xref: /freebsd-11-stable/sys/dev/drm2/i915/intel_iic.c (revision 4407d0072e9635b028e75cd6af9b476e57ee3838)
1 /*
2  * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
3  * Copyright © 2006-2008,2010 Intel Corporation
4  *   Jesse Barnes <jesse.barnes@intel.com>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23  * DEALINGS IN THE SOFTWARE.
24  *
25  * Authors:
26  *	Eric Anholt <eric@anholt.net>
27  *	Chris Wilson <chris@chris-wilson.co.uk>
28  */
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <dev/drm2/drmP.h>
33 #include <dev/drm2/i915/intel_drv.h>
34 #include <dev/drm2/i915/i915_drm.h>
35 #include <dev/drm2/i915/i915_drv.h>
36 #include <dev/iicbus/iic.h>
37 #include <dev/iicbus/iiconf.h>
38 #include <dev/iicbus/iicbus.h>
39 #include "iicbus_if.h"
40 #include "iicbb_if.h"
41 
42 struct gmbus_port {
43 	const char *name;
44 	int reg;
45 };
46 
47 static const struct gmbus_port gmbus_ports[] = {
48 	{ "ssc", GPIOB },
49 	{ "vga", GPIOA },
50 	{ "panel", GPIOC },
51 	{ "dpc", GPIOD },
52 	{ "dpb", GPIOE },
53 	{ "dpd", GPIOF },
54 };
55 
56 /* Intel GPIO access functions */
57 
58 #define I2C_RISEFALL_TIME 10
59 
60 /*
61  * FIXME Linux<->FreeBSD: dvo_ns2501.C wants the struct intel_gmbus
62  * below but it just has the device_t at hand. It still uses
63  * device_get_softc(), thus expects struct intel_gmbus to remain the
64  * first member.
65  */
66 struct intel_iic_softc {
67 	struct intel_gmbus *bus;
68 	device_t iic_dev;
69 	char name[32];
70 };
71 
72 static inline struct intel_gmbus *
to_intel_gmbus(device_t i2c)73 to_intel_gmbus(device_t i2c)
74 {
75 	struct intel_iic_softc *sc;
76 
77 	sc = device_get_softc(i2c);
78 	return sc->bus;
79 }
80 
intel_gmbus_is_forced_bit(device_t adapter)81 bool intel_gmbus_is_forced_bit(device_t adapter)
82 {
83 	struct intel_iic_softc *sc = device_get_softc(adapter);
84 	struct intel_gmbus *bus = sc->bus;
85 
86 	return bus->force_bit;
87 }
88 
89 void
intel_i2c_reset(struct drm_device * dev)90 intel_i2c_reset(struct drm_device *dev)
91 {
92 	struct drm_i915_private *dev_priv = dev->dev_private;
93 	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
94 }
95 
96 static int
intel_iicbus_reset(device_t idev,u_char speed,u_char addr,u_char * oldaddr)97 intel_iicbus_reset(device_t idev, u_char speed, u_char addr, u_char *oldaddr)
98 {
99 	struct intel_iic_softc *sc;
100 	struct drm_device *dev;
101 
102 	sc = device_get_softc(idev);
103 	dev = sc->bus->dev_priv->dev;
104 
105 	intel_i2c_reset(dev);
106 	return (0);
107 }
108 
intel_i2c_quirk_set(struct drm_i915_private * dev_priv,bool enable)109 static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable)
110 {
111 	u32 val;
112 
113 	/* When using bit bashing for I2C, this bit needs to be set to 1 */
114 	if (!IS_PINEVIEW(dev_priv->dev))
115 		return;
116 
117 	val = I915_READ(DSPCLK_GATE_D);
118 	if (enable)
119 		val |= DPCUNIT_CLOCK_GATE_DISABLE;
120 	else
121 		val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
122 	I915_WRITE(DSPCLK_GATE_D, val);
123 }
124 
get_reserved(struct intel_gmbus * bus)125 static u32 get_reserved(struct intel_gmbus *bus)
