xref: /linux/drivers/gpu/drm/i915/display/dvo_ivch.c (revision bca5cfbb694d66a1c482d0c347eee80f6afbc870)
1 /*
2  * Copyright © 2006 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *    Thomas Richter <thor@math.tu-berlin.de>
26  *
27  * Minor modifications (Dithering enable):
28  *    Thomas Richter <thor@math.tu-berlin.de>
29  *
30  */
31 
32 #include <drm/drm_print.h>
33 
34 #include "intel_display_types.h"
35 #include "intel_dvo_dev.h"
36 
37 /*
38  * register definitions for the i82807aa.
39  *
40  * Documentation on this chipset can be found in datasheet #29069001 at
41  * intel.com.
42  */
43 
44 /*
45  * VCH Revision & GMBus Base Addr
46  */
47 #define VR00		0x00
48 # define VR00_BASE_ADDRESS_MASK		0x007f
49 
50 /*
51  * Functionality Enable
52  */
53 #define VR01		0x01
54 
55 /*
56  * Enable the panel fitter
57  */
58 # define VR01_PANEL_FIT_ENABLE		(1 << 3)
59 /*
60  * Enables the LCD display.
61  *
62  * This must not be set while VR01_DVO_BYPASS_ENABLE is set.
63  */
64 # define VR01_LCD_ENABLE		(1 << 2)
65 /* Enables the DVO repeater. */
66 # define VR01_DVO_BYPASS_ENABLE		(1 << 1)
67 /* Enables the DVO clock */
68 # define VR01_DVO_ENABLE		(1 << 0)
69 /* Enable dithering for 18bpp panels. Not documented. */
70 # define VR01_DITHER_ENABLE             (1 << 4)
71 
72 /*
73  * LCD Interface Format
74  */
75 #define VR10		0x10
76 /* Enables LVDS output instead of CMOS */
77 # define VR10_LVDS_ENABLE		(1 << 4)
78 /* Enables 18-bit LVDS output. */
79 # define VR10_INTERFACE_1X18		(0 << 2)
80 /* Enables 24-bit LVDS or CMOS output */
81 # define VR10_INTERFACE_1X24		(1 << 2)
82 /* Enables 2x18-bit LVDS or CMOS output. */
83 # define VR10_INTERFACE_2X18		(2 << 2)
84 /* Enables 2x24-bit LVDS output */
85 # define VR10_INTERFACE_2X24		(3 << 2)
86 /* Mask that defines the depth of the pipeline */
87 # define VR10_INTERFACE_DEPTH_MASK      (3 << 2)
88 
89 /*
90  * VR20 LCD Horizontal Display Size
91  */
92 #define VR20	0x20
93 
94 /*
95  * LCD Vertical Display Size
96  */
97 #define VR21	0x21
98 
99 /*
100  * Panel power down status
101  */
102 #define VR30		0x30
103 /* Read only bit indicating that the panel is not in a safe poweroff state. */
104 # define VR30_PANEL_ON			(1 << 15)
105 
106 #define VR40		0x40
107 # define VR40_STALL_ENABLE		(1 << 13)
108 # define VR40_VERTICAL_INTERP_ENABLE	(1 << 12)
109 # define VR40_ENHANCED_PANEL_FITTING	(1 << 11)
110 # define VR40_HORIZONTAL_INTERP_ENABLE	(1 << 10)
111 # define VR40_AUTO_RATIO_ENABLE		(1 << 9)
112 # define VR40_CLOCK_GATING_ENABLE	(1 << 8)
113 
114 /*
115  * Panel Fitting Vertical Ratio
116  * (((image_height - 1) << 16) / ((panel_height - 1))) >> 2
117  */
118 #define VR41		0x41
119 
120 /*
121  * Panel Fitting Horizontal Ratio
122  * (((image_width - 1) << 16) / ((panel_width - 1))) >> 2
123  */
124 #define VR42		0x42
125 
126 /*
127  * Horizontal Image Size
128  */
129 #define VR43		0x43
130 
131 /* VR80 GPIO 0
132  */
133 #define VR80	    0x80
134 #define VR81	    0x81
135 #define VR82	    0x82
136 #define VR83	    0x83
137 #define VR84	    0x84
138 #define VR85	    0x85
139 #define VR86	    0x86
140 #define VR87	    0x87
141 
142 /* VR88 GPIO 8
143  */
144 #define VR88	    0x88
145 
146 /* Graphics BIOS scratch 0
147  */
148 #define VR8E	    0x8E
149 # define VR8E_PANEL_TYPE_MASK		(0xf << 0)
150 # define VR8E_PANEL_INTERFACE_CMOS	(0 << 4)
151 # define VR8E_PANEL_INTERFACE_LVDS	(1 << 4)
152 # define VR8E_FORCE_DEFAULT_PANEL	(1 << 5)
153 
154 /* Graphics BIOS scratch 1
155  */
156 #define VR8F	    0x8F
157 # define VR8F_VCH_PRESENT		(1 << 0)
158 # define VR8F_DISPLAY_CONN		(1 << 1)
159 # define VR8F_POWER_MASK		(0x3c)
160 # define VR8F_POWER_POS			(2)
161 
162 /* Some Bios implementations do not restore the DVO state upon
163  * resume from standby. Thus, this driver has to handle it
164  * instead. The following list contains all registers that
165  * require saving.
