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
30 #include <linux/delay.h>
31 #include <linux/i2c-algo-bit.h>
32 #include <linux/i2c.h>
33 #include <linux/module.h>
34
35 #include "psb_drv.h"
36 #include "psb_intel_drv.h"
37 #include "psb_intel_reg.h"
38
39 #define _wait_for(COND, MS, W) ({ \
40 unsigned long timeout__ = jiffies + msecs_to_jiffies(MS); \
41 int ret__ = 0; \
42 while (! (COND)) { \
43 if (time_after(jiffies, timeout__)) { \
44 ret__ = -ETIMEDOUT; \
45 break; \
46 } \
47 if (W && !(in_dbg_master())) \
48 msleep(W); \
49 } \
50 ret__; \
51 })
52
53 #define wait_for(COND, MS) _wait_for(COND, MS, 1)
54
55 #define GMBUS_REG_READ(reg) ioread32(dev_priv->gmbus_reg + (reg))
56 #define GMBUS_REG_WRITE(reg, val) iowrite32((val), dev_priv->gmbus_reg + (reg))
57
58 /* Intel GPIO access functions */
59
60 #define I2C_RISEFALL_TIME 20
61
62 static inline struct intel_gmbus *
to_intel_gmbus(struct i2c_adapter * i2c)63 to_intel_gmbus(struct i2c_adapter *i2c)
64 {
65 return container_of(i2c, struct intel_gmbus, adapter);
66 }
67
68 struct intel_gpio {
69 struct i2c_adapter adapter;
70 struct i2c_algo_bit_data algo;
71 struct drm_psb_private *dev_priv;
72 u32 reg;
73 };
74
75 void
gma_intel_i2c_reset(struct drm_device * dev)76 gma_intel_i2c_reset(struct drm_device *dev)
77 {
78 struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
79 GMBUS_REG_WRITE(GMBUS0, 0);
80 }
81
intel_i2c_quirk_set(struct drm_psb_private * dev_priv,bool enable)82 static void intel_i2c_quirk_set(struct drm_psb_private *dev_priv, bool enable)
83 {
84 /* When using bit bashing for I2C, this bit needs to be set to 1 */
85 /* FIXME: We are never Pineview, right?
86
87 u32 val;
88
89 if (!IS_PINEVIEW(dev_priv->dev))
90 return;
91
92 val = REG_READ(DSPCLK_GATE_D);
93 if (enable)
94 val |= DPCUNIT_CLOCK_GATE_DISABLE;
95 else
96 val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
97 REG_WRITE(DSPCLK_GATE_D, val);
98
99 return;
100 */
101 }
102
get_reserved(struct intel_gpio * gpio)103 static u32 get_reserved(struct intel_gpio *gpio)
104 {
105 struct drm_psb_private *dev_priv = gpio->dev_priv;
106 u32 reserved = 0;
107
108 /* On most chips, these bits must be preserved in software. */
109 reserved = GMBUS_REG_READ(gpio->reg) &
110 (GPIO_DATA_PULLUP_DISABLE |
111 GPIO_CLOCK_PULLUP_DISABLE);
112
113 return reserved;
114 }
115
get_clock(void * data)116 static int get_clock(void *data)
117 {
118 struct intel_gpio *gpio = data;
119 struct drm_psb_private *dev_priv = gpio->dev_priv;
120 u32 reserved = get_reserved(gpio);
121 GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_CLOCK_DIR_MASK);
122 GMBUS_REG_WRITE(gpio->reg, reserved);
123 return (GMBUS_REG_READ(gpio->reg) & GPIO_CLOCK_VAL_IN) != 0;
124 }
125
get_data(void * data)126 static int get_data(void *data)
127 {
128 struct intel_gpio *gpio = data;
129 struct drm_psb_private *dev_priv = gpio->dev_priv;
130 u32 reserved = get_reserved(gpio);
131 GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_DATA_DIR_MASK);
