xref: /openbmc/linux/drivers/gpu/drm/sti/sti_dvo.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics SA 2014
4  * Author: Vincent Abriou <vincent.abriou@st.com> for STMicroelectronics.
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_panel.h>
17 #include <drm/drm_probe_helper.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_putc(s, '\n');
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 int dvo_debugfs_init(struct sti_dvo *dvo, struct drm_minor *minor)
198 {
199 	unsigned int i;
200 
201 	for (i = 0; i < ARRAY_SIZE(dvo_debugfs_files); i++)
202 		dvo_debugfs_files[i].data = dvo;
203 
204 	return drm_debugfs_create_files(dvo_debugfs_files,
205 					ARRAY_SIZE(dvo_debugfs_files),
206 					minor->debugfs_root, minor);
207 }
208 
209 static void sti_dvo_disable(struct drm_bridge *bridge)
210 {
211 	struct sti_dvo *dvo = bridge->driver_private;
212 
213 	if (!dvo->enabled)
214 		return;
215 
216 	DRM_DEBUG_DRIVER("\n");
217 
218 	if (dvo->config->awg_fwgen_fct)
219 		writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
220 
221 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
222 
223 	if (dvo->panel)
224 		dvo->panel->funcs->disable(dvo->panel);
225 
226 	/* Disable/unprepare dvo clock */
227 	clk_disable_unprepare(dvo->clk_pix);
228 	clk_disable_unprepare(dvo->clk);
229 
230 	dvo->enabled = false;
231 }
232 
233 static void sti_dvo_pre_enable(struct drm_bridge *bridge)
234 {
235 	struct sti_dvo *dvo = bridge->driver_private;
236 	struct dvo_config *config = dvo->config;
237 	u32 val;
238 
239 	DRM_DEBUG_DRIVER("\n");
240 
241 	if (dvo->enabled)
242 		return;
243 
244 	/* Make sure DVO is disabled */
245 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
246 	writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
247 
248 	if (config->awg_fwgen_fct) {
249 		u8 nb_instr;
250 		u32 awg_ram_code[AWG_MAX_INST];
251 		/* Configure AWG */
252 		if (!dvo_awg_generate_code(dvo, &nb_instr, awg_ram_code))
253 			dvo_awg_configure(dvo, awg_ram_code, nb_instr);
254 		else
255 			return;
256 	}
257 
258 	/* Prepare/enable clocks */
259 	if (clk_prepare_enable(dvo->clk_pix))
260 		DRM_ERROR("Failed to prepare/enable dvo_pix clk\n");
261 	if (clk_prepare_enable(dvo->clk))
262 		DRM_ERROR("Failed to prepare/enable dvo clk\n");
263 
264 	if (dvo->panel)
265 		dvo->panel->funcs->enable(dvo->panel);
266 
267 	/* Set LUT */
268 	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
269 	writel(config->midbyte,  dvo->regs + DVO_LUT_PROG_MID);
270 	writel(config->highbyte, dvo->regs + DVO_LUT_PROG_HIGH);
271 
272 	/* Digital output formatter config */
273 	val = (config->flags | DVO_DOF_EN);
274 	writel(val, dvo->regs + DVO_DOF_CFG);
275 
276 	dvo->enabled = true;
277 }
278 
279 static void sti_dvo_set_mode(struct drm_bridge *bridge,
280 			     const struct drm_display_mode *mode,
281 			     const struct drm_display_mode *adjusted_mode)
282 {
283 	struct sti_dvo *dvo = bridge->driver_private;
284 	struct sti_mixer *mixer = to_sti_mixer(dvo->encoder->crtc);
285 	int rate = mode->clock * 1000;
286 	struct clk *clkp;
287 	int ret;
288 
289 	DRM_DEBUG_DRIVER("\n");
290 
291 	memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
292 
293 	/* According to the path used (main or aux), the dvo clocks should
294 	 * have a different parent clock. */
295 	if (mixer->id == STI_MIXER_MAIN)
296 		clkp = dvo->clk_main_parent;
297 	else
298 		clkp = dvo->clk_aux_parent;
299 
300 	if (clkp) {
301 		clk_set_parent(dvo->clk_pix, clkp);
