xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/edid.c (revision e2c75e76)
1 /*
2  * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
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 FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Ke Yu
25  *    Zhiyuan Lv <zhiyuan.lv@intel.com>
26  *
27  * Contributors:
28  *    Terrence Xu <terrence.xu@intel.com>
29  *    Changbin Du <changbin.du@intel.com>
30  *    Bing Niu <bing.niu@intel.com>
31  *    Zhi Wang <zhi.a.wang@intel.com>
32  *
33  */
34 
35 #include "i915_drv.h"
36 #include "gvt.h"
37 
38 #define GMBUS1_TOTAL_BYTES_SHIFT 16
39 #define GMBUS1_TOTAL_BYTES_MASK 0x1ff
40 #define gmbus1_total_byte_count(v) (((v) >> \
41 	GMBUS1_TOTAL_BYTES_SHIFT) & GMBUS1_TOTAL_BYTES_MASK)
42 #define gmbus1_slave_addr(v) (((v) & 0xff) >> 1)
43 #define gmbus1_slave_index(v) (((v) >> 8) & 0xff)
44 #define gmbus1_bus_cycle(v) (((v) >> 25) & 0x7)
45 
46 /* GMBUS0 bits definitions */
47 #define _GMBUS_PIN_SEL_MASK     (0x7)
48 
49 static unsigned char edid_get_byte(struct intel_vgpu *vgpu)
50 {
51 	struct intel_vgpu_i2c_edid *edid = &vgpu->display.i2c_edid;
52 	unsigned char chr = 0;
53 
54 	if (edid->state == I2C_NOT_SPECIFIED || !edid->slave_selected) {
55 		gvt_vgpu_err("Driver tries to read EDID without proper sequence!\n");
56 		return 0;
57 	}
58 	if (edid->current_edid_read >= EDID_SIZE) {
59 		gvt_vgpu_err("edid_get_byte() exceeds the size of EDID!\n");
60 		return 0;
61 	}
62 
63 	if (!edid->edid_available) {
64 		gvt_vgpu_err("Reading EDID but EDID is not available!\n");
65 		return 0;
66 	}
67 
68 	if (intel_vgpu_has_monitor_on_port(vgpu, edid->port)) {
69 		struct intel_vgpu_edid_data *edid_data =
70 			intel_vgpu_port(vgpu, edid->port)->edid;
71 
72 		chr = edid_data->edid_block[edid->current_edid_read];
73 		edid->current_edid_read++;
74 	} else {
75 		gvt_vgpu_err("No EDID available during the reading?\n");
76 	}
77 	return chr;
78 }
79 
80 static inline int get_port_from_gmbus0(u32 gmbus0)
81 {
82 	int port_select = gmbus0 & _GMBUS_PIN_SEL_MASK;
83 	int port = -EINVAL;
84 
85 	if (port_select == 2)
86 		port = PORT_E;
87 	else if (port_select == 4)
88 		port = PORT_C;
89 	else if (port_select == 5)
90 		port = PORT_B;
91 	else if (port_select == 6)
92 		port = PORT_D;
93 	return port;
94 }
95 
96 static void reset_gmbus_controller(struct intel_vgpu *vgpu)
97 {
98 	vgpu_vreg_t(vgpu, PCH_GMBUS2) = GMBUS_HW_RDY;
99 	if (!vgpu->display.i2c_edid.edid_available)
100 		vgpu_vreg_t(vgpu, PCH_GMBUS2) |= GMBUS_SATOER;
101 	vgpu->display.i2c_edid.gmbus.phase = GMBUS_IDLE_PHASE;
102 }
103 
104 /* GMBUS0 */
105 static int gmbus0_mmio_write(struct intel_vgpu *vgpu,
106 			unsigned int offset, void *p_data, unsigned int bytes)
107 {
108 	int port, pin_select;
109 
110 	memcpy(&vgpu_vreg(vgpu, offset), p_data, bytes);
111 
112 	pin_select = vgpu_vreg(vgpu, offset) & _GMBUS_PIN_SEL_MASK;
113 
114 	intel_vgpu_init_i2c_edid(vgpu);
115 
116 	if (pin_select == 0)
117 		return 0;
118 
119 	port = get_port_from_gmbus0(pin_select);
120 	if (WARN_ON(port < 0))
121 		return 0;
122 
123 	vgpu->display.i2c_edid.state = I2C_GMBUS;
124 	vgpu->display.i2c_edid.gmbus.phase = GMBUS_IDLE_PHASE;