126 {
127 	struct drm_i915_private *dev_priv = bus->dev_priv;
128 	struct drm_device *dev = dev_priv->dev;
129 	u32 reserved = 0;
130 
131 	/* On most chips, these bits must be preserved in software. */
132 	if (!IS_I830(dev) && !IS_845G(dev))
133 		reserved = I915_READ_NOTRACE(bus->gpio_reg) &
134 					     (GPIO_DATA_PULLUP_DISABLE |
135 					      GPIO_CLOCK_PULLUP_DISABLE);
136 
137 	return reserved;
138 }
139 
get_clock(device_t adapter)140 static int get_clock(device_t adapter)
141 {
142 	struct intel_iic_softc *sc = device_get_softc(adapter);
143 	struct intel_gmbus *bus = sc->bus;
144 	struct drm_i915_private *dev_priv = bus->dev_priv;
145 	u32 reserved = get_reserved(bus);
146 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_CLOCK_DIR_MASK);
147 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
148 	return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_CLOCK_VAL_IN) != 0;
149 }
150 
get_data(device_t adapter)151 static int get_data(device_t adapter)
152 {
153 	struct intel_iic_softc *sc = device_get_softc(adapter);
154 	struct intel_gmbus *bus = sc->bus;
155 	struct drm_i915_private *dev_priv = bus->dev_priv;
156 	u32 reserved = get_reserved(bus);
157 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_DATA_DIR_MASK);
158 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
159 	return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_DATA_VAL_IN) != 0;
160 }
161 
set_clock(device_t adapter,int state_high)162 static void set_clock(device_t adapter, int state_high)
163 {
164 	struct intel_iic_softc *sc = device_get_softc(adapter);
165 	struct intel_gmbus *bus = sc->bus;
166 	struct drm_i915_private *dev_priv = bus->dev_priv;
167 	u32 reserved = get_reserved(bus);
168 	u32 clock_bits;
169 
170 	if (state_high)
171 		clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
172 	else
173 		clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
174 			GPIO_CLOCK_VAL_MASK;
175 
176 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved | clock_bits);
177 	POSTING_READ(bus->gpio_reg);
178 }
179 
set_data(device_t adapter,int state_high)180 static void set_data(device_t adapter, int state_high)
181 {
182 	struct intel_iic_softc *sc = device_get_softc(adapter);
183 	struct intel_gmbus *bus = sc->bus;
184 	struct drm_i915_private *dev_priv = bus->dev_priv;
185 	u32 reserved = get_reserved(bus);
186 	u32 data_bits;
187 
188 	if (state_high)
189 		data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
190 	else
191 		data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
192 			GPIO_DATA_VAL_MASK;
193 
194 	I915_WRITE_NOTRACE(bus->gpio_reg, reserved | data_bits);
195 	POSTING_READ(bus->gpio_reg);
196 }
197 
198 static int
intel_gpio_pre_xfer(device_t adapter)199 intel_gpio_pre_xfer(device_t adapter)
200 {
201 	struct intel_iic_softc *sc = device_get_softc(adapter);
202 	struct intel_gmbus *bus = sc->bus;
203 	struct drm_i915_private *dev_priv = bus->dev_priv;
204 
205 	intel_i2c_reset(dev_priv->dev);
206 	intel_i2c_quirk_set(dev_priv, true);
207 	IICBB_SETSDA(adapter, 1);
208 	IICBB_SETSCL(adapter, 1);
