1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
4  *
5  * Author:
6  *	Mikko Perttunen <mperttunen@nvidia.com>
7  */
8 
9 #include <linux/clk-provider.h>
10 #include <linux/clk.h>
11 #include <linux/clkdev.h>
12 #include <linux/clk/tegra.h>
13 #include <linux/debugfs.h>
14 #include <linux/delay.h>
15 #include <linux/interconnect-provider.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/of_address.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_opp.h>
23 #include <linux/sort.h>
24 #include <linux/string.h>
25 
26 #include <soc/tegra/fuse.h>
27 #include <soc/tegra/mc.h>
28 
29 #include "mc.h"
30 
31 #define EMC_FBIO_CFG5				0x104
32 #define	EMC_FBIO_CFG5_DRAM_TYPE_MASK		0x3
33 #define	EMC_FBIO_CFG5_DRAM_TYPE_SHIFT		0
34 #define EMC_FBIO_CFG5_DRAM_WIDTH_X64		BIT(4)
35 
36 #define EMC_INTSTATUS				0x0
37 #define EMC_INTSTATUS_CLKCHANGE_COMPLETE	BIT(4)
38 
39 #define EMC_CFG					0xc
40 #define EMC_CFG_DRAM_CLKSTOP_PD			BIT(31)
41 #define EMC_CFG_DRAM_CLKSTOP_SR			BIT(30)
42 #define EMC_CFG_DRAM_ACPD			BIT(29)
43 #define EMC_CFG_DYN_SREF			BIT(28)
44 #define EMC_CFG_PWR_MASK			((0xF << 28) | BIT(18))
45 #define EMC_CFG_DSR_VTTGEN_DRV_EN		BIT(18)
46 
47 #define EMC_REFCTRL				0x20
48 #define EMC_REFCTRL_DEV_SEL_SHIFT		0
49 #define EMC_REFCTRL_ENABLE			BIT(31)
50 
51 #define EMC_TIMING_CONTROL			0x28
52 #define EMC_RC					0x2c
53 #define EMC_RFC					0x30
54 #define EMC_RAS					0x34
55 #define EMC_RP					0x38
56 #define EMC_R2W					0x3c
57 #define EMC_W2R					0x40
58 #define EMC_R2P					0x44
59 #define EMC_W2P					0x48
60 #define EMC_RD_RCD				0x4c
61 #define EMC_WR_RCD				0x50
62 #define EMC_RRD					0x54
63 #define EMC_REXT				0x58
64 #define EMC_WDV					0x5c
65 #define EMC_QUSE				0x60
66 #define EMC_QRST				0x64
67 #define EMC_QSAFE				0x68
68 #define EMC_RDV					0x6c
69 #define EMC_REFRESH				0x70
70 #define EMC_BURST_REFRESH_NUM			0x74
71 #define EMC_PDEX2WR				0x78
72 #define EMC_PDEX2RD				0x7c
73 #define EMC_PCHG2PDEN				0x80
74 #define EMC_ACT2PDEN				0x84
75 #define EMC_AR2PDEN				0x88
76 #define EMC_RW2PDEN				0x8c
77 #define EMC_TXSR				0x90
78 #define EMC_TCKE				0x94
79 #define EMC_TFAW				0x98
80 #define EMC_TRPAB				0x9c
81 #define EMC_TCLKSTABLE				0xa0
82 #define EMC_TCLKSTOP				0xa4
83 #define EMC_TREFBW				0xa8
84 #define EMC_ODT_WRITE				0xb0
85 #define EMC_ODT_READ				0xb4
86 #define EMC_WEXT				0xb8
87 #define EMC_CTT					0xbc
88 #define EMC_RFC_SLR				0xc0
89 #define EMC_MRS_WAIT_CNT2			0xc4
90 
91 #define EMC_MRS_WAIT_CNT			0xc8
92 #define EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT	0
93 #define EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK	\
