xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/amd/amdgpu/amdgpu_smu_v11_0_i2c.c (revision 2b73d18af7a98bc9907041875c671f63165f1d3e)
1 /*	$NetBSD: amdgpu_smu_v11_0_i2c.c,v 1.3 2021/12/19 12:21:29 riastradh Exp $	*/
2 
3 /*
4  * Copyright 2019 Advanced Micro Devices, Inc.
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 shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  */
25 
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: amdgpu_smu_v11_0_i2c.c,v 1.3 2021/12/19 12:21:29 riastradh Exp $");
28 
29 #include "smuio/smuio_11_0_0_offset.h"
30 #include "smuio/smuio_11_0_0_sh_mask.h"
31 
32 #include "smu_v11_0_i2c.h"
33 #include "amdgpu.h"
34 #include "soc15_common.h"
35 #include <drm/drm_fixed.h>
36 #include <drm/drm_drv.h>
37 #include "amdgpu_amdkfd.h"
38 #include <linux/i2c.h>
39 #include <linux/pci.h>
40 #include "amdgpu_ras.h"
41 
42 /* error codes */
43 #define I2C_OK                0
44 #define I2C_NAK_7B_ADDR_NOACK 1
45 #define I2C_NAK_TXDATA_NOACK  2
46 #define I2C_TIMEOUT           4
47 #define I2C_SW_TIMEOUT        8
48 #define I2C_ABORT             0x10
49 
50 /* I2C transaction flags */
51 #define I2C_NO_STOP	1
52 #define I2C_RESTART	2
53 
54 #define to_amdgpu_device(x) (container_of(x, struct amdgpu_ras, eeprom_control.eeprom_accessor))->adev
55 #define to_eeprom_control(x) container_of(x, struct amdgpu_ras_eeprom_control, eeprom_accessor)
56 
smu_v11_0_i2c_set_clock_gating(struct i2c_adapter * control,bool en)57 static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en)
58 {
59 	struct amdgpu_device *adev = to_amdgpu_device(control);
60 	uint32_t reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);
61 
62 	reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, en ? 1 : 0);
63 	WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
64 }
65 
66 
smu_v11_0_i2c_enable(struct i2c_adapter * control,bool enable)67 static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
68 {
69 	struct amdgpu_device *adev = to_amdgpu_device(control);
70 
71 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
72 }
73 
smu_v11_0_i2c_clear_status(struct i2c_adapter * control)74 static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
75 {
76 	struct amdgpu_device *adev = to_amdgpu_device(control);
77 	/* do */
78 	{
79 		RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);
80 
81 	} /* while (reg_CKSVII2C_ic_clr_intr == 0) */
82 }
83 
smu_v11_0_i2c_configure(struct i2c_adapter * control)84 static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
85 {
86 	struct amdgpu_device *adev = to_amdgpu_device(control);
87 	uint32_t reg = 0;
88 
89 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
90 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
91 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
92 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
93 	/* Standard mode */
94 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2);
95 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);
96 
97 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
98 }
99 
smu_v11_0_i2c_set_clock(struct i2c_adapter * control)100 static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
101 {
102 	struct amdgpu_device *adev = to_amdgpu_device(control);
103 
104 	/*
105 	 * Standard mode speed, These values are taken from SMUIO MAS,
106 	 * but are different from what is given is
107 	 * Synopsys spec. The values here are based on assumption
108 	 * that refclock is 100MHz
109 	 *
110 	 * Configuration for standard mode; Speed = 100kbps
111 	 * Scale linearly, for now only support standard speed clock
112 	 * This will work only with 100M ref clock
113 	 *
114 	 * TBD:Change the calculation to take into account ref clock values also.
