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 "amdgpu_dpm.h"
30 #include "soc15_common.h"
31 #include <drm/drm_fixed.h>
32 #include <drm/drm_drv.h>
33 #include "amdgpu_amdkfd.h"
34 #include <linux/i2c.h>
35 #include <linux/pci.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 #define I2C_X_RESTART         BIT(31)
46 
47 static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en)
48 {
49 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
50 	struct amdgpu_device *adev = smu_i2c->adev;
51 	uint32_t reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);
52 
53 	reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, en ? 1 : 0);
54 	WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
55 }
56 
57 /* The T_I2C_POLL_US is defined as follows:
58  *
59  * "Define a timer interval (t_i2c_poll) equal to 10 times the
60  *  signalling period for the highest I2C transfer speed used in the
61  *  system and supported by DW_apb_i2c. For instance, if the highest
62  *  I2C data transfer mode is 400 kb/s, then t_i2c_poll is 25 us."  --
63  * DesignWare DW_apb_i2c Databook, Version 1.21a, section 3.8.3.1,
64  * page 56, with grammar and syntax corrections.
65  *
66  * Vcc for our device is at 1.8V which puts it at 400 kHz,
67  * see Atmel AT24CM02 datasheet, section 8.3 DC Characteristics table, page 14.
68  *
69  * The procedure to disable the IP block is described in section
70  * 3.8.3 Disabling DW_apb_i2c on page 56.
71  */
72 #define I2C_SPEED_MODE_FAST     2
73 #define T_I2C_POLL_US           25
74 #define I2C_MAX_T_POLL_COUNT    1000
75 
76 static int smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
77 {
78 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
79 	struct amdgpu_device *adev = smu_i2c->adev;
80 
81 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
82 
83 	if (!enable) {
84 		int ii;
85 
86 		for (ii = I2C_MAX_T_POLL_COUNT; ii > 0; ii--) {
87 			u32 en_stat = RREG32_SOC15(SMUIO,
88 						   0,
89 						   mmCKSVII2C_IC_ENABLE_STATUS);
90 			if (REG_GET_FIELD(en_stat, CKSVII2C_IC_ENABLE_STATUS, IC_EN))
91 				udelay(T_I2C_POLL_US);
92 			else
93 				return I2C_OK;
94 		}
95 
96 		return I2C_ABORT;
97 	}
98 
99 	return I2C_OK;
100 }
101 
102 static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
103 {
104 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
105 	struct amdgpu_device *adev = smu_i2c->adev;
106 	/* do */
107 	{
108 		RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);
109 
110 	} /* while (reg_CKSVII2C_ic_clr_intr == 0) */
111 }
112 
113 static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
114 {
115 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
116 	struct amdgpu_device *adev = smu_i2c->adev;
117 	uint32_t reg = 0;
118 
119 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
120 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
121 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
122 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
123 	/* The values of IC_MAX_SPEED_MODE are,
124 	 * 1: standard mode, 0 - 100 Kb/s,
125 	 * 2: fast mode, <= 400 Kb/s, or fast mode plus, <= 1000 Kb/s,
126 	 * 3: high speed mode, <= 3.4 Mb/s.
127 	 */
128 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE,
129 			    I2C_SPEED_MODE_FAST);
130 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);
131 
132 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
133 }
134 
135 static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
136 {
137 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
138 	struct amdgpu_device *adev = smu_i2c->adev;
139 
140 	/*
141 	 * Standard mode speed, These values are taken from SMUIO MAS,
142 	 * but are different from what is given is
143 	 * Synopsys spec. The values here are based on assumption
144 	 * that refclock is 100MHz
145 	 *
146 	 * Configuration for standard mode; Speed = 100kbps
147 	 * Scale linearly, for now only support standard speed clock
148 	 * This will work only with 100M ref clock
149 	 *
150 	 * TBD:Change the calculation to take into account ref clock values also.
151 	 */
152 
153 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
154 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
155 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
156 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
157 }
158 
159 static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, u16 address)
160 {
161 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
162 	struct amdgpu_device *adev = smu_i2c->adev;
163 
164 	/* The IC_TAR::IC_TAR field is 10-bits wide.
