xref: /linux/drivers/gpu/drm/sti/sti_vtg.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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_TYPE_MASTER         0
19 #define VTG_TYPE_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 structure
76  *
77  * @dev: pointer to device driver
78  * @data: data associated to the device
79  * @irq: VTG irq
80  * @type: VTG type (main or aux)
81  * @notifier_list: notifier callback
82  * @crtc_id: the crtc id for vblank event
83  * @slave: slave vtg
84  * @link: List node to link the structure in lookup list
85  */
86 struct sti_vtg {
87 	struct device *dev;
88 	struct device_node *np;
89 	void __iomem *regs;
90 	int irq;
91 	u32 irq_status;
92 	struct raw_notifier_head notifier_list;
93 	int crtc_id;
94 	struct sti_vtg *slave;
95 	struct list_head link;
96 };
97 
98 static void vtg_register(struct sti_vtg *vtg)
99 {
100 	list_add_tail(&vtg->link, &vtg_lookup);
101 }
102 
103 struct sti_vtg *of_vtg_find(struct device_node *np)
104 {
105 	struct sti_vtg *vtg;
106 
107 	list_for_each_entry(vtg, &vtg_lookup, link) {
108 		if (vtg->np == np)
109 			return vtg;
110 	}
111 	return NULL;
112 }
113 EXPORT_SYMBOL(of_vtg_find);
114 
115 static void vtg_reset(struct sti_vtg *vtg)
116 {
117 	/* reset slave and then master */
118 	if (vtg->slave)
119 		vtg_reset(vtg->slave);
120 
121 	writel(1, vtg->regs + VTG_DRST_AUTOC);
122 }
123 
124 static void vtg_set_output_window(void __iomem *regs,
125 				  const struct drm_display_mode *mode)
126 {
127 	u32 video_top_field_start;
128 	u32 video_top_field_stop;
129 	u32 video_bottom_field_start;
130 	u32 video_bottom_field_stop;
131 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
132 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
133 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
134 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
135 
136 	/* Set output window to fit the display mode selected */
137 	video_top_field_start = (ystart << 16) | xstart;
138 	video_top_field_stop = (ystop << 16) | xstop;
139 
140 	/* Only progressive supported for now */
141 	video_bottom_field_start = video_top_field_start;
142 	video_bottom_field_stop = video_top_field_stop;
143 
144 	writel(video_top_field_start, regs + VTG_VID_TFO);
145 	writel(video_top_field_stop, regs + VTG_VID_TFS);
146 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
147 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
148 }
149 
150 static void vtg_set_mode(struct sti_vtg *vtg,
151 			 int type, const struct drm_display_mode *mode)
152 {
153 	u32 tmp;
154 
155 	if (vtg->slave)
156 		vtg_set_mode(vtg->slave, VTG_TYPE_SLAVE_BY_EXT0, mode);
157 
158 	/* Set the number of clock cycles per line */
159 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
160 
161 	/* Set Half Line Per Field (only progressive supported for now) */
162 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
163 
164 	/* Program output window */
165 	vtg_set_output_window(vtg->regs, mode);
166 
167 	/* prepare VTG set 1 for HDMI */
168 	tmp = (mode->hsync_end - mode->hsync_start + HDMI_DELAY) << 16;
169 	tmp |= HDMI_DELAY;
170 	writel(tmp, vtg->regs + VTG_H_HD_1);
171 
172 	tmp = (mode->vsync_end - mode->vsync_start + 1) << 16;
173 	tmp |= 1;
174 	writel(tmp, vtg->regs + VTG_TOP_V_VD_1);