132 GMBUS_REG_WRITE(gpio->reg, reserved);
133 return (GMBUS_REG_READ(gpio->reg) & GPIO_DATA_VAL_IN) != 0;
134 }
135
set_clock(void * data,int state_high)136 static void set_clock(void *data, int state_high)
137 {
138 struct intel_gpio *gpio = data;
139 struct drm_psb_private *dev_priv = gpio->dev_priv;
140 u32 reserved = get_reserved(gpio);
141 u32 clock_bits;
142
143 if (state_high)
144 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
145 else
146 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
147 GPIO_CLOCK_VAL_MASK;
148
149 GMBUS_REG_WRITE(gpio->reg, reserved | clock_bits);
150 GMBUS_REG_READ(gpio->reg); /* Posting */
151 }
152
set_data(void * data,int state_high)153 static void set_data(void *data, int state_high)
154 {
155 struct intel_gpio *gpio = data;
156 struct drm_psb_private *dev_priv = gpio->dev_priv;
157 u32 reserved = get_reserved(gpio);
158 u32 data_bits;
159
160 if (state_high)
161 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
162 else
163 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
164 GPIO_DATA_VAL_MASK;
165
166 GMBUS_REG_WRITE(gpio->reg, reserved | data_bits);
167 GMBUS_REG_READ(gpio->reg);
168 }
169
170 static struct i2c_adapter *
intel_gpio_create(struct drm_psb_private * dev_priv,u32 pin)171 intel_gpio_create(struct drm_psb_private *dev_priv, u32 pin)
172 {
173 static const int map_pin_to_reg[] = {
174 0,
175 GPIOB,
176 GPIOA,
177 GPIOC,
178 GPIOD,
179 GPIOE,
180 0,
181 GPIOF,
182 };
183 struct intel_gpio *gpio;
184
185 if (pin >= ARRAY_SIZE(map_pin_to_reg) || !map_pin_to_reg[pin])
186 return NULL;
187
188 gpio = kzalloc(sizeof(struct intel_gpio), GFP_KERNEL);
189 if (gpio == NULL)
190 return NULL;
191
192 gpio->reg = map_pin_to_reg[pin];
193 gpio->dev_priv = dev_priv;
194
195 snprintf(gpio->adapter.name, sizeof(gpio->adapter.name),
196 "gma500 GPIO%c", "?BACDE?F"[pin]);
197 gpio->adapter.owner = THIS_MODULE;
198 gpio->adapter.algo_data = &gpio->algo;
199 gpio->adapter.dev.parent = dev_priv->dev.dev;
200 gpio->algo.setsda = set_data;
201 gpio->algo.setscl = set_clock;
202 gpio->algo.getsda = get_data;
203 gpio->algo.getscl = get_clock;
204 gpio->algo.udelay = I2C_RISEFALL_TIME;
205 gpio->algo.timeout = usecs_to_jiffies(2200);
206 gpio->algo.data = gpio;
207
208 if (i2c_bit_add_bus(&gpio->adapter))
209 goto out_free;
210
211 return &gpio->adapter;
212
213 out_free:
214 kfree(gpio);
215 return NULL;
216 }
217
218 static int
intel_i2c_quirk_xfer(struct drm_psb_private * dev_priv,struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)219 intel_i2c_quirk_xfer(struct drm_psb_private *dev_priv,
220 struct i2c_adapter *adapter,
221 struct i2c_msg *msgs,
222 int num)
223 {
224 struct intel_gpio *gpio = container_of(adapter,
225 struct intel_gpio,
226 adapter);
227 int ret;
228
229 gma_intel_i2c_reset(&dev_priv->dev);
230
231 intel_i2c_quirk_set(dev_priv, true);
232 set_data(gpio, 1);
233 set_clock(gpio, 1);
234 udelay(I2C_RISEFALL_TIME);
235
236 ret = adapter->algo->master_xfer(adapter, msgs, num);
237
238 set_data(gpio, 1);
