xref: /openbsd/sys/dev/pci/drm/amd/amdgpu/amdgpu_i2c.c (revision 5ca02815)
1 /*
2  * Copyright 2007-8 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors: Dave Airlie
24  *          Alex Deucher
25  */
26 
27 #include <linux/export.h>
28 #include <linux/pci.h>
29 
30 #include <drm/drm_edid.h>
31 #include <drm/amdgpu_drm.h>
32 #include "amdgpu.h"
33 #include "amdgpu_i2c.h"
34 #include "amdgpu_atombios.h"
35 #include "atom.h"
36 #include "atombios_dp.h"
37 #include "atombios_i2c.h"
38 
39 #include <dev/i2c/i2cvar.h>
40 #include <dev/i2c/i2c_bitbang.h>
41 
42 /* bit banging i2c */
amdgpu_i2c_pre_xfer(struct i2c_adapter * i2c_adap)43 static int amdgpu_i2c_pre_xfer(struct i2c_adapter *i2c_adap)
44 {
45 	struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
46 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
47 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
48 	uint32_t temp;
49 
50 	mutex_lock(&i2c->mutex);
51 
52 	/* switch the pads to ddc mode */
53 	if (rec->hw_capable) {
54 		temp = RREG32(rec->mask_clk_reg);
55 		temp &= ~(1 << 16);
56 		WREG32(rec->mask_clk_reg, temp);
57 	}
58 
59 	/* clear the output pin values */
60 	temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
61 	WREG32(rec->a_clk_reg, temp);
62 
63 	temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
64 	WREG32(rec->a_data_reg, temp);
65 
66 	/* set the pins to input */
67 	temp = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
68 	WREG32(rec->en_clk_reg, temp);
69 
70 	temp = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
71 	WREG32(rec->en_data_reg, temp);
72 
73 	/* mask the gpio pins for software use */
74 	temp = RREG32(rec->mask_clk_reg) | rec->mask_clk_mask;
75 	WREG32(rec->mask_clk_reg, temp);
76 	temp = RREG32(rec->mask_clk_reg);
77 
78 	temp = RREG32(rec->mask_data_reg) | rec->mask_data_mask;
79 	WREG32(rec->mask_data_reg, temp);
80 	temp = RREG32(rec->mask_data_reg);
81 
82 	return 0;
83 }
84 
amdgpu_i2c_post_xfer(struct i2c_adapter * i2c_adap)85 static void amdgpu_i2c_post_xfer(struct i2c_adapter *i2c_adap)
86 {
87 	struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
88 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
89 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
90 	uint32_t temp;
91 
92 	/* unmask the gpio pins for software use */
93 	temp = RREG32(rec->mask_clk_reg) & ~rec->mask_clk_mask;
94 	WREG32(rec->mask_clk_reg, temp);
95 	temp = RREG32(rec->mask_clk_reg);
96 
97 	temp = RREG32(rec->mask_data_reg) & ~rec->mask_data_mask;
98 	WREG32(rec->mask_data_reg, temp);
99 	temp = RREG32(rec->mask_data_reg);
100 
101 	mutex_unlock(&i2c->mutex);
102 }
103 
amdgpu_i2c_get_clock(void * i2c_priv)104 static int amdgpu_i2c_get_clock(void *i2c_priv)
105 {
106 	struct amdgpu_i2c_chan *i2c = i2c_priv;
107 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
108 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
109 	uint32_t val;
110 
111 	/* read the value off the pin */
112 	val = RREG32(rec->y_clk_reg);
113 	val &= rec->y_clk_mask;
114 
115 	return (val != 0);
