_ZERO              0
41 #define DVO_LUT_Y_G               1
42 #define DVO_LUT_Y_G_DEL           2
43 #define DVO_LUT_CB_B              3
44 #define DVO_LUT_CB_B_DEL          4
45 #define DVO_LUT_CR_R              5
46 #define DVO_LUT_CR_R_DEL          6
47 #define DVO_LUT_HOLD              7
48 
49 struct dvo_config {
50 	u32 flags;
51 	u32 lowbyte;
52 	u32 midbyte;
53 	u32 highbyte;
54 	int (*awg_fwgen_fct)(
55 			struct awg_code_generation_params *fw_gen_params,
56 			struct awg_timing *timing);
57 };
58 
59 static struct dvo_config rgb_24bit_de_cfg = {
60 	.flags         = (0L << DVO_DOF_MOD_COUNT_SHIFT),
61 	.lowbyte       = DVO_LUT_CR_R,
62 	.midbyte       = DVO_LUT_Y_G,
63 	.highbyte      = DVO_LUT_CB_B,
64 	.awg_fwgen_fct = sti_awg_generate_code_data_enable_mode,
65 };
66 
67 /**
68  * STI digital video output structure
69  *
70  * @dev: driver device
71  * @drm_dev: pointer to drm device
72  * @mode: current display mode selected
73  * @regs: dvo registers
74  * @clk_pix: pixel clock for dvo
75  * @clk: clock for dvo
76  * @clk_main_parent: dvo parent clock if main path used
77  * @clk_aux_parent: dvo parent clock if aux path used
78  * @panel_node: panel node reference from device tree
79  * @panel: reference to the panel connected to the dvo
80  * @enabled: true if dvo is enabled else false
81  * @encoder: drm_encoder it is bound
82  */
83 struct sti_dvo {
84 	struct device dev;
85 	struct drm_device *drm_dev;
86 	struct drm_display_mode mode;
87 	void __iomem *regs;
88 	struct clk *clk_pix;
89 	struct clk *clk;
90 	struct clk *clk_main_parent;
91 	struct clk *clk_aux_parent;
92 	struct device_node *panel_node;
93 	struct drm_panel *panel;
94 	struct dvo_config *config;
95 	bool enabled;
96 	struct drm_encoder *encoder;
97 	struct drm_bridge *bridge;
98 };
99 
100 struct sti_dvo_connector {
101 	struct drm_connector drm_connector;
102 	struct drm_encoder *encoder;
103 	struct sti_dvo *dvo;
104 };
105 
106 #define to_sti_dvo_connector(x) \
107 	container_of(x, struct sti_dvo_connector, drm_connector)
108 
109 #define BLANKING_LEVEL 16
110 static int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
111 {
112 	struct drm_display_mode *mode = &dvo->mode;
113 	struct dvo_config *config = dvo->config;
114 	struct awg_code_generation_params fw_gen_params;
115 	struct awg_timing timing;
116 
117 	fw_gen_params.ram_code = ram_code;
118 	fw_gen_params.instruction_offset = 0;
119 
120 	timing.total_lines = mode->vtotal;
121 	timing.active_lines = mode->vdisplay;
122 	timing.blanking_lines = mode->vsync_start - mode->vdisplay;
123 	timing.trailing_lines = mode->vtotal - mode->vsync_start;
124 	timing.total_pixels = mode->htotal;
125 	timing.active_pixels = mode->hdisplay;
126 	timing.blanking_pixels = mode->hsync_start - mode->hdisplay;
127 	timing.trailing_pixels = mode->htotal - mode->hsync_start;
128 	timing.blanking_level = BLANKING_LEVEL;
129 
130 	if (config->awg_fwgen_fct(&fw_gen_params, &timing)) {
131 		DRM_ERROR("AWG firmware not properly generated\n");
132 		return -EINVAL;
133 	}
134 
135 	*ram_size = fw_gen_params.instruction_offset;
136 
137 	return 0;
138 }
139 
140 /* Configure AWG, writing instructions
141  *
142  * @dvo: pointer to DVO structure
143  * @awg_ram_code: pointer to AWG instructions table
144  * @nb: nb of AWG instructions
