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_bridge.h>
16 #include <drm/drm_device.h>
17 #include <drm/drm_panel.h>
18 #include <drm/drm_print.h>
19 #include <drm/drm_probe_helper.h>
20 
21 #include "sti_awg_utils.h"
22 #include "sti_drv.h"
23 #include "sti_mixer.h"
24 
25 /* DVO registers */
26 #define DVO_AWG_DIGSYNC_CTRL      0x0000
27 #define DVO_DOF_CFG               0x0004
28 #define DVO_LUT_PROG_LOW          0x0008
29 #define DVO_LUT_PROG_MID          0x000C
30 #define DVO_LUT_PROG_HIGH         0x0010
31 #define DVO_DIGSYNC_INSTR_I       0x0100
32 
33 #define DVO_AWG_CTRL_EN           BIT(0)
34 #define DVO_AWG_FRAME_BASED_SYNC  BIT(2)
35 
36 #define DVO_DOF_EN_LOWBYTE        BIT(0)
37 #define DVO_DOF_EN_MIDBYTE        BIT(1)
38 #define DVO_DOF_EN_HIGHBYTE       BIT(2)
39 #define DVO_DOF_EN                BIT(6)
40 #define DVO_DOF_MOD_COUNT_SHIFT   8
41 
42 #define DVO_LUT_ZERO              0
43 #define DVO_LUT_Y_G               1
44 #define DVO_LUT_Y_G_DEL           2
45 #define DVO_LUT_CB_B              3
46 #define DVO_LUT_CB_B_DEL          4
47 #define DVO_LUT_CR_R              5
48 #define DVO_LUT_CR_R_DEL          6
49 #define DVO_LUT_HOLD              7
50 
51 struct dvo_config {
52 	u32 flags;
53 	u32 lowbyte;
54 	u32 midbyte;
55 	u32 highbyte;
56 	int (*awg_fwgen_fct)(
57 			struct awg_code_generation_params *fw_gen_params,
58 			struct awg_timing *timing);
59 };
60 
61 static struct dvo_config rgb_24bit_de_cfg = {
62 	.flags         = (0L << DVO_DOF_MOD_COUNT_SHIFT),
63 	.lowbyte       = DVO_LUT_CR_R,
64 	.midbyte       = DVO_LUT_Y_G,
65 	.highbyte      = DVO_LUT_CB_B,
66 	.awg_fwgen_fct = sti_awg_generate_code_data_enable_mode,
67 };
68 
69 /*
70  * STI digital video output structure
71  *
72  * @dev: driver device
73  * @drm_dev: pointer to drm device
74  * @mode: current display mode selected
75  * @regs: dvo registers
76  * @clk_pix: pixel clock for dvo
77  * @clk: clock for dvo
78  * @clk_main_parent: dvo parent clock if main path used
79  * @clk_aux_parent: dvo parent clock if aux path used
80  * @panel_node: panel node reference from device tree
81  * @panel: reference to the panel connected to the dvo
82  * @enabled: true if dvo is enabled else false
83  * @encoder: drm_encoder it is bound
84  */
85 struct sti_dvo {
86 	struct device dev;
87 	struct drm_device *drm_dev;
88 	struct drm_display_mode mode;
89 	void __iomem *regs;
90 	struct clk *clk_pix;
91 	struct clk *clk;
92 	struct clk *clk_main_parent;
93 	struct clk *clk_aux_parent;
94 	struct device_node *panel_node;
95 	struct drm_panel *panel;
96 	struct dvo_config *config;
97 	bool enabled;
98 	struct drm_encoder *encoder;
99 	struct drm_bridge *bridge;
100 };
101 
102 struct sti_dvo_connector {
103 	struct drm_connector drm_connector;
104 	struct drm_encoder *encoder;
105 	struct sti_dvo *dvo;
106 };
107 
108 #define to_sti_dvo_connector(x) \
109 	container_of(x, struct sti_dvo_connector, drm_connector)
110 
111 #define BLANKING_LEVEL 16
dvo_awg_generate_code(struct sti_dvo * dvo,u8 * ram_size,u32 * ram_code)112 static int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
113 {
114 	struct drm_display_mode *mode = &dvo->mode;
115 	struct dvo_config *config = dvo->config;
116 	struct awg_code_generation_params fw_gen_params;
117 	struct awg_timing timing;
118 
119 	fw_gen_params.ram_code = ram_code;
120 	fw_gen_params.instruction_offset = 0;
121 
122 	timing.total_lines = mode->vtotal;