116 }
117 
118 
amdgpu_i2c_get_data(void * i2c_priv)119 static int amdgpu_i2c_get_data(void *i2c_priv)
120 {
121 	struct amdgpu_i2c_chan *i2c = i2c_priv;
122 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
123 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
124 	uint32_t val;
125 
126 	/* read the value off the pin */
127 	val = RREG32(rec->y_data_reg);
128 	val &= rec->y_data_mask;
129 
130 	return (val != 0);
131 }
132 
amdgpu_i2c_set_clock(void * i2c_priv,int clock)133 static void amdgpu_i2c_set_clock(void *i2c_priv, int clock)
134 {
135 	struct amdgpu_i2c_chan *i2c = i2c_priv;
136 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
137 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
138 	uint32_t val;
139 
140 	/* set pin direction */
141 	val = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
142 	val |= clock ? 0 : rec->en_clk_mask;
143 	WREG32(rec->en_clk_reg, val);
144 }
145 
amdgpu_i2c_set_data(void * i2c_priv,int data)146 static void amdgpu_i2c_set_data(void *i2c_priv, int data)
147 {
148 	struct amdgpu_i2c_chan *i2c = i2c_priv;
149 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
150 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
151 	uint32_t val;
152 
153 	/* set pin direction */
154 	val = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
155 	val |= data ? 0 : rec->en_data_mask;
156 	WREG32(rec->en_data_reg, val);
157 }
158 
159 void	amdgpu_bb_set_bits(void *, uint32_t);
160 void	amdgpu_bb_set_dir(void *, uint32_t);
161 uint32_t amdgpu_bb_read_bits(void *);
162 
163 int	amdgpu_acquire_bus(void *, int);
164 void	amdgpu_release_bus(void *, int);
165 int	amdgpu_send_start(void *, int);
166 int	amdgpu_send_stop(void *, int);
167 int	amdgpu_initiate_xfer(void *, i2c_addr_t, int);
168 int	amdgpu_read_byte(void *, u_int8_t *, int);
169 int	amdgpu_write_byte(void *, u_int8_t, int);
170 
171 #define AMDGPU_BB_SDA		(1 << I2C_BIT_SDA)
172 #define AMDGPU_BB_SCL		(1 << I2C_BIT_SCL)
173 
174 struct i2c_bitbang_ops amdgpu_bbops = {
175 	amdgpu_bb_set_bits,
176 	amdgpu_bb_set_dir,
177 	amdgpu_bb_read_bits,
178 	{ AMDGPU_BB_SDA, AMDGPU_BB_SCL, 0, 0 }
179 };
180 
181 void
amdgpu_bb_set_bits(void * cookie,uint32_t bits)182 amdgpu_bb_set_bits(void *cookie, uint32_t bits)
183 {
184 	amdgpu_i2c_set_clock(cookie, bits & AMDGPU_BB_SCL);
185 	amdgpu_i2c_set_data(cookie, bits & AMDGPU_BB_SDA);
186 }
187 
188 void
amdgpu_bb_set_dir(void * cookie,uint32_t bits)189 amdgpu_bb_set_dir(void *cookie, uint32_t bits)
190 {
191 }
192 
193 uint32_t
amdgpu_bb_read_bits(void * cookie)194 amdgpu_bb_read_bits(void *cookie)
195 {
196 	uint32_t bits = 0;
197 
198 	if (amdgpu_i2c_get_clock(cookie))
199 		bits |= AMDGPU_BB_SCL;
200 	if (amdgpu_i2c_get_data(cookie))
201 		bits |= AMDGPU_BB_SDA;
202 
203 	return bits;
204 }
205 
206 int
amdgpu_acquire_bus(void * cookie,int flags)207 amdgpu_acquire_bus(void *cookie, int flags)
208 {
209 	struct amdgpu_i2c_chan *i2c = cookie;
210 	amdgpu_i2c_pre_xfer(&i2c->adapter);
211 	return (0);
212 }
213 
214 void
