xref: /openbmc/linux/drivers/gpu/drm/sti/sti_vtg.c (revision 503290ce)
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_vtg.h"
17 
18 #define VTG_MODE_MASTER         0
19 #define VTG_MODE_SLAVE_BY_EXT0  1
20 
21 /* registers offset */
22 #define VTG_MODE            0x0000
23 #define VTG_CLKLN           0x0008
24 #define VTG_HLFLN           0x000C
25 #define VTG_DRST_AUTOC      0x0010
26 #define VTG_VID_TFO         0x0040
27 #define VTG_VID_TFS         0x0044
28 #define VTG_VID_BFO         0x0048
29 #define VTG_VID_BFS         0x004C
30 
31 #define VTG_HOST_ITS        0x0078
32 #define VTG_HOST_ITS_BCLR   0x007C
33 #define VTG_HOST_ITM_BCLR   0x0088
34 #define VTG_HOST_ITM_BSET   0x008C
35 
36 #define VTG_H_HD_1          0x00C0
37 #define VTG_TOP_V_VD_1      0x00C4
38 #define VTG_BOT_V_VD_1      0x00C8
39 #define VTG_TOP_V_HD_1      0x00CC
40 #define VTG_BOT_V_HD_1      0x00D0
41 
42 #define VTG_H_HD_2          0x00E0
43 #define VTG_TOP_V_VD_2      0x00E4
44 #define VTG_BOT_V_VD_2      0x00E8
45 #define VTG_TOP_V_HD_2      0x00EC
46 #define VTG_BOT_V_HD_2      0x00F0
47 
48 #define VTG_H_HD_3          0x0100
49 #define VTG_TOP_V_VD_3      0x0104
50 #define VTG_BOT_V_VD_3      0x0108
51 #define VTG_TOP_V_HD_3      0x010C
52 #define VTG_BOT_V_HD_3      0x0110
53 
54 #define VTG_H_HD_4          0x0120
55 #define VTG_TOP_V_VD_4      0x0124
56 #define VTG_BOT_V_VD_4      0x0128
57 #define VTG_TOP_V_HD_4      0x012c
58 #define VTG_BOT_V_HD_4      0x0130
59 
60 #define VTG_IRQ_BOTTOM      BIT(0)
61 #define VTG_IRQ_TOP         BIT(1)
62 #define VTG_IRQ_MASK        (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
63 
64 /* Delay introduced by the HDMI in nb of pixel */
65 #define HDMI_DELAY          (5)
66 
67 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
68 #define AWG_DELAY_HD        (-9)
69 #define AWG_DELAY_ED        (-8)
70 #define AWG_DELAY_SD        (-7)
71 
72 LIST_HEAD(vtg_lookup);
73 
74 /*
75  * STI VTG register offset structure
76  *
77  *@h_hd:     stores the VTG_H_HD_x     register offset
78  *@top_v_vd: stores the VTG_TOP_V_VD_x register offset
79  *@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
80  *@top_v_hd: stores the VTG_TOP_V_HD_x register offset
81  *@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
82  */
83 struct sti_vtg_regs_offs {
84 	u32 h_hd;
85 	u32 top_v_vd;
86 	u32 bot_v_vd;
87 	u32 top_v_hd;
88 	u32 bot_v_hd;
89 };
90 
91 #define VTG_MAX_SYNC_OUTPUT 4
92 static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
93 	{ VTG_H_HD_1,
94 	  VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
95 	{ VTG_H_HD_2,
96 	  VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
97 	{ VTG_H_HD_3,
98 	  VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
99 	{ VTG_H_HD_4,
100 	  VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
101 };
102 
103 /*
104  * STI VTG synchronisation parameters structure
105  *
106  *@hsync: sample number falling and rising edge
107  *@vsync_line_top: vertical top field line number falling and rising edge
108  *@vsync_line_bot: vertical bottom field line number falling and rising edge
109  *@vsync_off_top: vertical top field sample number rising and falling edge
110  *@vsync_off_bot: vertical bottom field sample number rising and falling edge
111  */
112 struct sti_vtg_sync_params {
113 	u32 hsync;
114 	u32 vsync_line_top;
115 	u32 vsync_line_bot;
116 	u32 vsync_off_top;
117 	u32 vsync_off_bot;
118 };
119 
120 /**
121  * STI VTG structure
122  *
123  * @dev: pointer to device driver
124  * @np: device node
125  * @regs: register mapping
126  * @sync_params: synchronisation parameters used to generate timings
127  * @irq: VTG irq
128  * @irq_status: store the IRQ status value
129  * @notifier_list: notifier callback
130  * @crtc: the CRTC for vblank event
131  * @slave: slave vtg
132  * @link: List node to link the structure in lookup list
133  */
134 struct sti_vtg {
135 	struct device *dev;
136 	struct device_node *np;
137 	void __iomem *regs;
138 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
139 	int irq;
140 	u32 irq_status;
141 	struct raw_notifier_head notifier_list;
142 	struct drm_crtc *crtc;
143 	struct sti_vtg *slave;
144 	struct list_head link;
145 };
146 
147 static void vtg_register(struct sti_vtg *vtg)
148 {
149 	list_add_tail(&vtg->link, &vtg_lookup);
150 }
151 
152 struct sti_vtg *of_vtg_find(struct device_node *np)
153 {
154 	struct sti_vtg *vtg;
155 
156 	list_for_each_entry(vtg, &vtg_lookup, link) {
157 		if (vtg->np == np)
158 			return vtg;
159 	}
160 	return NULL;
161 }
162 
163 static void vtg_reset(struct sti_vtg *vtg)
164 {
165 	/* reset slave and then master */
166 	if (vtg->slave)
167 		vtg_reset(vtg->slave);
168 
169 	writel(1, vtg->regs + VTG_DRST_AUTOC);
170 }
171 
172 static void vtg_set_output_window(void __iomem *regs,
173 				  const struct drm_display_mode *mode)
174 {
175 	u32 video_top_field_start;
176 	u32 video_top_field_stop;
177 	u32 video_bottom_field_start;
