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 #include "amdgpu_ras.h"
36 
37 /* error codes */
38 #define I2C_OK                0
39 #define I2C_NAK_7B_ADDR_NOACK 1
40 #define I2C_NAK_TXDATA_NOACK  2
41 #define I2C_TIMEOUT           4
42 #define I2C_SW_TIMEOUT        8
43 #define I2C_ABORT             0x10
44 
45 /* I2C transaction flags */
46 #define I2C_NO_STOP	1
47 #define I2C_RESTART	2
48 
49 #define to_amdgpu_device(x) (container_of(x, struct amdgpu_ras, eeprom_control.eeprom_accessor))->adev
50 #define to_eeprom_control(x) container_of(x, struct amdgpu_ras_eeprom_control, eeprom_accessor)
51 
52 static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en)
53 {
54 	struct amdgpu_device *adev = to_amdgpu_device(control);
55 	uint32_t reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);
56 
57 	reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, en ? 1 : 0);
58 	WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
59 }
60 
61 
62 static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
63 {
64 	struct amdgpu_device *adev = to_amdgpu_device(control);
65 
66 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
67 }
68 
69 static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
70 {
71 	struct amdgpu_device *adev = to_amdgpu_device(control);
72 	/* do */
73 	{
74 		RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);
75 
76 	} /* while (reg_CKSVII2C_ic_clr_intr == 0) */
77 }
78 
79 static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
80 {
81 	struct amdgpu_device *adev = to_amdgpu_device(control);
82 	uint32_t reg = 0;
83 
84 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
85 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
86 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
87 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
88 	/* Standard mode */
89 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2);
90 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);
91 
92 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
93 }
94 
95 static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
96 {
97 	struct amdgpu_device *adev = to_amdgpu_device(control);
98 
99 	/*
100 	 * Standard mode speed, These values are taken from SMUIO MAS,
101 	 * but are different from what is given is
102 	 * Synopsys spec. The values here are based on assumption
103 	 * that refclock is 100MHz
104 	 *
105 	 * Configuration for standard mode; Speed = 100kbps
106 	 * Scale linearly, for now only support standard speed clock
107 	 * This will work only with 100M ref clock
108 	 *
109 	 * TBD:Change the calculation to take into account ref clock values also.
110 	 */
111 
112 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
113 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
114 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
115 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
116 }
117 
118 static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, uint8_t address)
119 {
120 	struct amdgpu_device *adev = to_amdgpu_device(control);
121 
122 	/* Convert fromr 8-bit to 7-bit address */
123 	address >>= 1;
124 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, (address & 0xFF));
125 }
126 
127 static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
128 {
129 	struct amdgpu_device *adev = to_amdgpu_device(control);
130 	uint32_t ret = I2C_OK;
131 	uint32_t reg, reg_c_tx_abrt_source;
132 
133 	/*Check if transmission is completed */
134 	unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
135 
136 	do {
137 		if (time_after(jiffies, timeout_counter)) {
138 			ret |= I2C_SW_TIMEOUT;
139 			break;
140 		}
141 
142 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
143 
144 	} while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);
145 
146 	if (ret != I2C_OK)
147 		return ret;
148 
149 	/* This only checks if NAK is received and transaction got aborted */
150 	reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);
151 
152 	if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
153 		reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
154 		DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);
155 
156 		/* Check for stop due to NACK */
157 		if (REG_GET_FIELD(reg_c_tx_abrt_source,
158 				  CKSVII2C_IC_TX_ABRT_SOURCE,
159 				  ABRT_TXDATA_NOACK) == 1) {
160 
161 			ret |= I2C_NAK_TXDATA_NOACK;
162 
163 		} else if (REG_GET_FIELD(reg_c_tx_abrt_source,
164 					 CKSVII2C_IC_TX_ABRT_SOURCE,
165 					 ABRT_7B_ADDR_NOACK) == 1) {
166 
167 			ret |= I2C_NAK_7B_ADDR_NOACK;
168 		} else {
169 			ret |= I2C_ABORT;
170 		}
171 
172 		smu_v11_0_i2c_clear_status(control);
173 	}
174 
175 	return ret;
176 }
177 
178 static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
179 {
180 	struct amdgpu_device *adev = to_amdgpu_device(control);
181 	uint32_t ret = I2C_OK;
182 	uint32_t reg_ic_status, reg_c_tx_abrt_source;
183 
184 	reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
185 
186 	/* If slave is not present */
187 	if (REG_GET_FIELD(reg_c_tx_abrt_source,
188 			  CKSVII2C_IC_TX_ABRT_SOURCE,
189 			  ABRT_7B_ADDR_NOACK) == 1) {
190 		ret |= I2C_NAK_7B_ADDR_NOACK;
191 
192 		smu_v11_0_i2c_clear_status(control);
193 	} else {  /* wait till some data is there in RXFIFO */
194 		/* Poll for some byte in RXFIFO */
195 		unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
196 
197 		do {
198 			if (time_after(jiffies, timeout_counter)) {
199 				ret |= I2C_SW_TIMEOUT;
200 				break;
201 			}
202 
203 			reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
204 
205 		} while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
206 	}
207 
208 	return ret;
209 }
210 
211 
212 
213 
214 /**
215  * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
216  *
217  * @address: The I2C address of the slave device.
