xref: /linux/drivers/gpu/drm/sti/sti_dvo.c (revision 8795a739e5c72abeec51caf36b6df2b37e5720c5)
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/drm_atomic_helper.h>
15 #include <drm/drm_device.h>
16 #include <drm/drm_panel.h>
17 #include <drm/drm_print.h>
18 #include <drm/drm_probe_helper.h>
19 
20 #include "sti_awg_utils.h"
21 #include "sti_drv.h"
22 #include "sti_mixer.h"
23 
24 /* DVO registers */
25 #define DVO_AWG_DIGSYNC_CTRL      0x0000
26 #define DVO_DOF_CFG               0x0004
27 #define DVO_LUT_PROG_LOW          0x0008
28 #define DVO_LUT_PROG_MID          0x000C
29 #define DVO_LUT_PROG_HIGH         0x0010
30 #define DVO_DIGSYNC_INSTR_I       0x0100
31 
32 #define DVO_AWG_CTRL_EN           BIT(0)
33 #define DVO_AWG_FRAME_BASED_SYNC  BIT(2)
34 
35 #define DVO_DOF_EN_LOWBYTE        BIT(0)
36 #define DVO_DOF_EN_MIDBYTE        BIT(1)
37 #define DVO_DOF_EN_HIGHBYTE       BIT(2)
38 #define DVO_DOF_EN                BIT(6)
39 #define DVO_DOF_MOD_COUNT_SHIFT   8
40 
41 #define DVO_LUT_ZERO              0
42 #define DVO_LUT_Y_G               1
43 #define DVO_LUT_Y_G_DEL           2
44 #define DVO_LUT_CB_B              3
45 #define DVO_LUT_CB_B_DEL          4
46 #define DVO_LUT_CR_R              5
47 #define DVO_LUT_CR_R_DEL          6
48 #define DVO_LUT_HOLD              7
49 
50 struct dvo_config {
51 	u32 flags;
52 	u32 lowbyte;
53 	u32 midbyte;
54 	u32 highbyte;
55 	int (*awg_fwgen_fct)(
56 			struct awg_code_generation_params *fw_gen_params,
57 			struct awg_timing *timing);
58 };
59 
60 static struct dvo_config rgb_24bit_de_cfg = {
61 	.flags         = (0L << DVO_DOF_MOD_COUNT_SHIFT),
62 	.lowbyte       = DVO_LUT_CR_R,
63 	.midbyte       = DVO_LUT_Y_G,
64 	.highbyte      = DVO_LUT_CB_B,
65 	.awg_fwgen_fct = sti_awg_generate_code_data_enable_mode,
66 };
67 
68 /**
69  * STI digital video output structure
70  *
71  * @dev: driver device
72  * @drm_dev: pointer to drm device
73  * @mode: current display mode selected
74  * @regs: dvo registers
75  * @clk_pix: pixel clock for dvo
76  * @clk: clock for dvo
77  * @clk_main_parent: dvo parent clock if main path used
78  * @clk_aux_parent: dvo parent clock if aux path used
79  * @panel_node: panel node reference from device tree
80  * @panel: reference to the panel connected to the dvo
81  * @enabled: true if dvo is enabled else false
82  * @encoder: drm_encoder it is bound
83  */
84 struct sti_dvo {
85 	struct device dev;
86 	struct drm_device *drm_dev;
87 	struct drm_display_mode mode;
88 	void __iomem *regs;
89 	struct clk *clk_pix;
90 	struct clk *clk;
91 	struct clk *clk_main_parent;
92 	struct clk *clk_aux_parent;
93 	struct device_node *panel_node;
94 	struct drm_panel *panel;
95 	struct dvo_config *config;
96 	bool enabled;
97 	struct drm_encoder *encoder;
98 	struct drm_bridge *bridge;
99 };
100 
101 struct sti_dvo_connector {
102 	struct drm_connector drm_connector;
103 	struct drm_encoder *encoder;
104 	struct sti_dvo *dvo;
105 };
106 
107 #define to_sti_dvo_connector(x) \
108 	container_of(x, struct sti_dvo_connector, drm_connector)
109 
110 #define BLANKING_LEVEL 16
111 static int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
112 {
113 	struct drm_display_mode *mode = &dvo->mode;
114 	struct dvo_config *config = dvo->config;
115 	struct awg_code_generation_params fw_gen_params;
116 	struct awg_timing timing;
117 
118 	fw_gen_params.ram_code = ram_code;
119 	fw_gen_params.instruction_offset = 0;
120 
121 	timing.total_lines = mode->vtotal;
122 	timing.active_lines = mode->vdisplay;
123 	timing.blanking_lines = mode->vsync_start - mode->vdisplay;
124 	timing.trailing_lines = mode->vtotal - mode->vsync_start;
125 	timing.total_pixels = mode->htotal;
126 	timing.active_pixels = mode->hdisplay;