175 	writel(tmp, vtg->regs + VTG_BOT_V_VD_1);
176 
177 	tmp = HDMI_DELAY << 16;
178 	tmp |= HDMI_DELAY;
179 	writel(tmp, vtg->regs + VTG_TOP_V_HD_1);
180 	writel(tmp, vtg->regs + VTG_BOT_V_HD_1);
181 
182 	/* prepare VTG set 2 for for HD DCS */
183 	tmp = (mode->hsync_end - mode->hsync_start) << 16;
184 	writel(tmp, vtg->regs + VTG_H_HD_2);
185 
186 	tmp = (mode->vsync_end - mode->vsync_start + 1) << 16;
187 	tmp |= 1;
188 	writel(tmp, vtg->regs + VTG_TOP_V_VD_2);
189 	writel(tmp, vtg->regs + VTG_BOT_V_VD_2);
190 	writel(0, vtg->regs + VTG_TOP_V_HD_2);
191 	writel(0, vtg->regs + VTG_BOT_V_HD_2);
192 
193 	/* prepare VTG set 3 for HD Analog in HD mode */
194 	tmp = (mode->hsync_end - mode->hsync_start + AWG_DELAY_HD) << 16;
195 	tmp |= mode->htotal + AWG_DELAY_HD;
196 	writel(tmp, vtg->regs + VTG_H_HD_3);
197 
198 	tmp = (mode->vsync_end - mode->vsync_start) << 16;
199 	tmp |= mode->vtotal;
200 	writel(tmp, vtg->regs + VTG_TOP_V_VD_3);
201 	writel(tmp, vtg->regs + VTG_BOT_V_VD_3);
202 
203 	tmp = (mode->htotal + AWG_DELAY_HD) << 16;
204 	tmp |= mode->htotal + AWG_DELAY_HD;
205 	writel(tmp, vtg->regs + VTG_TOP_V_HD_3);
206 	writel(tmp, vtg->regs + VTG_BOT_V_HD_3);
207 
208 	/* Prepare VTG set 4 for DVO */
209 	tmp = (mode->hsync_end - mode->hsync_start) << 16;
210 	writel(tmp, vtg->regs + VTG_H_HD_4);
211 
212 	tmp = (mode->vsync_end - mode->vsync_start + 1) << 16;
213 	tmp |= 1;
214 	writel(tmp, vtg->regs + VTG_TOP_V_VD_4);
215 	writel(tmp, vtg->regs + VTG_BOT_V_VD_4);
216 	writel(0, vtg->regs + VTG_TOP_V_HD_4);
217 	writel(0, vtg->regs + VTG_BOT_V_HD_4);
218 
219 	/* mode */
220 	writel(type, vtg->regs + VTG_MODE);
221 }
222 
223 static void vtg_enable_irq(struct sti_vtg *vtg)
224 {
225 	/* clear interrupt status and mask */
226 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
227 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
228 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
229 }
230 
231 void sti_vtg_set_config(struct sti_vtg *vtg,
232 		const struct drm_display_mode *mode)
233 {
234 	/* write configuration */
235 	vtg_set_mode(vtg, VTG_TYPE_MASTER, mode);
236 
237 	vtg_reset(vtg);
238 
239 	/* enable irq for the vtg vblank synchro */
240 	if (vtg->slave)
241 		vtg_enable_irq(vtg->slave);
242 	else
243 		vtg_enable_irq(vtg);
244 }
245 EXPORT_SYMBOL(sti_vtg_set_config);
246 
247 /**
248  * sti_vtg_get_line_number
249  *
250  * @mode: display mode to be used
251  * @y:    line
252  *
253  * Return the line number according to the display mode taking
254  * into account the Sync and Back Porch information.
255  * Video frame line numbers start at 1, y starts at 0.
256  * In interlaced modes the start line is the field line number of the odd
257  * field, but y is still defined as a progressive frame.
258  */
259 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
260 {
261 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
262 
263 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
264 		start_line *= 2;
265 
266 	return start_line + y;
267 }
268 EXPORT_SYMBOL(sti_vtg_get_line_number);
269 
270 /**
271  * sti_vtg_get_pixel_number
272  *
273  * @mode: display mode to be used
274  * @x:    row
275  *
276  * Return the pixel number according to the display mode taking
277  * into account the Sync and Back Porch information.