125 
126 	vgpu_vreg_t(vgpu, PCH_GMBUS2) &= ~GMBUS_ACTIVE;
127 	vgpu_vreg_t(vgpu, PCH_GMBUS2) |= GMBUS_HW_RDY | GMBUS_HW_WAIT_PHASE;
128 
129 	if (intel_vgpu_has_monitor_on_port(vgpu, port) &&
130 			!intel_vgpu_port_is_dp(vgpu, port)) {
131 		vgpu->display.i2c_edid.port = port;
132 		vgpu->display.i2c_edid.edid_available = true;
133 		vgpu_vreg_t(vgpu, PCH_GMBUS2) &= ~GMBUS_SATOER;
134 	} else
135 		vgpu_vreg_t(vgpu, PCH_GMBUS2) |= GMBUS_SATOER;
136 	return 0;
137 }
138 
139 static int gmbus1_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
140 		void *p_data, unsigned int bytes)
141 {
142 	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
143 	u32 slave_addr;
144 	u32 wvalue = *(u32 *)p_data;
145 
146 	if (vgpu_vreg(vgpu, offset) & GMBUS_SW_CLR_INT) {
147 		if (!(wvalue & GMBUS_SW_CLR_INT)) {
148 			vgpu_vreg(vgpu, offset) &= ~GMBUS_SW_CLR_INT;
149 			reset_gmbus_controller(vgpu);
150 		}
151 		/*
152 		 * TODO: "This bit is cleared to zero when an event
153 		 * causes the HW_RDY bit transition to occur "
154 		 */
155 	} else {
156 		/*
157 		 * per bspec setting this bit can cause:
158 		 * 1) INT status bit cleared
159 		 * 2) HW_RDY bit asserted
160 		 */
161 		if (wvalue & GMBUS_SW_CLR_INT) {
162 			vgpu_vreg_t(vgpu, PCH_GMBUS2) &= ~GMBUS_INT;
163 			vgpu_vreg_t(vgpu, PCH_GMBUS2) |= GMBUS_HW_RDY;
164 		}
165 
166 		/* For virtualization, we suppose that HW is always ready,
167 		 * so GMBUS_SW_RDY should always be cleared
168 		 */
169 		if (wvalue & GMBUS_SW_RDY)
170 			wvalue &= ~GMBUS_SW_RDY;
171 
172 		i2c_edid->gmbus.total_byte_count =
173 			gmbus1_total_byte_count(wvalue);
174 		slave_addr = gmbus1_slave_addr(wvalue);
175 
176 		/* vgpu gmbus only support EDID */
177 		if (slave_addr == EDID_ADDR) {
178 			i2c_edid->slave_selected = true;
179 		} else if (slave_addr != 0) {
180 			gvt_dbg_dpy(
181 				"vgpu%d: unsupported gmbus slave addr(0x%x)\n"
182 				"	gmbus operations will be ignored.\n",
183 					vgpu->id, slave_addr);
184 		}
185 
186 		if (wvalue & GMBUS_CYCLE_INDEX)
187 			i2c_edid->current_edid_read =
188 				gmbus1_slave_index(wvalue);
189 
190 		i2c_edid->gmbus.cycle_type = gmbus1_bus_cycle(wvalue);
191 		switch (gmbus1_bus_cycle(wvalue)) {
192 		case GMBUS_NOCYCLE:
193 			break;
194 		case GMBUS_STOP:
195 			/* From spec:
196 			 * This can only cause a STOP to be generated
197 			 * if a GMBUS cycle is generated, the GMBUS is
198 			 * currently in a data/wait/idle phase, or it is in a
199 			 * WAIT phase
200 			 */
201 			if (gmbus1_bus_cycle(vgpu_vreg(vgpu, offset))
202 				!= GMBUS_NOCYCLE) {
203 				intel_vgpu_init_i2c_edid(vgpu);
204 				/* After the 'stop' cycle, hw state would become
205 				 * 'stop phase' and then 'idle phase' after a
206 				 * few milliseconds. In emulation, we just set
207 				 * it as 'idle phase' ('stop phase' is not
208 				 * visible in gmbus interface)
209 				 */
210 				i2c_edid->gmbus.phase = GMBUS_IDLE_PHASE;
211 				vgpu_vreg_t(vgpu, PCH_GMBUS2) &= ~GMBUS_ACTIVE;
212 			}
213 			break;
214 		case NIDX_NS_W:
215 		case IDX_NS_W:
216 		case NIDX_STOP:
217 		case IDX_STOP:
218 			/* From hw spec the GMBUS phase