145  */
146 static void dvo_awg_configure(struct sti_dvo *dvo, u32 *awg_ram_code, int nb)
147 {
148 	int i;
149 
150 	DRM_DEBUG_DRIVER("\n");
151 
152 	for (i = 0; i < nb; i++)
153 		writel(awg_ram_code[i],
154 		       dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
155 	for (i = nb; i < AWG_MAX_INST; i++)
156 		writel(0, dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
157 
158 	writel(DVO_AWG_CTRL_EN, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
159 }
160 
161 #define DBGFS_DUMP(reg) seq_printf(s, "\n  %-25s 0x%08X", #reg, \
162 				   readl(dvo->regs + reg))
163 
164 static void dvo_dbg_awg_microcode(struct seq_file *s, void __iomem *reg)
165 {
166 	unsigned int i;
167 
168 	seq_puts(s, "\n\n");
169 	seq_puts(s, "  DVO AWG microcode:");
170 	for (i = 0; i < AWG_MAX_INST; i++) {
171 		if (i % 8 == 0)
172 			seq_printf(s, "\n  %04X:", i);
173 		seq_printf(s, " %04X", readl(reg + i * 4));
174 	}
175 }
176 
177 static int dvo_dbg_show(struct seq_file *s, void *data)
178 {
179 	struct drm_info_node *node = s->private;
180 	struct sti_dvo *dvo = (struct sti_dvo *)node->info_ent->data;
181 
182 	seq_printf(s, "DVO: (vaddr = 0x%p)", dvo->regs);
183 	DBGFS_DUMP(DVO_AWG_DIGSYNC_CTRL);
184 	DBGFS_DUMP(DVO_DOF_CFG);
185 	DBGFS_DUMP(DVO_LUT_PROG_LOW);
186 	DBGFS_DUMP(DVO_LUT_PROG_MID);
187 	DBGFS_DUMP(DVO_LUT_PROG_HIGH);
188 	dvo_dbg_awg_microcode(s, dvo->regs + DVO_DIGSYNC_INSTR_I);
189 	seq_puts(s, "\n");
190 
191 	return 0;
192 }
193 
194 static struct drm_info_list dvo_debugfs_files[] = {
195 	{ "dvo", dvo_dbg_show, 0, NULL },
196 };
197 
198 static int dvo_debugfs_init(struct sti_dvo *dvo, struct drm_minor *minor)
199 {
200 	unsigned int i;
201 
202 	for (i = 0; i < ARRAY_SIZE(dvo_debugfs_files); i++)
203 		dvo_debugfs_files[i].data = dvo;
204 
205 	return drm_debugfs_create_files(dvo_debugfs_files,
206 					ARRAY_SIZE(dvo_debugfs_files),
207 					minor->debugfs_root, minor);
208 }
209 
210 static void sti_dvo_disable(struct drm_bridge *bridge)
211 {
212 	struct sti_dvo *dvo = bridge->driver_private;
213 
214 	if (!dvo->enabled)
215 		return;
216 
217 	DRM_DEBUG_DRIVER("\n");
218 
219 	if (dvo->config->awg_fwgen_fct)
220 		writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
221 
222 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
223 
224 	if (dvo->panel)
225 		dvo->panel->funcs->disable(dvo->panel);
226 
227 	/* Disable/unprepare dvo clock */
228 	clk_disable_unprepare(dvo->clk_pix);
229 	clk_disable_unprepare(dvo->clk);
230 
231 	dvo->enabled = false;
232 }
233 
234 static void sti_dvo_pre_enable(struct drm_bridge *bridge)
235 {
236 	struct sti_dvo *dvo = bridge->driver_private;
237 	struct dvo_config *config = dvo->config;
238 	u32 val;
239 
240 	DRM_DEBUG_DRIVER("\n");
241 
242 	if (dvo->enabled)
243 		return;
244 
245 	/* Make sure DVO is disabled */
246 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
247 	writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
248 
249 	if (config->awg_fwgen_fct) {
250 		u8 nb_instr;
251 		u32 awg_ram_code[AWG_MAX_INST];
252 		/* Configure AWG */
253 		if (!dvo_awg_generate_code(dvo, &nb_instr, awg_ram_code))
254 			dvo_awg_configure(dvo, awg_ram_code, nb_instr);
255 		else
256 			return;
257 	}
258 
259 	/* Prepare/enable clocks */
260 	if (clk_prepare_enable(dvo->clk_pix))