94 	(0x3FF << EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT)
95 #define EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT	16
96 #define EMC_MRS_WAIT_CNT_LONG_WAIT_MASK		\
97 	(0x3FF << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
98 
99 #define EMC_MRS					0xcc
100 #define EMC_MODE_SET_DLL_RESET			BIT(8)
101 #define EMC_MODE_SET_LONG_CNT			BIT(26)
102 #define EMC_EMRS				0xd0
103 #define EMC_REF					0xd4
104 #define EMC_PRE					0xd8
105 
106 #define EMC_SELF_REF				0xe0
107 #define EMC_SELF_REF_CMD_ENABLED		BIT(0)
108 #define EMC_SELF_REF_DEV_SEL_SHIFT		30
109 
110 #define EMC_MRW					0xe8
111 
112 #define EMC_MRR					0xec
113 #define EMC_MRR_MA_SHIFT			16
114 #define LPDDR2_MR4_TEMP_SHIFT			0
115 
116 #define EMC_XM2DQSPADCTRL3			0xf8
117 #define EMC_FBIO_SPARE				0x100
118 
119 #define EMC_FBIO_CFG6				0x114
120 #define EMC_EMRS2				0x12c
121 #define EMC_MRW2				0x134
122 #define EMC_MRW4				0x13c
123 #define EMC_EINPUT				0x14c
124 #define EMC_EINPUT_DURATION			0x150
125 #define EMC_PUTERM_EXTRA			0x154
126 #define EMC_TCKESR				0x158
127 #define EMC_TPD					0x15c
128 
129 #define EMC_AUTO_CAL_CONFIG			0x2a4
130 #define EMC_AUTO_CAL_CONFIG_AUTO_CAL_START	BIT(31)
131 #define EMC_AUTO_CAL_INTERVAL			0x2a8
132 #define EMC_AUTO_CAL_STATUS			0x2ac
133 #define EMC_AUTO_CAL_STATUS_ACTIVE		BIT(31)
134 #define EMC_STATUS				0x2b4
135 #define EMC_STATUS_TIMING_UPDATE_STALLED	BIT(23)
136 
137 #define EMC_CFG_2				0x2b8
138 #define EMC_CFG_2_MODE_SHIFT			0
139 #define EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR	BIT(6)
140 
141 #define EMC_CFG_DIG_DLL				0x2bc
142 #define EMC_CFG_DIG_DLL_PERIOD			0x2c0
143 #define EMC_RDV_MASK				0x2cc
144 #define EMC_WDV_MASK				0x2d0
145 #define EMC_CTT_DURATION			0x2d8
146 #define EMC_CTT_TERM_CTRL			0x2dc
147 #define EMC_ZCAL_INTERVAL			0x2e0
148 #define EMC_ZCAL_WAIT_CNT			0x2e4
149 
150 #define EMC_ZQ_CAL				0x2ec
151 #define EMC_ZQ_CAL_CMD				BIT(0)
152 #define EMC_ZQ_CAL_LONG				BIT(4)
153 #define EMC_ZQ_CAL_LONG_CMD_DEV0		\
154 	(DRAM_DEV_SEL_0 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
155 #define EMC_ZQ_CAL_LONG_CMD_DEV1		\
156 	(DRAM_DEV_SEL_1 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
157 
158 #define EMC_XM2CMDPADCTRL			0x2f0
159 #define EMC_XM2DQSPADCTRL			0x2f8
160 #define EMC_XM2DQSPADCTRL2			0x2fc
161 #define EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE	BIT(0)
162 #define EMC_XM2DQSPADCTRL2_VREF_ENABLE		BIT(5)
163 #define EMC_XM2DQPADCTRL			0x300
164 #define EMC_XM2DQPADCTRL2			0x304
165 #define EMC_XM2CLKPADCTRL			0x308
166 #define EMC_XM2COMPPADCTRL			0x30c
167 #define EMC_XM2VTTGENPADCTRL			0x310