302 		clk_set_parent(dvo->clk, clkp);
303 	}
304 
305 	/* DVO clocks = compositor clock */
306 	ret = clk_set_rate(dvo->clk_pix, rate);
307 	if (ret < 0) {
308 		DRM_ERROR("Cannot set rate (%dHz) for dvo_pix clk\n", rate);
309 		return;
310 	}
311 
312 	ret = clk_set_rate(dvo->clk, rate);
313 	if (ret < 0) {
314 		DRM_ERROR("Cannot set rate (%dHz) for dvo clk\n", rate);
315 		return;
316 	}
317 
318 	/* For now, we only support 24bit data enable (DE) synchro format */
319 	dvo->config = &rgb_24bit_de_cfg;
320 }
321 
322 static void sti_dvo_bridge_nope(struct drm_bridge *bridge)
323 {
324 	/* do nothing */
325 }
326 
327 static const struct drm_bridge_funcs sti_dvo_bridge_funcs = {
328 	.pre_enable = sti_dvo_pre_enable,
329 	.enable = sti_dvo_bridge_nope,
330 	.disable = sti_dvo_disable,
331 	.post_disable = sti_dvo_bridge_nope,
332 	.mode_set = sti_dvo_set_mode,
333 };
334 
335 static int sti_dvo_connector_get_modes(struct drm_connector *connector)
336 {
337 	struct sti_dvo_connector *dvo_connector
338 		= to_sti_dvo_connector(connector);
339 	struct sti_dvo *dvo = dvo_connector->dvo;
340 
341 	if (dvo->panel)
342 		return dvo->panel->funcs->get_modes(dvo->panel);
343 
344 	return 0;
345 }
346 
347 #define CLK_TOLERANCE_HZ 50
348 
349 static int sti_dvo_connector_mode_valid(struct drm_connector *connector,
350 					struct drm_display_mode *mode)
351 {
352 	int target = mode->clock * 1000;
353 	int target_min = target - CLK_TOLERANCE_HZ;
354 	int target_max = target + CLK_TOLERANCE_HZ;
355 	int result;
356 	struct sti_dvo_connector *dvo_connector
357 		= to_sti_dvo_connector(connector);
358 	struct sti_dvo *dvo = dvo_connector->dvo;
359 
360 	result = clk_round_rate(dvo->clk_pix, target);
361 
362 	DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
363 			 target, result);
364 
365 	if ((result < target_min) || (result > target_max)) {
366 		DRM_DEBUG_DRIVER("dvo pixclk=%d not supported\n", target);
367 		return MODE_BAD;
368 	}
369 
370 	return MODE_OK;
371 }
372 
373 static const
374 struct drm_connector_helper_funcs sti_dvo_connector_helper_funcs = {
375 	.get_modes = sti_dvo_connector_get_modes,
376 	.mode_valid = sti_dvo_connector_mode_valid,
377 };
378 
379 static enum drm_connector_status
380 sti_dvo_connector_detect(struct drm_connector *connector, bool force)
381 {
382 	struct sti_dvo_connector *dvo_connector
383 		= to_sti_dvo_connector(connector);
384 	struct sti_dvo *dvo = dvo_connector->dvo;
385 
386 	DRM_DEBUG_DRIVER("\n");
387 
388 	if (!dvo->panel) {
389 		dvo->panel = of_drm_find_panel(dvo->panel_node);
390 		if (IS_ERR(dvo->panel))
391 			dvo->panel = NULL;
392 		else
393 			drm_panel_attach(dvo->panel, connector);
394 	}
395 
396 	if (dvo->panel)
397 		return connector_status_connected;
398 
399 	return connector_status_disconnected;
400 }
401 
402 static int sti_dvo_late_register(struct drm_connector *connector)
403 {
404 	struct sti_dvo_connector *dvo_connector
405 		= to_sti_dvo_connector(connector);
406 	struct sti_dvo *dvo = dvo_connector->dvo;
407 
408 	if (dvo_debugfs_init(dvo, dvo->drm_dev->primary)) {
409 		DRM_ERROR("DVO debugfs setup failed\n");
410 		return -EINVAL;
411 	}
412 
413 	return 0;
414 }
415 
416 static const struct drm_connector_funcs sti_dvo_connector_funcs = {
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 	drm_bridge_add(bridge);
469 
470 	err = drm_bridge_attach(encoder, bridge, NULL);
471 	if (err) {
472 		DRM_ERROR("Failed to attach bridge\n");
473 		return err;
474 	}
475 