209 	udelay(I2C_RISEFALL_TIME);
210 	return 0;
211 }
212 
213 static void
intel_gpio_post_xfer(device_t adapter)214 intel_gpio_post_xfer(device_t adapter)
215 {
216 	struct intel_iic_softc *sc = device_get_softc(adapter);
217 	struct intel_gmbus *bus = sc->bus;
218 	struct drm_i915_private *dev_priv = bus->dev_priv;
219 
220 	IICBB_SETSDA(adapter, 1);
221 	IICBB_SETSCL(adapter, 1);
222 	intel_i2c_quirk_set(dev_priv, false);
223 }
224 
225 static void
intel_gpio_setup(struct intel_gmbus * bus,u32 pin)226 intel_gpio_setup(struct intel_gmbus *bus, u32 pin)
227 {
228 	struct drm_i915_private *dev_priv = bus->dev_priv;
229 
230 	/* -1 to map pin pair to gmbus index */
231 	bus->gpio_reg = dev_priv->gpio_mmio_base + gmbus_ports[pin - 1].reg;
232 }
233 
234 static int
gmbus_xfer_read(struct drm_i915_private * dev_priv,struct iic_msg * msg,u32 gmbus1_index)235 gmbus_xfer_read(struct drm_i915_private *dev_priv, struct iic_msg *msg,
236 		u32 gmbus1_index)
237 {
238 	int reg_offset = dev_priv->gpio_mmio_base;
239 	u16 len = msg->len;
240 	u8 *buf = msg->buf;
241 
242 	I915_WRITE(GMBUS1 + reg_offset,
243 		   gmbus1_index |
244 		   GMBUS_CYCLE_WAIT |
245 		   (len << GMBUS_BYTE_COUNT_SHIFT) |
246 		   (msg->slave << (GMBUS_SLAVE_ADDR_SHIFT - 1)) |
247 		   GMBUS_SLAVE_READ | GMBUS_SW_RDY);
248 	while (len) {
249 		int ret;
250 		u32 val, loop = 0;
251 		u32 gmbus2;
252 
253 		ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
254 			       (GMBUS_SATOER | GMBUS_HW_RDY),
255 			       50);
256 		if (ret)
257 			return -ETIMEDOUT;
258 		if (gmbus2 & GMBUS_SATOER)
259 			return -ENXIO;
260 
261 		val = I915_READ(GMBUS3 + reg_offset);
262 		do {
263 			*buf++ = val & 0xff;
264 			val >>= 8;
265 		} while (--len && ++loop < 4);
266 	}
267 
268 	return 0;
269 }
270 
271 static int
gmbus_xfer_write(struct drm_i915_private * dev_priv,struct iic_msg * msg)272 gmbus_xfer_write(struct drm_i915_private *dev_priv, struct iic_msg *msg)
273 {
274 	int reg_offset = dev_priv->gpio_mmio_base;
275 	u16 len = msg->len;
276 	u8 *buf = msg->buf;
277 	u32 val, loop;
278 
279 	val = loop = 0;
280 	while (len && loop < 4) {
281 		val |= *buf++ << (8 * loop++);
282 		len -= 1;
283 	}
284 
285 	I915_WRITE(GMBUS3 + reg_offset, val);
286 	I915_WRITE(GMBUS1 + reg_offset,
287 		   GMBUS_CYCLE_WAIT |
288 		   (msg->len << GMBUS_BYTE_COUNT_SHIFT) |
289 		   (msg->slave << (GMBUS_SLAVE_ADDR_SHIFT - 1)) |
290 		   GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
291 	while (len) {
292 		int ret;
293 		u32 gmbus2;
294 
295 		val = loop = 0;
296 		do {
297 			val |= *buf++ << (8 * loop);
298 		} while (--len && ++loop < 4);
299 
300 		I915_WRITE(GMBUS3 + reg_offset, val);
301 
302 		ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
303 			       (GMBUS_SATOER | GMBUS_HW_RDY),
304 			       50);
305 		if (ret)
306 			return -ETIMEDOUT;
307 		if (gmbus2 & GMBUS_SATOER)
308 			return -ENXIO;
309 	}
310 	return 0;
311 }
312 
313 /*
314  * The gmbus controller can combine a 1 or 2 byte write with a read that
315  * immediately follows it by using an "INDEX" cycle.