239 set_clock(gpio, 1);
240 intel_i2c_quirk_set(dev_priv, false);
241
242 return ret;
243 }
244
245 static int
gmbus_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)246 gmbus_xfer(struct i2c_adapter *adapter,
247 struct i2c_msg *msgs,
248 int num)
249 {
250 struct intel_gmbus *bus = container_of(adapter,
251 struct intel_gmbus,
252 adapter);
253 struct drm_psb_private *dev_priv = adapter->algo_data;
254 int i, reg_offset;
255
256 if (bus->force_bit)
257 return intel_i2c_quirk_xfer(dev_priv,
258 bus->force_bit, msgs, num);
259
260 reg_offset = 0;
261
262 GMBUS_REG_WRITE(GMBUS0 + reg_offset, bus->reg0);
263
264 for (i = 0; i < num; i++) {
265 u16 len = msgs[i].len;
266 u8 *buf = msgs[i].buf;
267
268 if (msgs[i].flags & I2C_M_RD) {
269 GMBUS_REG_WRITE(GMBUS1 + reg_offset,
270 GMBUS_CYCLE_WAIT |
271 (i + 1 == num ? GMBUS_CYCLE_STOP : 0) |
272 (len << GMBUS_BYTE_COUNT_SHIFT) |
273 (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
274 GMBUS_SLAVE_READ | GMBUS_SW_RDY);
275 GMBUS_REG_READ(GMBUS2+reg_offset);
276 do {
277 u32 val, loop = 0;
278
279 if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
280 (GMBUS_SATOER | GMBUS_HW_RDY), 50))
281 goto timeout;
282 if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
283 goto clear_err;
284
285 val = GMBUS_REG_READ(GMBUS3 + reg_offset);
286 do {
287 *buf++ = val & 0xff;
288 val >>= 8;
289 } while (--len && ++loop < 4);
290 } while (len);
291 } else {
292 u32 val, loop;
293
294 val = loop = 0;
295 do {
296 val |= *buf++ << (8 * loop);
297 } while (--len && ++loop < 4);
298
299 GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
300 GMBUS_REG_WRITE(GMBUS1 + reg_offset,
301 (i + 1 == num ? GMBUS_CYCLE_STOP : GMBUS_CYCLE_WAIT) |
302 (msgs[i].len << GMBUS_BYTE_COUNT_SHIFT) |
303 (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
304 GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
305 GMBUS_REG_READ(GMBUS2+reg_offset);
306
307 while (len) {
308 if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
309 (GMBUS_SATOER | GMBUS_HW_RDY), 50))
310 goto timeout;
311 if (GMBUS_REG_READ(GMBUS2 + reg_offset) &
312 GMBUS_SATOER)
313 goto clear_err;
314
315 val = loop = 0;
316 do {
317 val |= *buf++ << (8 * loop);
318 } while (--len && ++loop < 4);
319
320 GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
321 GMBUS_REG_READ(GMBUS2+reg_offset);
322 }
323 }
324
325 if (i + 1 < num && wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50))
326 goto timeout;
327 if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
328 goto clear_err;
329 }
330
331 goto done;
332
333 clear_err:
334 /* Toggle the Software Clear Interrupt bit. This has the effect
335 * of resetting the GMBUS controller and so clearing the
336 * BUS_ERROR raised by the target's NAK.
337 */
338 GMBUS_REG_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
339 GMBUS_REG_WRITE(GMBUS1 + reg_offset, 0);
340
341 done:
342 /* Mark the GMBUS interface as disabled. We will re-enable it at the
343 * start of the next xfer, till then let it sleep.