127 	timing.blanking_pixels = mode->hsync_start - mode->hdisplay;
128 	timing.trailing_pixels = mode->htotal - mode->hsync_start;
129 	timing.blanking_level = BLANKING_LEVEL;
130 
131 	if (config->awg_fwgen_fct(&fw_gen_params, &timing)) {
132 		DRM_ERROR("AWG firmware not properly generated\n");
133 		return -EINVAL;
134 	}
135 
136 	*ram_size = fw_gen_params.instruction_offset;
137 
138 	return 0;
139 }
140 
141 /* Configure AWG, writing instructions
142  *
143  * @dvo: pointer to DVO structure
144  * @awg_ram_code: pointer to AWG instructions table
145  * @nb: nb of AWG instructions
146  */
147 static void dvo_awg_configure(struct sti_dvo *dvo, u32 *awg_ram_code, int nb)
148 {
149 	int i;
150 
151 	DRM_DEBUG_DRIVER("\n");
152 
153 	for (i = 0; i < nb; i++)
154 		writel(awg_ram_code[i],
155 		       dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
156 	for (i = nb; i < AWG_MAX_INST; i++)
157 		writel(0, dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
158 
159 	writel(DVO_AWG_CTRL_EN, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
160 }
161 
162 #define DBGFS_DUMP(reg) seq_printf(s, "\n  %-25s 0x%08X", #reg, \
163 				   readl(dvo->regs + reg))
164 
165 static void dvo_dbg_awg_microcode(struct seq_file *s, void __iomem *reg)
166 {
167 	unsigned int i;
168 
169 	seq_puts(s, "\n\n");
170 	seq_puts(s, "  DVO AWG microcode:");
171 	for (i = 0; i < AWG_MAX_INST; i++) {
172 		if (i % 8 == 0)
173 			seq_printf(s, "\n  %04X:", i);
174 		seq_printf(s, " %04X", readl(reg + i * 4));
175 	}
176 }
177 
178 static int dvo_dbg_show(struct seq_file *s, void *data)
179 {
180 	struct drm_info_node *node = s->private;
181 	struct sti_dvo *dvo = (struct sti_dvo *)node->info_ent->data;
182 
183 	seq_printf(s, "DVO: (vaddr = 0x%p)", dvo->regs);
184 	DBGFS_DUMP(DVO_AWG_DIGSYNC_CTRL);
185 	DBGFS_DUMP(DVO_DOF_CFG);
186 	DBGFS_DUMP(DVO_LUT_PROG_LOW);
187 	DBGFS_DUMP(DVO_LUT_PROG_MID);
188 	DBGFS_DUMP(DVO_LUT_PROG_HIGH);
189 	dvo_dbg_awg_microcode(s, dvo->regs + DVO_DIGSYNC_INSTR_I);
190 	seq_putc(s, '\n');
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 	drm_panel_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 	drm_panel_enable(dvo->panel);
265 
266 	/* Set LUT */
267 	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
268 	writel(config->midbyte,  dvo->regs + DVO_LUT_PROG_MID);
269 	writel(config->highbyte, dvo->regs + DVO_LUT_PROG_HIGH);
270 
271 	/* Digital output formatter config */
272 	val = (config->flags | DVO_DOF_EN);
273 	writel(val, dvo->regs + DVO_DOF_CFG);
274 
275 	dvo->enabled = true;
276 }
277 
278 static void sti_dvo_set_mode(struct drm_bridge *bridge,
279 			     const struct drm_display_mode *mode,
280 			     const struct drm_display_mode *adjusted_mode)
281 {
282 	struct sti_dvo *dvo = bridge->driver_private;
283 	struct sti_mixer *mixer = to_sti_mixer(dvo->encoder->crtc);
284 	int rate = mode->clock * 1000;
285 	struct clk *clkp;
286 	int ret;
287 
288 	DRM_DEBUG_DRIVER("\n");
289 
290 	memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
291 
292 	/* According to the path used (main or aux), the dvo clocks should
293 	 * have a different parent clock. */
294 	if (mixer->id == STI_MIXER_MAIN)
295 		clkp = dvo->clk_main_parent;
296 	else
297 		clkp = dvo->clk_aux_parent;
298 
299 	if (clkp) {
300 		clk_set_parent(dvo->clk_pix, clkp);
301 		clk_set_parent(dvo->clk, clkp);
302 	}
303 
304 	/* DVO clocks = compositor clock */
305 	ret = clk_set_rate(dvo->clk_pix, rate);
306 	if (ret < 0) {
307 		DRM_ERROR("Cannot set rate (%dHz) for dvo_pix clk\n", rate);
308 		return;
309 	}
310 
311 	ret = clk_set_rate(dvo->clk, rate);
312 	if (ret < 0) {
313 		DRM_ERROR("Cannot set rate (%dHz) for dvo clk\n", rate);
314 		return;
315 	}
316 