316  */
317 static bool
gmbus_is_index_read(struct iic_msg * msgs,int i,int num)318 gmbus_is_index_read(struct iic_msg *msgs, int i, int num)
319 {
320 	return (i + 1 < num &&
321 		!(msgs[i].flags & I2C_M_RD) && msgs[i].len <= 2 &&
322 		(msgs[i + 1].flags & I2C_M_RD));
323 }
324 
325 static int
gmbus_xfer_index_read(struct drm_i915_private * dev_priv,struct iic_msg * msgs)326 gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct iic_msg *msgs)
327 {
328 	int reg_offset = dev_priv->gpio_mmio_base;
329 	u32 gmbus1_index = 0;
330 	u32 gmbus5 = 0;
331 	int ret;
332 
333 	if (msgs[0].len == 2)
334 		gmbus5 = GMBUS_2BYTE_INDEX_EN |
335 			 msgs[0].buf[1] | (msgs[0].buf[0] << 8);
336 	if (msgs[0].len == 1)
337 		gmbus1_index = GMBUS_CYCLE_INDEX |
338 			       (msgs[0].buf[0] << GMBUS_SLAVE_INDEX_SHIFT);
339 
340 	/* GMBUS5 holds 16-bit index */
341 	if (gmbus5)
342 		I915_WRITE(GMBUS5 + reg_offset, gmbus5);
343 
344 	ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus1_index);
345 
346 	/* Clear GMBUS5 after each index transfer */
347 	if (gmbus5)
348 		I915_WRITE(GMBUS5 + reg_offset, 0);
349 
350 	return ret;
351 }
352 
353 static int
gmbus_xfer(device_t adapter,struct iic_msg * msgs,uint32_t num)354 gmbus_xfer(device_t adapter,
355 	   struct iic_msg *msgs,
356 	   uint32_t num)
357 {
358 	struct intel_iic_softc *sc = device_get_softc(adapter);
359 	struct intel_gmbus *bus = sc->bus;
360 	struct drm_i915_private *dev_priv = bus->dev_priv;
361 	int i, reg_offset;
362 	int ret = 0;
363 
364 	sx_xlock(&dev_priv->gmbus_mutex);
365 
366 	if (bus->force_bit) {
367 		ret = -IICBUS_TRANSFER(bus->bbbus, msgs, num);
368 		goto out;
369 	}
370 
371 	reg_offset = dev_priv->gpio_mmio_base;
372 
373 	I915_WRITE(GMBUS0 + reg_offset, bus->reg0);
374 
375 	for (i = 0; i < num; i++) {
376 		u32 gmbus2;
377 
378 		if (gmbus_is_index_read(msgs, i, num)) {
379 			ret = gmbus_xfer_index_read(dev_priv, &msgs[i]);
380 			i += 1;  /* set i to the index of the read xfer */
381 		} else if (msgs[i].flags & I2C_M_RD) {
382 			ret = gmbus_xfer_read(dev_priv, &msgs[i], 0);
383 		} else {
384 			ret = gmbus_xfer_write(dev_priv, &msgs[i]);
385 		}
386 
387 		if (ret == -ETIMEDOUT)
388 			goto timeout;
389 		if (ret == -ENXIO)
390 			goto clear_err;
391 
392 		ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
393 			       (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE),
394 			       50);
395 		if (ret)
396 			goto timeout;
397 		if (gmbus2 & GMBUS_SATOER)
398 			goto clear_err;
399 	}
400 
401 	/* Generate a STOP condition on the bus. Note that gmbus can't generata
402 	 * a STOP on the very first cycle. To simplify the code we
403 	 * unconditionally generate the STOP condition with an additional gmbus
404 	 * cycle. */
405 	I915_WRITE(GMBUS1 + reg_offset, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
406 
407 	/* Mark the GMBUS interface as disabled after waiting for idle.
408 	 * We will re-enable it at the start of the next xfer,
409 	 * till then let it sleep.
410 	 */
411 	if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0,
412 		     10)) {
413 		DRM_DEBUG_KMS("GMBUS [%s] timed out waiting for idle\n",
414 			 device_get_desc(adapter));
415 		ret = -ETIMEDOUT;
416 	}
417 	I915_WRITE(GMBUS0 + reg_offset, 0);
418 	goto out;
419 
420 clear_err:
421 	/*
422 	 * Wait for bus to IDLE before clearing NAK.
423 	 * If we clear the NAK while bus is still active, then it will stay
424 	 * active and the next transaction may fail.
425 	 *
426 	 * If no ACK is received during the address phase of a transaction, the
427 	 * adapter must report -ENXIO. It is not clear what to return if no ACK
428 	 * is received at other times. But we have to be careful to not return
429 	 * spurious -ENXIO because that will prevent i2c and drm edid functions
430 	 * from retrying. So return -ENXIO only when gmbus properly quiescents -
431 	 * timing out seems to happen when there _is_ a ddc chip present, but
432 	 * it's slow responding and only answers on the 2nd retry.