278  * Pixels are counted from 0.
279  */
280 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
281 {
282 	return mode.htotal - mode.hsync_start + x;
283 }
284 EXPORT_SYMBOL(sti_vtg_get_pixel_number);
285 
286 int sti_vtg_register_client(struct sti_vtg *vtg,
287 		struct notifier_block *nb, int crtc_id)
288 {
289 	if (vtg->slave)
290 		return sti_vtg_register_client(vtg->slave, nb, crtc_id);
291 
292 	vtg->crtc_id = crtc_id;
293 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
294 }
295 EXPORT_SYMBOL(sti_vtg_register_client);
296 
297 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
298 {
299 	if (vtg->slave)
300 		return sti_vtg_unregister_client(vtg->slave, nb);
301 
302 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
303 }
304 EXPORT_SYMBOL(sti_vtg_unregister_client);
305 
306 static irqreturn_t vtg_irq_thread(int irq, void *arg)
307 {
308 	struct sti_vtg *vtg = arg;
309 	u32 event;
310 
311 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
312 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
313 
314 	raw_notifier_call_chain(&vtg->notifier_list, event, &vtg->crtc_id);
315 
316 	return IRQ_HANDLED;
317 }
318 
319 static irqreturn_t vtg_irq(int irq, void *arg)
320 {
321 	struct sti_vtg *vtg = arg;
322 
323 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
324 
325 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
326 
327 	/* force sync bus write */
328 	readl(vtg->regs + VTG_HOST_ITS);
329 
330 	return IRQ_WAKE_THREAD;
331 }
332 
333 static int vtg_probe(struct platform_device *pdev)
334 {
335 	struct device *dev = &pdev->dev;
336 	struct device_node *np;
337 	struct sti_vtg *vtg;
338 	struct resource *res;
339 	int ret;
340 
341 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
342 	if (!vtg)
343 		return -ENOMEM;
344 
345 	vtg->dev = dev;
346 	vtg->np = pdev->dev.of_node;
347 
348 	/* Get Memory ressources */
349 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
350 	if (!res) {
351 		DRM_ERROR("Get memory resource failed\n");
352 		return -ENOMEM;
353 	}
354 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
355 
356 	np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
357 	if (np) {
358 		vtg->slave = of_vtg_find(np);
359 
360 		if (!vtg->slave)
361 			return -EPROBE_DEFER;
362 	} else {
363 		vtg->irq = platform_get_irq(pdev, 0);
364 		if (IS_ERR_VALUE(vtg->irq)) {
365 			DRM_ERROR("Failed to get VTG interrupt\n");
366 			return vtg->irq;
367 		}
368 
369 		RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
370 
371 		ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
372 				vtg_irq_thread, IRQF_ONESHOT,
373 				dev_name(dev), vtg);
374 		if (IS_ERR_VALUE(ret)) {
375 			DRM_ERROR("Failed to register VTG interrupt\n");
376 			return ret;
377 		}
378 	}
379 
380 	vtg_register(vtg);
381 	platform_set_drvdata(pdev, vtg);
382 
383 	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
384 
385 	return 0;
386 }
387 
388 static int vtg_remove(struct platform_device *pdev)
389 {
390 	return 0;
391 }
392 
393 static const struct of_device_id vtg_of_match[] = {
394 	{ .compatible = "st,vtg", },
395 	{ /* sentinel */ }
396 };
397 MODULE_DEVICE_TABLE(of, vtg_of_match);
398 
399 struct platform_driver sti_vtg_driver = {
400 	.driver = {
401 		.name = "sti-vtg",
402 		.owner = THIS_MODULE,
403 		.of_match_table = vtg_of_match,
404 	},
405 	.probe	= vtg_probe,
406 	.remove = vtg_remove,
407 };
408 
409 module_platform_driver(sti_vtg_driver);
410 
411 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
412 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
413 MODULE_LICENSE("GPL");
414