166  */
167 static const u16 backup_addresses[] = {
168 	0x11, 0x12,
169 	0x18, 0x19, 0x1a, 0x1f,
170 	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
171 	0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
172 	0x8e, 0x8f,
173 	0x10		/* this must come last */
174 };
175 
176 
177 struct ivch_priv {
178 	bool quiet;
179 
180 	u16 width, height;
181 
182 	/* Register backup */
183 
184 	u16 reg_backup[ARRAY_SIZE(backup_addresses)];
185 };
186 
187 
188 static void ivch_dump_regs(struct intel_dvo_device *dvo);
189 /*
190  * Reads a register on the ivch.
191  *
192  * Each of the 256 registers are 16 bits long.
193  */
194 static bool ivch_read(struct intel_dvo_device *dvo, int addr, u16 *data)
195 {
196 	struct ivch_priv *priv = dvo->dev_priv;
197 	struct i2c_adapter *adapter = dvo->i2c_bus;
198 	u8 out_buf[1];
199 	u8 in_buf[2];
200 
201 	struct i2c_msg msgs[] = {
202 		{
203 			.addr = dvo->target_addr,
204 			.flags = I2C_M_RD,
205 			.len = 0,
206 		},
207 		{
208 			.addr = 0,
209 			.flags = I2C_M_NOSTART,
210 			.len = 1,
211 			.buf = out_buf,
212 		},
213 		{
214 			.addr = dvo->target_addr,
215 			.flags = I2C_M_RD | I2C_M_NOSTART,
216 			.len = 2,
217 			.buf = in_buf,
218 		}
219 	};
220 
221 	out_buf[0] = addr;
222 
223 	if (i2c_transfer(adapter, msgs, 3) == 3) {
224 		*data = (in_buf[1] << 8) | in_buf[0];
225 		return true;
226 	}
227 
228 	if (!priv->quiet) {
229 		DRM_DEBUG_KMS("Unable to read register 0x%02x from "
230 				"%s:%02x.\n",
231 			  addr, adapter->name, dvo->target_addr);
232 	}
233 	return false;
234 }
235 
236 /* Writes a 16-bit register on the ivch */
237 static bool ivch_write(struct intel_dvo_device *dvo, int addr, u16 data)
238 {
239 	struct ivch_priv *priv = dvo->dev_priv;
240 	struct i2c_adapter *adapter = dvo->i2c_bus;
241 	u8 out_buf[3];
242 	struct i2c_msg msg = {
243 		.addr = dvo->target_addr,
244 		.flags = 0,
245 		.len = 3,
246 		.buf = out_buf,
247 	};
248 
249 	out_buf[0] = addr;
250 	out_buf[1] = data & 0xff;
251 	out_buf[2] = data >> 8;
252 
253 	if (i2c_transfer(adapter, &msg, 1) == 1)
254 		return true;
255 
256 	if (!priv->quiet) {
257 		DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d.\n",
258 			  addr, adapter->name, dvo->target_addr);
259 	}
260 
261 	return false;
262 }
263 
264 /* Probes the given bus and target address for an ivch */
265 static bool ivch_init(struct intel_dvo_device *dvo,
266 		      struct i2c_adapter *adapter)
267 {
268 	struct ivch_priv *priv;
269 	u16 temp;
270 	int i;
271 
272 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
273 	if (priv == NULL)
274 		return false;
275 
276 	dvo->i2c_bus = adapter;
277 	dvo->dev_priv = priv;
278 	priv->quiet = true;
279 
280 	if (!ivch_read(dvo, VR00, &temp))
281 		goto out;
282 	priv->quiet = false;
283 
284 	/* Since the identification bits are probably zeroes, which doesn't seem
285 	 * very unique, check that the value in the base address field matches
286 	 * the address it's responding on.