218  * @data: The data to transmit over the bus.
219  * @numbytes: The amount of data to transmit.
220  * @i2c_flag: Flags for transmission
221  *
222  * Returns 0 on success or error.
223  */
224 static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
225 				  uint8_t address, uint8_t *data,
226 				  uint32_t numbytes, uint32_t i2c_flag)
227 {
228 	struct amdgpu_device *adev = to_amdgpu_device(control);
229 	uint32_t bytes_sent, reg, ret = 0;
230 	unsigned long  timeout_counter;
231 
232 	bytes_sent = 0;
233 
234 	DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
235 		 (uint16_t)address, numbytes);
236 
237 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
238 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
239 			       16, 1, data, numbytes, false);
240 	}
241 
242 	/* Set the I2C slave address */
243 	smu_v11_0_i2c_set_address(control, address);
244 	/* Enable I2C */
245 	smu_v11_0_i2c_enable(control, true);
246 
247 	/* Clear status bits */
248 	smu_v11_0_i2c_clear_status(control);
249 
250 
251 	timeout_counter = jiffies + msecs_to_jiffies(20);
252 
253 	while (numbytes > 0) {
254 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
255 		if (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
256 			do {
257 				reg = 0;
258 				/*
259 				 * Prepare transaction, no need to set RESTART. I2C engine will send
260 				 * START as soon as it sees data in TXFIFO
261 				 */
262 				if (bytes_sent == 0)
263 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
264 							    (i2c_flag & I2C_RESTART) ? 1 : 0);
265 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, data[bytes_sent]);
266 
267 				/* determine if we need to send STOP bit or not */
268 				if (numbytes == 1)
269 					/* Final transaction, so send stop unless I2C_NO_STOP */
270 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
271 							    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
272 				/* Write */
273 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
274 				WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
275 
276 				/* Record that the bytes were transmitted */
277 				bytes_sent++;
278 				numbytes--;
279 
280 				reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
281 
282 			} while (numbytes &&  REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF));
283 		}
284 
285 		/*
286 		 * We waited too long for the transmission FIFO to become not-full.
287 		 * Exit the loop with error.
288 		 */
289 		if (time_after(jiffies, timeout_counter)) {
290 			ret |= I2C_SW_TIMEOUT;
291 			goto Err;
292 		}
293 	}
294 
295 	ret = smu_v11_0_i2c_poll_tx_status(control);
296 
297 Err:
298 	/* Any error, no point in proceeding */
299 	if (ret != I2C_OK) {
300 		if (ret & I2C_SW_TIMEOUT)
301 			DRM_ERROR("TIMEOUT ERROR !!!");
302 
303 		if (ret & I2C_NAK_7B_ADDR_NOACK)
304 			DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
305 
306 
307 		if (ret & I2C_NAK_TXDATA_NOACK)
308 			DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
309 	}
310 
311 	return ret;
312 }
313 
314 
315 /**
316  * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
317  *
318  * @address: The I2C address of the slave device.