115 	 */
116 
117 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
118 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
119 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
120 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
121 }
122 
smu_v11_0_i2c_set_address(struct i2c_adapter * control,uint8_t address)123 static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, uint8_t address)
124 {
125 	struct amdgpu_device *adev = to_amdgpu_device(control);
126 
127 	/* Convert fromr 8-bit to 7-bit address */
128 	address >>= 1;
129 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, (address & 0xFF));
130 }
131 
smu_v11_0_i2c_poll_tx_status(struct i2c_adapter * control)132 static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
133 {
134 	struct amdgpu_device *adev = to_amdgpu_device(control);
135 	uint32_t ret = I2C_OK;
136 	uint32_t reg, reg_c_tx_abrt_source;
137 
138 	/*Check if transmission is completed */
139 	unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
140 
141 	do {
142 		if (time_after(jiffies, timeout_counter)) {
143 			ret |= I2C_SW_TIMEOUT;
144 			break;
145 		}
146 
147 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
148 
149 	} while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);
150 
151 	if (ret != I2C_OK)
152 		return ret;
153 
154 	/* This only checks if NAK is received and transaction got aborted */
155 	reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);
156 
157 	if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
158 		reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
159 		DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);
160 
161 		/* Check for stop due to NACK */
162 		if (REG_GET_FIELD(reg_c_tx_abrt_source,
163 				  CKSVII2C_IC_TX_ABRT_SOURCE,
164 				  ABRT_TXDATA_NOACK) == 1) {
165 
166 			ret |= I2C_NAK_TXDATA_NOACK;
167 
168 		} else if (REG_GET_FIELD(reg_c_tx_abrt_source,
169 					 CKSVII2C_IC_TX_ABRT_SOURCE,
170 					 ABRT_7B_ADDR_NOACK) == 1) {
171 
172 			ret |= I2C_NAK_7B_ADDR_NOACK;
173 		} else {
174 			ret |= I2C_ABORT;
175 		}
176 
177 		smu_v11_0_i2c_clear_status(control);
178 	}
179 
180 	return ret;
181 }
182 
smu_v11_0_i2c_poll_rx_status(struct i2c_adapter * control)183 static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
184 {
185 	struct amdgpu_device *adev = to_amdgpu_device(control);
186 	uint32_t ret = I2C_OK;
187 	uint32_t reg_ic_status, reg_c_tx_abrt_source;
188 
189 	reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
190 
191 	/* If slave is not present */
192 	if (REG_GET_FIELD(reg_c_tx_abrt_source,
193 			  CKSVII2C_IC_TX_ABRT_SOURCE,
194 			  ABRT_7B_ADDR_NOACK) == 1) {
195 		ret |= I2C_NAK_7B_ADDR_NOACK;
196 
197 		smu_v11_0_i2c_clear_status(control);
198 	} else {  /* wait till some data is there in RXFIFO */
199 		/* Poll for some byte in RXFIFO */
200 		unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
201 
202 		do {
203 			if (time_after(jiffies, timeout_counter)) {
204 				ret |= I2C_SW_TIMEOUT;
205 				break;
206 			}
207 
208 			reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
209 
210 		} while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
211 	}
212 
213 	return ret;
214 }
215 
216 
217 
218 
219 /**
220  * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
221  *
222  * @address: The I2C address of the slave device.
223  * @data: The data to transmit over the bus.
224  * @numbytes: The amount of data to transmit.
225  * @i2c_flag: Flags for transmission
226  *
227  * Returns 0 on success or error.