261 		DRM_ERROR("Failed to prepare/enable dvo_pix clk\n");
262 	if (clk_prepare_enable(dvo->clk))
263 		DRM_ERROR("Failed to prepare/enable dvo clk\n");
264 
265 	if (dvo->panel)
266 		dvo->panel->funcs->enable(dvo->panel);
267 
268 	/* Set LUT */
269 	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
270 	writel(config->midbyte,  dvo->regs + DVO_LUT_PROG_MID);
271 	writel(config->highbyte, dvo->regs + DVO_LUT_PROG_HIGH);
272 
273 	/* Digital output formatter config */
274 	val = (config->flags | DVO_DOF_EN);
275 	writel(val, dvo->regs + DVO_DOF_CFG);
276 
277 	dvo->enabled = true;
278 }
279 
280 static void sti_dvo_set_mode(struct drm_bridge *bridge,
281 			     struct drm_display_mode *mode,
282 			     struct drm_display_mode *adjusted_mode)
283 {
284 	struct sti_dvo *dvo = bridge->driver_private;
285 	struct sti_mixer *mixer = to_sti_mixer(dvo->encoder->crtc);
286 	int rate = mode->clock * 1000;
287 	struct clk *clkp;
288 	int ret;
289 
290 	DRM_DEBUG_DRIVER("\n");
291 
292 	memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
293 
294 	/* According to the path used (main or aux), the dvo clocks should
295 	 * have a different parent clock. */
296 	if (mixer->id == STI_MIXER_MAIN)
297 		clkp = dvo->clk_main_parent;
298 	else
299 		clkp = dvo->clk_aux_parent;
300 
301 	if (clkp) {
302 		clk_set_parent(dvo->clk_pix, clkp);
303 		clk_set_parent(dvo->clk, clkp);
304 	}
305 
306 	/* DVO clocks = compositor clock */
307 	ret = clk_set_rate(dvo->clk_pix, rate);
308 	if (ret < 0) {
309 		DRM_ERROR("Cannot set rate (%dHz) for dvo_pix clk\n", rate);
310 		return;
311 	}
312 
313 	ret = clk_set_rate(dvo->clk, rate);
314 	if (ret < 0) {
315 		DRM_ERROR("Cannot set rate (%dHz) for dvo clk\n", rate);
316 		return;
317 	}
318 
319 	/* For now, we only support 24bit data enable (DE) synchro format */
320 	dvo->config = &rgb_24bit_de_cfg;
321 }
322 
323 static void sti_dvo_bridge_nope(struct drm_bridge *bridge)
324 {
325 	/* do nothing */
326 }
327 
328 static const struct drm_bridge_funcs sti_dvo_bridge_funcs = {
329 	.pre_enable = sti_dvo_pre_enable,
330 	.enable = sti_dvo_bridge_nope,
331 	.disable = sti_dvo_disable,
332 	.post_disable = sti_dvo_bridge_nope,
333 	.mode_set = sti_dvo_set_mode,
334 };
335 
336 static int sti_dvo_connector_get_modes(struct drm_connector *connector)
337 {
338 	struct sti_dvo_connector *dvo_connector
339 		= to_sti_dvo_connector(connector);
340 	struct sti_dvo *dvo = dvo_connector->dvo;
341 
342 	if (dvo->panel)
343 		return dvo->panel->funcs->get_modes(dvo->panel);
344 
345 	return 0;
346 }
347 
348 #define CLK_TOLERANCE_HZ 50
349 
350 static int sti_dvo_connector_mode_valid(struct drm_connector *connector,
351 					struct drm_display_mode *mode)
352 {
353 	int target = mode->clock * 1000;
354 	int target_min = target - CLK_TOLERANCE_HZ;
355 	int target_max = target + CLK_TOLERANCE_HZ;
356 	int result;
357 	struct sti_dvo_connector *dvo_connector
358 		= to_sti_dvo_connector(connector);
359 	struct sti_dvo *dvo = dvo_connector->dvo;
360 
361 	result = clk_round_rate(dvo->clk_pix, target);
362 
363 	DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
364 			 target, result);
365 
366 	if ((result < target_min) || (result > target_max)) {
367 		DRM_DEBUG_DRIVER("dvo pixclk=%d not supported\n", target);