219 			 * transition like this:
220 			 * START (-->INDEX) -->DATA
221 			 */
222 			i2c_edid->gmbus.phase = GMBUS_DATA_PHASE;
223 			vgpu_vreg_t(vgpu, PCH_GMBUS2) |= GMBUS_ACTIVE;
224 			break;
225 		default:
226 			gvt_vgpu_err("Unknown/reserved GMBUS cycle detected!\n");
227 			break;
228 		}
229 		/*
230 		 * From hw spec the WAIT state will be
231 		 * cleared:
232 		 * (1) in a new GMBUS cycle
233 		 * (2) by generating a stop
234 		 */
235 		vgpu_vreg(vgpu, offset) = wvalue;
236 	}
237 	return 0;
238 }
239 
240 static int gmbus3_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
241 	void *p_data, unsigned int bytes)
242 {
243 	WARN_ON(1);
244 	return 0;
245 }
246 
247 static int gmbus3_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
248 		void *p_data, unsigned int bytes)
249 {
250 	int i;
251 	unsigned char byte_data;
252 	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
253 	int byte_left = i2c_edid->gmbus.total_byte_count -
254 				i2c_edid->current_edid_read;
255 	int byte_count = byte_left;
256 	u32 reg_data = 0;
257 
258 	/* Data can only be recevied if previous settings correct */
259 	if (vgpu_vreg_t(vgpu, PCH_GMBUS1) & GMBUS_SLAVE_READ) {
260 		if (byte_left <= 0) {
261 			memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
262 			return 0;
263 		}
264 
265 		if (byte_count > 4)
266 			byte_count = 4;
267 		for (i = 0; i < byte_count; i++) {
268 			byte_data = edid_get_byte(vgpu);
269 			reg_data |= (byte_data << (i << 3));
270 		}
271 
272 		memcpy(&vgpu_vreg(vgpu, offset), &reg_data, byte_count);
273 		memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
274 
275 		if (byte_left <= 4) {
276 			switch (i2c_edid->gmbus.cycle_type) {
277 			case NIDX_STOP:
278 			case IDX_STOP:
279 				i2c_edid->gmbus.phase = GMBUS_IDLE_PHASE;
280 				break;
281 			case NIDX_NS_W:
282 			case IDX_NS_W:
283 			default:
284 				i2c_edid->gmbus.phase = GMBUS_WAIT_PHASE;
285 				break;
286 			}
287 			intel_vgpu_init_i2c_edid(vgpu);
288 		}
289 		/*
290 		 * Read GMBUS3 during send operation,
291 		 * return the latest written value
292 		 */
293 	} else {
294 		memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
295 		gvt_vgpu_err("warning: gmbus3 read with nothing returned\n");
296 	}
297 	return 0;
298 }
299 
300 static int gmbus2_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
301 		void *p_data, unsigned int bytes)
302 {
303 	u32 value = vgpu_vreg(vgpu, offset);
304 
305 	if (!(vgpu_vreg(vgpu, offset) & GMBUS_INUSE))
306 		vgpu_vreg(vgpu, offset) |= GMBUS_INUSE;
307 	memcpy(p_data, (void *)&value, bytes);
308 	return 0;
309 }
310 
311 static int gmbus2_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
312 		void *p_data, unsigned int bytes)
313 {
314 	u32 wvalue = *(u32 *)p_data;
315 
316 	if (wvalue & GMBUS_INUSE)
317 		vgpu_vreg(vgpu, offset) &= ~GMBUS_INUSE;
318 	/* All other bits are read-only */
319 	return 0;
320 }
321 
322 /**
323  * intel_gvt_i2c_handle_gmbus_read - emulate gmbus register mmio read
324  * @vgpu: a vGPU
325  *
326  * This function is used to emulate gmbus register mmio read
327  *
328  * Returns:
329  * Zero on success, negative error code if failed.