287 	 */
288 	if ((temp & VR00_BASE_ADDRESS_MASK) != dvo->target_addr) {
289 		DRM_DEBUG_KMS("ivch detect failed due to address mismatch "
290 			  "(%d vs %d)\n",
291 			  (temp & VR00_BASE_ADDRESS_MASK), dvo->target_addr);
292 		goto out;
293 	}
294 
295 	ivch_read(dvo, VR20, &priv->width);
296 	ivch_read(dvo, VR21, &priv->height);
297 
298 	/* Make a backup of the registers to be able to restore them
299 	 * upon suspend.
300 	 */
301 	for (i = 0; i < ARRAY_SIZE(backup_addresses); i++)
302 		ivch_read(dvo, backup_addresses[i], priv->reg_backup + i);
303 
304 	ivch_dump_regs(dvo);
305 
306 	return true;
307 
308 out:
309 	kfree(priv);
310 	return false;
311 }
312 
313 static enum drm_connector_status ivch_detect(struct intel_dvo_device *dvo)
314 {
315 	return connector_status_connected;
316 }
317 
318 static enum drm_mode_status ivch_mode_valid(struct intel_dvo_device *dvo,
319 					    const struct drm_display_mode *mode)
320 {
321 	if (mode->clock > 112000)
322 		return MODE_CLOCK_HIGH;
323 
324 	return MODE_OK;
325 }
326 
327 /* Restore the DVO registers after a resume
328  * from RAM. Registers have been saved during
329  * the initialization.
330  */
331 static void ivch_reset(struct intel_dvo_device *dvo)
332 {
333 	struct ivch_priv *priv = dvo->dev_priv;
334 	int i;
335 
336 	DRM_DEBUG_KMS("Resetting the IVCH registers\n");
337 
338 	ivch_write(dvo, VR10, 0x0000);
339 
340 	for (i = 0; i < ARRAY_SIZE(backup_addresses); i++)
341 		ivch_write(dvo, backup_addresses[i], priv->reg_backup[i]);
342 }
343 
344 /* Sets the power state of the panel connected to the ivch */
345 static void ivch_dpms(struct intel_dvo_device *dvo, bool enable)
346 {
347 	int i;
348 	u16 vr01, vr30, backlight;
349 
350 	ivch_reset(dvo);
351 
352 	/* Set the new power state of the panel. */
353 	if (!ivch_read(dvo, VR01, &vr01))
354 		return;
355 
356 	if (enable)
357 		backlight = 1;
358 	else
359 		backlight = 0;
360 
361 	ivch_write(dvo, VR80, backlight);
362 
363 	if (enable)
364 		vr01 |= VR01_LCD_ENABLE | VR01_DVO_ENABLE;
365 	else
366 		vr01 &= ~(VR01_LCD_ENABLE | VR01_DVO_ENABLE);
367 
368 	ivch_write(dvo, VR01, vr01);
369 
370 	/* Wait for the panel to make its state transition */
371 	for (i = 0; i < 100; i++) {
372 		if (!ivch_read(dvo, VR30, &vr30))
373 			break;
374 
375 		if (((vr30 & VR30_PANEL_ON) != 0) == enable)
376 			break;
377 		udelay(1000);
378 	}
379 	/* wait some more; vch may fail to resync sometimes without this */
380 	udelay(16 * 1000);
381 }
382 
383 static bool ivch_get_hw_state(struct intel_dvo_device *dvo)
384 {
385 	u16 vr01;
386 
387 	ivch_reset(dvo);
388 
389 	/* Set the new power state of the panel. */
390 	if (!ivch_read(dvo, VR01, &vr01))
391 		return false;
392 
393 	if (vr01 & VR01_LCD_ENABLE)
394 		return true;
395 	else
396 		return false;
397 }
398 
399 static void ivch_mode_set(struct intel_dvo_device *dvo,
400 			  const struct drm_display_mode *mode,
401 			  const struct drm_display_mode *adjusted_mode)
402 {
403 	struct ivch_priv *priv = dvo->dev_priv;
404 	u16 vr40 = 0;
405 	u16 vr01 = 0;
406 	u16 vr10;