368 		return MODE_BAD;
369 	}
370 
371 	return MODE_OK;
372 }
373 
374 static const
375 struct drm_connector_helper_funcs sti_dvo_connector_helper_funcs = {
376 	.get_modes = sti_dvo_connector_get_modes,
377 	.mode_valid = sti_dvo_connector_mode_valid,
378 };
379 
380 static enum drm_connector_status
381 sti_dvo_connector_detect(struct drm_connector *connector, bool force)
382 {
383 	struct sti_dvo_connector *dvo_connector
384 		= to_sti_dvo_connector(connector);
385 	struct sti_dvo *dvo = dvo_connector->dvo;
386 
387 	DRM_DEBUG_DRIVER("\n");
388 
389 	if (!dvo->panel) {
390 		dvo->panel = of_drm_find_panel(dvo->panel_node);
391 		if (dvo->panel)
392 			drm_panel_attach(dvo->panel, connector);
393 	}
394 
395 	if (dvo->panel)
396 		return connector_status_connected;
397 
398 	return connector_status_disconnected;
399 }
400 
401 static int sti_dvo_late_register(struct drm_connector *connector)
402 {
403 	struct sti_dvo_connector *dvo_connector
404 		= to_sti_dvo_connector(connector);
405 	struct sti_dvo *dvo = dvo_connector->dvo;
406 
407 	if (dvo_debugfs_init(dvo, dvo->drm_dev->primary)) {
408 		DRM_ERROR("DVO debugfs setup failed\n");
409 		return -EINVAL;
410 	}
411 
412 	return 0;
413 }
414 
415 static const struct drm_connector_funcs sti_dvo_connector_funcs = {
416 	.dpms = drm_atomic_helper_connector_dpms,
417 	.fill_modes = drm_helper_probe_single_connector_modes,
418 	.detect = sti_dvo_connector_detect,
419 	.destroy = drm_connector_cleanup,
420 	.reset = drm_atomic_helper_connector_reset,
421 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
422 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
423 	.late_register = sti_dvo_late_register,
424 };
425 
426 static struct drm_encoder *sti_dvo_find_encoder(struct drm_device *dev)
427 {
428 	struct drm_encoder *encoder;
429 
430 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
431 		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
432 			return encoder;
433 	}
434 
435 	return NULL;
436 }
437 
438 static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
439 {
440 	struct sti_dvo *dvo = dev_get_drvdata(dev);
441 	struct drm_device *drm_dev = data;
442 	struct drm_encoder *encoder;
443 	struct sti_dvo_connector *connector;
444 	struct drm_connector *drm_connector;
445 	struct drm_bridge *bridge;
446 	int err;
447 
448 	/* Set the drm device handle */
449 	dvo->drm_dev = drm_dev;
450 
451 	encoder = sti_dvo_find_encoder(drm_dev);
452 	if (!encoder)
453 		return -ENOMEM;
454 
455 	connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
456 	if (!connector)
457 		return -ENOMEM;
458 
459 	connector->dvo = dvo;
460 
461 	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
462 	if (!bridge)
463 		return -ENOMEM;
464 
465 	bridge->driver_private = dvo;
466 	bridge->funcs = &sti_dvo_bridge_funcs;
467 	bridge->of_node = dvo->dev.of_node;
468 	err = drm_bridge_add(bridge);
469 	if (err) {
470 		DRM_ERROR("Failed to add bridge\n");
471 		return err;
472 	}
473 
474 	err = drm_bridge_attach(encoder, bridge, NULL);
475 	if (err) {
476 		DRM_ERROR("Failed to attach bridge\n");
477 		return err;
478 	}
479 
480 	dvo->bridge = bridge;
481 	connector->encoder = encoder;
482 	dvo->encoder = encoder;
483 
484 	drm_connector = (struct drm_connector *)connector;
485 
