xref: /openbmc/linux/drivers/gpu/drm/sti/sti_vtg.c (revision bdfd36ef)
1 /*
2  * Copyright (C) STMicroelectronics SA 2014
3  * Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
4  *          Fabien Dessenne <fabien.dessenne@st.com>
5  *          Vincent Abriou <vincent.abriou@st.com>
6  *          for STMicroelectronics.
7  * License terms:  GNU General Public License (GPL), version 2
8  */
9 
10 #include <linux/module.h>
11 #include <linux/notifier.h>
12 #include <linux/platform_device.h>
13 
14 #include <drm/drmP.h>
15 
16 #include "sti_drv.h"
17 #include "sti_vtg.h"
18 
19 #define VTG_MODE_MASTER         0
20 #define VTG_MODE_SLAVE_BY_EXT0  1
21 
22 /* registers offset */
23 #define VTG_MODE            0x0000
24 #define VTG_CLKLN           0x0008
25 #define VTG_HLFLN           0x000C
26 #define VTG_DRST_AUTOC      0x0010
27 #define VTG_VID_TFO         0x0040
28 #define VTG_VID_TFS         0x0044
29 #define VTG_VID_BFO         0x0048
30 #define VTG_VID_BFS         0x004C
31 
32 #define VTG_HOST_ITS        0x0078
33 #define VTG_HOST_ITS_BCLR   0x007C
34 #define VTG_HOST_ITM_BCLR   0x0088
35 #define VTG_HOST_ITM_BSET   0x008C
36 
37 #define VTG_H_HD_1          0x00C0
38 #define VTG_TOP_V_VD_1      0x00C4
39 #define VTG_BOT_V_VD_1      0x00C8
40 #define VTG_TOP_V_HD_1      0x00CC
41 #define VTG_BOT_V_HD_1      0x00D0
42 
43 #define VTG_H_HD_2          0x00E0
44 #define VTG_TOP_V_VD_2      0x00E4
45 #define VTG_BOT_V_VD_2      0x00E8
46 #define VTG_TOP_V_HD_2      0x00EC
47 #define VTG_BOT_V_HD_2      0x00F0
48 
49 #define VTG_H_HD_3          0x0100
50 #define VTG_TOP_V_VD_3      0x0104
51 #define VTG_BOT_V_VD_3      0x0108
52 #define VTG_TOP_V_HD_3      0x010C
53 #define VTG_BOT_V_HD_3      0x0110
54 
55 #define VTG_H_HD_4          0x0120
56 #define VTG_TOP_V_VD_4      0x0124
57 #define VTG_BOT_V_VD_4      0x0128
58 #define VTG_TOP_V_HD_4      0x012c
59 #define VTG_BOT_V_HD_4      0x0130
60 
61 #define VTG_IRQ_BOTTOM      BIT(0)
62 #define VTG_IRQ_TOP         BIT(1)
63 #define VTG_IRQ_MASK        (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
64 
65 /* Delay introduced by the HDMI in nb of pixel */
66 #define HDMI_DELAY          (5)
67 
68 /* Delay introduced by the DVO in nb of pixel */
69 #define DVO_DELAY           (7)
70 
71 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
72 #define AWG_DELAY_HD        (-9)
73 #define AWG_DELAY_ED        (-8)
74 #define AWG_DELAY_SD        (-7)
75 
76 static LIST_HEAD(vtg_lookup);
77 
78 /*
79  * STI VTG register offset structure
80  *
81  *@h_hd:     stores the VTG_H_HD_x     register offset
82  *@top_v_vd: stores the VTG_TOP_V_VD_x register offset
83  *@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
84  *@top_v_hd: stores the VTG_TOP_V_HD_x register offset
85  *@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
86  */
87 struct sti_vtg_regs_offs {
88 	u32 h_hd;
89 	u32 top_v_vd;
90 	u32 bot_v_vd;
91 	u32 top_v_hd;
92 	u32 bot_v_hd;
93 };
94 
95 #define VTG_MAX_SYNC_OUTPUT 4
96 static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
97 	{ VTG_H_HD_1,
98 	  VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
99 	{ VTG_H_HD_2,
100 	  VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
101 	{ VTG_H_HD_3,
102 	  VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
103 	{ VTG_H_HD_4,
104 	  VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
105 };
106 
107 /*
108  * STI VTG synchronisation parameters structure
109  *
110  *@hsync: sample number falling and rising edge
111  *@vsync_line_top: vertical top field line number falling and rising edge
112  *@vsync_line_bot: vertical bottom field line number falling and rising edge
113  *@vsync_off_top: vertical top field sample number rising and falling edge
114  *@vsync_off_bot: vertical bottom field sample number rising and falling edge
115  */
116 struct sti_vtg_sync_params {
117 	u32 hsync;
118 	u32 vsync_line_top;
119 	u32 vsync_line_bot;
120 	u32 vsync_off_top;
121 	u32 vsync_off_bot;
122 };
123 
124 /**
125  * STI VTG structure
126  *
127  * @dev: pointer to device driver
128  * @np: device node
129  * @regs: register mapping
130  * @sync_params: synchronisation parameters used to generate timings
131  * @irq: VTG irq
132  * @irq_status: store the IRQ status value
133  * @notifier_list: notifier callback
134  * @crtc: the CRTC for vblank event
135  * @slave: slave vtg
136  * @link: List node to link the structure in lookup list
137  */
138 struct sti_vtg {
139 	struct device *dev;
140 	struct device_node *np;
141 	void __iomem *regs;
142 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
143 	int irq;
144 	u32 irq_status;
145 	struct raw_notifier_head notifier_list;
146 	struct drm_crtc *crtc;
147 	struct sti_vtg *slave;
148 	struct list_head link;
149 };
150 
151 static void vtg_register(struct sti_vtg *vtg)
152 {
153 	list_add_tail(&vtg->link, &vtg_lookup);
154 }
155 
156 struct sti_vtg *of_vtg_find(struct device_node *np)
157 {
158 	struct sti_vtg *vtg;
159 
160 	list_for_each_entry(vtg, &vtg_lookup, link) {
161 		if (vtg->np == np)
162 			return vtg;
163 	}
164 	return NULL;
165 }
166 
167 static void vtg_reset(struct sti_vtg *vtg)
168 {
169 	/* reset slave and then master */
170 	if (vtg->slave)
