xref: /openbmc/linux/drivers/gpu/drm/sti/sti_vtg.c (revision 275876e2)
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_IRQ_BOTTOM      BIT(0)
55 #define VTG_IRQ_TOP         BIT(1)
56 #define VTG_IRQ_MASK        (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
57 
58 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
59 #define AWG_DELAY_HD        (-9)
60 #define AWG_DELAY_ED        (-8)
61 #define AWG_DELAY_SD        (-7)
62 
63 LIST_HEAD(vtg_lookup);
64 
65 /**
66  * STI VTG structure
67  *
68  * @dev: pointer to device driver
69  * @data: data associated to the device
70  * @irq: VTG irq
71  * @type: VTG type (main or aux)
72  * @notifier_list: notifier callback
73  * @crtc_id: the crtc id for vblank event
74  * @slave: slave vtg
75  * @link: List node to link the structure in lookup list
76  */
77 struct sti_vtg {
78 	struct device *dev;
79 	struct device_node *np;
80 	void __iomem *regs;
81 	int irq;
82 	u32 irq_status;
83 	struct raw_notifier_head notifier_list;
84 	int crtc_id;
85 	struct sti_vtg *slave;
86 	struct list_head link;
87 };
88 
89 static void vtg_register(struct sti_vtg *vtg)
90 {
91 	list_add_tail(&vtg->link, &vtg_lookup);
92 }
93 
94 struct sti_vtg *of_vtg_find(struct device_node *np)
95 {
96 	struct sti_vtg *vtg;
97 
98 	list_for_each_entry(vtg, &vtg_lookup, link) {
99 		if (vtg->np == np)
100 			return vtg;
101 	}
102 	return NULL;
103 }
104 EXPORT_SYMBOL(of_vtg_find);
105 
106 static void vtg_reset(struct sti_vtg *vtg)
107 {
108 	/* reset slave and then master */
109 	if (vtg->slave)
110 		vtg_reset(vtg->slave);
111 
112 	writel(1, vtg->regs + VTG_DRST_AUTOC);
113 }
114 
115 static void vtg_set_mode(struct sti_vtg *vtg,
116 			 int type, const struct drm_display_mode *mode)
117 {
118 	u32 tmp;
119 
120 	if (vtg->slave)
121 		vtg_set_mode(vtg->slave, VTG_TYPE_SLAVE_BY_EXT0, mode);
122 
123 	writel(mode->htotal, vtg->regs + VTG_CLKLN);
124 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
125 
126 	tmp = (mode->vtotal - mode->vsync_start + 1) << 16;
127 	tmp |= mode->htotal - mode->hsync_start;
128 	writel(tmp, vtg->regs + VTG_VID_TFO);
129 	writel(tmp, vtg->regs + VTG_VID_BFO);
130 
131 	tmp = (mode->vdisplay + mode->vtotal - mode->vsync_start + 1) << 16;
132 	tmp |= mode->hdisplay + mode->htotal - mode->hsync_start;
133 	writel(tmp, vtg->regs + VTG_VID_TFS);
134 	writel(tmp, vtg->regs + VTG_VID_BFS);
135 
136 	/* prepare VTG set 1 and 2 for HDMI and VTG set 3 for HD DAC */
137 	tmp = (mode->hsync_end - mode->hsync_start) << 16;
138 	writel(tmp, vtg->regs + VTG_H_HD_1);
139 	writel(tmp, vtg->regs + VTG_H_HD_2);
140 
141 	tmp = (mode->vsync_end - mode->vsync_start + 1) << 16;
142 	tmp |= 1;
143 	writel(tmp, vtg->regs + VTG_TOP_V_VD_1);
144 	writel(tmp, vtg->regs + VTG_BOT_V_VD_1);
145 	writel(0, vtg->regs + VTG_TOP_V_HD_1);
146 	writel(0, vtg->regs + VTG_BOT_V_HD_1);
147 
148 	/* prepare VTG set 2 for for HD DCS */
149 	writel(tmp, vtg->regs + VTG_TOP_V_VD_2);
150 	writel(tmp, vtg->regs + VTG_BOT_V_VD_2);
151 	writel(0, vtg->regs + VTG_TOP_V_HD_2);
152 	writel(0, vtg->regs + VTG_BOT_V_HD_2);
153 
154 	/* prepare VTG set 3 for HD Analog in HD mode */
155 	tmp = (mode->hsync_end - mode->hsync_start + AWG_DELAY_HD) << 16;
156 	tmp |= mode->htotal + AWG_DELAY_HD;
157 	writel(tmp, vtg->regs + VTG_H_HD_3);
158 
159 	tmp = (mode->vsync_end - mode->vsync_start) << 16;
160 	tmp |= mode->vtotal;
161 	writel(tmp, vtg->regs + VTG_TOP_V_VD_3);
162 	writel(tmp, vtg->regs + VTG_BOT_V_VD_3);
163 
164 	tmp = (mode->htotal + AWG_DELAY_HD) << 16;
165 	tmp |= mode->htotal + AWG_DELAY_HD;
166 	writel(tmp, vtg->regs + VTG_TOP_V_HD_3);
167 	writel(tmp, vtg->regs + VTG_BOT_V_HD_3);
168 
169 	/* mode */
170 	writel(type, vtg->regs + VTG_MODE);
171 }
172 
173 static void vtg_enable_irq(struct sti_vtg *vtg)
174 {
175 	/* clear interrupt status and mask */
176 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
177 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
178 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
179 }
180 
181 void sti_vtg_set_config(struct sti_vtg *vtg,
182 		const struct drm_display_mode *mode)
183 {
184 	/* write configuration */
185 	vtg_set_mode(vtg, VTG_TYPE_MASTER, mode);
186 
187 	vtg_reset(vtg);
188 
189 	/* enable irq for the vtg vblank synchro */
190 	if (vtg->slave)
191 		vtg_enable_irq(vtg->slave);
192 	else
193 		vtg_enable_irq(vtg);
194 }
195 EXPORT_SYMBOL(sti_vtg_set_config);
196 
197 /**
198  * sti_vtg_get_line_number
199  *
200  * @mode: display mode to be used
201  * @y:    line
202  *
203  * Return the line number according to the display mode taking
204  * into account the Sync and Back Porch information.