165 	 * It takes a 7-bit or 10-bit addresses as an address,
166 	 * i.e. no read/write bit--no wire format, just the address.
167 	 */
168 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, address & 0x3FF);
169 }
170 
171 static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
172 {
173 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
174 	struct amdgpu_device *adev = smu_i2c->adev;
175 	uint32_t ret = I2C_OK;
176 	uint32_t reg, reg_c_tx_abrt_source;
177 
178 	/*Check if transmission is completed */
179 	unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
180 
181 	do {
182 		if (time_after(jiffies, timeout_counter)) {
183 			ret |= I2C_SW_TIMEOUT;
184 			break;
185 		}
186 
187 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
188 
189 	} while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);
190 
191 	if (ret != I2C_OK)
192 		return ret;
193 
194 	/* This only checks if NAK is received and transaction got aborted */
195 	reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);
196 
197 	if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
198 		reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
199 		DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);
200 
201 		/* Check for stop due to NACK */
202 		if (REG_GET_FIELD(reg_c_tx_abrt_source,
203 				  CKSVII2C_IC_TX_ABRT_SOURCE,
204 				  ABRT_TXDATA_NOACK) == 1) {
205 
206 			ret |= I2C_NAK_TXDATA_NOACK;
207 
208 		} else if (REG_GET_FIELD(reg_c_tx_abrt_source,
209 					 CKSVII2C_IC_TX_ABRT_SOURCE,
210 					 ABRT_7B_ADDR_NOACK) == 1) {
211 
212 			ret |= I2C_NAK_7B_ADDR_NOACK;
213 		} else {
214 			ret |= I2C_ABORT;
215 		}
216 
217 		smu_v11_0_i2c_clear_status(control);
218 	}
219 
220 	return ret;
221 }
222 
223 static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
224 {
225 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
226 	struct amdgpu_device *adev = smu_i2c->adev;
227 	uint32_t ret = I2C_OK;
228 	uint32_t reg_ic_status, reg_c_tx_abrt_source;
229 
230 	reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
231 
232 	/* If slave is not present */
233 	if (REG_GET_FIELD(reg_c_tx_abrt_source,
234 			  CKSVII2C_IC_TX_ABRT_SOURCE,
235 			  ABRT_7B_ADDR_NOACK) == 1) {
236 		ret |= I2C_NAK_7B_ADDR_NOACK;
237 
238 		smu_v11_0_i2c_clear_status(control);
239 	} else {  /* wait till some data is there in RXFIFO */
240 		/* Poll for some byte in RXFIFO */
241 		unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
242 
243 		do {
244 			if (time_after(jiffies, timeout_counter)) {
245 				ret |= I2C_SW_TIMEOUT;
246 				break;
247 			}
248 
249 			reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
250 
251 		} while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
252 	}
253 
254 	return ret;
255 }
256 
257 /**
258  * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
259  *
260  * @control: I2C adapter reference
261  * @address: The I2C address of the slave device.
262  * @data: The data to transmit over the bus.
263  * @numbytes: The amount of data to transmit.
264  * @i2c_flag: Flags for transmission
265  *
266  * Returns 0 on success or error.
267  */
268 static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
269 				       u16 address, u8 *data,
270 				       u32 numbytes, u32 i2c_flag)
271 {
272 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
273 	struct amdgpu_device *adev = smu_i2c->adev;
274 	u32 bytes_sent, reg, ret = I2C_OK;
275 	unsigned long  timeout_counter;
276 
277 	bytes_sent = 0;
278 
279 	DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
280 			 address, numbytes);
281 
282 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
283 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
284 			       16, 1, data, numbytes, false);
285 	}
286 
287 	/* Set the I2C slave address */
288 	smu_v11_0_i2c_set_address(control, address);
289 	/* Enable I2C */
290 	smu_v11_0_i2c_enable(control, true);
291 
292 	/* Clear status bits */
293 	smu_v11_0_i2c_clear_status(control);
294 
295 	timeout_counter = jiffies + msecs_to_jiffies(20);
296 
297 	while (numbytes > 0) {
298 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
299 		if (!REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
300 			/*
301 			 * We waited for too long for the transmission
302 			 * FIFO to become not-full.  Exit the loop
303 			 * with error.