171 		vtg_reset(vtg->slave);
172 
173 	writel(1, vtg->regs + VTG_DRST_AUTOC);
174 }
175 
176 static void vtg_set_output_window(void __iomem *regs,
177 				  const struct drm_display_mode *mode)
178 {
179 	u32 video_top_field_start;
180 	u32 video_top_field_stop;
181 	u32 video_bottom_field_start;
182 	u32 video_bottom_field_stop;
183 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
184 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
185 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
186 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
187 
188 	/* Set output window to fit the display mode selected */
189 	video_top_field_start = (ystart << 16) | xstart;
190 	video_top_field_stop = (ystop << 16) | xstop;
191 
192 	/* Only progressive supported for now */
193 	video_bottom_field_start = video_top_field_start;
194 	video_bottom_field_stop = video_top_field_stop;
195 
196 	writel(video_top_field_start, regs + VTG_VID_TFO);
197 	writel(video_top_field_stop, regs + VTG_VID_TFS);
198 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
199 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
200 }
201 
202 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
203 				    int delay,
204 				    const struct drm_display_mode *mode)
205 {
206 	long clocksperline, start, stop;
207 	u32 risesync_top, fallsync_top;
208 	u32 risesync_offs_top, fallsync_offs_top;
209 
210 	clocksperline = mode->htotal;
211 
212 	/* Get the hsync position */
213 	start = 0;
214 	stop = mode->hsync_end - mode->hsync_start;
215 
216 	start += delay;
217 	stop  += delay;
218 
219 	if (start < 0)
220 		start += clocksperline;
221 	else if (start >= clocksperline)
222 		start -= clocksperline;
223 
224 	if (stop < 0)
225 		stop += clocksperline;
226 	else if (stop >= clocksperline)
227 		stop -= clocksperline;
228 
229 	sync->hsync = (stop << 16) | start;
230 
231 	/* Get the vsync position */
232 	if (delay >= 0) {
233 		risesync_top = 1;
234 		fallsync_top = risesync_top;
235 		fallsync_top += mode->vsync_end - mode->vsync_start;
236 
237 		fallsync_offs_top = (u32)delay;
238 		risesync_offs_top = (u32)delay;
239 	} else {
240 		risesync_top = mode->vtotal;
241 		fallsync_top = mode->vsync_end - mode->vsync_start;
242 
243 		fallsync_offs_top = clocksperline + delay;
244 		risesync_offs_top = clocksperline + delay;
245 	}
246 
247 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
248 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
249 
250 	/* Only progressive supported for now */
251 	sync->vsync_line_bot = sync->vsync_line_top;
252 	sync->vsync_off_bot = sync->vsync_off_top;
253 }
254 
255 static void vtg_set_mode(struct sti_vtg *vtg,
256 			 int type,
257 			 struct sti_vtg_sync_params *sync,
258 			 const struct drm_display_mode *mode)
259 {
260 	unsigned int i;
261 
262 	if (vtg->slave)
263 		vtg_set_mode(vtg->slave, VTG_MODE_SLAVE_BY_EXT0,
264 			     vtg->sync_params, mode);
265 
266 	/* Set the number of clock cycles per line */
267 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
268 
269 	/* Set Half Line Per Field (only progressive supported for now) */
270 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
271 
272 	/* Program output window */
273 	vtg_set_output_window(vtg->regs, mode);
274 
275 	/* Set hsync and vsync position for HDMI */
276 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
277 
278 	/* Set hsync and vsync position for HD DCS */
279 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
280 
281 	/* Set hsync and vsync position for HDF */
282 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
283 
284 	/* Set hsync and vsync position for DVO */
285 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);
286 
287 	/* Progam the syncs outputs */
288 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
289 		writel(sync[i].hsync,
290 		       vtg->regs + vtg_regs_offs[i].h_hd);
291 		writel(sync[i].vsync_line_top,
292 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
293 		writel(sync[i].vsync_line_bot,
294 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
295 		writel(sync[i].vsync_off_top,
296 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
297 		writel(sync[i].vsync_off_bot,
298 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
299 	}
300 
301 	/* mode */
302 	writel(type, vtg->regs + VTG_MODE);
303 }
304 
305 static void vtg_enable_irq(struct sti_vtg *vtg)
306 {
307 	/* clear interrupt status and mask */
308 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
309 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
310 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
311 }
312 
313 void sti_vtg_set_config(struct sti_vtg *vtg,
314 		const struct drm_display_mode *mode)
315 {
316 	/* write configuration */
317 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
318 
319 	vtg_reset(vtg);
320 
321 	/* enable irq for the vtg vblank synchro */
322 	if (vtg->slave)
323 		vtg_enable_irq(vtg->slave);
324 	else
325 		vtg_enable_irq(vtg);
326 }
327 
328 /**
329  * sti_vtg_get_line_number
330  *
331  * @mode: display mode to be used
332  * @y:    line
333  *
334  * Return the line number according to the display mode taking
335  * into account the Sync and Back Porch information.