123 	timing.active_lines = mode->vdisplay;
124 	timing.blanking_lines = mode->vsync_start - mode->vdisplay;
125 	timing.trailing_lines = mode->vtotal - mode->vsync_start;
126 	timing.total_pixels = mode->htotal;
127 	timing.active_pixels = mode->hdisplay;
128 	timing.blanking_pixels = mode->hsync_start - mode->hdisplay;
129 	timing.trailing_pixels = mode->htotal - mode->hsync_start;
130 	timing.blanking_level = BLANKING_LEVEL;
131 
132 	if (config->awg_fwgen_fct(&fw_gen_params, &timing)) {
133 		DRM_ERROR("AWG firmware not properly generated\n");
134 		return -EINVAL;
135 	}
136 
137 	*ram_size = fw_gen_params.instruction_offset;
138 
139 	return 0;
140 }
141 
142 /* Configure AWG, writing instructions
143  *
144  * @dvo: pointer to DVO structure
145  * @awg_ram_code: pointer to AWG instructions table
146  * @nb: nb of AWG instructions
147  */
dvo_awg_configure(struct sti_dvo * dvo,u32 * awg_ram_code,int nb)148 static void dvo_awg_configure(struct sti_dvo *dvo, u32 *awg_ram_code, int nb)
149 {
150 	int i;
151 
152 	DRM_DEBUG_DRIVER("\n");
153 
154 	for (i = 0; i < nb; i++)
155 		writel(awg_ram_code[i],
156 		       dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
157 	for (i = nb; i < AWG_MAX_INST; i++)
158 		writel(0, dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
159 
160 	writel(DVO_AWG_CTRL_EN, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
161 }
162 
163 #define DBGFS_DUMP(reg) seq_printf(s, "\n  %-25s 0x%08X", #reg, \
164 				   readl(dvo->regs + reg))
165 
dvo_dbg_awg_microcode(struct seq_file * s,void __iomem * reg)166 static void dvo_dbg_awg_microcode(struct seq_file *s, void __iomem *reg)
167 {
168 	unsigned int i;
169 
170 	seq_puts(s, "\n\n");
171 	seq_puts(s, "  DVO AWG microcode:");
172 	for (i = 0; i < AWG_MAX_INST; i++) {
173 		if (i % 8 == 0)
174 			seq_printf(s, "\n  %04X:", i);
175 		seq_printf(s, " %04X", readl(reg + i * 4));
176 	}
177 }
178 
dvo_dbg_show(struct seq_file * s,void * data)179 static int dvo_dbg_show(struct seq_file *s, void *data)
180 {
181 	struct drm_info_node *node = s->private;
182 	struct sti_dvo *dvo = (struct sti_dvo *)node->info_ent->data;
183 
184 	seq_printf(s, "DVO: (vaddr = 0x%p)", dvo->regs);
185 	DBGFS_DUMP(DVO_AWG_DIGSYNC_CTRL);
186 	DBGFS_DUMP(DVO_DOF_CFG);
187 	DBGFS_DUMP(DVO_LUT_PROG_LOW);
188 	DBGFS_DUMP(DVO_LUT_PROG_MID);
189 	DBGFS_DUMP(DVO_LUT_PROG_HIGH);
190 	dvo_dbg_awg_microcode(s, dvo->regs + DVO_DIGSYNC_INSTR_I);
191 	seq_putc(s, '\n');
192 	return 0;
193 }
194 
195 static struct drm_info_list dvo_debugfs_files[] = {
196 	{ "dvo", dvo_dbg_show, 0, NULL },
197 };
198 
dvo_debugfs_init(struct sti_dvo * dvo,struct drm_minor * minor)199 static void dvo_debugfs_init(struct sti_dvo *dvo, struct drm_minor *minor)
200 {
201 	unsigned int i;
202 
203 	for (i = 0; i < ARRAY_SIZE(dvo_debugfs_files); i++)
204 		dvo_debugfs_files[i].data = dvo;
205 
206 	drm_debugfs_create_files(dvo_debugfs_files,
207 				 ARRAY_SIZE(dvo_debugfs_files),
208 				 minor->debugfs_root, minor);
209 }
210 
sti_dvo_disable(struct drm_bridge * bridge)211 static void sti_dvo_disable(struct drm_bridge *bridge)
212 {
213 	struct sti_dvo *dvo = bridge->driver_private;
214 
215 	if (!dvo->enabled)
216 		return;
217 
218 	DRM_DEBUG_DRIVER("\n");
219 
220 	if (dvo->config->awg_fwgen_fct)
221 		writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
222 
223 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
224 
225 	drm_panel_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 