433 	 */
434 	ret = -ENXIO;
435 	if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0,
436 		     10)) {
437 		DRM_DEBUG_KMS("GMBUS [%s] timed out after NAK\n",
438 			      device_get_desc(adapter));
439 		ret = -ETIMEDOUT;
440 	}
441 
442 	/* Toggle the Software Clear Interrupt bit. This has the effect
443 	 * of resetting the GMBUS controller and so clearing the
444 	 * BUS_ERROR raised by the slave's NAK.
445 	 */
446 	I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
447 	I915_WRITE(GMBUS1 + reg_offset, 0);
448 	I915_WRITE(GMBUS0 + reg_offset, 0);
449 
450 	DRM_DEBUG_KMS("GMBUS [%s] NAK for addr: %04x %c(%d)\n",
451 			 device_get_desc(adapter), msgs[i].slave >> 1,
452 			 (msgs[i].flags & I2C_M_RD) ? 'r' : 'w', msgs[i].len);
453 
454 	goto out;
455 
456 timeout:
457 	DRM_INFO("GMBUS [%s] timed out, falling back to bit banging on pin %d\n",
458 		 device_get_desc(adapter), bus->reg0 & 0xff);
459 	I915_WRITE(GMBUS0 + reg_offset, 0);
460 
461 	/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
462 	bus->force_bit = 1;
463 	ret = -IICBUS_TRANSFER(bus->bbbus, msgs, num);
464 
465 out:
466 	sx_xunlock(&dev_priv->gmbus_mutex);
467 	return -ret;
468 }
469 
470 static int
intel_gmbus_probe(device_t dev)471 intel_gmbus_probe(device_t dev)
472 {
473 
474 	return (BUS_PROBE_SPECIFIC);
475 }
476 
477 static int
intel_gmbus_attach(device_t idev)478 intel_gmbus_attach(device_t idev)
479 {
480 	struct intel_iic_softc *sc;
481 	struct drm_device *dev;
482 	struct drm_i915_private *dev_priv;
483 	int pin, port;
484 
485 	sc = device_get_softc(idev);
486 	pin = device_get_unit(idev);
487 	port = pin + 1; /* +1 to map gmbus index to pin pair */
488 
489 	snprintf(sc->name, sizeof(sc->name), "i915 gmbus %s",
490 	    intel_gmbus_is_port_valid(port) ? gmbus_ports[pin].name :
491 	    "reserved");
492 	device_set_desc(idev, sc->name);
493 
494 	dev = device_get_softc(device_get_parent(idev));
495 	dev_priv = dev->dev_private;
496 	sc->bus = &dev_priv->gmbus[pin];
497 
498 	/* add bus interface device */
499 	sc->iic_dev = device_add_child(idev, "iicbus", -1);
500 	if (sc->iic_dev == NULL)
501 		return (ENXIO);
502 	device_quiet(sc->iic_dev);
503 	bus_generic_attach(idev);
504 
505 	return (0);
506 }
507 
508 static int
intel_gmbus_detach(device_t idev)509 intel_gmbus_detach(device_t idev)
510 {
511 
512 	bus_generic_detach(idev);
513 	device_delete_children(idev);
514 
515 	return (0);
516 }
517 
518 static device_method_t intel_gmbus_methods[] = {
519 	DEVMETHOD(device_probe,		intel_gmbus_probe),
520 	DEVMETHOD(device_attach,	intel_gmbus_attach),
521 	DEVMETHOD(device_detach,	intel_gmbus_detach),
522 	DEVMETHOD(iicbus_reset,		intel_iicbus_reset),
523 	DEVMETHOD(iicbus_transfer,	gmbus_xfer),
524 	DEVMETHOD_END
525 };