228  */
smu_v11_0_i2c_transmit(struct i2c_adapter * control,uint8_t address,uint8_t * data,uint32_t numbytes,uint32_t i2c_flag)229 static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
230 				  uint8_t address, uint8_t *data,
231 				  uint32_t numbytes, uint32_t i2c_flag)
232 {
233 	struct amdgpu_device *adev = to_amdgpu_device(control);
234 	uint32_t bytes_sent, reg, ret = 0;
235 	unsigned long  timeout_counter;
236 
237 	bytes_sent = 0;
238 
239 	DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
240 		 (uint16_t)address, numbytes);
241 
242 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
243 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
244 			       16, 1, data, numbytes, false);
245 	}
246 
247 	/* Set the I2C slave address */
248 	smu_v11_0_i2c_set_address(control, address);
249 	/* Enable I2C */
250 	smu_v11_0_i2c_enable(control, true);
251 
252 	/* Clear status bits */
253 	smu_v11_0_i2c_clear_status(control);
254 
255 
256 	timeout_counter = jiffies + msecs_to_jiffies(20);
257 
258 	while (numbytes > 0) {
259 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
260 		if (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
261 			do {
262 				reg = 0;
263 				/*
264 				 * Prepare transaction, no need to set RESTART. I2C engine will send
265 				 * START as soon as it sees data in TXFIFO
266 				 */
267 				if (bytes_sent == 0)
268 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
269 							    (i2c_flag & I2C_RESTART) ? 1 : 0);
270 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, data[bytes_sent]);
271 
272 				/* determine if we need to send STOP bit or not */
273 				if (numbytes == 1)
274 					/* Final transaction, so send stop unless I2C_NO_STOP */
275 					reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
276 							    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
277 				/* Write */
278 				reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
279 				WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
280 
281 				/* Record that the bytes were transmitted */
282 				bytes_sent++;
283 				numbytes--;
284 
285 				reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
286 
287 			} while (numbytes &&  REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF));
288 		}
289 
290 		/*
291 		 * We waited too long for the transmission FIFO to become not-full.
292 		 * Exit the loop with error.
293 		 */
294 		if (time_after(jiffies, timeout_counter)) {
295 			ret |= I2C_SW_TIMEOUT;
296 			goto Err;
297 		}
298 	}
299 
300 	ret = smu_v11_0_i2c_poll_tx_status(control);
301 
302 Err:
303 	/* Any error, no point in proceeding */
304 	if (ret != I2C_OK) {
305 		if (ret & I2C_SW_TIMEOUT)
306 			DRM_ERROR("TIMEOUT ERROR !!!");
307 
308 		if (ret & I2C_NAK_7B_ADDR_NOACK)
309 			DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
310 
311 
312 		if (ret & I2C_NAK_TXDATA_NOACK)
313 			DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
314 	}
315 
316 	return ret;
317 }
318 
319 
320 /**
321  * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
322  *
323  * @address: The I2C address of the slave device.
324  * @numbytes: The amount of data to transmit.
325  * @i2c_flag: Flags for transmission
326  *
327  * Returns 0 on success or error.
328  */
smu_v11_0_i2c_receive(struct i2c_adapter * control,uint8_t address,uint8_t * data,uint32_t numbytes,uint8_t i2c_flag)329 static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
330 				 uint8_t address, uint8_t *data,
331 				 uint32_t numbytes, uint8_t i2c_flag)
332 {
333 	struct amdgpu_device *adev = to_amdgpu_device(control);
334 	uint32_t bytes_received, ret = I2C_OK;
335 
336 	bytes_received = 0;
337 
338 	/* Set the I2C slave address */
339 	smu_v11_0_i2c_set_address(control, address);
340 
341 	/* Enable I2C */
342 	smu_v11_0_i2c_enable(control, true);
343 
344 	while (numbytes > 0) {
345 		uint32_t reg = 0;
346 
347 		smu_v11_0_i2c_clear_status(control);
348 
349 
350 		/* Prepare transaction */
351 