319  * @numbytes: The amount of data to transmit.
320  * @i2c_flag: Flags for transmission
321  *
322  * Returns 0 on success or error.
323  */
324 static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
325 				 uint8_t address, uint8_t *data,
326 				 uint32_t numbytes, uint8_t i2c_flag)
327 {
328 	struct amdgpu_device *adev = to_amdgpu_device(control);
329 	uint32_t bytes_received, ret = I2C_OK;
330 
331 	bytes_received = 0;
332 
333 	/* Set the I2C slave address */
334 	smu_v11_0_i2c_set_address(control, address);
335 
336 	/* Enable I2C */
337 	smu_v11_0_i2c_enable(control, true);
338 
339 	while (numbytes > 0) {
340 		uint32_t reg = 0;
341 
342 		smu_v11_0_i2c_clear_status(control);
343 
344 
345 		/* Prepare transaction */
346 
347 		/* Each time we disable I2C, so this is not a restart */
348 		if (bytes_received == 0)
349 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
350 					    (i2c_flag & I2C_RESTART) ? 1 : 0);
351 
352 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
353 		/* Read */
354 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);
355 
356 		/* Transmitting last byte */
357 		if (numbytes == 1)
358 			/* Final transaction, so send stop if requested */
359 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
360 					    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
361 
362 		WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
363 
364 		ret = smu_v11_0_i2c_poll_rx_status(control);
365 
366 		/* Any error, no point in proceeding */
367 		if (ret != I2C_OK) {
368 			if (ret & I2C_SW_TIMEOUT)
369 				DRM_ERROR("TIMEOUT ERROR !!!");
370 
371 			if (ret & I2C_NAK_7B_ADDR_NOACK)
372 				DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
373 
374 			if (ret & I2C_NAK_TXDATA_NOACK)
375 				DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
376 
377 			break;
378 		}
379 
380 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
381 		data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);
382 
383 		/* Record that the bytes were received */
384 		bytes_received++;
385 		numbytes--;
386 	}
387 
388 	DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
389 		  (uint16_t)address, bytes_received);
390 
391 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
392 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
393 			       16, 1, data, bytes_received, false);
394 	}
395 
396 	return ret;
397 }
398 
399 static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
400 {
401 	struct amdgpu_device *adev = to_amdgpu_device(control);
402 	uint32_t reg = 0;
403 
404 	/* Enable I2C engine; */
405 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
406 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
407 
408 	/* Abort previous transaction */
409 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
410 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
411 
412 	DRM_DEBUG_DRIVER("I2C_Abort() Done.");
413 }
414 
415 
416 static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
417 {
418 	struct amdgpu_device *adev = to_amdgpu_device(control);
419 
420 	const uint32_t IDLE_TIMEOUT = 1024;
421 	uint32_t timeout_count = 0;
422 	uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;
423 
424 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
425 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
426 
427 
428 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
429 	    (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
430 		/*
431 		 * Nobody is using I2C engine, but engine remains active because
432 		 * someone missed to send STOP
433 		 */
434 		smu_v11_0_i2c_abort(control);
435 	} else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
436 		/* Nobody is using I2C engine */
437 		return true;
438 	}
439 
440 	/* Keep reading activity bit until it's cleared */
441 	do {
442 		reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);
443 
444 		if (REG_GET_FIELD(reg_ic_clr_activity,
445 		    CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
446 			return true;
447 
448 		++timeout_count;
449 
450 	} while (timeout_count < IDLE_TIMEOUT);
451 
452 	return false;
453 }
454 