344 */
345 GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
346 return i;
347
348 timeout:
349 DRM_INFO("GMBUS timed out, falling back to bit banging on pin %d [%s]\n",
350 bus->reg0 & 0xff, bus->adapter.name);
351 GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
352
353 /* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
354 bus->force_bit = intel_gpio_create(dev_priv, bus->reg0 & 0xff);
355 if (!bus->force_bit)
356 return -ENOMEM;
357
358 return intel_i2c_quirk_xfer(dev_priv, bus->force_bit, msgs, num);
359 }
360
gmbus_func(struct i2c_adapter * adapter)361 static u32 gmbus_func(struct i2c_adapter *adapter)
362 {
363 struct intel_gmbus *bus = container_of(adapter,
364 struct intel_gmbus,
365 adapter);
366
367 if (bus->force_bit)
368 bus->force_bit->algo->functionality(bus->force_bit);
369
370 return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
371 /* I2C_FUNC_10BIT_ADDR | */
372 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
373 I2C_FUNC_SMBUS_BLOCK_PROC_CALL);
374 }
375
376 static const struct i2c_algorithm gmbus_algorithm = {
377 .master_xfer = gmbus_xfer,
378 .functionality = gmbus_func
379 };
380
381 /**
382 * gma_intel_setup_gmbus() - instantiate all Intel i2c GMBuses
383 * @dev: DRM device
384 */
gma_intel_setup_gmbus(struct drm_device * dev)385 int gma_intel_setup_gmbus(struct drm_device *dev)
386 {
387 static const char *names[GMBUS_NUM_PORTS] = {
388 "disabled",
389 "ssc",
390 "vga",
391 "panel",
392 "dpc",
393 "dpb",
394 "reserved",
395 "dpd",
396 };
397 struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
398 int ret, i;
399
400 dev_priv->gmbus = kcalloc(GMBUS_NUM_PORTS, sizeof(struct intel_gmbus),
401 GFP_KERNEL);
402 if (dev_priv->gmbus == NULL)
403 return -ENOMEM;
404
405 if (IS_MRST(dev))
406 dev_priv->gmbus_reg = dev_priv->aux_reg;
407 else
408 dev_priv->gmbus_reg = dev_priv->vdc_reg;
409
410 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
411 struct intel_gmbus *bus = &dev_priv->gmbus[i];
412
413 bus->adapter.owner = THIS_MODULE;
414 snprintf(bus->adapter.name,
415 sizeof(bus->adapter.name),
416 "gma500 gmbus %s",
417 names[i]);
418
419 bus->adapter.dev.parent = dev->dev;
420 bus->adapter.algo_data = dev_priv;
421
422 bus->adapter.algo = &gmbus_algorithm;
423 ret = i2c_add_adapter(&bus->adapter);
424 if (ret)
425 goto err;
426
427 /* By default use a conservative clock rate */
428 bus->reg0 = i | GMBUS_RATE_100KHZ;
429
430 /* XXX force bit banging until GMBUS is fully debugged */
431 bus->force_bit = intel_gpio_create(dev_priv, i);
432 }
433
434 gma_intel_i2c_reset(&dev_priv->dev);
435
436 return 0;
437
438 err:
439 while (i--) {
440 struct intel_gmbus *bus = &dev_priv->gmbus[i];
441 i2c_del_adapter(&bus->adapter);
442 }
443 kfree(dev_priv->gmbus);
444 dev_priv->gmbus = NULL;
445 return ret;
446 }
447
gma_intel_gmbus_set_speed(struct i2c_adapter * adapter,int speed)448 void gma_intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
449 {
450 struct intel_gmbus *bus = to_intel_gmbus(adapter);
451
452 /* speed:
453 * 0x0 = 100 KHz
454 * 0x1 = 50 KHz
455 * 0x2 = 400 KHz
456 * 0x3 = 1000 Khz
457 */
458 bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | (speed << 8);
459 }
460
gma_intel_gmbus_force_bit(struct i2c_adapter * adapter,bool force_bit)461 void gma_intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
462 {
463 struct intel_gmbus *bus = to_intel_gmbus(adapter);
464
465 if (force_bit) {
466 if (bus->force_bit == NULL) {
467 struct drm_psb_private *dev_priv = adapter->algo_data;
468 bus->force_bit = intel_gpio_create(dev_priv,
469 bus->reg0 & 0xff);
470 }
471 } else {
472 if (bus->force_bit) {
473 i2c_del_adapter(bus->force_bit);
474 kfree(bus->force_bit);
475 bus->force_bit = NULL;
476 }
477 }
478 }
479
gma_intel_teardown_gmbus(struct drm_device * dev)480 void gma_intel_teardown_gmbus(struct drm_device *dev)
481 {
482 struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
483 int i;
484
485 if (dev_priv->gmbus == NULL)
486 return;
487
488 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
489 struct intel_gmbus *bus = &dev_priv->gmbus[i];
490 if (bus->force_bit) {
491 i2c_del_adapter(bus->force_bit);
492 kfree(bus->force_bit);
493 }
494 i2c_del_adapter(&bus->adapter);
495 }
496
497 dev_priv->gmbus_reg = NULL; /* iounmap is done in driver_unload */
498 kfree(dev_priv->gmbus);
499 dev_priv->gmbus = NULL;
500 }
501