352 		/* Each time we disable I2C, so this is not a restart */
353 		if (bytes_received == 0)
354 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
355 					    (i2c_flag & I2C_RESTART) ? 1 : 0);
356 
357 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
358 		/* Read */
359 		reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);
360 
361 		/* Transmitting last byte */
362 		if (numbytes == 1)
363 			/* Final transaction, so send stop if requested */
364 			reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
365 					    (i2c_flag & I2C_NO_STOP) ? 0 : 1);
366 
367 		WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
368 
369 		ret = smu_v11_0_i2c_poll_rx_status(control);
370 
371 		/* Any error, no point in proceeding */
372 		if (ret != I2C_OK) {
373 			if (ret & I2C_SW_TIMEOUT)
374 				DRM_ERROR("TIMEOUT ERROR !!!");
375 
376 			if (ret & I2C_NAK_7B_ADDR_NOACK)
377 				DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
378 
379 			if (ret & I2C_NAK_TXDATA_NOACK)
380 				DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
381 
382 			break;
383 		}
384 
385 		reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
386 		data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);
387 
388 		/* Record that the bytes were received */
389 		bytes_received++;
390 		numbytes--;
391 	}
392 
393 	DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
394 		  (uint16_t)address, bytes_received);
395 
396 	if (drm_debug_enabled(DRM_UT_DRIVER)) {
397 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
398 			       16, 1, data, bytes_received, false);
399 	}
400 
401 	return ret;
402 }
403 
smu_v11_0_i2c_abort(struct i2c_adapter * control)404 static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
405 {
406 	struct amdgpu_device *adev = to_amdgpu_device(control);
407 	uint32_t reg = 0;
408 
409 	/* Enable I2C engine; */
410 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
411 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
412 
413 	/* Abort previous transaction */
414 	reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
415 	WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
416 
417 	DRM_DEBUG_DRIVER("I2C_Abort() Done.");
418 }
419 
420 
smu_v11_0_i2c_activity_done(struct i2c_adapter * control)421 static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
422 {
423 	struct amdgpu_device *adev = to_amdgpu_device(control);
424 
425 	const uint32_t IDLE_TIMEOUT = 1024;
426 	uint32_t timeout_count = 0;
427 	uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;
428 
429 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
430 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
431 
432 
433 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
434 	    (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
435 		/*
436 		 * Nobody is using I2C engine, but engine remains active because
437 		 * someone missed to send STOP
438 		 */
439 		smu_v11_0_i2c_abort(control);
440 	} else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
441 		/* Nobody is using I2C engine */
442 		return true;
443 	}
444 
445 	/* Keep reading activity bit until it's cleared */
446 	do {
447 		reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);
448 
449 		if (REG_GET_FIELD(reg_ic_clr_activity,
450 		    CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
451 			return true;
452 
453 		++timeout_count;
454 
455 	} while (timeout_count < IDLE_TIMEOUT);
456 
457 	return false;
458 }
459 
smu_v11_0_i2c_init(struct i2c_adapter * control)460 static void smu_v11_0_i2c_init(struct i2c_adapter *control)
461 {
462 	/* Disable clock gating */
463 	smu_v11_0_i2c_set_clock_gating(control, false);
464 
465 	if (!smu_v11_0_i2c_activity_done(control))
466 		DRM_WARN("I2C busy !");
467 
468 	/* Disable I2C */
469 	smu_v11_0_i2c_enable(control, false);
470 
471 	/* Configure I2C to operate as master and in standard mode */
472 	smu_v11_0_i2c_configure(control);
473 
474 	/* Initialize the clock to 50 kHz default */
475 	smu_v11_0_i2c_set_clock(control);
476 
477 }