sti_dvo_pre_enable(struct drm_bridge * bridge)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 	drm_panel_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 
sti_dvo_set_mode(struct drm_bridge * bridge,const struct drm_display_mode * mode,const struct drm_display_mode * adjusted_mode)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 	drm_mode_copy(&dvo->mode, 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 
sti_dvo_bridge_nope(struct drm_bridge * bridge)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 
sti_dvo_connector_get_modes(struct drm_connector * connector)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 drm_panel_get_modes(dvo->panel, connector);
343 
344 	return 0;
345 }
346 
347 #define CLK_TOLERANCE_HZ 50
348 
349 static enum drm_mode_status
sti_dvo_connector_mode_valid(struct drm_connector * connector,struct drm_display_mode * mode)350 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
sti_dvo_connector_detect(struct drm_connector * connector,bool force)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 (IS_ERR(dvo->panel))
392 			dvo->panel = NULL;
393 	}
394 
395 	if (dvo->panel)
396 		return connector_status_connected;
397 
398 	return connector_status_disconnected;
399 }
400 
sti_dvo_late_register(struct drm_connector * connector)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 	dvo_debugfs_init(dvo, dvo->drm_dev->primary);
408 
409 	return 0;
410 }
411 
412 static const struct drm_connector_funcs sti_dvo_connector_funcs = {
413 	.fill_modes = drm_helper_probe_single_connector_modes,
414 	.detect = sti_dvo_connector_detect,
415 	.destroy = drm_connector_cleanup,
416 	.reset = drm_atomic_helper_connector_reset,
417 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
418 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
419 	.late_register = sti_dvo_late_register,
420 };
421 
sti_dvo_find_encoder(struct drm_device * dev)422 static struct drm_encoder *sti_dvo_find_encoder(struct drm_device *dev)
423 {
424 	struct drm_encoder *encoder;
425 
426 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
427 		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
428 			return encoder;
429 	}
430 
431 	return NULL;
432 }
433 
sti_dvo_bind(struct device * dev,struct device * master,void * data)434 static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
435 {
436 	struct sti_dvo *dvo = dev_get_drvdata(dev);
437 	struct drm_device *drm_dev = data;
438 	struct drm_encoder *encoder;
439 	struct sti_dvo_connector *connector;
440 	struct drm_connector *drm_connector;
441 	struct drm_bridge *bridge;
442 	int err;
443 
444 	/* Set the drm device handle */
445 	dvo->drm_dev = drm_dev;
446 
447 	encoder = sti_dvo_find_encoder(drm_dev);
448 	if (!encoder)
449 		return -ENOMEM;
450 
451 	connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
452 	if (!connector)
453 		return -ENOMEM;
454 
455 	connector->dvo = dvo;
456 
457 	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
458 	if (!bridge)
459 		return -ENOMEM;
460 
461 	bridge->driver_private = dvo;
462 	bridge->funcs = &sti_dvo_bridge_funcs;
463 	bridge->of_node = dvo->dev.of_node;
464 	drm_bridge_add(bridge);
465 
466 	err = drm_bridge_attach(encoder, bridge, NULL, 0);
467 	if (err)
468 		return err;
469 
470 	dvo->bridge = bridge;
471 	connector->encoder = encoder;
472 	dvo->encoder = encoder;
473 
474 	drm_connector = (struct drm_connector *)connector;
475 