317 	/* For now, we only support 24bit data enable (DE) synchro format */
318 	dvo->config = &rgb_24bit_de_cfg;
319 }
320 
321 static void sti_dvo_bridge_nope(struct drm_bridge *bridge)
322 {
323 	/* do nothing */
324 }
325 
326 static const struct drm_bridge_funcs sti_dvo_bridge_funcs = {
327 	.pre_enable = sti_dvo_pre_enable,
328 	.enable = sti_dvo_bridge_nope,
329 	.disable = sti_dvo_disable,
330 	.post_disable = sti_dvo_bridge_nope,
331 	.mode_set = sti_dvo_set_mode,
332 };
333 
334 static int sti_dvo_connector_get_modes(struct drm_connector *connector)
335 {
336 	struct sti_dvo_connector *dvo_connector
337 		= to_sti_dvo_connector(connector);
338 	struct sti_dvo *dvo = dvo_connector->dvo;
339 
340 	if (dvo->panel)
341 		return drm_panel_get_modes(dvo->panel);
342 
343 	return 0;
344 }
345 
346 #define CLK_TOLERANCE_HZ 50
347 
348 static int sti_dvo_connector_mode_valid(struct drm_connector *connector,
349 					struct drm_display_mode *mode)
350 {
351 	int target = mode->clock * 1000;
352 	int target_min = target - CLK_TOLERANCE_HZ;
353 	int target_max = target + CLK_TOLERANCE_HZ;
354 	int result;
355 	struct sti_dvo_connector *dvo_connector
356 		= to_sti_dvo_connector(connector);
357 	struct sti_dvo *dvo = dvo_connector->dvo;
358 
359 	result = clk_round_rate(dvo->clk_pix, target);
360 
361 	DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
362 			 target, result);
363 
364 	if ((result < target_min) || (result > target_max)) {
365 		DRM_DEBUG_DRIVER("dvo pixclk=%d not supported\n", target);
366 		return MODE_BAD;
367 	}
368 
369 	return MODE_OK;
370 }
371 
372 static const
373 struct drm_connector_helper_funcs sti_dvo_connector_helper_funcs = {
374 	.get_modes = sti_dvo_connector_get_modes,
375 	.mode_valid = sti_dvo_connector_mode_valid,
376 };
377 
378 static enum drm_connector_status
379 sti_dvo_connector_detect(struct drm_connector *connector, bool force)
380 {
381 	struct sti_dvo_connector *dvo_connector
382 		= to_sti_dvo_connector(connector);
383 	struct sti_dvo *dvo = dvo_connector->dvo;
384 
385 	DRM_DEBUG_DRIVER("\n");
386 
387 	if (!dvo->panel) {
388 		dvo->panel = of_drm_find_panel(dvo->panel_node);
389 		if (IS_ERR(dvo->panel))
390 			dvo->panel = NULL;
391 		else
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 	.fill_modes = drm_helper_probe_single_connector_modes,
417 	.detect = sti_dvo_connector_detect,
418 	.destroy = drm_connector_cleanup,
419 	.reset = drm_atomic_helper_connector_reset,
420 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
421 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
422 	.late_register = sti_dvo_late_register,
423 };
424 
425 static struct drm_encoder *sti_dvo_find_encoder(struct drm_device *dev)
426 {
427 	struct drm_encoder *encoder;
428 
429 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
430 		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
431 			return encoder;
432 	}
433 
434 	return NULL;
435 }
436 
437 static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
438 {
439 	struct sti_dvo *dvo = dev_get_drvdata(dev);
440 	struct drm_device *drm_dev = data;
441 	struct drm_encoder *encoder;
442 	struct sti_dvo_connector *connector;
443 	struct drm_connector *drm_connector;
444 	struct drm_bridge *bridge;
445 	int err;
446 
447 	/* Set the drm device handle */
448 	dvo->drm_dev = drm_dev;
449 
450 	encoder = sti_dvo_find_encoder(drm_dev);
451 	if (!encoder)
452 		return -ENOMEM;
453 
454 	connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
455 	if (!connector)
456 		return -ENOMEM;
457 
458 	connector->dvo = dvo;
459 
460 	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
461 	if (!bridge)
462 		return -ENOMEM;
463 
464 	bridge->driver_private = dvo;
465 	bridge->funcs = &sti_dvo_bridge_funcs;