amdgpu_release_bus(void * cookie,int flags)215 amdgpu_release_bus(void *cookie, int flags)
216 {
217 	struct amdgpu_i2c_chan *i2c = cookie;
218 	amdgpu_i2c_post_xfer(&i2c->adapter);
219 }
220 
221 int
amdgpu_send_start(void * cookie,int flags)222 amdgpu_send_start(void *cookie, int flags)
223 {
224 	return (i2c_bitbang_send_start(cookie, flags, &amdgpu_bbops));
225 }
226 
227 int
amdgpu_send_stop(void * cookie,int flags)228 amdgpu_send_stop(void *cookie, int flags)
229 {
230 	return (i2c_bitbang_send_stop(cookie, flags, &amdgpu_bbops));
231 }
232 
233 int
amdgpu_initiate_xfer(void * cookie,i2c_addr_t addr,int flags)234 amdgpu_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
235 {
236 	return (i2c_bitbang_initiate_xfer(cookie, addr, flags, &amdgpu_bbops));
237 }
238 
239 int
amdgpu_read_byte(void * cookie,u_int8_t * bytep,int flags)240 amdgpu_read_byte(void *cookie, u_int8_t *bytep, int flags)
241 {
242 	return (i2c_bitbang_read_byte(cookie, bytep, flags, &amdgpu_bbops));
243 }
244 
245 int
amdgpu_write_byte(void * cookie,u_int8_t byte,int flags)246 amdgpu_write_byte(void *cookie, u_int8_t byte, int flags)
247 {
248 	return (i2c_bitbang_write_byte(cookie, byte, flags, &amdgpu_bbops));
249 }
250 
251 static const struct i2c_algorithm amdgpu_atombios_i2c_algo = {
252 	.master_xfer = amdgpu_atombios_i2c_xfer,
253 	.functionality = amdgpu_atombios_i2c_func,
254 };
255 
amdgpu_i2c_create(struct drm_device * dev,const struct amdgpu_i2c_bus_rec * rec,const char * name)256 struct amdgpu_i2c_chan *amdgpu_i2c_create(struct drm_device *dev,
257 					  const struct amdgpu_i2c_bus_rec *rec,
258 					  const char *name)
259 {
260 	struct amdgpu_i2c_chan *i2c;
261 	int ret;
262 
263 	/* don't add the mm_i2c bus unless hw_i2c is enabled */
264 	if (rec->mm_i2c && (amdgpu_hw_i2c == 0))
265 		return NULL;
266 
267 	i2c = kzalloc(sizeof(struct amdgpu_i2c_chan), GFP_KERNEL);
268 	if (i2c == NULL)
269 		return NULL;
270 
271 	i2c->rec = *rec;
272 #ifdef __linux__
273 	i2c->adapter.owner = THIS_MODULE;
274 	i2c->adapter.class = I2C_CLASS_DDC;
275 	i2c->adapter.dev.parent = dev->dev;
276 #endif
277 	i2c->dev = dev;
278 	i2c_set_adapdata(&i2c->adapter, i2c);
279 	rw_init(&i2c->mutex, "agiic");
280 	if (rec->hw_capable &&
281 	    amdgpu_hw_i2c) {
282 		/* hw i2c using atom */
283 		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
284 			 "AMDGPU i2c hw bus %s", name);
285 		i2c->adapter.algo = &amdgpu_atombios_i2c_algo;
286 		ret = i2c_add_adapter(&i2c->adapter);
287 		if (ret)
288 			goto out_free;
289 	} else {
290 		/* set the amdgpu bit adapter */
291 		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
292 			 "AMDGPU i2c bit bus %s", name);
293 		i2c->adapter.algo_data = &i2c->bit;
294 #ifdef notyet
295 		i2c->bit.pre_xfer = amdgpu_i2c_pre_xfer;
296 		i2c->bit.post_xfer = amdgpu_i2c_post_xfer;
297 		i2c->bit.setsda = amdgpu_i2c_set_data;
298 		i2c->bit.setscl = amdgpu_i2c_set_clock;
299 		i2c->bit.getsda = amdgpu_i2c_get_data;
300 		i2c->bit.getscl = amdgpu_i2c_get_clock;
301 		i2c->bit.udelay = 10;