526 static driver_t intel_gmbus_driver = {
527 	"intel_gmbus",
528 	intel_gmbus_methods,
529 	sizeof(struct intel_iic_softc)
530 };
531 static devclass_t intel_gmbus_devclass;
532 DRIVER_MODULE_ORDERED(intel_gmbus, drmn, intel_gmbus_driver,
533     intel_gmbus_devclass, 0, 0, SI_ORDER_FIRST);
534 DRIVER_MODULE(iicbus, intel_gmbus, iicbus_driver, iicbus_devclass, 0, 0);
535 
536 static int
intel_iicbb_probe(device_t dev)537 intel_iicbb_probe(device_t dev)
538 {
539 
540 	return (BUS_PROBE_DEFAULT);
541 }
542 
543 static int
intel_iicbb_attach(device_t idev)544 intel_iicbb_attach(device_t idev)
545 {
546 	struct intel_iic_softc *sc;
547 	struct drm_device *dev;
548 	struct drm_i915_private *dev_priv;
549 	int pin, port;
550 
551 	sc = device_get_softc(idev);
552 	pin = device_get_unit(idev);
553 	port = pin + 1;
554 
555 	snprintf(sc->name, sizeof(sc->name), "i915 iicbb %s",
556 	    intel_gmbus_is_port_valid(port) ? gmbus_ports[pin].name :
557 	    "reserved");
558 	device_set_desc(idev, sc->name);
559 
560 	dev = device_get_softc(device_get_parent(idev));
561 	dev_priv = dev->dev_private;
562 	sc->bus = &dev_priv->gmbus[pin];
563 
564 	/* add generic bit-banging code */
565 	sc->iic_dev = device_add_child(idev, "iicbb_nostop", -1);
566 	if (sc->iic_dev == NULL)
567 		return (ENXIO);
568 	device_quiet(sc->iic_dev);
569 	bus_generic_attach(idev);
570 
571 	return (0);
572 }
573 
574 static int
intel_iicbb_detach(device_t idev)575 intel_iicbb_detach(device_t idev)
576 {
577 
578 	bus_generic_detach(idev);
579 	device_delete_children(idev);
580 
581 	return (0);
582 }
583 
584 static device_method_t intel_iicbb_methods[] =	{
585 	DEVMETHOD(device_probe,		intel_iicbb_probe),
586 	DEVMETHOD(device_attach,	intel_iicbb_attach),
587 	DEVMETHOD(device_detach,	intel_iicbb_detach),
588 
589 	DEVMETHOD(bus_add_child,	bus_generic_add_child),
590 	DEVMETHOD(bus_print_child,	bus_generic_print_child),
591 
592 	DEVMETHOD(iicbb_callback,	iicbus_null_callback),
593 	DEVMETHOD(iicbb_reset,		intel_iicbus_reset),
594 	DEVMETHOD(iicbb_setsda,		set_data),
595 	DEVMETHOD(iicbb_setscl,		set_clock),
596 	DEVMETHOD(iicbb_getsda,		get_data),
597 	DEVMETHOD(iicbb_getscl,		get_clock),
598 	DEVMETHOD(iicbb_pre_xfer,	intel_gpio_pre_xfer),
599 	DEVMETHOD(iicbb_post_xfer,	intel_gpio_post_xfer),
600 	DEVMETHOD_END
601 };
602 static driver_t intel_iicbb_driver = {
603 	"intel_iicbb",
604 	intel_iicbb_methods,
605 	sizeof(struct intel_iic_softc)
606 };
607 static devclass_t intel_iicbb_devclass;
608 DRIVER_MODULE_ORDERED(intel_iicbb, drmn, intel_iicbb_driver,
609     intel_iicbb_devclass, 0, 0, SI_ORDER_FIRST);
610 
611 /*
612  * XXX This is a copy of struct iicbb_softc in sys/dev/iicbus/iicbb.c.
613  * There should really be a shared definition.