178 	u32 video_bottom_field_stop;
179 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
180 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
181 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
182 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
183 
184 	/* Set output window to fit the display mode selected */
185 	video_top_field_start = (ystart << 16) | xstart;
186 	video_top_field_stop = (ystop << 16) | xstop;
187 
188 	/* Only progressive supported for now */
189 	video_bottom_field_start = video_top_field_start;
190 	video_bottom_field_stop = video_top_field_stop;
191 
192 	writel(video_top_field_start, regs + VTG_VID_TFO);
193 	writel(video_top_field_stop, regs + VTG_VID_TFS);
194 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
195 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
196 }
197 
198 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
199 				    int delay,
200 				    const struct drm_display_mode *mode)
201 {
202 	long clocksperline, start, stop;
203 	u32 risesync_top, fallsync_top;
204 	u32 risesync_offs_top, fallsync_offs_top;
205 
206 	clocksperline = mode->htotal;
207 
208 	/* Get the hsync position */
209 	start = 0;
210 	stop = mode->hsync_end - mode->hsync_start;
211 
212 	start += delay;
213 	stop  += delay;
214 
215 	if (start < 0)
216 		start += clocksperline;
217 	else if (start >= clocksperline)
218 		start -= clocksperline;
219 
220 	if (stop < 0)
221 		stop += clocksperline;
222 	else if (stop >= clocksperline)
223 		stop -= clocksperline;
224 
225 	sync->hsync = (stop << 16) | start;
226 
227 	/* Get the vsync position */
228 	if (delay >= 0) {
229 		risesync_top = 1;
230 		fallsync_top = risesync_top;
231 		fallsync_top += mode->vsync_end - mode->vsync_start;
232 
233 		fallsync_offs_top = (u32)delay;
234 		risesync_offs_top = (u32)delay;
235 	} else {
236 		risesync_top = mode->vtotal;
237 		fallsync_top = mode->vsync_end - mode->vsync_start;
238 
239 		fallsync_offs_top = clocksperline + delay;
240 		risesync_offs_top = clocksperline + delay;
241 	}
242 
243 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
244 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
245 
246 	/* Only progressive supported for now */
247 	sync->vsync_line_bot = sync->vsync_line_top;
248 	sync->vsync_off_bot = sync->vsync_off_top;
249 }
250 
251 static void vtg_set_mode(struct sti_vtg *vtg,
252 			 int type,
253 			 struct sti_vtg_sync_params *sync,
254 			 const struct drm_display_mode *mode)
255 {
256 	unsigned int i;
257 
258 	if (vtg->slave)
259 		vtg_set_mode(vtg->slave, VTG_MODE_SLAVE_BY_EXT0,
260 			     vtg->sync_params, mode);
261 
262 	/* Set the number of clock cycles per line */
263 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
264 
265 	/* Set Half Line Per Field (only progressive supported for now) */
266 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
267 
268 	/* Program output window */
269 	vtg_set_output_window(vtg->regs, mode);
270 
271 	/* Set hsync and vsync position for HDMI */
272 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
273 
274 	/* Set hsync and vsync position for HD DCS */
275 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
276 
277 	/* Set hsync and vsync position for HDF */
278 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
279 
280 	/* Set hsync and vsync position for DVO */
281 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], 0, mode);
282 
283 	/* Progam the syncs outputs */
284 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
285 		writel(sync[i].hsync,
286 		       vtg->regs + vtg_regs_offs[i].h_hd);
287 		writel(sync[i].vsync_line_top,
288 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
289 		writel(sync[i].vsync_line_bot,
290 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
291 		writel(sync[i].vsync_off_top,
292 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
293 		writel(sync[i].vsync_off_bot,
294 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
295 	}
296 
297 	/* mode */
298 	writel(type, vtg->regs + VTG_MODE);
299 }
300 
301 static void vtg_enable_irq(struct sti_vtg *vtg)
302 {
303 	/* clear interrupt status and mask */
304 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
305 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
306 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
307 }
308 
309 void sti_vtg_set_config(struct sti_vtg *vtg,
310 		const struct drm_display_mode *mode)
311 {
312 	/* write configuration */
313 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
314 
315 	vtg_reset(vtg);
316 
317 	/* enable irq for the vtg vblank synchro */
318 	if (vtg->slave)
319 		vtg_enable_irq(vtg->slave);
320 	else
321 		vtg_enable_irq(vtg);
322 }
323 
324 /**
325  * sti_vtg_get_line_number
326  *
327  * @mode: display mode to be used
328  * @y:    line
329  *
330  * Return the line number according to the display mode taking
331  * into account the Sync and Back Porch information.