302 		i2c->bit.timeout = usecs_to_jiffies(2200);	/* from VESA */
303 		i2c->bit.data = i2c;
304 #else
305 		i2c->bit.ic.ic_cookie = i2c;
306 		i2c->bit.ic.ic_acquire_bus = amdgpu_acquire_bus;
307 		i2c->bit.ic.ic_release_bus = amdgpu_release_bus;
308 		i2c->bit.ic.ic_send_start = amdgpu_send_start;
309 		i2c->bit.ic.ic_send_stop = amdgpu_send_stop;
310 		i2c->bit.ic.ic_initiate_xfer = amdgpu_initiate_xfer;
311 		i2c->bit.ic.ic_read_byte = amdgpu_read_byte;
312 		i2c->bit.ic.ic_write_byte = amdgpu_write_byte;
313 #endif
314 		ret = i2c_bit_add_bus(&i2c->adapter);
315 		if (ret) {
316 			DRM_ERROR("Failed to register bit i2c %s\n", name);
317 			goto out_free;
318 		}
319 	}
320 
321 	return i2c;
322 out_free:
323 	kfree(i2c);
324 	return NULL;
325 
326 }
327 
amdgpu_i2c_destroy(struct amdgpu_i2c_chan * i2c)328 void amdgpu_i2c_destroy(struct amdgpu_i2c_chan *i2c)
329 {
330 	if (!i2c)
331 		return;
332 	WARN_ON(i2c->has_aux);
333 	i2c_del_adapter(&i2c->adapter);
334 	kfree(i2c);
335 }
336 
337 /* Add the default buses */
amdgpu_i2c_init(struct amdgpu_device * adev)338 void amdgpu_i2c_init(struct amdgpu_device *adev)
339 {
340 	if (amdgpu_hw_i2c)
341 		DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
342 
343 	amdgpu_atombios_i2c_init(adev);
344 }
345 
346 /* remove all the buses */
amdgpu_i2c_fini(struct amdgpu_device * adev)347 void amdgpu_i2c_fini(struct amdgpu_device *adev)
348 {
349 	int i;
350 
351 	for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
352 		if (adev->i2c_bus[i]) {
353 			amdgpu_i2c_destroy(adev->i2c_bus[i]);
354 			adev->i2c_bus[i] = NULL;
355 		}
356 	}
357 }
358 
359 /* Add additional buses */
amdgpu_i2c_add(struct amdgpu_device * adev,const struct amdgpu_i2c_bus_rec * rec,const char * name)360 void amdgpu_i2c_add(struct amdgpu_device *adev,
361 		    const struct amdgpu_i2c_bus_rec *rec,
362 		    const char *name)
363 {
364 	struct drm_device *dev = adev_to_drm(adev);
365 	int i;
366 
367 	for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
368 		if (!adev->i2c_bus[i]) {
369 			adev->i2c_bus[i] = amdgpu_i2c_create(dev, rec, name);
370 			return;
371 		}
372 	}
373 }
374 
375 /* looks up bus based on id */
376 struct amdgpu_i2c_chan *
amdgpu_i2c_lookup(struct amdgpu_device * adev,const struct amdgpu_i2c_bus_rec * i2c_bus)377 amdgpu_i2c_lookup(struct amdgpu_device *adev,
378 		  const struct amdgpu_i2c_bus_rec *i2c_bus)
379 {
380 	int i;
381 
382 	for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
383 		if (adev->i2c_bus[i] &&
384 		    (adev->i2c_bus[i]->rec.i2c_id == i2c_bus->i2c_id)) {
385 			return adev->i2c_bus[i];
386 		}
387 	}
388 	return NULL;
389 }
390 
amdgpu_i2c_get_byte(struct amdgpu_i2c_chan * i2c_bus,u8 slave_addr,u8 addr,u8 * val)391 static void amdgpu_i2c_get_byte(struct amdgpu_i2c_chan *i2c_bus,
392 				 u8 slave_addr,
393 				 u8 addr,
394 				 u8 *val)
395 {
396 	u8 out_buf[2];
397 	u8 in_buf[2];
398 	struct i2c_msg msgs[] = {
399 		{
400 			.addr = slave_addr,
401 			.flags = 0,
402 			.len = 1,
403 			.buf = out_buf,
404 		},
405 		{