614  */
615 struct iicbb_softc {
616 	device_t iicbus;
617 	int udelay;		/* signal toggle delay in usec */
618 };
619 
620 static int
iicbb_nostop_transfer_impl(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)621 iicbb_nostop_transfer_impl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
622 {
623 	int i, error, lenread, lenwrote, addr;
624 	struct iicbb_softc *sc;
625 	device_t bus;
626 	bool started;
627 
628 	sc = device_get_softc(dev);
629 	bus = sc->iicbus;
630 	started = false;
631 	for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
632 		addr = msgs[i].slave;
633 		if (msgs[i].flags & IIC_M_RD)
634 			addr |= LSB;
635 		else
636 			addr &= ~LSB;
637 
638 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
639 			if (i == 0)
640 				error = iicbus_start(bus, addr, 0);
641 			else
642 				error = iicbus_repeated_start(bus, addr, 0);
643 			if (error != 0)
644 				break;
645 			started = true;
646 		}
647 
648 		if ((msgs[i].flags & IIC_M_RD) != 0)
649 			error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
650 			    &lenread, IIC_LAST_READ, 0);
651 		else
652 			error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
653 			    &lenwrote, 0);
654 	}
655 	if (started)
656 		iicbus_stop(bus);
657 	return (error);
658 }
659 
660 static int
iicbb_nostop_transfer(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)661 iicbb_nostop_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
662 {
663 	int error;
664 
665 	error = IICBB_PRE_XFER(device_get_parent(dev));
666 	if (error)
667 		return (error);
668 
669 	error = iicbb_nostop_transfer_impl(dev, msgs, nmsgs);
670 
671 	IICBB_POST_XFER(device_get_parent(dev));
672 	return (error);
673 }
674 
675 static device_method_t iicbb_nostop_methods[] = {
676 	DEVMETHOD(iicbus_transfer,	iicbb_nostop_transfer),
677 
678 	DEVMETHOD_END
679 };
680 
681 static devclass_t iicbb_nostop_devclass;
682 
683 DEFINE_CLASS_1(iicbb_nostop, iicbb_nostop_driver, iicbb_nostop_methods,
684     sizeof(struct iicbb_softc), iicbb_driver);
685 DRIVER_MODULE(iicbb_nostop, intel_iicbb, iicbb_nostop_driver,
686     iicbb_nostop_devclass, NULL, NULL);
687 
688 /**
689  * intel_gmbus_setup - instantiate all Intel i2c GMBuses
690  * @dev: DRM device
691  */
intel_setup_gmbus(struct drm_device * dev)692 int intel_setup_gmbus(struct drm_device *dev)
693 {
694 	struct drm_i915_private *dev_priv = dev->dev_private;
695 	device_t iic_dev;
696 	int ret, i;
697 
698 	if (HAS_PCH_SPLIT(dev))
699 		dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
700 	else
701 		dev_priv->gpio_mmio_base = 0;
702 
703 	sx_init(&dev_priv->gmbus_mutex, "gmbus");
704 
705 	/*
706 	 * The Giant there is recursed, most likely.  Normally, the
707 	 * intel_setup_gmbus() is called from the attach method of the
708 	 * driver.
709 	 */
710 	mtx_lock(&Giant);
711 	for (i = 0; i < GMBUS_NUM_PORTS; i++) {
712 		struct intel_gmbus *bus = &dev_priv->gmbus[i];
713 		u32 port = i + 1; /* +1 to map gmbus index to pin pair */
714 
715 		bus->dev_priv = dev_priv;
716 
717 		/* By default use a conservative clock rate */
718 		bus->reg0 = port | GMBUS_RATE_100KHZ;
719 
720 		/* gmbus seems to be broken on i830 */
721 		if (IS_I830(dev))
722 			bus->force_bit = 1;
723 
724 		intel_gpio_setup(bus, port);
725 
726 		/*
727 		 * bbbus_bridge
728 		 *
729 		 * Initialized bbbus_bridge before gmbus_bridge, since
730 		 * gmbus may decide to force quirk transfer in the
731 		 * attachment code.