205  * Video frame line numbers start at 1, y starts at 0.
206  * In interlaced modes the start line is the field line number of the odd
207  * field, but y is still defined as a progressive frame.
208  */
209 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
210 {
211 	u32 start_line = mode.vtotal - mode.vsync_start + 1;
212 
213 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
214 		start_line *= 2;
215 
216 	return start_line + y;
217 }
218 EXPORT_SYMBOL(sti_vtg_get_line_number);
219 
220 /**
221  * sti_vtg_get_pixel_number
222  *
223  * @mode: display mode to be used
224  * @x:    row
225  *
226  * Return the pixel number according to the display mode taking
227  * into account the Sync and Back Porch information.
228  * Pixels are counted from 0.
229  */
230 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
231 {
232 	return mode.htotal - mode.hsync_start + x;
233 }
234 EXPORT_SYMBOL(sti_vtg_get_pixel_number);
235 
236 int sti_vtg_register_client(struct sti_vtg *vtg,
237 		struct notifier_block *nb, int crtc_id)
238 {
239 	if (vtg->slave)
240 		return sti_vtg_register_client(vtg->slave, nb, crtc_id);
241 
242 	vtg->crtc_id = crtc_id;
243 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
244 }
245 EXPORT_SYMBOL(sti_vtg_register_client);
246 
247 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
248 {
249 	if (vtg->slave)
250 		return sti_vtg_unregister_client(vtg->slave, nb);
251 
252 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
253 }
254 EXPORT_SYMBOL(sti_vtg_unregister_client);
255 
256 static irqreturn_t vtg_irq_thread(int irq, void *arg)
257 {
258 	struct sti_vtg *vtg = arg;
259 	u32 event;
260 
261 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
262 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
263 
264 	raw_notifier_call_chain(&vtg->notifier_list, event, &vtg->crtc_id);
265 
266 	return IRQ_HANDLED;
267 }
268 
269 static irqreturn_t vtg_irq(int irq, void *arg)
270 {
271 	struct sti_vtg *vtg = arg;
272 
273 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
274 
275 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
276 
277 	/* force sync bus write */
278 	readl(vtg->regs + VTG_HOST_ITS);
279 
280 	return IRQ_WAKE_THREAD;
281 }
282 
283 static int vtg_probe(struct platform_device *pdev)
284 {
285 	struct device *dev = &pdev->dev;
286 	struct device_node *np;
287 	struct sti_vtg *vtg;
288 	struct resource *res;
289 	char irq_name[32];
290 	int ret;
291 
292 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
293 	if (!vtg)
294 		return -ENOMEM;
295 
296 	vtg->dev = dev;
297 	vtg->np = pdev->dev.of_node;
298 
299 	/* Get Memory ressources */
300 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
301 	if (!res) {
302 		DRM_ERROR("Get memory resource failed\n");
303 		return -ENOMEM;
304 	}
305 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
306 
307 	np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
308 	if (np) {
309 		vtg->slave = of_vtg_find(np);
310 
311 		if (!vtg->slave)
312 			return -EPROBE_DEFER;
313 	} else {
314 		vtg->irq = platform_get_irq(pdev, 0);
315 		if (IS_ERR_VALUE(vtg->irq)) {
316 			DRM_ERROR("Failed to get VTG interrupt\n");
317 			return vtg->irq;
318 		}
319 
320 		snprintf(irq_name, sizeof(irq_name), "vsync-%s",
321 				dev_name(vtg->dev));
322 
323 		RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
324 
325 		ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
326 				vtg_irq_thread, IRQF_ONESHOT, irq_name, vtg);
327 		if (IS_ERR_VALUE(ret)) {
328 			DRM_ERROR("Failed to register VTG interrupt\n");
329 			return ret;
330 		}
331 	}
332 
333 	vtg_register(vtg);
334 	platform_set_drvdata(pdev, vtg);
335 
336 	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
337 
338 	return 0;
339 }
340 
341 static int vtg_remove(struct platform_device *pdev)
342 {
343 	return 0;
344 }
345 
346 static const struct of_device_id vtg_of_match[] = {
347 	{ .compatible = "st,vtg", },
348 	{ /* sentinel */ }
349 };
350 MODULE_DEVICE_TABLE(of, vtg_of_match);
351 
352 struct platform_driver sti_vtg_driver = {
353 	.driver = {
354 		.name = "sti-vtg",
355 		.owner = THIS_MODULE,
356 		.of_match_table = vtg_of_match,
357 	},
358 	.probe	= vtg_probe,
359 	.remove = vtg_remove,
360 };
361 
362 module_platform_driver(sti_vtg_driver);
363 
364 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
365 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
366 MODULE_LICENSE("GPL");
367