1 /*
2  * Copyright 2019 Advanced Micro Devices, Inc.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  */
23 
24 #include "smuio/smuio_11_0_0_offset.h"
25 #include "smuio/smuio_11_0_0_sh_mask.h"
26 
27 #include "smu_v11_0_i2c.h"
28 #include "amdgpu.h"
29 #include "soc15_common.h"
30 #include <drm/drm_fixed.h>
31 #include <drm/drm_drv.h>
32 #include "amdgpu_amdkfd.h"
33 #include <linux/i2c.h>
34 #include <linux/pci.h>
35 
36 /* error codes */
37 #define I2C_OK                0
38 #define I2C_NAK_7B_ADDR_NOACK 1
39 #define I2C_NAK_TXDATA_NOACK  2
40 #define I2C_TIMEOUT           4
41 #define I2C_SW_TIMEOUT        8
42 #define I2C_ABORT             0x10
43 
44 /* I2C transaction flags */
45 #define I2C_NO_STOP	1
46 #define I2C_RESTART	2
47 
48 #define to_amdgpu_device(x) (container_of(x, struct amdgpu_device, pm.smu_i2c))
49 
50 static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en)
51 {
52 	struct amdgpu_device *adev = to_amdgpu_device(control);
53 	uint32_t reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);
54 
55 	reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, en ? 1 : 0);
56 	WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
57 }
58 
59 
60 static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
61 {
62 	struct amdgpu_device *adev = to_amdgpu_device(control);
63 
64 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
65 }
66 
67 static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
68 {
69 	struct amdgpu_device *adev = to_amdgpu_device(control);
70 	/* do */
71 	{
72 		RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);
73 
74 	} /* while (reg_CKSVII2C_ic_clr_intr == 0) */
75 }
76 
77 static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
78 {
79 	struct amdgpu_device *adev = to_amdgpu_device(control);
80 	uint32_t reg = 0;
81 
82 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
83 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
84 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
85 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
86 	/* Standard mode */
87 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2);
88 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);
89 
90 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
91 }
92 
93 static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
94 {
95 	struct amdgpu_device *adev = to_amdgpu_device(control);
96 
97 	/*
98 	 * Standard mode speed, These values are taken from SMUIO MAS,
99 	 * but are different from what is given is
100 	 * Synopsys spec. The values here are based on assumption
101 	 * that refclock is 100MHz
102 	 *
103 	 * Configuration for standard mode; Speed = 100kbps
104 	 * Scale linearly, for now only support standard speed clock
105 	 * This will work only with 100M ref clock
106 	 *
107 	 * TBD:Change the calculation to take into account ref clock values also.
108 	 */
109 
110 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
111 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
112 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
113 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
114 }
115 
116 static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, uint8_t address)
117 {
118 	struct amdgpu_device *adev = to_amdgpu_device(control);
119 
120 	/* Convert fromr 8-bit to 7-bit address */
121 	address >>= 1;
122 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, (address & 0xFF));
123 }
124 
125 static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
126 {
127 	struct amdgpu_device *adev = to_amdgpu_device(control);
128 	uint32_t ret = I2C_OK;
129 	uint32_t reg, reg_c_tx_abrt_source;
130 
131 	/*Check if transmission is completed */
132 	unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
133 
134 	do {
135 		if (time_after(jiffies, timeout_counter)) {
136 			ret |= I2C_SW_TIMEOUT;
137 			break;
138 		}
139 
140 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
141 
142 	} while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);
143 
144 	if (ret != I2C_OK)
145 		return ret;
146 
147 	/* This only checks if NAK is received and transaction got aborted */
148 	reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);
149 
150 	if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
151 		reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
152 		DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);
153 
154 		/* Check for stop due to NACK */
155 		if (REG_GET_FIELD(reg_c_tx_abrt_source,
156 				  CKSVII2C_IC_TX_ABRT_SOURCE,
157 				  ABRT_TXDATA_NOACK) == 1) {
158 
159 			ret |= I2C_NAK_TXDATA_NOACK;
160 