304 			 */
305 			if (time_after(jiffies, timeout_counter)) {
306 				ret |= I2C_SW_TIMEOUT;
307 				goto Err;
308 			}
309 		} else {
310 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT,
311 					    data[bytes_sent]);
312 
313 			/* Final message, final byte, must generate a
314 			 * STOP to release the bus, i.e. don't hold
315 			 * SCL low.
316 			 */
317 			if (numbytes == 1 && i2c_flag & I2C_M_STOP)
318 				reg = REG_SET_FIELD(reg,
319 						    CKSVII2C_IC_DATA_CMD,
320 						    STOP, 1);
321 
322 			if (bytes_sent == 0 && i2c_flag & I2C_X_RESTART)
323 				reg = REG_SET_FIELD(reg,
324 						    CKSVII2C_IC_DATA_CMD,
325 						    RESTART, 1);
326 
327 			/* Write */
328 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
329 			WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
330 
331 			/* Record that the bytes were transmitted */
332 			bytes_sent++;
333 			numbytes--;
334 		}
335 	}
336 
337 	ret = smu_v11_0_i2c_poll_tx_status(control);
338 Err:
339 	/* Any error, no point in proceeding */
340 	if (ret != I2C_OK) {
341 		if (ret & I2C_SW_TIMEOUT)
342 			DRM_ERROR("TIMEOUT ERROR !!!");
343 
344 		if (ret & I2C_NAK_7B_ADDR_NOACK)
345 			DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
346 
347 
348 		if (ret & I2C_NAK_TXDATA_NOACK)
349 			DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
350 	}
351 
352 	return ret;
353 }
354 
355 
356 /**
357  * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
358  *
359  * @control: I2C adapter reference
360  * @address: The I2C address of the slave device.
361  * @data: Placeholder to store received data.
362  * @numbytes: The amount of data to transmit.
363  * @i2c_flag: Flags for transmission
364  *
365  * Returns 0 on success or error.
366  */
367 static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
368 				      u16 address, u8 *data,
369 				      u32 numbytes, u32 i2c_flag)
370 {
371 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
372 	struct amdgpu_device *adev = smu_i2c->adev;
373 	uint32_t bytes_received, ret = I2C_OK;
374 
375 	bytes_received = 0;
376 
377 	/* Set the I2C slave address */
378 	smu_v11_0_i2c_set_address(control, address);
379 
380 	/* Enable I2C */
381 	smu_v11_0_i2c_enable(control, true);
382 
383 	while (numbytes > 0) {
384 		uint32_t reg = 0;
385 
386 		smu_v11_0_i2c_clear_status(control);
387 
388 		/* Prepare transaction */
389 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
390 		/* Read */
391 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);
392 
393 		/* Final message, final byte, must generate a STOP
394 		 * to release the bus, i.e. don't hold SCL low.
