xref: /openbmc/linux/drivers/gpu/drm/sti/sti_vtg.c (revision 2359ccdd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics SA 2014
4  * Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
5  *          Fabien Dessenne <fabien.dessenne@st.com>
6  *          Vincent Abriou <vincent.abriou@st.com>
7  *          for STMicroelectronics.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/notifier.h>
12 #include <linux/of_platform.h>
13 #include <linux/platform_device.h>
14 
15 #include <drm/drmP.h>
16 
17 #include "sti_drv.h"
18 #include "sti_vtg.h"
19 
20 #define VTG_MODE_MASTER         0
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 /*
77  * STI VTG register offset structure
78  *
79  *@h_hd:     stores the VTG_H_HD_x     register offset
80  *@top_v_vd: stores the VTG_TOP_V_VD_x register offset
81  *@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
82  *@top_v_hd: stores the VTG_TOP_V_HD_x register offset
83  *@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
84  */
85 struct sti_vtg_regs_offs {
86 	u32 h_hd;
87 	u32 top_v_vd;
88 	u32 bot_v_vd;
89 	u32 top_v_hd;
90 	u32 bot_v_hd;
91 };
92 
93 #define VTG_MAX_SYNC_OUTPUT 4
94 static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
95 	{ VTG_H_HD_1,
96 	  VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
97 	{ VTG_H_HD_2,
98 	  VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
99 	{ VTG_H_HD_3,
100 	  VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
101 	{ VTG_H_HD_4,
102 	  VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
103 };
104 
105 /*
106  * STI VTG synchronisation parameters structure
107  *
108  *@hsync: sample number falling and rising edge
109  *@vsync_line_top: vertical top field line number falling and rising edge
110  *@vsync_line_bot: vertical bottom field line number falling and rising edge
111  *@vsync_off_top: vertical top field sample number rising and falling edge
112  *@vsync_off_bot: vertical bottom field sample number rising and falling edge
113  */
114 struct sti_vtg_sync_params {
115 	u32 hsync;
116 	u32 vsync_line_top;
117 	u32 vsync_line_bot;
118 	u32 vsync_off_top;
119 	u32 vsync_off_bot;
120 };
121 
122 /**
123  * STI VTG structure
124  *
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  */
132 struct sti_vtg {
133 	void __iomem *regs;
134 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
135 	int irq;
136 	u32 irq_status;
137 	struct raw_notifier_head notifier_list;
138 	struct drm_crtc *crtc;
139 };
140 
141 struct sti_vtg *of_vtg_find(struct device_node *np)
142 {
143 	struct platform_device *pdev;
144 
145 	pdev = of_find_device_by_node(np);
146 	if (!pdev)
147 		return NULL;
148 
149 	return (struct sti_vtg *)platform_get_drvdata(pdev);
150 }
151 
152 static void vtg_reset(struct sti_vtg *vtg)
153 {
154 	writel(1, vtg->regs + VTG_DRST_AUTOC);
155 }
156 
157 static void vtg_set_output_window(void __iomem *regs,
158 				  const struct drm_display_mode *mode)
159 {
160 	u32 video_top_field_start;
161 	u32 video_top_field_stop;
162 	u32 video_bottom_field_start;
163 	u32 video_bottom_field_stop;
164 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
165 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
166 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
167 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
168 
169 	/* Set output window to fit the display mode selected */
170 	video_top_field_start = (ystart << 16) | xstart;
171 	video_top_field_stop = (ystop << 16) | xstop;
172 
173 	/* Only progressive supported for now */
174 	video_bottom_field_start = video_top_field_start;
175 	video_bottom_field_stop = video_top_field_stop;
176 
177 	writel(video_top_field_start, regs + VTG_VID_TFO);
178 	writel(video_top_field_stop, regs + VTG_VID_TFS);
179 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
180 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
181 }
182 
183 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
184 				    int delay,
185 				    const struct drm_display_mode *mode)
186 {
187 	long clocksperline, start, stop;
188 	u32 risesync_top, fallsync_top;
189 	u32 risesync_offs_top, fallsync_offs_top;
190 
191 	clocksperline = mode->htotal;
192 
193 	/* Get the hsync position */
194 	start = 0;
195 	stop = mode->hsync_end - mode->hsync_start;
196 
197 	start += delay;
198 	stop  += delay;
199 
200 	if (start < 0)
201 		start += clocksperline;
202 	else if (start >= clocksperline)
203 		start -= clocksperline;
204 
205 	if (stop < 0)
206 		stop += clocksperline;
207 	else if (stop >= clocksperline)
208 		stop -= clocksperline;
209 
210 	sync->hsync = (stop << 16) | start;
211 
212 	/* Get the vsync position */
213 	if (delay >= 0) {
214 		risesync_top = 1;
215 		fallsync_top = risesync_top;
216 		fallsync_top += mode->vsync_end - mode->vsync_start;
217 
218 		fallsync_offs_top = (u32)delay;
219 		risesync_offs_top = (u32)delay;
220 	} else {
221 		risesync_top = mode->vtotal;
222 		fallsync_top = mode->vsync_end - mode->vsync_start;
223 
224 		fallsync_offs_top = clocksperline + delay;
225 		risesync_offs_top = clocksperline + delay;
226 	}
227 
228 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
229 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
230 
231 	/* Only progressive supported for now */
232 	sync->vsync_line_bot = sync->vsync_line_top;
233 	sync->vsync_off_bot = sync->vsync_off_top;
234 }
235 
236 static void vtg_set_mode(struct sti_vtg *vtg,
237 			 int type,
238 			 struct sti_vtg_sync_params *sync,
239 			 const struct drm_display_mode *mode)
240 {
241 	unsigned int i;
242 
243 	/* Set the number of clock cycles per line */
244 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