476 	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
477 
478 	drm_connector_init(drm_dev, drm_connector,
479 			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
480 	drm_connector_helper_add(drm_connector,
481 				 &sti_dvo_connector_helper_funcs);
482 
483 	err = drm_connector_attach_encoder(drm_connector, encoder);
484 	if (err) {
485 		DRM_ERROR("Failed to attach a connector to a encoder\n");
486 		goto err_sysfs;
487 	}
488 
489 	return 0;
490 
491 err_sysfs:
492 	drm_bridge_remove(bridge);
493 	return -EINVAL;
494 }
495 
sti_dvo_unbind(struct device * dev,struct device * master,void * data)496 static void sti_dvo_unbind(struct device *dev,
497 			   struct device *master, void *data)
498 {
499 	struct sti_dvo *dvo = dev_get_drvdata(dev);
500 
501 	drm_bridge_remove(dvo->bridge);
502 }
503 
504 static const struct component_ops sti_dvo_ops = {
505 	.bind = sti_dvo_bind,
506 	.unbind = sti_dvo_unbind,
507 };
508 
sti_dvo_probe(struct platform_device * pdev)509 static int sti_dvo_probe(struct platform_device *pdev)
510 {
511 	struct device *dev = &pdev->dev;
512 	struct sti_dvo *dvo;
513 	struct resource *res;
514 	struct device_node *np = dev->of_node;
515 
516 	DRM_INFO("%s\n", __func__);
517 
518 	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
519 	if (!dvo) {
520 		DRM_ERROR("Failed to allocate memory for DVO\n");
521 		return -ENOMEM;
522 	}
523 
524 	dvo->dev = pdev->dev;
525 
526 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
527 	if (!res) {
528 		DRM_ERROR("Invalid dvo resource\n");
529 		return -ENOMEM;
530 	}
531 	dvo->regs = devm_ioremap(dev, res->start,
532 			resource_size(res));
533 	if (!dvo->regs)
534 		return -ENOMEM;
535 
536 	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
537 	if (IS_ERR(dvo->clk_pix)) {
538 		DRM_ERROR("Cannot get dvo_pix clock\n");
539 		return PTR_ERR(dvo->clk_pix);
540 	}
541 
542 	dvo->clk = devm_clk_get(dev, "dvo");
543 	if (IS_ERR(dvo->clk)) {
544 		DRM_ERROR("Cannot get dvo clock\n");
545 		return PTR_ERR(dvo->clk);
546 	}
547 
548 	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
549 	if (IS_ERR(dvo->clk_main_parent)) {
550 		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
551 		dvo->clk_main_parent = NULL;
552 	}
553 
554 	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
555 	if (IS_ERR(dvo->clk_aux_parent)) {
556 		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
557 		dvo->clk_aux_parent = NULL;
558 	}
559 
560 	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
561 	if (!dvo->panel_node)
562 		DRM_ERROR("No panel associated to the dvo output\n");
563 	of_node_put(dvo->panel_node);
564 
565 	platform_set_drvdata(pdev, dvo);
566 
567 	return component_add(&pdev->dev, &sti_dvo_ops);
568 }
569 
sti_dvo_remove(struct platform_device * pdev)570 static int sti_dvo_remove(struct platform_device *pdev)
571 {
572 	component_del(&pdev->dev, &sti_dvo_ops);
573 	return 0;
574 }
575 
576 static const struct of_device_id dvo_of_match[] = {
577 	{ .compatible = "st,stih407-dvo", },
578 	{ /* end node */ }
579 };
580 MODULE_DEVICE_TABLE(of, dvo_of_match);
581 
582 struct platform_driver sti_dvo_driver = {
583 	.driver = {
584 		.name = "sti-dvo",
585 		.owner = THIS_MODULE,
586 		.of_match_table = dvo_of_match,
587 	},
588 	.probe = sti_dvo_probe,
589 	.remove = sti_dvo_remove,
590 };
591 
592 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
593 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
594 MODULE_LICENSE("GPL");
595