395 		 */
396 		if (numbytes == 1 && i2c_flag & I2C_M_STOP)
397 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD,
398 					    STOP, 1);
399 
400 		if (bytes_received == 0 && i2c_flag & I2C_X_RESTART)
401 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD,
402 					    RESTART, 1);
403 
404 		WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
405 
406 		ret = smu_v11_0_i2c_poll_rx_status(control);
407 
408 		/* Any error, no point in proceeding */
409 		if (ret != I2C_OK) {
410 			if (ret & I2C_SW_TIMEOUT)
411 				DRM_ERROR("TIMEOUT ERROR !!!");
412 
413 			if (ret & I2C_NAK_7B_ADDR_NOACK)
414 				DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
415 
416 			if (ret & I2C_NAK_TXDATA_NOACK)
417 				DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
418 
419 			break;
420 		}
421 
422 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
423 		data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);
424 
425 		/* Record that the bytes were received */
426 		bytes_received++;
427 		numbytes--;
428 	}
429 
430 	DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
431 		  (uint16_t)address, bytes_received);
432 
433 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
434 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
435 			       16, 1, data, bytes_received, false);
436 	}
437 
438 	return ret;
439 }
440 
441 static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
442 {
443 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
444 	struct amdgpu_device *adev = smu_i2c->adev;
445 	uint32_t reg = 0;
446 
447 	/* Enable I2C engine; */
448 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
449 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
450 
451 	/* Abort previous transaction */
452 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
453 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
454 
455 	DRM_DEBUG_DRIVER("I2C_Abort() Done.");
456 }
457 
458 static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
459 {
460 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
461 	struct amdgpu_device *adev = smu_i2c->adev;
462 
463 	const uint32_t IDLE_TIMEOUT = 1024;
464 	uint32_t timeout_count = 0;
465 	uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;
466 
467 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
468 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
469 
470 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
471 	    (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
472 		/*
473 		 * Nobody is using I2C engine, but engine remains active because
474 		 * someone missed to send STOP
475 		 */
476 		smu_v11_0_i2c_abort(control);
477 	} else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
478 		/* Nobody is using I2C engine */
479 		return true;
480 	}
481 
482 	/* Keep reading activity bit until it's cleared */
483 	do {
484 		reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);
485 
486 		if (REG_GET_FIELD(reg_ic_clr_activity,
487 		    CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
488 			return true;
489 
490 		++timeout_count;
491 
492 	} while (timeout_count < IDLE_TIMEOUT);
493 
494 	return false;
495 }
496 
497 static void smu_v11_0_i2c_init(struct i2c_adapter *control)
498 {
499 	int res;
500 
501 	/* Disable clock gating */
502 	smu_v11_0_i2c_set_clock_gating(control, false);
503 
504 	if (!smu_v11_0_i2c_activity_done(control))
505 		DRM_WARN("I2C busy !");
506 
507 	/* Disable I2C */
508 	res = smu_v11_0_i2c_enable(control, false);
509 	if (res != I2C_OK)
510 		smu_v11_0_i2c_abort(control);
511 
512 	/* Configure I2C to operate as master and in standard mode */
513 	smu_v11_0_i2c_configure(control);
514 
515 	/* Initialize the clock to 50 kHz default */
516 	smu_v11_0_i2c_set_clock(control);
517 
518 }
519 
520 static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
521 {
522 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
523 	struct amdgpu_device *adev = smu_i2c->adev;
524 	u32 status, enable, en_stat;
525 	int res;
526 
527 	res = smu_v11_0_i2c_enable(control, false);
528 	if (res != I2C_OK) {
529 		status  = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
530 		enable  = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
531 		en_stat = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
532 
533 		/* Nobody is using the I2C engine, yet it remains
534 		 * active, possibly because someone missed to send
535 		 * STOP.
536 		 */
537 		DRM_DEBUG_DRIVER("Aborting from fini: status:0x%08x "
538 				 "enable:0x%08x enable_stat:0x%08x",
539 				 status, enable, en_stat);
540 		smu_v11_0_i2c_abort(control);
541 	}