332  * Video frame line numbers start at 1, y starts at 0.
333  * In interlaced modes the start line is the field line number of the odd
334  * field, but y is still defined as a progressive frame.
335  */
336 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
337 {
338 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
339 
340 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
341 		start_line *= 2;
342 
343 	return start_line + y;
344 }
345 
346 /**
347  * sti_vtg_get_pixel_number
348  *
349  * @mode: display mode to be used
350  * @x:    row
351  *
352  * Return the pixel number according to the display mode taking
353  * into account the Sync and Back Porch information.
354  * Pixels are counted from 0.
355  */
356 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
357 {
358 	return mode.htotal - mode.hsync_start + x;
359 }
360 
361 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
362 			    struct drm_crtc *crtc)
363 {
364 	if (vtg->slave)
365 		return sti_vtg_register_client(vtg->slave, nb, crtc);
366 
367 	vtg->crtc = crtc;
368 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
369 }
370 
371 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
372 {
373 	if (vtg->slave)
374 		return sti_vtg_unregister_client(vtg->slave, nb);
375 
376 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
377 }
378 
379 static irqreturn_t vtg_irq_thread(int irq, void *arg)
380 {
381 	struct sti_vtg *vtg = arg;
382 	u32 event;
383 
384 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
385 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
386 
387 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
388 
389 	return IRQ_HANDLED;
390 }
391 
392 static irqreturn_t vtg_irq(int irq, void *arg)
393 {
394 	struct sti_vtg *vtg = arg;
395 
396 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
397 
398 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
399 
400 	/* force sync bus write */
401 	readl(vtg->regs + VTG_HOST_ITS);
402 
403 	return IRQ_WAKE_THREAD;
404 }
405 
406 static int vtg_probe(struct platform_device *pdev)
407 {
408 	struct device *dev = &pdev->dev;
409 	struct device_node *np;
410 	struct sti_vtg *vtg;
411 	struct resource *res;
412 	int ret;
413 
414 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
415 	if (!vtg)
416 		return -ENOMEM;
417 
418 	vtg->dev = dev;
419 	vtg->np = pdev->dev.of_node;
420 
421 	/* Get Memory ressources */
422 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
423 	if (!res) {
424 		DRM_ERROR("Get memory resource failed\n");
425 		return -ENOMEM;
426 	}
427 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
428 
429 	np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
430 	if (np) {
431 		vtg->slave = of_vtg_find(np);
432 
433 		if (!vtg->slave)
434 			return -EPROBE_DEFER;
435 	} else {
436 		vtg->irq = platform_get_irq(pdev, 0);
437 		if (IS_ERR_VALUE(vtg->irq)) {
438 			DRM_ERROR("Failed to get VTG interrupt\n");
439 			return vtg->irq;
440 		}
441 
442 		RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
443 
444 		ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
445 				vtg_irq_thread, IRQF_ONESHOT,
446 				dev_name(dev), vtg);
447 		if (IS_ERR_VALUE(ret)) {
448 			DRM_ERROR("Failed to register VTG interrupt\n");
449 			return ret;
450 		}
451 	}
452 
453 	vtg_register(vtg);
454 	platform_set_drvdata(pdev, vtg);
455 
456 	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
457 
458 	return 0;
459 }
460 
461 static int vtg_remove(struct platform_device *pdev)
462 {
463 	return 0;
464 }
465 
466 static const struct of_device_id vtg_of_match[] = {
467 	{ .compatible = "st,vtg", },
468 	{ /* sentinel */ }
469 };
470 MODULE_DEVICE_TABLE(of, vtg_of_match);
471 
472 struct platform_driver sti_vtg_driver = {
473 	.driver = {
474 		.name = "sti-vtg",
475 		.owner = THIS_MODULE,
476 		.of_match_table = vtg_of_match,
477 	},
478 	.probe	= vtg_probe,
479 	.remove = vtg_remove,
480 };
481 
482 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
483 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
484 MODULE_LICENSE("GPL");
485