168 #define EMC_XM2VTTGENPADCTRL2			0x314
169 #define EMC_XM2VTTGENPADCTRL3			0x318
170 #define EMC_XM2DQSPADCTRL4			0x320
171 #define EMC_DLL_XFORM_DQS0			0x328
172 #define EMC_DLL_XFORM_DQS1			0x32c
173 #define EMC_DLL_XFORM_DQS2			0x330
174 #define EMC_DLL_XFORM_DQS3			0x334
175 #define EMC_DLL_XFORM_DQS4			0x338
176 #define EMC_DLL_XFORM_DQS5			0x33c
177 #define EMC_DLL_XFORM_DQS6			0x340
178 #define EMC_DLL_XFORM_DQS7			0x344
179 #define EMC_DLL_XFORM_QUSE0			0x348
180 #define EMC_DLL_XFORM_QUSE1			0x34c
181 #define EMC_DLL_XFORM_QUSE2			0x350
182 #define EMC_DLL_XFORM_QUSE3			0x354
183 #define EMC_DLL_XFORM_QUSE4			0x358
184 #define EMC_DLL_XFORM_QUSE5			0x35c
185 #define EMC_DLL_XFORM_QUSE6			0x360
186 #define EMC_DLL_XFORM_QUSE7			0x364
187 #define EMC_DLL_XFORM_DQ0			0x368
188 #define EMC_DLL_XFORM_DQ1			0x36c
189 #define EMC_DLL_XFORM_DQ2			0x370
190 #define EMC_DLL_XFORM_DQ3			0x374
191 #define EMC_DLI_TRIM_TXDQS0			0x3a8
192 #define EMC_DLI_TRIM_TXDQS1			0x3ac
193 #define EMC_DLI_TRIM_TXDQS2			0x3b0
194 #define EMC_DLI_TRIM_TXDQS3			0x3b4
195 #define EMC_DLI_TRIM_TXDQS4			0x3b8
196 #define EMC_DLI_TRIM_TXDQS5			0x3bc
197 #define EMC_DLI_TRIM_TXDQS6			0x3c0
198 #define EMC_DLI_TRIM_TXDQS7			0x3c4
199 #define EMC_STALL_THEN_EXE_AFTER_CLKCHANGE	0x3cc
200 #define EMC_SEL_DPD_CTRL			0x3d8
201 #define EMC_SEL_DPD_CTRL_DATA_SEL_DPD		BIT(8)
202 #define EMC_SEL_DPD_CTRL_ODT_SEL_DPD		BIT(5)
203 #define EMC_SEL_DPD_CTRL_RESET_SEL_DPD		BIT(4)
204 #define EMC_SEL_DPD_CTRL_CA_SEL_DPD		BIT(3)
205 #define EMC_SEL_DPD_CTRL_CLK_SEL_DPD		BIT(2)
206 #define EMC_SEL_DPD_CTRL_DDR3_MASK	\
207 	((0xf << 2) | BIT(8))
208 #define EMC_SEL_DPD_CTRL_MASK \
209 	((0x3 << 2) | BIT(5) | BIT(8))
210 #define EMC_PRE_REFRESH_REQ_CNT			0x3dc
211 #define EMC_DYN_SELF_REF_CONTROL		0x3e0
212 #define EMC_TXSRDLL				0x3e4
213 #define EMC_CCFIFO_ADDR				0x3e8
214 #define EMC_CCFIFO_DATA				0x3ec
215 #define EMC_CCFIFO_STATUS			0x3f0
216 #define EMC_CDB_CNTL_1				0x3f4
217 #define EMC_CDB_CNTL_2				0x3f8
218 #define EMC_XM2CLKPADCTRL2			0x3fc
219 #define EMC_AUTO_CAL_CONFIG2			0x458
220 #define EMC_AUTO_CAL_CONFIG3			0x45c
221 #define EMC_IBDLY				0x468
222 #define EMC_DLL_XFORM_ADDR0			0x46c
223 #define EMC_DLL_XFORM_ADDR1			0x470
224 #define EMC_DLL_XFORM_ADDR2			0x474
225 #define EMC_DSR_VTTGEN_DRV			0x47c
226 #define EMC_TXDSRVTTGEN				0x480
227 #define EMC_XM2CMDPADCTRL4			0x484
228 #define EMC_XM2CMDPADCTRL5			0x488
229 #define EMC_DLL_XFORM_DQS8			0x4a0
230 #define EMC_DLL_XFORM_DQS9			0x4a4
231 #define EMC_DLL_XFORM_DQS10			0x4a8
232 #define EMC_DLL_XFORM_DQS11			0x4ac
233 #define EMC_DLL_XFORM_DQS12			0x4b0
234 #define EMC_DLL_XFORM_DQS13			0x4b4