476 	dvo->bridge = bridge;
477 	connector->encoder = encoder;
478 	dvo->encoder = encoder;
479 
480 	drm_connector = (struct drm_connector *)connector;
481 
482 	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
483 
484 	drm_connector_init(drm_dev, drm_connector,
485 			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
486 	drm_connector_helper_add(drm_connector,
487 				 &sti_dvo_connector_helper_funcs);
488 
489 	err = drm_connector_attach_encoder(drm_connector, encoder);
490 	if (err) {
491 		DRM_ERROR("Failed to attach a connector to a encoder\n");
492 		goto err_sysfs;
493 	}
494 
495 	return 0;
496 
497 err_sysfs:
498 	drm_bridge_remove(bridge);
499 	return -EINVAL;
500 }
501 
502 static void sti_dvo_unbind(struct device *dev,
503 			   struct device *master, void *data)
504 {
505 	struct sti_dvo *dvo = dev_get_drvdata(dev);
506 
507 	drm_bridge_remove(dvo->bridge);
508 }
509 
510 static const struct component_ops sti_dvo_ops = {
511 	.bind = sti_dvo_bind,
512 	.unbind = sti_dvo_unbind,
513 };
514 
515 static int sti_dvo_probe(struct platform_device *pdev)
516 {
517 	struct device *dev = &pdev->dev;
518 	struct sti_dvo *dvo;
519 	struct resource *res;
520 	struct device_node *np = dev->of_node;
521 
522 	DRM_INFO("%s\n", __func__);
523 
524 	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
525 	if (!dvo) {
526 		DRM_ERROR("Failed to allocate memory for DVO\n");
527 		return -ENOMEM;
528 	}
529 
530 	dvo->dev = pdev->dev;
531 
532 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
533 	if (!res) {
534 		DRM_ERROR("Invalid dvo resource\n");
535 		return -ENOMEM;
536 	}
537 	dvo->regs = devm_ioremap_nocache(dev, res->start,
538 			resource_size(res));
539 	if (!dvo->regs)
540 		return -ENOMEM;
541 
542 	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
543 	if (IS_ERR(dvo->clk_pix)) {
544 		DRM_ERROR("Cannot get dvo_pix clock\n");
545 		return PTR_ERR(dvo->clk_pix);
546 	}
547 
548 	dvo->clk = devm_clk_get(dev, "dvo");
549 	if (IS_ERR(dvo->clk)) {
550 		DRM_ERROR("Cannot get dvo clock\n");
551 		return PTR_ERR(dvo->clk);
552 	}
553 
554 	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
555 	if (IS_ERR(dvo->clk_main_parent)) {
556 		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
557 		dvo->clk_main_parent = NULL;
558 	}
559 
560 	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
561 	if (IS_ERR(dvo->clk_aux_parent)) {
562 		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
563 		dvo->clk_aux_parent = NULL;
564 	}
565 
566 	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
567 	if (!dvo->panel_node)
568 		DRM_ERROR("No panel associated to the dvo output\n");
569 	of_node_put(dvo->panel_node);
570 
571 	platform_set_drvdata(pdev, dvo);
572 
573 	return component_add(&pdev->dev, &sti_dvo_ops);
574 }
575 
576 static int sti_dvo_remove(struct platform_device *pdev)
577 {
578 	component_del(&pdev->dev, &sti_dvo_ops);
579 	return 0;
580 }
581 
582 static const struct of_device_id dvo_of_match[] = {
583 	{ .compatible = "st,stih407-dvo", },
584 	{ /* end node */ }
585 };
586 MODULE_DEVICE_TABLE(of, dvo_of_match);
587 
588 struct platform_driver sti_dvo_driver = {
589 	.driver = {
590 		.name = "sti-dvo",
591 		.owner = THIS_MODULE,
592 		.of_match_table = dvo_of_match,
593 	},
594 	.probe = sti_dvo_probe,
595 	.remove = sti_dvo_remove,
596 };
597 
598 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
599 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
600 MODULE_LICENSE("GPL");
601