xref: /linux/drivers/gpu/drm/sti/sti_vtg.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
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 
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 DVO in nb of pixel */
68 #define DVO_DELAY           (7)
69 
70 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
71 #define AWG_DELAY_HD        (-9)
72 #define AWG_DELAY_ED        (-8)
73 #define AWG_DELAY_SD        (-7)
74 
75 static LIST_HEAD(vtg_lookup);
76 
77 /*
78  * STI VTG register offset structure
79  *
80  *@h_hd:     stores the VTG_H_HD_x     register offset
81  *@top_v_vd: stores the VTG_TOP_V_VD_x register offset
82  *@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
83  *@top_v_hd: stores the VTG_TOP_V_HD_x register offset
84  *@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
85  */
86 struct sti_vtg_regs_offs {
87 	u32 h_hd;
88 	u32 top_v_vd;
89 	u32 bot_v_vd;
90 	u32 top_v_hd;
91 	u32 bot_v_hd;
92 };
93 
94 #define VTG_MAX_SYNC_OUTPUT 4
95 static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
96 	{ VTG_H_HD_1,
97 	  VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
98 	{ VTG_H_HD_2,
99 	  VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
100 	{ VTG_H_HD_3,
101 	  VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
102 	{ VTG_H_HD_4,
103 	  VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
104 };
105 
106 /*
107  * STI VTG synchronisation parameters structure
108  *
109  *@hsync: sample number falling and rising edge
110  *@vsync_line_top: vertical top field line number falling and rising edge
111  *@vsync_line_bot: vertical bottom field line number falling and rising edge
112  *@vsync_off_top: vertical top field sample number rising and falling edge
113  *@vsync_off_bot: vertical bottom field sample number rising and falling edge
114  */
115 struct sti_vtg_sync_params {
116 	u32 hsync;
117 	u32 vsync_line_top;
118 	u32 vsync_line_bot;
119 	u32 vsync_off_top;
120 	u32 vsync_off_bot;
121 };
122 
123 /**
124  * STI VTG structure
125  *
126  * @dev: pointer to device driver
127  * @np: device node
128  * @regs: register mapping
129  * @sync_params: synchronisation parameters used to generate timings
130  * @irq: VTG irq
131  * @irq_status: store the IRQ status value
132  * @notifier_list: notifier callback
133  * @crtc: the CRTC for vblank event
134  * @link: List node to link the structure in lookup list
135  */
136 struct sti_vtg {
137 	struct device *dev;
138 	struct device_node *np;
139 	void __iomem *regs;
140 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
141 	int irq;
142 	u32 irq_status;
143 	struct raw_notifier_head notifier_list;
144 	struct drm_crtc *crtc;
145 	struct list_head link;
146 };
147 
148 static void vtg_register(struct sti_vtg *vtg)
149 {
150 	list_add_tail(&vtg->link, &vtg_lookup);
151 }
152 
153 struct sti_vtg *of_vtg_find(struct device_node *np)
154 {
155 	struct sti_vtg *vtg;
156 
157 	list_for_each_entry(vtg, &vtg_lookup, link) {
158 		if (vtg->np == np)
159 			return vtg;
160 	}
161 	return NULL;
162 }
163 
164 static void vtg_reset(struct sti_vtg *vtg)
165 {
166 	writel(1, vtg->regs + VTG_DRST_AUTOC);
167 }
168 
169 static void vtg_set_output_window(void __iomem *regs,
170 				  const struct drm_display_mode *mode)
171 {
172 	u32 video_top_field_start;
173 	u32 video_top_field_stop;
174 	u32 video_bottom_field_start;
175 	u32 video_bottom_field_stop;
176 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
177 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
178 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
179 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
180 
181 	/* Set output window to fit the display mode selected */
182 	video_top_field_start = (ystart << 16) | xstart;
183 	video_top_field_stop = (ystop << 16) | xstop;
184 
185 	/* Only progressive supported for now */
186 	video_bottom_field_start = video_top_field_start;
187 	video_bottom_field_stop = video_top_field_stop;
188 
189 	writel(video_top_field_start, regs + VTG_VID_TFO);
190 	writel(video_top_field_stop, regs + VTG_VID_TFS);
191 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
192 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
193 }
194 
195 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
196 				    int delay,
197 				    const struct drm_display_mode *mode)
198 {
199 	long clocksperline, start, stop;
200 	u32 risesync_top, fallsync_top;
201 	u32 risesync_offs_top, fallsync_offs_top;
202 
203 	clocksperline = mode->htotal;
204 
205 	/* Get the hsync position */
206 	start = 0;
207 	stop = mode->hsync_end - mode->hsync_start;
208 
209 	start += delay;
210 	stop  += delay;
211 
212 	if (start < 0)
213 		start += clocksperline;
214 	else if (start >= clocksperline)
215 		start -= clocksperline;
216 
217 	if (stop < 0)
218 		stop += clocksperline;
219 	else if (stop >= clocksperline)
220 		stop -= clocksperline;
221 
222 	sync->hsync = (stop << 16) | start;
223 
224 	/* Get the vsync position */
225 	if (delay >= 0) {
226 		risesync_top = 1;
227 		fallsync_top = risesync_top;
228 		fallsync_top += mode->vsync_end - mode->vsync_start;
229 
230 		fallsync_offs_top = (u32)delay;
231 		risesync_offs_top = (u32)delay;
232 	} else {
233 		risesync_top = mode->vtotal;
234 		fallsync_top = mode->vsync_end - mode->vsync_start;
235 
236 		fallsync_offs_top = clocksperline + delay;
237 		risesync_offs_top = clocksperline + delay;
238 	}
239 
240 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
241 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
242 
243 	/* Only progressive supported for now */
244 	sync->vsync_line_bot = sync->vsync_line_top;
245 	sync->vsync_off_bot = sync->vsync_off_top;
246 }
247 
248 static void vtg_set_mode(struct sti_vtg *vtg,
249 			 int type,
250 			 struct sti_vtg_sync_params *sync,
251 			 const struct drm_display_mode *mode)
252 {
253 	unsigned int i;
254 
255 	/* Set the number of clock cycles per line */