478 
smu_v11_0_i2c_fini(struct i2c_adapter * control)479 static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
480 {
481 	struct amdgpu_device *adev = to_amdgpu_device(control);
482 	uint32_t reg_ic_enable_status, reg_ic_enable;
483 
484 	smu_v11_0_i2c_enable(control, false);
485 
486 	/* Double check if disabled, else force abort */
487 	reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
488 	reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
489 
490 	if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
491 	    (REG_GET_FIELD(reg_ic_enable_status,
492 			   CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
493 		/*
494 		 * Nobody is using I2C engine, but engine remains active because
495 		 * someone missed to send STOP
496 		 */
497 		smu_v11_0_i2c_abort(control);
498 	}
499 
500 	/* Restore clock gating */
501 
502 	/*
503 	 * TODO Reenabling clock gating seems to break subsequent SMU operation
504 	 *      on the I2C bus. My guess is that SMU doesn't disable clock gating like
505 	 *      we do here before working with the bus. So for now just don't restore
506 	 *      it but later work with SMU to see if they have this issue and can
507 	 *      update their code appropriately
508 	 */
509 	/* smu_v11_0_i2c_set_clock_gating(control, true); */
510 
511 }
512 
smu_v11_0_i2c_bus_lock(struct i2c_adapter * control)513 static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
514 {
515 	struct amdgpu_device *adev = to_amdgpu_device(control);
516 
517 	/* Send  PPSMC_MSG_RequestI2CBus */
518 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
519 		goto Fail;
520 
521 
522 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle, true))
523 		return true;
524 
525 Fail:
526 	return false;
527 }
528 
smu_v11_0_i2c_bus_unlock(struct i2c_adapter * control)529 static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
530 {
531 	struct amdgpu_device *adev = to_amdgpu_device(control);
532 
533 	/* Send  PPSMC_MSG_RequestI2CBus */
534 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
535 		goto Fail;
536 
537 	/* Send  PPSMC_MSG_ReleaseI2CBus */
538 	if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle,
539 							     false))
540 		return true;
541 
542 Fail:
543 	return false;
544 }
545 
546 /***************************** EEPROM I2C GLUE ****************************/
547 
smu_v11_0_i2c_eeprom_read_data(struct i2c_adapter * control,uint8_t address,uint8_t * data,uint32_t numbytes)548 static uint32_t smu_v11_0_i2c_eeprom_read_data(struct i2c_adapter *control,
549 					       uint8_t address,
550 					       uint8_t *data,
551 					       uint32_t numbytes)
552 {
553 	uint32_t  ret = 0;
554 
555 	/* First 2 bytes are dummy write to set EEPROM address */
556 	ret = smu_v11_0_i2c_transmit(control, address, data, 2, I2C_NO_STOP);
557 	if (ret != I2C_OK)
558 		goto Fail;
559 
560 	/* Now read data starting with that address */
561 	ret = smu_v11_0_i2c_receive(control, address, data + 2, numbytes - 2,
562 				    I2C_RESTART);
563 
564 Fail:
565 	if (ret != I2C_OK)
566 		DRM_ERROR("ReadData() - I2C error occurred :%x", ret);
567 
568 	return ret;
569 }
570 
smu_v11_0_i2c_eeprom_write_data(struct i2c_adapter * control,uint8_t address,uint8_t * data,uint32_t numbytes)571 static uint32_t smu_v11_0_i2c_eeprom_write_data(struct i2c_adapter *control,
572 						uint8_t address,
573 						uint8_t *data,
574 						uint32_t numbytes)
575 {
576 	uint32_t  ret;
577 
578 	ret = smu_v11_0_i2c_transmit(control, address, data, numbytes, 0);
579 
580 	if (ret != I2C_OK)
581 		DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
582 	else
583 		/*
584 		 * According to EEPROM spec there is a MAX of 10 ms required for
585 		 * EEPROM to flush internal RX buffer after STOP was issued at the
586 		 * end of write transaction. During this time the EEPROM will not be
587 		 * responsive to any more commands - so wait a bit more.
588 		 *
589 		 * TODO Improve to wait for first ACK for slave address after
590 		 * internal write cycle done.