161 		} else if (REG_GET_FIELD(reg_c_tx_abrt_source,
162 					 CKSVII2C_IC_TX_ABRT_SOURCE,
163 					 ABRT_7B_ADDR_NOACK) == 1) {
164 
165 			ret |= I2C_NAK_7B_ADDR_NOACK;
166 		} else {
167 			ret |= I2C_ABORT;
168 		}
169 
170 		smu_v11_0_i2c_clear_status(control);
171 	}
172 
173 	return ret;
174 }
175 
176 static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
177 {
178 	struct amdgpu_device *adev = to_amdgpu_device(control);
179 	uint32_t ret = I2C_OK;
180 	uint32_t reg_ic_status, reg_c_tx_abrt_source;
181 
182 	reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
183 
184 	/* If slave is not present */
185 	if (REG_GET_FIELD(reg_c_tx_abrt_source,
186 			  CKSVII2C_IC_TX_ABRT_SOURCE,
187 			  ABRT_7B_ADDR_NOACK) == 1) {
188 		ret |= I2C_NAK_7B_ADDR_NOACK;
189 
190 		smu_v11_0_i2c_clear_status(control);
191 	} else {  /* wait till some data is there in RXFIFO */
192 		/* Poll for some byte in RXFIFO */
193 		unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
194 
195 		do {
196 			if (time_after(jiffies, timeout_counter)) {
197 				ret |= I2C_SW_TIMEOUT;
198 				break;
199 			}
200 
201 			reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
202 
203 		} while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
204 	}
205 
206 	return ret;
207 }
208 
209 
210 
211 
212 /**
213  * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
214  *
215  * @address: The I2C address of the slave device.
216  * @data: The data to transmit over the bus.
217  * @numbytes: The amount of data to transmit.
218  * @i2c_flag: Flags for transmission
219  *
220  * Returns 0 on success or error.
221  */
222 static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
223 				  uint8_t address, uint8_t *data,
224 				  uint32_t numbytes, uint32_t i2c_flag)
225 {
226 	struct amdgpu_device *adev = to_amdgpu_device(control);
227 	uint32_t bytes_sent, reg, ret = 0;
228 	unsigned long  timeout_counter;
229 
230 	bytes_sent = 0;
231 
232 	DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
233 		 (uint16_t)address, numbytes);
234 
235 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
236 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
237 			       16, 1, data, numbytes, false);
238 	}
239 
240 	/* Set the I2C slave address */
241 	smu_v11_0_i2c_set_address(control, address);
242 	/* Enable I2C */
243 	smu_v11_0_i2c_enable(control, true);
244 
245 	/* Clear status bits */
246 	smu_v11_0_i2c_clear_status(control);
247 
248 
249 	timeout_counter = jiffies + msecs_to_jiffies(20);
250 
251 	while (numbytes > 0) {
252 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
253 		if (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
254 			do {
255 				reg = 0;
256 				/*
257 				 * Prepare transaction, no need to set RESTART. I2C engine will send
258 				 * START as soon as it sees data in TXFIFO
259 				 */
260 				if (bytes_sent == 0)
261 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
262 							    (i2c_flag & I2C_RESTART) ? 1 : 0);
263 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, data[bytes_sent]);
264 
265 				/* determine if we need to send STOP bit or not */
266 				if (numbytes == 1)
267 					/* Final transaction, so send stop unless I2C_NO_STOP */
268 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
269 							    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
270 				/* Write */
271 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
272 				WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
273 
274 				/* Record that the bytes were transmitted */
275 				bytes_sent++;
276 				numbytes--;
277 
278 				reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
279 
280 			} while (numbytes &&  REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF));
281 		}
282 
283 		/*
284 		 * We waited too long for the transmission FIFO to become not-full.
285 		 * Exit the loop with error.
286 		 */
287 		if (time_after(jiffies, timeout_counter)) {
288 			ret |= I2C_SW_TIMEOUT;
289 			goto Err;
290 		}
291 	}
292 
293 	ret = smu_v11_0_i2c_poll_tx_status(control);
294 
295 Err:
296 	/* Any error, no point in proceeding */
297 	if (ret != I2C_OK) {
298 		if (ret & I2C_SW_TIMEOUT)
299 			DRM_ERROR("TIMEOUT ERROR !!!");
300 
301 		if (ret & I2C_NAK_7B_ADDR_NOACK)
302 			DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
303 
304 
305 		if (ret & I2C_NAK_TXDATA_NOACK)
306 			DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
307 	}
308 
309 	return ret;
310 }
311 
312 
313 /**
314  * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
315  *
316  * @address: The I2C address of the slave device.