336  * Video frame line numbers start at 1, y starts at 0.
337  * In interlaced modes the start line is the field line number of the odd
338  * field, but y is still defined as a progressive frame.
339  */
340 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
341 {
342 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
343 
344 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
345 		start_line *= 2;
346 
347 	return start_line + y;
348 }
349 
350 /**
351  * sti_vtg_get_pixel_number
352  *
353  * @mode: display mode to be used
354  * @x:    row
355  *
356  * Return the pixel number according to the display mode taking
357  * into account the Sync and Back Porch information.
358  * Pixels are counted from 0.
359  */
360 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
361 {
362 	return mode.htotal - mode.hsync_start + x;
363 }
364 
365 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
366 			    struct drm_crtc *crtc)
367 {
368 	if (vtg->slave)
369 		return sti_vtg_register_client(vtg->slave, nb, crtc);
370 
371 	vtg->crtc = crtc;
372 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
373 }
374 
375 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
376 {
377 	if (vtg->slave)
378 		return sti_vtg_unregister_client(vtg->slave, nb);
379 
380 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
381 }
382 
383 static irqreturn_t vtg_irq_thread(int irq, void *arg)
384 {
385 	struct sti_vtg *vtg = arg;
386 	u32 event;
387 
388 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
389 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
390 
391 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
392 
393 	return IRQ_HANDLED;
394 }
395 
396 static irqreturn_t vtg_irq(int irq, void *arg)
397 {
398 	struct sti_vtg *vtg = arg;
399 
400 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
401 
402 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
403 
404 	/* force sync bus write */
405 	readl(vtg->regs + VTG_HOST_ITS);
406 
407 	return IRQ_WAKE_THREAD;
408 }
409 
410 static int vtg_probe(struct platform_device *pdev)
411 {
412 	struct device *dev = &pdev->dev;
413 	struct device_node *np;
414 	struct sti_vtg *vtg;
415 	struct resource *res;
416 	int ret;
417 
418 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
419 	if (!vtg)
420 		return -ENOMEM;
421 
422 	vtg->dev = dev;
423 	vtg->np = pdev->dev.of_node;
424 
425 	/* Get Memory ressources */
426 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
427 	if (!res) {
428 		DRM_ERROR("Get memory resource failed\n");
429 		return -ENOMEM;
430 	}
431 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
432 
433 	np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
434 	if (np) {
435 		vtg->slave = of_vtg_find(np);
436 		of_node_put(np);
437 
438 		if (!vtg->slave)
439 			return -EPROBE_DEFER;
440 	} else {
441 		vtg->irq = platform_get_irq(pdev, 0);
442 		if (vtg->irq < 0) {
443 			DRM_ERROR("Failed to get VTG interrupt\n");
444 			return vtg->irq;
445 		}
446 
447 		RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
448 
449 		ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
450 				vtg_irq_thread, IRQF_ONESHOT,
451 				dev_name(dev), vtg);
452 		if (ret < 0) {
453 			DRM_ERROR("Failed to register VTG interrupt\n");
454 			return ret;
455 		}
456 	}
457 
458 	vtg_register(vtg);
459 	platform_set_drvdata(pdev, vtg);
460 
461 	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
462 
463 	return 0;
464 }
465 
466 static int vtg_remove(struct platform_device *pdev)
467 {
468 	return 0;
469 }
470 
471 static const struct of_device_id vtg_of_match[] = {
472 	{ .compatible = "st,vtg", },
473 	{ /* sentinel */ }
474 };
475 MODULE_DEVICE_TABLE(of, vtg_of_match);
476 
477 struct platform_driver sti_vtg_driver = {
478 	.driver = {
479 		.name = "sti-vtg",
480 		.owner = THIS_MODULE,
481 		.of_match_table = vtg_of_match,
482 	},
483 	.probe	= vtg_probe,
484 	.remove = vtg_remove,
485 };
486 
487 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
488 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
489 MODULE_LICENSE("GPL");
490