732 		 */
733 		bus->bbbus_bridge = device_add_child(dev->dev,
734 		    "intel_iicbb", i);
735 		if (bus->bbbus_bridge == NULL) {
736 			DRM_ERROR("bbbus bridge %d creation failed\n", i);
737 			ret = -ENXIO;
738 			goto err;
739 		}
740 		device_quiet(bus->bbbus_bridge);
741 		ret = -device_probe_and_attach(bus->bbbus_bridge);
742 		if (ret != 0) {
743 			DRM_ERROR("bbbus bridge %d attach failed, %d\n", i,
744 			    ret);
745 			goto err;
746 		}
747 
748 		/* bbbus */
749 		iic_dev = device_find_child(bus->bbbus_bridge,
750 		    "iicbb_nostop", -1);
751 		if (iic_dev == NULL) {
752 			DRM_ERROR("bbbus bridge doesn't have iicbb child\n");
753 			goto err;
754 		}
755 		iic_dev = device_find_child(iic_dev, "iicbus", -1);
756 		if (iic_dev == NULL) {
757 			DRM_ERROR(
758 		"bbbus bridge doesn't have iicbus grandchild\n");
759 			goto err;
760 		}
761 
762 		bus->bbbus = iic_dev;
763 
764 		/* gmbus_bridge */
765 		bus->gmbus_bridge = device_add_child(dev->dev,
766 		    "intel_gmbus", i);
767 		if (bus->gmbus_bridge == NULL) {
768 			DRM_ERROR("gmbus bridge %d creation failed\n", i);
769 			ret = -ENXIO;
770 			goto err;
771 		}
772 		device_quiet(bus->gmbus_bridge);
773 		ret = -device_probe_and_attach(bus->gmbus_bridge);
774 		if (ret != 0) {
775 			DRM_ERROR("gmbus bridge %d attach failed, %d\n", i,
776 			    ret);
777 			ret = -ENXIO;
778 			goto err;
779 		}
780 
781 		/* gmbus */
782 		iic_dev = device_find_child(bus->gmbus_bridge,
783 		    "iicbus", -1);
784 		if (iic_dev == NULL) {
785 			DRM_ERROR("gmbus bridge doesn't have iicbus child\n");
786 			goto err;
787 		}
788 
789 		bus->gmbus = iic_dev;
790 	}
791 	mtx_unlock(&Giant);
792 
793 	intel_i2c_reset(dev_priv->dev);
794 
795 	return 0;
796 
797 err:
798 	while (--i) {
799 		struct intel_gmbus *bus = &dev_priv->gmbus[i];
800 		if (bus->gmbus_bridge != NULL)
801 			device_delete_child(dev->dev, bus->gmbus_bridge);
802 		if (bus->bbbus_bridge != NULL)
803 			device_delete_child(dev->dev, bus->bbbus_bridge);
804 	}
805 	mtx_unlock(&Giant);
806 	sx_destroy(&dev_priv->gmbus_mutex);
807 	return ret;
808 }
809 
intel_gmbus_get_adapter(struct drm_i915_private * dev_priv,unsigned port)810 device_t intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
811 					    unsigned port)
812 {
813 	WARN_ON(!intel_gmbus_is_port_valid(port));
814 	/* -1 to map pin pair to gmbus index */
815 	return (intel_gmbus_is_port_valid(port)) ?
816 		dev_priv->gmbus[port - 1].gmbus : NULL;
817 }
818 
intel_gmbus_set_speed(device_t adapter,int speed)819 void intel_gmbus_set_speed(device_t adapter, int speed)
820 {
821 	struct intel_gmbus *bus = to_intel_gmbus(adapter);
822 
823 	bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | speed;
824 }
825 
intel_gmbus_force_bit(device_t adapter,bool force_bit)826 void intel_gmbus_force_bit(device_t adapter, bool force_bit)
827 {
828 	struct intel_gmbus *bus = to_intel_gmbus(adapter);
829 
830 	bus->force_bit += force_bit ? 1 : -1;
831 	DRM_DEBUG_KMS("%sabling bit-banging on %s. force bit now %d\n",
832 		      force_bit ? "en" : "dis", device_get_desc(adapter),
833 		      bus->force_bit);
834 }
835 
intel_teardown_gmbus(struct drm_device * dev)836 void intel_teardown_gmbus(struct drm_device *dev)
837 {
838 	struct drm_i915_private *dev_priv = dev->dev_private;
839 	int i;
840 	int ret;
841 
842 	for (i = 0; i < GMBUS_NUM_PORTS; i++) {
843 		struct intel_gmbus *bus = &dev_priv->gmbus[i];
844 
845 		mtx_lock(&Giant);
846 		ret = device_delete_child(dev->dev, bus->gmbus_bridge);
847 		mtx_unlock(&Giant);
848 
849 		KASSERT(ret == 0, ("unable to detach iic gmbus %s: %d",
850 		    device_get_desc(bus->gmbus_bridge), ret));
851 
852 		mtx_lock(&Giant);
853 		ret = device_delete_child(dev->dev, bus->bbbus_bridge);
854 		mtx_unlock(&Giant);
855 
856 		KASSERT(ret == 0, ("unable to detach iic bbbus %s: %d",
857 		    device_get_desc(bus->bbbus_bridge), ret));
858 	}
859 
860 	sx_destroy(&dev_priv->gmbus_mutex);
861 }
862