317  * @numbytes: The amount of data to transmit.
318  * @i2c_flag: Flags for transmission
319  *
320  * Returns 0 on success or error.
321  */
322 static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
323 				 uint8_t address, uint8_t *data,
324 				 uint32_t numbytes, uint8_t i2c_flag)
325 {
326 	struct amdgpu_device *adev = to_amdgpu_device(control);
327 	uint32_t bytes_received, ret = I2C_OK;
328 
329 	bytes_received = 0;
330 
331 	/* Set the I2C slave address */
332 	smu_v11_0_i2c_set_address(control, address);
333 
334 	/* Enable I2C */
335 	smu_v11_0_i2c_enable(control, true);
336 
337 	while (numbytes > 0) {
338 		uint32_t reg = 0;
339 
340 		smu_v11_0_i2c_clear_status(control);
341 
342 
343 		/* Prepare transaction */
344 
345 		/* Each time we disable I2C, so this is not a restart */
346 		if (bytes_received == 0)
347 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
348 					    (i2c_flag & I2C_RESTART) ? 1 : 0);
349 
350 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
351 		/* Read */
352 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);
353 
354 		/* Transmitting last byte */
355 		if (numbytes == 1)
356 			/* Final transaction, so send stop if requested */
357 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
358 					    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
359 
360 		WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
361 
362 		ret = smu_v11_0_i2c_poll_rx_status(control);
363 
364 		/* Any error, no point in proceeding */
365 		if (ret != I2C_OK) {
366 			if (ret & I2C_SW_TIMEOUT)
367 				DRM_ERROR("TIMEOUT ERROR !!!");
368 
369 			if (ret & I2C_NAK_7B_ADDR_NOACK)
370 				DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
371 
372 			if (ret & I2C_NAK_TXDATA_NOACK)
373 				DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
374 
375 			break;
376 		}
377 
378 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
379 		data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);
380 
381 		/* Record that the bytes were received */
382 		bytes_received++;
383 		numbytes--;
384 	}
385 
386 	DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
387 		  (uint16_t)address, bytes_received);
388 
389 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
390 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
391 			       16, 1, data, bytes_received, false);
392 	}
393 
394 	return ret;
395 }
396 
397 static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
398 {
399 	struct amdgpu_device *adev = to_amdgpu_device(control);
400 	uint32_t reg = 0;
401 
402 	/* Enable I2C engine; */
403 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
404 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
405 
406 	/* Abort previous transaction */
407 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
408 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
409 
410 	DRM_DEBUG_DRIVER("I2C_Abort() Done.");
411 }
412 
413 
414 static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
415 {
416 	struct amdgpu_device *adev = to_amdgpu_device(control);
417 
418 	const uint32_t IDLE_TIMEOUT = 1024;
419 	uint32_t timeout_count = 0;
420 	uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;
421 
422 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
423 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
424 
425 
426 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
427 	    (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
428 		/*
429 		 * Nobody is using I2C engine, but engine remains active because
430 		 * someone missed to send STOP
431 		 */
432 		smu_v11_0_i2c_abort(control);
433 	} else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
434 		/* Nobody is using I2C engine */
435 		return true;
436 	}
437 
438 	/* Keep reading activity bit until it's cleared */
439 	do {
440 		reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);
441 
442 		if (REG_GET_FIELD(reg_ic_clr_activity,
443 		    CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
444 			return true;
445 
446 		++timeout_count;
447 
448 	} while (timeout_count < IDLE_TIMEOUT);
449 
450 	return false;
451 }