542 
543 	/* Restore clock gating */
544 
545 	/*
546 	 * TODO Reenabling clock gating seems to break subsequent SMU operation
547 	 *      on the I2C bus. My guess is that SMU doesn't disable clock gating like
548 	 *      we do here before working with the bus. So for now just don't restore
549 	 *      it but later work with SMU to see if they have this issue and can
550 	 *      update their code appropriately
551 	 */
552 	/* smu_v11_0_i2c_set_clock_gating(control, true); */
553 
554 }
555 
556 static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
557 {
558 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
559 	struct amdgpu_device *adev = smu_i2c->adev;
560 
561 	/* Send  PPSMC_MSG_RequestI2CBus */
562 	if (!amdgpu_dpm_smu_i2c_bus_access(adev, true))
563 		return true;
564 
565 	return false;
566 }
567 
568 static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
569 {
570 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(control);
571 	struct amdgpu_device *adev = smu_i2c->adev;
572 
573 	/* Send  PPSMC_MSG_ReleaseI2CBus */
574 	if (!amdgpu_dpm_smu_i2c_bus_access(adev, false))
575 		return true;
576 
577 	return false;
578 }
579 
580 /***************************** I2C GLUE ****************************/
581 
582 static uint32_t smu_v11_0_i2c_read_data(struct i2c_adapter *control,
583 					struct i2c_msg *msg, uint32_t i2c_flag)
584 {
585 	uint32_t  ret;
586 
587 	ret = smu_v11_0_i2c_receive(control, msg->addr, msg->buf, msg->len, i2c_flag);
588 
589 	if (ret != I2C_OK)
590 		DRM_ERROR("ReadData() - I2C error occurred :%x", ret);
591 
592 	return ret;
593 }
594 
595 static uint32_t smu_v11_0_i2c_write_data(struct i2c_adapter *control,
596 					struct i2c_msg *msg, uint32_t i2c_flag)
597 {
598 	uint32_t  ret;
599 
600 	ret = smu_v11_0_i2c_transmit(control, msg->addr, msg->buf, msg->len, i2c_flag);
601 
602 	if (ret != I2C_OK)
603 		DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
604 
605 	return ret;
606 
607 }
608 
609 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
610 {
611 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(i2c);
612 	struct amdgpu_device *adev = smu_i2c->adev;
613 
614 	mutex_lock(&smu_i2c->mutex);
615 	if (!smu_v11_0_i2c_bus_lock(i2c))
616 		DRM_ERROR("Failed to lock the bus from SMU");
617 	else
618 		adev->pm.bus_locked = true;
619 }
620 
621 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
622 {
623 	WARN_ONCE(1, "This operation not supposed to run in atomic context!");
624 	return false;
625 }
626 
627 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
628 {
629 	struct amdgpu_smu_i2c_bus *smu_i2c = i2c_get_adapdata(i2c);
630 	struct amdgpu_device *adev = smu_i2c->adev;
631 
632 	if (!smu_v11_0_i2c_bus_unlock(i2c))
633 		DRM_ERROR("Failed to unlock the bus from SMU");
634 	else
635 		adev->pm.bus_locked = false;
636 	mutex_unlock(&smu_i2c->mutex);
637 }
638 
639 static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
640 	.lock_bus = lock_bus,
641 	.trylock_bus = trylock_bus,
642 	.unlock_bus = unlock_bus,
643 };
644 
645 static int smu_v11_0_i2c_xfer(struct i2c_adapter *i2c_adap,
646 			      struct i2c_msg *msg, int num)
647 {
648 	int i, ret;
649 	u16 addr, dir;
650 
651 	smu_v11_0_i2c_init(i2c_adap);
652 
653 	/* From the client's point of view, this sequence of
654 	 * messages-- the array i2c_msg *msg, is a single transaction
655 	 * on the bus, starting with START and ending with STOP.
656 	 *
657 	 * The client is welcome to send any sequence of messages in
658 	 * this array, as processing under this function here is
659 	 * striving to be agnostic.
660 	 *
661 	 * Record the first address and direction we see. If either
662 	 * changes for a subsequent message, generate ReSTART. The
663 	 * DW_apb_i2c databook, v1.21a, specifies that ReSTART is
664 	 * generated when the direction changes, with the default IP
665 	 * block parameter settings, but it doesn't specify if ReSTART
666 	 * is generated when the address changes (possibly...). We
667 	 * don't rely on the default IP block parameter settings as
668 	 * the block is shared and they may change.
669 	 */
670 	if (num > 0) {
671 		addr = msg[0].addr;
672 		dir  = msg[0].flags & I2C_M_RD;
673 	}
674 
675 	for (i = 0; i < num; i++) {
676 		u32 i2c_flag = 0;
677 
678 		if (msg[i].addr != addr || (msg[i].flags ^ dir) & I2C_M_RD) {
679 			addr = msg[i].addr;
680 			dir  = msg[i].flags & I2C_M_RD;
681 			i2c_flag |= I2C_X_RESTART;
682 		}
683 
684 		if (i == num - 1) {
685 			/* Set the STOP bit on the last message, so
686 			 * that the IP block generates a STOP after
687 			 * the last byte of the message.
