xref: /openbmc/linux/drivers/gpu/drm/sti/sti_vtg.c (revision e15a5365)
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/io.h>
12 #include <linux/notifier.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 
16 #include <drm/drm_modes.h>
17 #include <drm/drm_print.h>
18 
19 #include "sti_drv.h"
20 #include "sti_vtg.h"
21 
22 #define VTG_MODE_MASTER         0
23 
24 /* registers offset */
25 #define VTG_MODE            0x0000
26 #define VTG_CLKLN           0x0008
27 #define VTG_HLFLN           0x000C
28 #define VTG_DRST_AUTOC      0x0010
29 #define VTG_VID_TFO         0x0040
30 #define VTG_VID_TFS         0x0044
31 #define VTG_VID_BFO         0x0048
32 #define VTG_VID_BFS         0x004C
33 
34 #define VTG_HOST_ITS        0x0078
35 #define VTG_HOST_ITS_BCLR   0x007C
36 #define VTG_HOST_ITM_BCLR   0x0088
37 #define VTG_HOST_ITM_BSET   0x008C
38 
39 #define VTG_H_HD_1          0x00C0
40 #define VTG_TOP_V_VD_1      0x00C4
41 #define VTG_BOT_V_VD_1      0x00C8
42 #define VTG_TOP_V_HD_1      0x00CC
43 #define VTG_BOT_V_HD_1      0x00D0
44 
45 #define VTG_H_HD_2          0x00E0
46 #define VTG_TOP_V_VD_2      0x00E4
47 #define VTG_BOT_V_VD_2      0x00E8
48 #define VTG_TOP_V_HD_2      0x00EC
49 #define VTG_BOT_V_HD_2      0x00F0
50 
51 #define VTG_H_HD_3          0x0100
52 #define VTG_TOP_V_VD_3      0x0104
53 #define VTG_BOT_V_VD_3      0x0108
54 #define VTG_TOP_V_HD_3      0x010C
55 #define VTG_BOT_V_HD_3      0x0110
56 
57 #define VTG_H_HD_4          0x0120
58 #define VTG_TOP_V_VD_4      0x0124
59 #define VTG_BOT_V_VD_4      0x0128
60 #define VTG_TOP_V_HD_4      0x012c
61 #define VTG_BOT_V_HD_4      0x0130
62 
63 #define VTG_IRQ_BOTTOM      BIT(0)
64 #define VTG_IRQ_TOP         BIT(1)
65 #define VTG_IRQ_MASK        (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
66 
67 /* Delay introduced by the HDMI in nb of pixel */
68 #define HDMI_DELAY          (5)
69 
70 /* Delay introduced by the DVO in nb of pixel */
71 #define DVO_DELAY           (7)
72 
73 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
74 #define AWG_DELAY_HD        (-9)
75 #define AWG_DELAY_ED        (-8)
76 #define AWG_DELAY_SD        (-7)
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  * @regs: register mapping
128  * @sync_params: synchronisation parameters used to generate timings
129  * @irq: VTG irq
130  * @irq_status: store the IRQ status value
131  * @notifier_list: notifier callback
132  * @crtc: the CRTC for vblank event
133  */
134 struct sti_vtg {
135 	void __iomem *regs;
136 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
137 	int irq;
138 	u32 irq_status;
139 	struct raw_notifier_head notifier_list;
140 	struct drm_crtc *crtc;
141 };
142 
143 struct sti_vtg *of_vtg_find(struct device_node *np)
144 {
145 	struct platform_device *pdev;
146 
147 	pdev = of_find_device_by_node(np);
148 	if (!pdev)
149 		return NULL;
150 
151 	return (struct sti_vtg *)platform_get_drvdata(pdev);
152 }
153 
154 static void vtg_reset(struct sti_vtg *vtg)
155 {
156 	writel(1, vtg->regs + VTG_DRST_AUTOC);
157 }
158 
159 static void vtg_set_output_window(void __iomem *regs,
160 				  const struct drm_display_mode *mode)
161 {
162 	u32 video_top_field_start;
163 	u32 video_top_field_stop;
164 	u32 video_bottom_field_start;
165 	u32 video_bottom_field_stop;
166 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
167 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
168 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
169 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
170 
171 	/* Set output window to fit the display mode selected */
172 	video_top_field_start = (ystart << 16) | xstart;
173 	video_top_field_stop = (ystop << 16) | xstop;
174 
175 	/* Only progressive supported for now */
176 	video_bottom_field_start = video_top_field_start;
177 	video_bottom_field_stop = video_top_field_stop;
178 
179 	writel(video_top_field_start, regs + VTG_VID_TFO);
180 	writel(video_top_field_stop, regs + VTG_VID_TFS);