591 		 */
592 		msleep(10);
593 
594 	return ret;
595 
596 }
597 
lock_bus(struct i2c_adapter * i2c,unsigned int flags)598 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
599 {
600 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
601 
602 	if (!smu_v11_0_i2c_bus_lock(i2c)) {
603 		DRM_ERROR("Failed to lock the bus from SMU");
604 		return;
605 	}
606 
607 	control->bus_locked = true;
608 }
609 
trylock_bus(struct i2c_adapter * i2c,unsigned int flags)610 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
611 {
612 	WARN_ONCE(1, "This operation not supposed to run in atomic context!");
613 	return false;
614 }
615 
unlock_bus(struct i2c_adapter * i2c,unsigned int flags)616 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
617 {
618 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
619 
620 	if (!smu_v11_0_i2c_bus_unlock(i2c)) {
621 		DRM_ERROR("Failed to unlock the bus from SMU");
622 		return;
623 	}
624 
625 	control->bus_locked = false;
626 }
627 
628 static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
629 	.lock_bus = lock_bus,
630 	.trylock_bus = trylock_bus,
631 	.unlock_bus = unlock_bus,
632 };
633 
smu_v11_0_i2c_eeprom_i2c_xfer(struct i2c_adapter * i2c_adap,struct i2c_msg * msgs,int num)634 static int smu_v11_0_i2c_eeprom_i2c_xfer(struct i2c_adapter *i2c_adap,
635 			      struct i2c_msg *msgs, int num)
636 {
637 	int i, ret;
638 	struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c_adap);
639 
640 	if (!control->bus_locked) {
641 		DRM_ERROR("I2C bus unlocked, stopping transaction!");
642 		return -EIO;
643 	}
644 
645 	smu_v11_0_i2c_init(i2c_adap);
646 
647 	for (i = 0; i < num; i++) {
648 		if (msgs[i].flags & I2C_M_RD)
649 			ret = smu_v11_0_i2c_eeprom_read_data(i2c_adap,
650 							(uint8_t)msgs[i].addr,
651 							msgs[i].buf, msgs[i].len);
652 		else
653 			ret = smu_v11_0_i2c_eeprom_write_data(i2c_adap,
654 							 (uint8_t)msgs[i].addr,
655 							 msgs[i].buf, msgs[i].len);
656 
657 		if (ret != I2C_OK) {
658 			num = -EIO;
659 			break;
660 		}
661 	}
662 
663 	smu_v11_0_i2c_fini(i2c_adap);
664 	return num;
665 }
666 
smu_v11_0_i2c_eeprom_i2c_func(struct i2c_adapter * adap)667 static u32 smu_v11_0_i2c_eeprom_i2c_func(struct i2c_adapter *adap)
668 {
669 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
670 }
671 
672 
673 static const struct i2c_algorithm smu_v11_0_i2c_eeprom_i2c_algo = {
674 	.master_xfer = smu_v11_0_i2c_eeprom_i2c_xfer,
675 	.functionality = smu_v11_0_i2c_eeprom_i2c_func,
676 };
677 
smu_v11_0_i2c_eeprom_control_init(struct i2c_adapter * control)678 int smu_v11_0_i2c_eeprom_control_init(struct i2c_adapter *control)
679 {
680 	struct amdgpu_device *adev = to_amdgpu_device(control);
681 	int res;
682 
683 	control->owner = THIS_MODULE;
684 	control->class = I2C_CLASS_SPD;
685 	control->dev.parent = pci_dev_dev(adev->pdev);
686 	control->algo = &smu_v11_0_i2c_eeprom_i2c_algo;
687 	snprintf(control->name, sizeof(control->name), "RAS EEPROM");
688 	control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;
689 
690 	res = i2c_add_adapter(control);
691 	if (res)
692 		DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
693 
694 	return res;
695 }
696 
smu_v11_0_i2c_eeprom_control_fini(struct i2c_adapter * control)697 void smu_v11_0_i2c_eeprom_control_fini(struct i2c_adapter *control)
698 {
699 	i2c_del_adapter(control);
700 }
701 
702 /*
703  * Keep this for future unit test if bugs arise
704  */
705 #if 0
706 #define I2C_TARGET_ADDR 0xA0
707 
708 bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
709 {
710 
711 	uint32_t ret = I2C_OK;
712 	uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};
713 
714 
715 	DRM_INFO("Begin");
716 
717 	if (!smu_v11_0_i2c_bus_lock(control)) {
718 		DRM_ERROR("Failed to lock the bus!.");
719 		return false;
720 	}
721 
722 	smu_v11_0_i2c_init(control);
723 
724 	/* Write 0xde to address 0x0000 on the EEPROM */
725 	ret = smu_v11_0_i2c_eeprom_write_data(control, I2C_TARGET_ADDR, data, 6);
726 
727 	ret = smu_v11_0_i2c_eeprom_read_data(control, I2C_TARGET_ADDR, data, 6);
728 
729 	smu_v11_0_i2c_fini(control);
730 
731 	smu_v11_0_i2c_bus_unlock(control);
732 
733 
734 	DRM_INFO("End");
735 	return true;
736 }
737 #endif
738