245 
246 	/* Set Half Line Per Field (only progressive supported for now) */
247 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
248 
249 	/* Program output window */
250 	vtg_set_output_window(vtg->regs, mode);
251 
252 	/* Set hsync and vsync position for HDMI */
253 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
254 
255 	/* Set hsync and vsync position for HD DCS */
256 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
257 
258 	/* Set hsync and vsync position for HDF */
259 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
260 
261 	/* Set hsync and vsync position for DVO */
262 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);
263 
264 	/* Progam the syncs outputs */
265 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
266 		writel(sync[i].hsync,
267 		       vtg->regs + vtg_regs_offs[i].h_hd);
268 		writel(sync[i].vsync_line_top,
269 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
270 		writel(sync[i].vsync_line_bot,
271 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
272 		writel(sync[i].vsync_off_top,
273 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
274 		writel(sync[i].vsync_off_bot,
275 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
276 	}
277 
278 	/* mode */
279 	writel(type, vtg->regs + VTG_MODE);
280 }
281 
282 static void vtg_enable_irq(struct sti_vtg *vtg)
283 {
284 	/* clear interrupt status and mask */
285 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
286 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
287 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
288 }
289 
290 void sti_vtg_set_config(struct sti_vtg *vtg,
291 		const struct drm_display_mode *mode)
292 {
293 	/* write configuration */
294 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
295 
296 	vtg_reset(vtg);
297 
298 	vtg_enable_irq(vtg);
299 }
300 
301 /**
302  * sti_vtg_get_line_number
303  *
304  * @mode: display mode to be used
305  * @y:    line
306  *
307  * Return the line number according to the display mode taking
308  * into account the Sync and Back Porch information.
309  * Video frame line numbers start at 1, y starts at 0.
310  * In interlaced modes the start line is the field line number of the odd
311  * field, but y is still defined as a progressive frame.
312  */
313 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
314 {
315 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
316 
317 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
318 		start_line *= 2;
319 
320 	return start_line + y;
321 }
322 
323 /**
324  * sti_vtg_get_pixel_number
325  *
326  * @mode: display mode to be used
327  * @x:    row
328  *
329  * Return the pixel number according to the display mode taking
330  * into account the Sync and Back Porch information.
331  * Pixels are counted from 0.
332  */
333 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
334 {
335 	return mode.htotal - mode.hsync_start + x;
336 }
337 
338 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
339 			    struct drm_crtc *crtc)
340 {
341 	vtg->crtc = crtc;
342 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
343 }
344 
345 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
346 {
347 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
348 }
349 
350 static irqreturn_t vtg_irq_thread(int irq, void *arg)
351 {
352 	struct sti_vtg *vtg = arg;
353 	u32 event;
354 
355 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
356 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
357 
358 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
359 
360 	return IRQ_HANDLED;
361 }
362 
363 static irqreturn_t vtg_irq(int irq, void *arg)
364 {
365 	struct sti_vtg *vtg = arg;
366 
367 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
368 
369 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
370 
371 	/* force sync bus write */
372 	readl(vtg->regs + VTG_HOST_ITS);
373 
374 	return IRQ_WAKE_THREAD;
375 }
376 
377 static int vtg_probe(struct platform_device *pdev)
378 {
379 	struct device *dev = &pdev->dev;
380 	struct sti_vtg *vtg;
381 	struct resource *res;
382 	int ret;
383 
384 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
385 	if (!vtg)
386 		return -ENOMEM;
387 
388 	/* Get Memory ressources */
389 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
390 	if (!res) {
391 		DRM_ERROR("Get memory resource failed\n");
392 		return -ENOMEM;
393 	}
394 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
395 	if (!vtg->regs) {
396 		DRM_ERROR("failed to remap I/O memory\n");
397 		return -ENOMEM;
398 	}
399 
400 	vtg->irq = platform_get_irq(pdev, 0);
401 	if (vtg->irq < 0) {
402 		DRM_ERROR("Failed to get VTG interrupt\n");
403 		return vtg->irq;
404 	}
405 
406 	RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
407 
408 	ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
409 					vtg_irq_thread, IRQF_ONESHOT,
410 					dev_name(dev), vtg);
411 	if (ret < 0) {
412 		DRM_ERROR("Failed to register VTG interrupt\n");
413 		return ret;
414 	}
415 
416 	platform_set_drvdata(pdev, vtg);
417 
418 	DRM_INFO("%s %s\n", __func__, dev_name(dev));
419 
420 	return 0;
421 }
422 
423 static const struct of_device_id vtg_of_match[] = {
424 	{ .compatible = "st,vtg", },
425 	{ /* sentinel */ }
426 };
427 MODULE_DEVICE_TABLE(of, vtg_of_match);
428 
429 struct platform_driver sti_vtg_driver = {
430 	.driver = {
431 		.name = "sti-vtg",
432 		.owner = THIS_MODULE,
433 		.of_match_table = vtg_of_match,
434 	},
435 	.probe	= vtg_probe,
436 };
437 
438 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
439 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
440 MODULE_LICENSE("GPL");
441