452 
453 static void smu_v11_0_i2c_init(struct i2c_adapter *control)
454 {
455 	/* Disable clock gating */
456 	smu_v11_0_i2c_set_clock_gating(control, false);
457 
458 	if (!smu_v11_0_i2c_activity_done(control))
459 		DRM_WARN("I2C busy !");
460 
461 	/* Disable I2C */
462 	smu_v11_0_i2c_enable(control, false);
463 
464 	/* Configure I2C to operate as master and in standard mode */
465 	smu_v11_0_i2c_configure(control);
466 
467 	/* Initialize the clock to 50 kHz default */
468 	smu_v11_0_i2c_set_clock(control);
469 
470 }
471 
472 static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
473 {
474 	struct amdgpu_device *adev = to_amdgpu_device(control);
475 	uint32_t reg_ic_enable_status, reg_ic_enable;
476 
477 	smu_v11_0_i2c_enable(control, false);
478 
479 	/* Double check if disabled, else force abort */
480 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
481 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
482 
483 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
484 	    (REG_GET_FIELD(reg_ic_enable_status,
485 			   CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
486 		/*
487 		 * Nobody is using I2C engine, but engine remains active because
488 		 * someone missed to send STOP
489 		 */
490 		smu_v11_0_i2c_abort(control);
491 	}
492 
493 	/* Restore clock gating */
494 
495 	/*
496 	 * TODO Reenabling clock gating seems to break subsequent SMU operation
497 	 *      on the I2C bus. My guess is that SMU doesn't disable clock gating like
498 	 *      we do here before working with the bus. So for now just don't restore
499 	 *      it but later work with SMU to see if they have this issue and can
500 	 *      update their code appropriately
501 	 */
502 	/* smu_v11_0_i2c_set_clock_gating(control, true); */
503 
504 }
505 
506 static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
507 {
508 	struct amdgpu_device *adev = to_amdgpu_device(control);
509 
510 	/* Send  PPSMC_MSG_RequestI2CBus */
511 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
512 		goto Fail;
513 
514 
515 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle, true))
516 		return true;
517 
518 Fail:
519 	return false;
520 }
521 
522 static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
523 {
524 	struct amdgpu_device *adev = to_amdgpu_device(control);
525 
526 	/* Send  PPSMC_MSG_RequestI2CBus */
527 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
528 		goto Fail;
529 
530 	/* Send  PPSMC_MSG_ReleaseI2CBus */
531 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle,
532 							     false))
533 		return true;
534 
535 Fail:
536 	return false;
537 }
538 
539 /***************************** I2C GLUE ****************************/
540 
541 static uint32_t smu_v11_0_i2c_read_data(struct i2c_adapter *control,
542 					uint8_t address,
543 					uint8_t *data,
544 					uint32_t numbytes)
545 {
546 	uint32_t  ret = 0;
547 
548 	/* First 2 bytes are dummy write to set EEPROM address */
549 	ret = smu_v11_0_i2c_transmit(control, address, data, 2, I2C_NO_STOP);
550 	if (ret != I2C_OK)
551 		goto Fail;
552 
553 	/* Now read data starting with that address */
554 	ret = smu_v11_0_i2c_receive(control, address, data + 2, numbytes - 2,
555 				    I2C_RESTART);
556 
557 Fail:
558 	if (ret != I2C_OK)
559 		DRM_ERROR("ReadData() - I2C error occurred :%x", ret);
560 
561 	return ret;
562 }
563 
564 static uint32_t smu_v11_0_i2c_write_data(struct i2c_adapter *control,
565 					 uint8_t address,
566 					 uint8_t *data,
567 					 uint32_t numbytes)
568 {
569 	uint32_t  ret;
570 
571 	ret = smu_v11_0_i2c_transmit(control, address, data, numbytes, 0);
572 
573 	if (ret != I2C_OK)
574 		DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
575 	else
576 		/*
577 		 * According to EEPROM spec there is a MAX of 10 ms required for
578 		 * EEPROM to flush internal RX buffer after STOP was issued at the
579 		 * end of write transaction. During this time the EEPROM will not be
580 		 * responsive to any more commands - so wait a bit more.
581 		 *
582 		 * TODO Improve to wait for first ACK for slave address after
583 		 * internal write cycle done.