330  *
331  */
332 int intel_gvt_i2c_handle_gmbus_read(struct intel_vgpu *vgpu,
333 	unsigned int offset, void *p_data, unsigned int bytes)
334 {
335 	if (WARN_ON(bytes > 8 && (offset & (bytes - 1))))
336 		return -EINVAL;
337 
338 	if (offset == i915_mmio_reg_offset(PCH_GMBUS2))
339 		return gmbus2_mmio_read(vgpu, offset, p_data, bytes);
340 	else if (offset == i915_mmio_reg_offset(PCH_GMBUS3))
341 		return gmbus3_mmio_read(vgpu, offset, p_data, bytes);
342 
343 	memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
344 	return 0;
345 }
346 
347 /**
348  * intel_gvt_i2c_handle_gmbus_write - emulate gmbus register mmio write
349  * @vgpu: a vGPU
350  *
351  * This function is used to emulate gmbus register mmio write
352  *
353  * Returns:
354  * Zero on success, negative error code if failed.
355  *
356  */
357 int intel_gvt_i2c_handle_gmbus_write(struct intel_vgpu *vgpu,
358 		unsigned int offset, void *p_data, unsigned int bytes)
359 {
360 	if (WARN_ON(bytes > 8 && (offset & (bytes - 1))))
361 		return -EINVAL;
362 
363 	if (offset == i915_mmio_reg_offset(PCH_GMBUS0))
364 		return gmbus0_mmio_write(vgpu, offset, p_data, bytes);
365 	else if (offset == i915_mmio_reg_offset(PCH_GMBUS1))
366 		return gmbus1_mmio_write(vgpu, offset, p_data, bytes);
367 	else if (offset == i915_mmio_reg_offset(PCH_GMBUS2))
368 		return gmbus2_mmio_write(vgpu, offset, p_data, bytes);
369 	else if (offset == i915_mmio_reg_offset(PCH_GMBUS3))
370 		return gmbus3_mmio_write(vgpu, offset, p_data, bytes);
371 
372 	memcpy(&vgpu_vreg(vgpu, offset), p_data, bytes);
373 	return 0;
374 }
375 
376 enum {
377 	AUX_CH_CTL = 0,
378 	AUX_CH_DATA1,
379 	AUX_CH_DATA2,
380 	AUX_CH_DATA3,
381 	AUX_CH_DATA4,
382 	AUX_CH_DATA5
383 };
384 
385 static inline int get_aux_ch_reg(unsigned int offset)
386 {
387 	int reg;
388 
389 	switch (offset & 0xff) {
390 	case 0x10:
391 		reg = AUX_CH_CTL;
392 		break;
393 	case 0x14:
394 		reg = AUX_CH_DATA1;
395 		break;
396 	case 0x18:
397 		reg = AUX_CH_DATA2;
398 		break;
399 	case 0x1c:
400 		reg = AUX_CH_DATA3;
401 		break;
402 	case 0x20:
403 		reg = AUX_CH_DATA4;
404 		break;
405 	case 0x24:
406 		reg = AUX_CH_DATA5;
407 		break;
408 	default:
409 		reg = -1;
410 		break;
411 	}
412 	return reg;
413 }
414 
415 #define AUX_CTL_MSG_LENGTH(reg) \
416 	((reg & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >> \
417 		DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT)
418 
419 /**
420  * intel_gvt_i2c_handle_aux_ch_write - emulate AUX channel register write
421  * @vgpu: a vGPU
422  *
423  * This function is used to emulate AUX channel register write
424  *
425  */
426 void intel_gvt_i2c_handle_aux_ch_write(struct intel_vgpu *vgpu,
427 				int port_idx,
428 				unsigned int offset,
429 				void *p_data)
430 {
431 	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
432 	int msg_length, ret_msg_size;
433 	int msg, addr, ctrl, op;
434 	u32 value = *(u32 *)p_data;
435 	int aux_data_for_write = 0;
436 	int reg = get_aux_ch_reg(offset);
437 
438 	if (reg != AUX_CH_CTL) {
439 		vgpu_vreg(vgpu, offset) = value;
440 		return;
441 	}
442 
443 	msg_length = AUX_CTL_MSG_LENGTH(value);
444 	// check the msg in DATA register.