407 
408 	ivch_reset(dvo);
409 
410 	vr10 = priv->reg_backup[ARRAY_SIZE(backup_addresses) - 1];
411 
412 	/* Enable dithering for 18 bpp pipelines */
413 	vr10 &= VR10_INTERFACE_DEPTH_MASK;
414 	if (vr10 == VR10_INTERFACE_2X18 || vr10 == VR10_INTERFACE_1X18)
415 		vr01 = VR01_DITHER_ENABLE;
416 
417 	vr40 = (VR40_STALL_ENABLE | VR40_VERTICAL_INTERP_ENABLE |
418 		VR40_HORIZONTAL_INTERP_ENABLE);
419 
420 	if (mode->hdisplay != adjusted_mode->crtc_hdisplay ||
421 	    mode->vdisplay != adjusted_mode->crtc_vdisplay) {
422 		u16 x_ratio, y_ratio;
423 
424 		vr01 |= VR01_PANEL_FIT_ENABLE;
425 		vr40 |= VR40_CLOCK_GATING_ENABLE;
426 		x_ratio = (((mode->hdisplay - 1) << 16) /
427 			   (adjusted_mode->crtc_hdisplay - 1)) >> 2;
428 		y_ratio = (((mode->vdisplay - 1) << 16) /
429 			   (adjusted_mode->crtc_vdisplay - 1)) >> 2;
430 		ivch_write(dvo, VR42, x_ratio);
431 		ivch_write(dvo, VR41, y_ratio);
432 	} else {
433 		vr01 &= ~VR01_PANEL_FIT_ENABLE;
434 		vr40 &= ~VR40_CLOCK_GATING_ENABLE;
435 	}
436 	vr40 &= ~VR40_AUTO_RATIO_ENABLE;
437 
438 	ivch_write(dvo, VR01, vr01);
439 	ivch_write(dvo, VR40, vr40);
440 }
441 
442 static void ivch_dump_regs(struct intel_dvo_device *dvo)
443 {
444 	u16 val;
445 
446 	ivch_read(dvo, VR00, &val);
447 	DRM_DEBUG_KMS("VR00: 0x%04x\n", val);
448 	ivch_read(dvo, VR01, &val);
449 	DRM_DEBUG_KMS("VR01: 0x%04x\n", val);
450 	ivch_read(dvo, VR10, &val);
451 	DRM_DEBUG_KMS("VR10: 0x%04x\n", val);
452 	ivch_read(dvo, VR30, &val);
453 	DRM_DEBUG_KMS("VR30: 0x%04x\n", val);
454 	ivch_read(dvo, VR40, &val);
455 	DRM_DEBUG_KMS("VR40: 0x%04x\n", val);
456 
457 	/* GPIO registers */
458 	ivch_read(dvo, VR80, &val);
459 	DRM_DEBUG_KMS("VR80: 0x%04x\n", val);
460 	ivch_read(dvo, VR81, &val);
461 	DRM_DEBUG_KMS("VR81: 0x%04x\n", val);
462 	ivch_read(dvo, VR82, &val);
463 	DRM_DEBUG_KMS("VR82: 0x%04x\n", val);
464 	ivch_read(dvo, VR83, &val);
465 	DRM_DEBUG_KMS("VR83: 0x%04x\n", val);
466 	ivch_read(dvo, VR84, &val);
467 	DRM_DEBUG_KMS("VR84: 0x%04x\n", val);
468 	ivch_read(dvo, VR85, &val);
469 	DRM_DEBUG_KMS("VR85: 0x%04x\n", val);
470 	ivch_read(dvo, VR86, &val);
471 	DRM_DEBUG_KMS("VR86: 0x%04x\n", val);
472 	ivch_read(dvo, VR87, &val);
473 	DRM_DEBUG_KMS("VR87: 0x%04x\n", val);
474 	ivch_read(dvo, VR88, &val);
475 	DRM_DEBUG_KMS("VR88: 0x%04x\n", val);
476 
477 	/* Scratch register 0 - AIM Panel type */
478 	ivch_read(dvo, VR8E, &val);
479 	DRM_DEBUG_KMS("VR8E: 0x%04x\n", val);
480 
481 	/* Scratch register 1 - Status register */
482 	ivch_read(dvo, VR8F, &val);
483 	DRM_DEBUG_KMS("VR8F: 0x%04x\n", val);
484 }
485 
486 static void ivch_destroy(struct intel_dvo_device *dvo)
487 {
488 	struct ivch_priv *priv = dvo->dev_priv;
489 
490 	if (priv) {
491 		kfree(priv);
492 		dvo->dev_priv = NULL;
493 	}
494 }
495 
496 const struct intel_dvo_dev_ops ivch_ops = {
497 	.init = ivch_init,
498 	.dpms = ivch_dpms,
499 	.get_hw_state = ivch_get_hw_state,
500 	.mode_valid = ivch_mode_valid,
501 	.mode_set = ivch_mode_set,
502 	.detect = ivch_detect,
503 	.dump_regs = ivch_dump_regs,
504 	.destroy = ivch_destroy,
505 };
506