181 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
182 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
183 }
184 
185 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
186 				    int delay,
187 				    const struct drm_display_mode *mode)
188 {
189 	long clocksperline, start, stop;
190 	u32 risesync_top, fallsync_top;
191 	u32 risesync_offs_top, fallsync_offs_top;
192 
193 	clocksperline = mode->htotal;
194 
195 	/* Get the hsync position */
196 	start = 0;
197 	stop = mode->hsync_end - mode->hsync_start;
198 
199 	start += delay;
200 	stop  += delay;
201 
202 	if (start < 0)
203 		start += clocksperline;
204 	else if (start >= clocksperline)
205 		start -= clocksperline;
206 
207 	if (stop < 0)
208 		stop += clocksperline;
209 	else if (stop >= clocksperline)
210 		stop -= clocksperline;
211 
212 	sync->hsync = (stop << 16) | start;
213 
214 	/* Get the vsync position */
215 	if (delay >= 0) {
216 		risesync_top = 1;
217 		fallsync_top = risesync_top;
218 		fallsync_top += mode->vsync_end - mode->vsync_start;
219 
220 		fallsync_offs_top = (u32)delay;
221 		risesync_offs_top = (u32)delay;
222 	} else {
223 		risesync_top = mode->vtotal;
224 		fallsync_top = mode->vsync_end - mode->vsync_start;
225 
226 		fallsync_offs_top = clocksperline + delay;
227 		risesync_offs_top = clocksperline + delay;
228 	}
229 
230 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
231 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
232 
233 	/* Only progressive supported for now */
234 	sync->vsync_line_bot = sync->vsync_line_top;
235 	sync->vsync_off_bot = sync->vsync_off_top;
236 }
237 
238 static void vtg_set_mode(struct sti_vtg *vtg,
239 			 int type,
240 			 struct sti_vtg_sync_params *sync,
241 			 const struct drm_display_mode *mode)
242 {
243 	unsigned int i;
244 
245 	/* Set the number of clock cycles per line */
246 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
247 
248 	/* Set Half Line Per Field (only progressive supported for now) */
249 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
250 
251 	/* Program output window */
252 	vtg_set_output_window(vtg->regs, mode);
253 
254 	/* Set hsync and vsync position for HDMI */
255 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
256 
257 	/* Set hsync and vsync position for HD DCS */
258 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
259 
260 	/* Set hsync and vsync position for HDF */
261 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
262 
263 	/* Set hsync and vsync position for DVO */
264 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);
265 
266 	/* Progam the syncs outputs */
267 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
268 		writel(sync[i].hsync,
269 		       vtg->regs + vtg_regs_offs[i].h_hd);
270 		writel(sync[i].vsync_line_top,
271 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
272 		writel(sync[i].vsync_line_bot,
273 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
274 		writel(sync[i].vsync_off_top,
275 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
276 		writel(sync[i].vsync_off_bot,
277 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
278 	}
279 
280 	/* mode */
281 	writel(type, vtg->regs + VTG_MODE);
282 }
283 
284 static void vtg_enable_irq(struct sti_vtg *vtg)
285 {
286 	/* clear interrupt status and mask */
287 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
288 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
289 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
290 }
291 
292 void sti_vtg_set_config(struct sti_vtg *vtg,
293 		const struct drm_display_mode *mode)
294 {
295 	/* write configuration */
296 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
297 
298 	vtg_reset(vtg);
299 
300 	vtg_enable_irq(vtg);
301 }
302 
303 /**
304  * sti_vtg_get_line_number
305  *
306  * @mode: display mode to be used
307  * @y:    line
308  *
309  * Return the line number according to the display mode taking
310  * into account the Sync and Back Porch information.