235 #define EMC_DLL_XFORM_DQS14			0x4b8
236 #define EMC_DLL_XFORM_DQS15			0x4bc
237 #define EMC_DLL_XFORM_QUSE8			0x4c0
238 #define EMC_DLL_XFORM_QUSE9			0x4c4
239 #define EMC_DLL_XFORM_QUSE10			0x4c8
240 #define EMC_DLL_XFORM_QUSE11			0x4cc
241 #define EMC_DLL_XFORM_QUSE12			0x4d0
242 #define EMC_DLL_XFORM_QUSE13			0x4d4
243 #define EMC_DLL_XFORM_QUSE14			0x4d8
244 #define EMC_DLL_XFORM_QUSE15			0x4dc
245 #define EMC_DLL_XFORM_DQ4			0x4e0
246 #define EMC_DLL_XFORM_DQ5			0x4e4
247 #define EMC_DLL_XFORM_DQ6			0x4e8
248 #define EMC_DLL_XFORM_DQ7			0x4ec
249 #define EMC_DLI_TRIM_TXDQS8			0x520
250 #define EMC_DLI_TRIM_TXDQS9			0x524
251 #define EMC_DLI_TRIM_TXDQS10			0x528
252 #define EMC_DLI_TRIM_TXDQS11			0x52c
253 #define EMC_DLI_TRIM_TXDQS12			0x530
254 #define EMC_DLI_TRIM_TXDQS13			0x534
255 #define EMC_DLI_TRIM_TXDQS14			0x538
256 #define EMC_DLI_TRIM_TXDQS15			0x53c
257 #define EMC_CDB_CNTL_3				0x540
258 #define EMC_XM2DQSPADCTRL5			0x544
259 #define EMC_XM2DQSPADCTRL6			0x548
260 #define EMC_XM2DQPADCTRL3			0x54c
261 #define EMC_DLL_XFORM_ADDR3			0x550
262 #define EMC_DLL_XFORM_ADDR4			0x554
263 #define EMC_DLL_XFORM_ADDR5			0x558
264 #define EMC_CFG_PIPE				0x560
265 #define EMC_QPOP				0x564
266 #define EMC_QUSE_WIDTH				0x568
267 #define EMC_PUTERM_WIDTH			0x56c
268 #define EMC_BGBIAS_CTL0				0x570
269 #define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX BIT(3)
270 #define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN BIT(2)
271 #define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD	BIT(1)
272 #define EMC_PUTERM_ADJ				0x574
273 
274 #define DRAM_DEV_SEL_ALL			0
275 #define DRAM_DEV_SEL_0				BIT(31)
276 #define DRAM_DEV_SEL_1				BIT(30)
277 
278 #define EMC_CFG_POWER_FEATURES_MASK		\
279 	(EMC_CFG_DYN_SREF | EMC_CFG_DRAM_ACPD | EMC_CFG_DRAM_CLKSTOP_SR | \
280 	EMC_CFG_DRAM_CLKSTOP_PD | EMC_CFG_DSR_VTTGEN_DRV_EN)
281 #define EMC_REFCTRL_DEV_SEL(n) (((n > 1) ? 0 : 2) << EMC_REFCTRL_DEV_SEL_SHIFT)
282 #define EMC_DRAM_DEV_SEL(n) ((n > 1) ? DRAM_DEV_SEL_ALL : DRAM_DEV_SEL_0)
283 
284 /* Maximum amount of time in us. to wait for changes to become effective */
285 #define EMC_STATUS_UPDATE_TIMEOUT		1000
286 
287 enum emc_dram_type {
288 	DRAM_TYPE_DDR3 = 0,
289 	DRAM_TYPE_DDR1 = 1,
290 	DRAM_TYPE_LPDDR3 = 2,
291 	DRAM_TYPE_DDR2 = 3
292 };
293 
294 enum emc_dll_change {
295 	DLL_CHANGE_NONE,
296 	DLL_CHANGE_ON,
297 	DLL_CHANGE_OFF
298 };
299 
300 static const unsigned long emc_burst_regs[] = {
301 	EMC_RC,
302 	EMC_RFC,
303 	EMC_RFC_SLR,
304 	EMC_RAS,
305 	EMC_RP,
306 	EMC_R2W,
307 	EMC_W2R,
308 	EMC_R2P,
309 	EMC_W2P,
310 	EMC_RD_RCD,
311 	EMC_WR_RCD,
312 	EMC_RRD,
313 	EMC_REXT,
314 	EMC_WEXT,