406 			.addr = slave_addr,
407 			.flags = I2C_M_RD,
408 			.len = 1,
409 			.buf = in_buf,
410 		}
411 	};
412 
413 	out_buf[0] = addr;
414 	out_buf[1] = 0;
415 
416 	if (i2c_transfer(&i2c_bus->adapter, msgs, 2) == 2) {
417 		*val = in_buf[0];
418 		DRM_DEBUG("val = 0x%02x\n", *val);
419 	} else {
420 		DRM_DEBUG("i2c 0x%02x 0x%02x read failed\n",
421 			  addr, *val);
422 	}
423 }
424 
amdgpu_i2c_put_byte(struct amdgpu_i2c_chan * i2c_bus,u8 slave_addr,u8 addr,u8 val)425 static void amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus,
426 				 u8 slave_addr,
427 				 u8 addr,
428 				 u8 val)
429 {
430 	uint8_t out_buf[2];
431 	struct i2c_msg msg = {
432 		.addr = slave_addr,
433 		.flags = 0,
434 		.len = 2,
435 		.buf = out_buf,
436 	};
437 
438 	out_buf[0] = addr;
439 	out_buf[1] = val;
440 
441 	if (i2c_transfer(&i2c_bus->adapter, &msg, 1) != 1)
442 		DRM_DEBUG("i2c 0x%02x 0x%02x write failed\n",
443 			  addr, val);
444 }
445 
446 /* ddc router switching */
447 void
amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector * amdgpu_connector)448 amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector *amdgpu_connector)
449 {
450 	u8 val = 0;
451 
452 	if (!amdgpu_connector->router.ddc_valid)
453 		return;
454 
455 	if (!amdgpu_connector->router_bus)
456 		return;
457 
458 	amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
459 			    amdgpu_connector->router.i2c_addr,
460 			    0x3, &val);
461 	val &= ~amdgpu_connector->router.ddc_mux_control_pin;
462 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
463 			    amdgpu_connector->router.i2c_addr,
464 			    0x3, val);
465 	amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
466 			    amdgpu_connector->router.i2c_addr,
467 			    0x1, &val);
468 	val &= ~amdgpu_connector->router.ddc_mux_control_pin;
469 	val |= amdgpu_connector->router.ddc_mux_state;
470 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
471 			    amdgpu_connector->router.i2c_addr,
472 			    0x1, val);
473 }
474 
475 /* clock/data router switching */
476 void
amdgpu_i2c_router_select_cd_port(const struct amdgpu_connector * amdgpu_connector)477 amdgpu_i2c_router_select_cd_port(const struct amdgpu_connector *amdgpu_connector)
478 {
479 	u8 val;
480 
481 	if (!amdgpu_connector->router.cd_valid)
482 		return;
483 
484 	if (!amdgpu_connector->router_bus)
485 		return;
486 
487 	amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
488 			    amdgpu_connector->router.i2c_addr,
489 			    0x3, &val);
490 	val &= ~amdgpu_connector->router.cd_mux_control_pin;
491 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
492 			    amdgpu_connector->router.i2c_addr,
493 			    0x3, val);
494 	amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
495 			    amdgpu_connector->router.i2c_addr,
496 			    0x1, &val);
497 	val &= ~amdgpu_connector->router.cd_mux_control_pin;
498 	val |= amdgpu_connector->router.cd_mux_state;
499 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
500 			    amdgpu_connector->router.i2c_addr,
501 			    0x1, val);
502 }
503