256 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
257 
258 	/* Set Half Line Per Field (only progressive supported for now) */
259 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
260 
261 	/* Program output window */
262 	vtg_set_output_window(vtg->regs, mode);
263 
264 	/* Set hsync and vsync position for HDMI */
265 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
266 
267 	/* Set hsync and vsync position for HD DCS */
268 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
269 
270 	/* Set hsync and vsync position for HDF */
271 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
272 
273 	/* Set hsync and vsync position for DVO */
274 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);
275 
276 	/* Progam the syncs outputs */
277 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
278 		writel(sync[i].hsync,
279 		       vtg->regs + vtg_regs_offs[i].h_hd);
280 		writel(sync[i].vsync_line_top,
281 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
282 		writel(sync[i].vsync_line_bot,
283 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
284 		writel(sync[i].vsync_off_top,
285 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
286 		writel(sync[i].vsync_off_bot,
287 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
288 	}
289 
290 	/* mode */
291 	writel(type, vtg->regs + VTG_MODE);
292 }
293 
294 static void vtg_enable_irq(struct sti_vtg *vtg)
295 {
296 	/* clear interrupt status and mask */
297 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
298 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
299 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
300 }
301 
302 void sti_vtg_set_config(struct sti_vtg *vtg,
303 		const struct drm_display_mode *mode)
304 {
305 	/* write configuration */
306 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
307 
308 	vtg_reset(vtg);
309 
310 	vtg_enable_irq(vtg);
311 }
312 
313 /**
314  * sti_vtg_get_line_number
315  *
316  * @mode: display mode to be used
317  * @y:    line
318  *
319  * Return the line number according to the display mode taking
320  * into account the Sync and Back Porch information.
321  * Video frame line numbers start at 1, y starts at 0.
322  * In interlaced modes the start line is the field line number of the odd
323  * field, but y is still defined as a progressive frame.
324  */
325 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
326 {
327 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
328 
329 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
330 		start_line *= 2;
331 
332 	return start_line + y;
333 }
334 
335 /**
336  * sti_vtg_get_pixel_number
337  *
338  * @mode: display mode to be used
339  * @x:    row
340  *
341  * Return the pixel number according to the display mode taking
342  * into account the Sync and Back Porch information.
343  * Pixels are counted from 0.
344  */
345 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
346 {
347 	return mode.htotal - mode.hsync_start + x;
348 }
349 
350 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
351 			    struct drm_crtc *crtc)
352 {
353 	vtg->crtc = crtc;
354 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
355 }
356 
357 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
358 {
359 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
360 }
361 
362 static irqreturn_t vtg_irq_thread(int irq, void *arg)
363 {
364 	struct sti_vtg *vtg = arg;
365 	u32 event;
366 
367 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
368 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
369 
370 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
371 
372 	return IRQ_HANDLED;
373 }
374 
375 static irqreturn_t vtg_irq(int irq, void *arg)
376 {
377 	struct sti_vtg *vtg = arg;
378 
379 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
380 
381 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
382 
383 	/* force sync bus write */
384 	readl(vtg->regs + VTG_HOST_ITS);
385 
386 	return IRQ_WAKE_THREAD;
387 }
388 
389 static int vtg_probe(struct platform_device *pdev)
390 {
391 	struct device *dev = &pdev->dev;
392 	struct sti_vtg *vtg;
393 	struct resource *res;
394 	int ret;
395 
396 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
397 	if (!vtg)
398 		return -ENOMEM;
399 
400 	vtg->dev = dev;
401 	vtg->np = pdev->dev.of_node;
402 
403 	/* Get Memory ressources */
404 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
405 	if (!res) {
406 		DRM_ERROR("Get memory resource failed\n");
407 		return -ENOMEM;
408 	}
409 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
410 	if (!vtg->regs) {
411 		DRM_ERROR("failed to remap I/O memory\n");
412 		return -ENOMEM;
413 	}
414 
415 	vtg->irq = platform_get_irq(pdev, 0);
416 	if (vtg->irq < 0) {
417 		DRM_ERROR("Failed to get VTG interrupt\n");
418 		return vtg->irq;
419 	}
420 
421 	RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
422 
423 	ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
424 					vtg_irq_thread, IRQF_ONESHOT,
425 					dev_name(dev), vtg);
426 	if (ret < 0) {
427 		DRM_ERROR("Failed to register VTG interrupt\n");
428 		return ret;
429 	}
430 
431 	vtg_register(vtg);
432 	platform_set_drvdata(pdev, vtg);
433 
434 	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
435 
436 	return 0;
437 }
438 
439 static int vtg_remove(struct platform_device *pdev)
440 {
441 	return 0;
442 }
443 
444 static const struct of_device_id vtg_of_match[] = {
445 	{ .compatible = "st,vtg", },
446 	{ /* sentinel */ }
447 };
448 MODULE_DEVICE_TABLE(of, vtg_of_match);
449 
450 struct platform_driver sti_vtg_driver = {
451 	.driver = {
452 		.name = "sti-vtg",
453 		.owner = THIS_MODULE,
454 		.of_match_table = vtg_of_match,
455 	},
456 	.probe	= vtg_probe,
457 	.remove = vtg_remove,
458 };
459 
460 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
461 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
462 MODULE_LICENSE("GPL");
463