688 			 */
689 			i2c_flag |= I2C_M_STOP;
690 		}
691 
692 		if (msg[i].flags & I2C_M_RD)
693 			ret = smu_v11_0_i2c_read_data(i2c_adap,
694 						      msg + i,
695 						      i2c_flag);
696 		else
697 			ret = smu_v11_0_i2c_write_data(i2c_adap,
698 						       msg + i,
699 						       i2c_flag);
700 
701 		if (ret != I2C_OK) {
702 			num = -EIO;
703 			break;
704 		}
705 	}
706 
707 	smu_v11_0_i2c_fini(i2c_adap);
708 	return num;
709 }
710 
711 static u32 smu_v11_0_i2c_func(struct i2c_adapter *adap)
712 {
713 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
714 }
715 
716 static const struct i2c_algorithm smu_v11_0_i2c_algo = {
717 	.master_xfer = smu_v11_0_i2c_xfer,
718 	.functionality = smu_v11_0_i2c_func,
719 };
720 
721 static const struct i2c_adapter_quirks smu_v11_0_i2c_control_quirks = {
722 	.flags = I2C_AQ_NO_ZERO_LEN,
723 };
724 
725 int smu_v11_0_i2c_control_init(struct amdgpu_device *adev)
726 {
727 	struct amdgpu_smu_i2c_bus *smu_i2c = &adev->pm.smu_i2c[0];
728 	struct i2c_adapter *control = &smu_i2c->adapter;
729 	int res;
730 
731 	smu_i2c->adev = adev;
732 	smu_i2c->port = 0;
733 	mutex_init(&smu_i2c->mutex);
734 	control->owner = THIS_MODULE;
735 	control->class = I2C_CLASS_HWMON;
736 	control->dev.parent = &adev->pdev->dev;
737 	control->algo = &smu_v11_0_i2c_algo;
738 	snprintf(control->name, sizeof(control->name), "AMDGPU SMU 0");
739 	control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;
740 	control->quirks = &smu_v11_0_i2c_control_quirks;
741 	i2c_set_adapdata(control, smu_i2c);
742 
743 	adev->pm.ras_eeprom_i2c_bus = &adev->pm.smu_i2c[0].adapter;
744 	adev->pm.fru_eeprom_i2c_bus = &adev->pm.smu_i2c[0].adapter;
745 
746 	res = i2c_add_adapter(control);
747 	if (res)
748 		DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
749 
750 	return res;
751 }
752 
753 void smu_v11_0_i2c_control_fini(struct amdgpu_device *adev)
754 {
755 	struct i2c_adapter *control = adev->pm.ras_eeprom_i2c_bus;
756 
757 	i2c_del_adapter(control);
758 	adev->pm.ras_eeprom_i2c_bus = NULL;
759 	adev->pm.fru_eeprom_i2c_bus = NULL;
760 }
761 
762 /*
763  * Keep this for future unit test if bugs arise
764  */
765 #if 0
766 #define I2C_TARGET_ADDR 0xA0
767 
768 bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
769 {
770 
771 	uint32_t ret = I2C_OK;
772 	uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};
773 
774 
775 	DRM_INFO("Begin");
776 
777 	if (!smu_v11_0_i2c_bus_lock(control)) {
778 		DRM_ERROR("Failed to lock the bus!.");
779 		return false;
780 	}
781 
782 	smu_v11_0_i2c_init(control);
783 
784 	/* Write 0xde to address 0x0000 on the EEPROM */
785 	ret = smu_v11_0_i2c_write_data(control, I2C_TARGET_ADDR, data, 6);
786 
787 	ret = smu_v11_0_i2c_read_data(control, I2C_TARGET_ADDR, data, 6);
788 
789 	smu_v11_0_i2c_fini(control);
790 
791 	smu_v11_0_i2c_bus_unlock(control);
792 
793 
794 	DRM_INFO("End");
795 	return true;
796 }
797 #endif
798