445 	msg = vgpu_vreg(vgpu, offset + 4);
446 	addr = (msg >> 8) & 0xffff;
447 	ctrl = (msg >> 24) & 0xff;
448 	op = ctrl >> 4;
449 	if (!(value & DP_AUX_CH_CTL_SEND_BUSY)) {
450 		/* The ctl write to clear some states */
451 		return;
452 	}
453 
454 	/* Always set the wanted value for vms. */
455 	ret_msg_size = (((op & 0x1) == GVT_AUX_I2C_READ) ? 2 : 1);
456 	vgpu_vreg(vgpu, offset) =
457 		DP_AUX_CH_CTL_DONE |
458 		((ret_msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) &
459 		DP_AUX_CH_CTL_MESSAGE_SIZE_MASK);
460 
461 	if (msg_length == 3) {
462 		if (!(op & GVT_AUX_I2C_MOT)) {
463 			/* stop */
464 			intel_vgpu_init_i2c_edid(vgpu);
465 		} else {
466 			/* start or restart */
467 			i2c_edid->aux_ch.i2c_over_aux_ch = true;
468 			i2c_edid->aux_ch.aux_ch_mot = true;
469 			if (addr == 0) {
470 				/* reset the address */
471 				intel_vgpu_init_i2c_edid(vgpu);
472 			} else if (addr == EDID_ADDR) {
473 				i2c_edid->state = I2C_AUX_CH;
474 				i2c_edid->port = port_idx;
475 				i2c_edid->slave_selected = true;
476 				if (intel_vgpu_has_monitor_on_port(vgpu,
477 					port_idx) &&
478 					intel_vgpu_port_is_dp(vgpu, port_idx))
479 					i2c_edid->edid_available = true;
480 			}
481 		}
482 	} else if ((op & 0x1) == GVT_AUX_I2C_WRITE) {
483 		/* TODO
484 		 * We only support EDID reading from I2C_over_AUX. And
485 		 * we do not expect the index mode to be used. Right now
486 		 * the WRITE operation is ignored. It is good enough to
487 		 * support the gfx driver to do EDID access.
488 		 */
489 	} else {
490 		if (WARN_ON((op & 0x1) != GVT_AUX_I2C_READ))
491 			return;
492 		if (WARN_ON(msg_length != 4))
493 			return;
494 		if (i2c_edid->edid_available && i2c_edid->slave_selected) {
495 			unsigned char val = edid_get_byte(vgpu);
496 
497 			aux_data_for_write = (val << 16);
498 		} else
499 			aux_data_for_write = (0xff << 16);
500 	}
501 	/* write the return value in AUX_CH_DATA reg which includes:
502 	 * ACK of I2C_WRITE
503 	 * returned byte if it is READ
504 	 */
505 	aux_data_for_write |= GVT_AUX_I2C_REPLY_ACK << 24;
506 	vgpu_vreg(vgpu, offset + 4) = aux_data_for_write;
507 }
508 
509 /**
510  * intel_vgpu_init_i2c_edid - initialize vGPU i2c edid emulation
511  * @vgpu: a vGPU
512  *
513  * This function is used to initialize vGPU i2c edid emulation stuffs
514  *
515  */
516 void intel_vgpu_init_i2c_edid(struct intel_vgpu *vgpu)
517 {
518 	struct intel_vgpu_i2c_edid *edid = &vgpu->display.i2c_edid;
519 
520 	edid->state = I2C_NOT_SPECIFIED;
521 
522 	edid->port = -1;
523 	edid->slave_selected = false;
524 	edid->edid_available = false;
525 	edid->current_edid_read = 0;
526 
527 	memset(&edid->gmbus, 0, sizeof(struct intel_vgpu_i2c_gmbus));
528 
529 	edid->aux_ch.i2c_over_aux_ch = false;
530 	edid->aux_ch.aux_ch_mot = false;
531 }
532