584 		 */
585 		msleep(10);
586 
587 	return ret;
588 
589 }
590 
591 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
592 {
593 	struct amdgpu_device *adev = to_amdgpu_device(i2c);
594 
595 	if (!smu_v11_0_i2c_bus_lock(i2c)) {
596 		DRM_ERROR("Failed to lock the bus from SMU");
597 		return;
598 	}
599 
600 	adev->pm.bus_locked = true;
601 }
602 
603 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
604 {
605 	WARN_ONCE(1, "This operation not supposed to run in atomic context!");
606 	return false;
607 }
608 
609 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
610 {
611 	struct amdgpu_device *adev = to_amdgpu_device(i2c);
612 
613 	if (!smu_v11_0_i2c_bus_unlock(i2c)) {
614 		DRM_ERROR("Failed to unlock the bus from SMU");
615 		return;
616 	}
617 
618 	adev->pm.bus_locked = false;
619 }
620 
621 static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
622 	.lock_bus = lock_bus,
623 	.trylock_bus = trylock_bus,
624 	.unlock_bus = unlock_bus,
625 };
626 
627 static int smu_v11_0_i2c_xfer(struct i2c_adapter *i2c_adap,
628 			      struct i2c_msg *msgs, int num)
629 {
630 	int i, ret;
631 	struct amdgpu_device *adev = to_amdgpu_device(i2c_adap);
632 
633 	if (!adev->pm.bus_locked) {
634 		DRM_ERROR("I2C bus unlocked, stopping transaction!");
635 		return -EIO;
636 	}
637 
638 	smu_v11_0_i2c_init(i2c_adap);
639 
640 	for (i = 0; i < num; i++) {
641 		if (msgs[i].flags & I2C_M_RD)
642 			ret = smu_v11_0_i2c_read_data(i2c_adap,
643 						      (uint8_t)msgs[i].addr,
644 						      msgs[i].buf, msgs[i].len);
645 		else
646 			ret = smu_v11_0_i2c_write_data(i2c_adap,
647 						       (uint8_t)msgs[i].addr,
648 						       msgs[i].buf, msgs[i].len);
649 
650 		if (ret != I2C_OK) {
651 			num = -EIO;
652 			break;
653 		}
654 	}
655 
656 	smu_v11_0_i2c_fini(i2c_adap);
657 	return num;
658 }
659 
660 static u32 smu_v11_0_i2c_func(struct i2c_adapter *adap)
661 {
662 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
663 }
664 
665 
666 static const struct i2c_algorithm smu_v11_0_i2c_algo = {
667 	.master_xfer = smu_v11_0_i2c_xfer,
668 	.functionality = smu_v11_0_i2c_func,
669 };
670 
671 int smu_v11_0_i2c_control_init(struct i2c_adapter *control)
672 {
673 	struct amdgpu_device *adev = to_amdgpu_device(control);
674 	int res;
675 
676 	control->owner = THIS_MODULE;
677 	control->class = I2C_CLASS_SPD;
678 	control->dev.parent = &adev->pdev->dev;
679 	control->algo = &smu_v11_0_i2c_algo;
680 	snprintf(control->name, sizeof(control->name), "AMDGPU SMU");
681 	control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;
682 
683 	res = i2c_add_adapter(control);
684 	if (res)
685 		DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
686 
687 	return res;
688 }
689 
690 void smu_v11_0_i2c_control_fini(struct i2c_adapter *control)
691 {
692 	i2c_del_adapter(control);
693 }
694 
695 /*
696  * Keep this for future unit test if bugs arise
697  */
698 #if 0
699 #define I2C_TARGET_ADDR 0xA0
700 
701 bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
702 {
703 
704 	uint32_t ret = I2C_OK;
705 	uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};
706 
707 
708 	DRM_INFO("Begin");
709 
710 	if (!smu_v11_0_i2c_bus_lock(control)) {
711 		DRM_ERROR("Failed to lock the bus!.");
712 		return false;
713 	}
714 
715 	smu_v11_0_i2c_init(control);
716 
717 	/* Write 0xde to address 0x0000 on the EEPROM */
718 	ret = smu_v11_0_i2c_write_data(control, I2C_TARGET_ADDR, data, 6);
719 
720 	ret = smu_v11_0_i2c_read_data(control, I2C_TARGET_ADDR, data, 6);
721 
722 	smu_v11_0_i2c_fini(control);
723 
724 	smu_v11_0_i2c_bus_unlock(control);
725 
726 
727 	DRM_INFO("End");
728 	return true;
729 }
730 #endif
731