455 static void smu_v11_0_i2c_init(struct i2c_adapter *control)
456 {
457 	/* Disable clock gating */
458 	smu_v11_0_i2c_set_clock_gating(control, false);
459 
460 	if (!smu_v11_0_i2c_activity_done(control))
461 		DRM_WARN("I2C busy !");
462 
463 	/* Disable I2C */
464 	smu_v11_0_i2c_enable(control, false);
465 
466 	/* Configure I2C to operate as master and in standard mode */
467 	smu_v11_0_i2c_configure(control);
468 
469 	/* Initialize the clock to 50 kHz default */
470 	smu_v11_0_i2c_set_clock(control);
471 
472 }
473 
474 static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
475 {
476 	struct amdgpu_device *adev = to_amdgpu_device(control);
477 	uint32_t reg_ic_enable_status, reg_ic_enable;
478 
479 	smu_v11_0_i2c_enable(control, false);
480 
481 	/* Double check if disabled, else force abort */
482 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
483 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
484 
485 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
486 	    (REG_GET_FIELD(reg_ic_enable_status,
487 			   CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
488 		/*
489 		 * Nobody is using I2C engine, but engine remains active because
490 		 * someone missed to send STOP
491 		 */
492 		smu_v11_0_i2c_abort(control);
493 	}
494 
495 	/* Restore clock gating */
496 
497 	/*
498 	 * TODO Reenabling clock gating seems to break subsequent SMU operation
499 	 *      on the I2C bus. My guess is that SMU doesn't disable clock gating like
500 	 *      we do here before working with the bus. So for now just don't restore
501 	 *      it but later work with SMU to see if they have this issue and can
502 	 *      update their code appropriately
503 	 */
504 	/* smu_v11_0_i2c_set_clock_gating(control, true); */
505 
506 }
507 
508 static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
509 {
510 	struct amdgpu_device *adev = to_amdgpu_device(control);
511 
512 	/* Send  PPSMC_MSG_RequestI2CBus */
513 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
514 		goto Fail;
515 
516 
517 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle, true))
518 		return true;
519 
520 Fail:
521 	return false;
522 }
523 
524 static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
525 {
526 	struct amdgpu_device *adev = to_amdgpu_device(control);
527 
528 	/* Send  PPSMC_MSG_RequestI2CBus */
529 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
530 		goto Fail;
531 
532 	/* Send  PPSMC_MSG_ReleaseI2CBus */
533 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle,
534 							     false))
535 		return true;
536 
537 Fail:
538 	return false;
539 }
540 
541 /***************************** EEPROM I2C GLUE ****************************/
542 
543 static uint32_t smu_v11_0_i2c_eeprom_read_data(struct i2c_adapter *control,
544 					       uint8_t address,
545 					       uint8_t *data,
546 					       uint32_t numbytes)
547 {
548 	uint32_t  ret = 0;
549 
550 	/* First 2 bytes are dummy write to set EEPROM address */
551 	ret = smu_v11_0_i2c_transmit(control, address, data, 2, I2C_NO_STOP);
552 	if (ret != I2C_OK)
553 		goto Fail;
554 
555 	/* Now read data starting with that address */
556 	ret = smu_v11_0_i2c_receive(control, address, data + 2, numbytes - 2,
557 				    I2C_RESTART);
558 
559 Fail:
560 	if (ret != I2C_OK)
561 		DRM_ERROR("ReadData() - I2C error occurred :%x", ret);
562 
563 	return ret;
564 }
565 
566 static uint32_t smu_v11_0_i2c_eeprom_write_data(struct i2c_adapter *control,
567 						uint8_t address,
568 						uint8_t *data,
569 						uint32_t numbytes)
570 {
571 	uint32_t  ret;
572 
573 	ret = smu_v11_0_i2c_transmit(control, address, data, numbytes, 0);
574 
575 	if (ret != I2C_OK)
576 		DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
577 	else
578 		/*
579 		 * According to EEPROM spec there is a MAX of 10 ms required for
580 		 * EEPROM to flush internal RX buffer after STOP was issued at the
581 		 * end of write transaction. During this time the EEPROM will not be
582 		 * responsive to any more commands - so wait a bit more.
583 		 *
584 		 * TODO Improve to wait for first ACK for slave address after
585 		 * internal write cycle done.