311  * Video frame line numbers start at 1, y starts at 0.
312  * In interlaced modes the start line is the field line number of the odd
313  * field, but y is still defined as a progressive frame.
314  */
315 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
316 {
317 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
318 
319 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
320 		start_line *= 2;
321 
322 	return start_line + y;
323 }
324 
325 /**
326  * sti_vtg_get_pixel_number
327  *
328  * @mode: display mode to be used
329  * @x:    row
330  *
331  * Return the pixel number according to the display mode taking
332  * into account the Sync and Back Porch information.
333  * Pixels are counted from 0.
334  */
335 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
336 {
337 	return mode.htotal - mode.hsync_start + x;
338 }
339 
340 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
341 			    struct drm_crtc *crtc)
342 {
343 	vtg->crtc = crtc;
344 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
345 }
346 
347 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
348 {
349 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
350 }
351 
352 static irqreturn_t vtg_irq_thread(int irq, void *arg)
353 {
354 	struct sti_vtg *vtg = arg;
355 	u32 event;
356 
357 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
358 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
359 
360 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
361 
362 	return IRQ_HANDLED;
363 }
364 
365 static irqreturn_t vtg_irq(int irq, void *arg)
366 {
367 	struct sti_vtg *vtg = arg;
368 
369 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
370 
371 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
372 
373 	/* force sync bus write */
374 	readl(vtg->regs + VTG_HOST_ITS);
375 
376 	return IRQ_WAKE_THREAD;
377 }
378 
379 static int vtg_probe(struct platform_device *pdev)
380 {
381 	struct device *dev = &pdev->dev;
382 	struct sti_vtg *vtg;
383 	struct resource *res;
384 	int ret;
385 
386 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
387 	if (!vtg)
388 		return -ENOMEM;
389 
390 	/* Get Memory ressources */
391 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
392 	if (!res) {
393 		DRM_ERROR("Get memory resource failed\n");
394 		return -ENOMEM;
395 	}
396 	vtg->regs = devm_ioremap(dev, res->start, resource_size(res));
397 	if (!vtg->regs) {
398 		DRM_ERROR("failed to remap I/O memory\n");
399 		return -ENOMEM;
400 	}
401 
402 	vtg->irq = platform_get_irq(pdev, 0);
403 	if (vtg->irq < 0) {
404 		DRM_ERROR("Failed to get VTG interrupt\n");
405 		return vtg->irq;
406 	}
407 
408 	RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
409 
410 	ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
411 					vtg_irq_thread, IRQF_ONESHOT,
412 					dev_name(dev), vtg);
413 	if (ret < 0) {
414 		DRM_ERROR("Failed to register VTG interrupt\n");
415 		return ret;
416 	}
417 
418 	platform_set_drvdata(pdev, vtg);
419 
420 	DRM_INFO("%s %s\n", __func__, dev_name(dev));
421 
422 	return 0;
423 }
424 
425 static const struct of_device_id vtg_of_match[] = {
426 	{ .compatible = "st,vtg", },
427 	{ /* sentinel */ }
428 };
429 MODULE_DEVICE_TABLE(of, vtg_of_match);
430 
431 struct platform_driver sti_vtg_driver = {
432 	.driver = {
433 		.name = "sti-vtg",
434 		.owner = THIS_MODULE,
435 		.of_match_table = vtg_of_match,
436 	},
437 	.probe	= vtg_probe,
438 };
439 
440 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
441 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
442 MODULE_LICENSE("GPL");
443