486 	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
487 
488 	drm_connector_init(drm_dev, drm_connector,
489 			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
490 	drm_connector_helper_add(drm_connector,
491 				 &sti_dvo_connector_helper_funcs);
492 
493 	err = drm_mode_connector_attach_encoder(drm_connector, encoder);
494 	if (err) {
495 		DRM_ERROR("Failed to attach a connector to a encoder\n");
496 		goto err_sysfs;
497 	}
498 
499 	return 0;
500 
501 err_sysfs:
502 	drm_bridge_remove(bridge);
503 	return -EINVAL;
504 }
505 
506 static void sti_dvo_unbind(struct device *dev,
507 			   struct device *master, void *data)
508 {
509 	struct sti_dvo *dvo = dev_get_drvdata(dev);
510 
511 	drm_bridge_remove(dvo->bridge);
512 }
513 
514 static const struct component_ops sti_dvo_ops = {
515 	.bind = sti_dvo_bind,
516 	.unbind = sti_dvo_unbind,
517 };
518 
519 static int sti_dvo_probe(struct platform_device *pdev)
520 {
521 	struct device *dev = &pdev->dev;
522 	struct sti_dvo *dvo;
523 	struct resource *res;
524 	struct device_node *np = dev->of_node;
525 
526 	DRM_INFO("%s\n", __func__);
527 
528 	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
529 	if (!dvo) {
530 		DRM_ERROR("Failed to allocate memory for DVO\n");
531 		return -ENOMEM;
532 	}
533 
534 	dvo->dev = pdev->dev;
535 
536 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
537 	if (!res) {
538 		DRM_ERROR("Invalid dvo resource\n");
539 		return -ENOMEM;
540 	}
541 	dvo->regs = devm_ioremap_nocache(dev, res->start,
542 			resource_size(res));
543 	if (!dvo->regs)
544 		return -ENOMEM;
545 
546 	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
547 	if (IS_ERR(dvo->clk_pix)) {
548 		DRM_ERROR("Cannot get dvo_pix clock\n");
549 		return PTR_ERR(dvo->clk_pix);
550 	}
551 
552 	dvo->clk = devm_clk_get(dev, "dvo");
553 	if (IS_ERR(dvo->clk)) {
554 		DRM_ERROR("Cannot get dvo clock\n");
555 		return PTR_ERR(dvo->clk);
556 	}
557 
558 	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
559 	if (IS_ERR(dvo->clk_main_parent)) {
560 		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
561 		dvo->clk_main_parent = NULL;
562 	}
563 
564 	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
565 	if (IS_ERR(dvo->clk_aux_parent)) {
566 		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
567 		dvo->clk_aux_parent = NULL;
568 	}
569 
570 	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
571 	if (!dvo->panel_node)
572 		DRM_ERROR("No panel associated to the dvo output\n");
573 	of_node_put(dvo->panel_node);
574 
575 	platform_set_drvdata(pdev, dvo);
576 
577 	return component_add(&pdev->dev, &sti_dvo_ops);
578 }
579 
580 static int sti_dvo_remove(struct platform_device *pdev)
581 {
582 	component_del(&pdev->dev, &sti_dvo_ops);
583 	return 0;
584 }
585 
586 static struct of_device_id dvo_of_match[] = {
587 	{ .compatible = "st,stih407-dvo", },
588 	{ /* end node */ }
589 };
590 MODULE_DEVICE_TABLE(of, dvo_of_match);
591 
592 struct platform_driver sti_dvo_driver = {
593 	.driver = {
594 		.name = "sti-dvo",
595 		.owner = THIS_MODULE,
596 		.of_match_table = dvo_of_match,
597 	},
598 	.probe = sti_dvo_probe,
599 	.remove = sti_dvo_remove,
600 };
601 
602 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
603 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
604 MODULE_LICENSE("GPL");
605