586 		 */
587 		msleep(10);
588 
589 	return ret;
590 
591 }
592 
593 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
594 {
595 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
596 
597 	if (!smu_v11_0_i2c_bus_lock(i2c)) {
598 		DRM_ERROR("Failed to lock the bus from SMU");
599 		return;
600 	}
601 
602 	control->bus_locked = true;
603 }
604 
605 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
606 {
607 	WARN_ONCE(1, "This operation not supposed to run in atomic context!");
608 	return false;
609 }
610 
611 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
612 {
613 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
614 
615 	if (!smu_v11_0_i2c_bus_unlock(i2c)) {
616 		DRM_ERROR("Failed to unlock the bus from SMU");
617 		return;
618 	}
619 
620 	control->bus_locked = false;
621 }
622 
623 static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
624 	.lock_bus = lock_bus,
625 	.trylock_bus = trylock_bus,
626 	.unlock_bus = unlock_bus,
627 };
628 
629 static int smu_v11_0_i2c_eeprom_i2c_xfer(struct i2c_adapter *i2c_adap,
630 			      struct i2c_msg *msgs, int num)
631 {
632 	int i, ret;
633 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c_adap);
634 
635 	if (!control->bus_locked) {
636 		DRM_ERROR("I2C bus unlocked, stopping transaction!");
637 		return -EIO;
638 	}
639 
640 	smu_v11_0_i2c_init(i2c_adap);
641 
642 	for (i = 0; i < num; i++) {
643 		if (msgs[i].flags & I2C_M_RD)
644 			ret = smu_v11_0_i2c_eeprom_read_data(i2c_adap,
645 							(uint8_t)msgs[i].addr,
646 							msgs[i].buf, msgs[i].len);
647 		else
648 			ret = smu_v11_0_i2c_eeprom_write_data(i2c_adap,
649 							 (uint8_t)msgs[i].addr,
650 							 msgs[i].buf, msgs[i].len);
651 
652 		if (ret != I2C_OK) {
653 			num = -EIO;
654 			break;
655 		}
656 	}
657 
658 	smu_v11_0_i2c_fini(i2c_adap);
659 	return num;
660 }
661 
662 static u32 smu_v11_0_i2c_eeprom_i2c_func(struct i2c_adapter *adap)
663 {
664 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
665 }
666 
667 
668 static const struct i2c_algorithm smu_v11_0_i2c_eeprom_i2c_algo = {
669 	.master_xfer = smu_v11_0_i2c_eeprom_i2c_xfer,
670 	.functionality = smu_v11_0_i2c_eeprom_i2c_func,
671 };
672 
673 int smu_v11_0_i2c_eeprom_control_init(struct i2c_adapter *control)
674 {
675 	struct amdgpu_device *adev = to_amdgpu_device(control);
676 	int res;
677 
678 	control->owner = THIS_MODULE;
679 	control->class = I2C_CLASS_SPD;
680 	control->dev.parent = &adev->pdev->dev;
681 	control->algo = &smu_v11_0_i2c_eeprom_i2c_algo;
682 	snprintf(control->name, sizeof(control->name), "RAS EEPROM");
683 	control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;
684 
685 	res = i2c_add_adapter(control);
686 	if (res)
687 		DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
688 
689 	return res;
690 }
691 
692 void smu_v11_0_i2c_eeprom_control_fini(struct i2c_adapter *control)
693 {
694 	i2c_del_adapter(control);
695 }
696 
697 /*
698  * Keep this for future unit test if bugs arise
699  */
700 #if 0
701 #define I2C_TARGET_ADDR 0xA0
702 
703 bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
704 {
705 
706 	uint32_t ret = I2C_OK;
707 	uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};
708 
709 
710 	DRM_INFO("Begin");
711 
712 	if (!smu_v11_0_i2c_bus_lock(control)) {
713 		DRM_ERROR("Failed to lock the bus!.");
714 		return false;
715 	}
716 
717 	smu_v11_0_i2c_init(control);
718 
719 	/* Write 0xde to address 0x0000 on the EEPROM */
720 	ret = smu_v11_0_i2c_eeprom_write_data(control, I2C_TARGET_ADDR, data, 6);
721 
722 	ret = smu_v11_0_i2c_eeprom_read_data(control, I2C_TARGET_ADDR, data, 6);
723 
724 	smu_v11_0_i2c_fini(control);
725 
726 	smu_v11_0_i2c_bus_unlock(control);
727 
728 
729 	DRM_INFO("End");
730 	return true;
731 }
732 #endif
733