466 	bridge->of_node = dvo->dev.of_node;
467 	drm_bridge_add(bridge);
468 
469 	err = drm_bridge_attach(encoder, bridge, NULL);
470 	if (err) {
471 		DRM_ERROR("Failed to attach bridge\n");
472 		return err;
473 	}
474 
475 	dvo->bridge = bridge;
476 	connector->encoder = encoder;
477 	dvo->encoder = encoder;
478 
479 	drm_connector = (struct drm_connector *)connector;
480 
481 	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
482 
483 	drm_connector_init(drm_dev, drm_connector,
484 			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
485 	drm_connector_helper_add(drm_connector,
486 				 &sti_dvo_connector_helper_funcs);
487 
488 	err = drm_connector_attach_encoder(drm_connector, encoder);
489 	if (err) {
490 		DRM_ERROR("Failed to attach a connector to a encoder\n");
491 		goto err_sysfs;
492 	}
493 
494 	return 0;
495 
496 err_sysfs:
497 	drm_bridge_remove(bridge);
498 	return -EINVAL;
499 }
500 
501 static void sti_dvo_unbind(struct device *dev,
502 			   struct device *master, void *data)
503 {
504 	struct sti_dvo *dvo = dev_get_drvdata(dev);
505 
506 	drm_bridge_remove(dvo->bridge);
507 }
508 
509 static const struct component_ops sti_dvo_ops = {
510 	.bind = sti_dvo_bind,
511 	.unbind = sti_dvo_unbind,
512 };
513 
514 static int sti_dvo_probe(struct platform_device *pdev)
515 {
516 	struct device *dev = &pdev->dev;
517 	struct sti_dvo *dvo;
518 	struct resource *res;
519 	struct device_node *np = dev->of_node;
520 
521 	DRM_INFO("%s\n", __func__);
522 
523 	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
524 	if (!dvo) {
525 		DRM_ERROR("Failed to allocate memory for DVO\n");
526 		return -ENOMEM;
527 	}
528 
529 	dvo->dev = pdev->dev;
530 
531 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
532 	if (!res) {
533 		DRM_ERROR("Invalid dvo resource\n");
534 		return -ENOMEM;
535 	}
536 	dvo->regs = devm_ioremap_nocache(dev, res->start,
537 			resource_size(res));
538 	if (!dvo->regs)
539 		return -ENOMEM;
540 
541 	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
542 	if (IS_ERR(dvo->clk_pix)) {
543 		DRM_ERROR("Cannot get dvo_pix clock\n");
544 		return PTR_ERR(dvo->clk_pix);
545 	}
546 
547 	dvo->clk = devm_clk_get(dev, "dvo");
548 	if (IS_ERR(dvo->clk)) {
549 		DRM_ERROR("Cannot get dvo clock\n");
550 		return PTR_ERR(dvo->clk);
551 	}
552 
553 	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
554 	if (IS_ERR(dvo->clk_main_parent)) {
555 		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
556 		dvo->clk_main_parent = NULL;
557 	}
558 
559 	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
560 	if (IS_ERR(dvo->clk_aux_parent)) {
561 		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
562 		dvo->clk_aux_parent = NULL;
563 	}
564 
565 	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
566 	if (!dvo->panel_node)
567 		DRM_ERROR("No panel associated to the dvo output\n");
568 	of_node_put(dvo->panel_node);
569 
570 	platform_set_drvdata(pdev, dvo);
571 
572 	return component_add(&pdev->dev, &sti_dvo_ops);
573 }
574 
575 static int sti_dvo_remove(struct platform_device *pdev)
576 {
577 	component_del(&pdev->dev, &sti_dvo_ops);
578 	return 0;
579 }
580 
581 static const struct of_device_id dvo_of_match[] = {
582 	{ .compatible = "st,stih407-dvo", },
583 	{ /* end node */ }
584 };
585 MODULE_DEVICE_TABLE(of, dvo_of_match);
586 
587 struct platform_driver sti_dvo_driver = {
588 	.driver = {
589 		.name = "sti-dvo",
590 		.owner = THIS_MODULE,
591 		.of_match_table = dvo_of_match,
592 	},
593 	.probe = sti_dvo_probe,
594 	.remove = sti_dvo_remove,
595 };
596 
597 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
598 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
599 MODULE_LICENSE("GPL");
600