315 	EMC_WDV,
316 	EMC_WDV_MASK,
317 	EMC_QUSE,
318 	EMC_QUSE_WIDTH,
319 	EMC_IBDLY,
320 	EMC_EINPUT,
321 	EMC_EINPUT_DURATION,
322 	EMC_PUTERM_EXTRA,
323 	EMC_PUTERM_WIDTH,
324 	EMC_PUTERM_ADJ,
325 	EMC_CDB_CNTL_1,
326 	EMC_CDB_CNTL_2,
327 	EMC_CDB_CNTL_3,
328 	EMC_QRST,
329 	EMC_QSAFE,
330 	EMC_RDV,
331 	EMC_RDV_MASK,
332 	EMC_REFRESH,
333 	EMC_BURST_REFRESH_NUM,
334 	EMC_PRE_REFRESH_REQ_CNT,
335 	EMC_PDEX2WR,
336 	EMC_PDEX2RD,
337 	EMC_PCHG2PDEN,
338 	EMC_ACT2PDEN,
339 	EMC_AR2PDEN,
340 	EMC_RW2PDEN,
341 	EMC_TXSR,
342 	EMC_TXSRDLL,
343 	EMC_TCKE,
344 	EMC_TCKESR,
345 	EMC_TPD,
346 	EMC_TFAW,
347 	EMC_TRPAB,
348 	EMC_TCLKSTABLE,
349 	EMC_TCLKSTOP,
350 	EMC_TREFBW,
351 	EMC_FBIO_CFG6,
352 	EMC_ODT_WRITE,
353 	EMC_ODT_READ,
354 	EMC_FBIO_CFG5,
355 	EMC_CFG_DIG_DLL,
356 	EMC_CFG_DIG_DLL_PERIOD,
357 	EMC_DLL_XFORM_DQS0,
358 	EMC_DLL_XFORM_DQS1,
359 	EMC_DLL_XFORM_DQS2,
360 	EMC_DLL_XFORM_DQS3,
361 	EMC_DLL_XFORM_DQS4,
362 	EMC_DLL_XFORM_DQS5,
363 	EMC_DLL_XFORM_DQS6,
364 	EMC_DLL_XFORM_DQS7,
365 	EMC_DLL_XFORM_DQS8,
366 	EMC_DLL_XFORM_DQS9,
367 	EMC_DLL_XFORM_DQS10,
368 	EMC_DLL_XFORM_DQS11,
369 	EMC_DLL_XFORM_DQS12,
370 	EMC_DLL_XFORM_DQS13,
371 	EMC_DLL_XFORM_DQS14,
372 	EMC_DLL_XFORM_DQS15,
373 	EMC_DLL_XFORM_QUSE0,
374 	EMC_DLL_XFORM_QUSE1,
375 	EMC_DLL_XFORM_QUSE2,
376 	EMC_DLL_XFORM_QUSE3,
377 	EMC_DLL_XFORM_QUSE4,
378 	EMC_DLL_XFORM_QUSE5,
379 	EMC_DLL_XFORM_QUSE6,
380 	EMC_DLL_XFORM_QUSE7,
381 	EMC_DLL_XFORM_ADDR0,
382 	EMC_DLL_XFORM_ADDR1,
383 	EMC_DLL_XFORM_ADDR2,
384 	EMC_DLL_XFORM_ADDR3,
385 	EMC_DLL_XFORM_ADDR4,
386 	EMC_DLL_XFORM_ADDR5,
387 	EMC_DLL_XFORM_QUSE8,
388 	EMC_DLL_XFORM_QUSE9,
389 	EMC_DLL_XFORM_QUSE10,
390 	EMC_DLL_XFORM_QUSE11,
391 	EMC_DLL_XFORM_QUSE12,
392 	EMC_DLL_XFORM_QUSE13,
393 	EMC_DLL_XFORM_QUSE14,
394 	EMC_DLL_XFORM_QUSE15,
395 	EMC_DLI_TRIM_TXDQS0,
396 	EMC_DLI_TRIM_TXDQS1,
397 	EMC_DLI_TRIM_TXDQS2,
398 	EMC_DLI_TRIM_TXDQS3,
399 	EMC_DLI_TRIM_TXDQS4,
400 	EMC_DLI_TRIM_TXDQS5,
401 	EMC_DLI_TRIM_TXDQS6,
402 	EMC_DLI_TRIM_TXDQS7,
403 	EMC_DLI_TRIM_TXDQS8,
404 	EMC_DLI_TRIM_TXDQS9,
405 	EMC_DLI_TRIM_TXDQS10,
406 	EMC_DLI_TRIM_TXDQS11,
407 	EMC_DLI_TRIM_TXDQS12,
408 	EMC_DLI_TRIM_TXDQS13,
409 	EMC_DLI_TRIM_TXDQS14,
410 	EMC_DLI_TRIM_TXDQS15,
411 	EMC_DLL_XFORM_DQ0,
412 	EMC_DLL_XFORM_DQ1,
413 	EMC_DLL_XFORM_DQ2,
414 	EMC_DLL_XFORM_DQ3,
415 	EMC_DLL_XFORM_DQ4,
416 	EMC_DLL_XFORM_DQ5,
417 	EMC_DLL_XFORM_DQ6,
418 	EMC_DLL_XFORM_DQ7,
419 	EMC_XM2CMDPADCTRL,
420 	EMC_XM2CMDPADCTRL4,
421 	EMC_XM2CMDPADCTRL5,
422 	EMC_XM2DQPADCTRL2,
423 	EMC_XM2DQPADCTRL3,
424 	EMC_XM2CLKPADCTRL,
425 	EMC_XM2CLKPADCTRL2,
426 	EMC_XM2COMPPADCTRL,
427 	EMC_XM2VTTGENPADCTRL,
428 	EMC_XM2VTTGENPADCTRL2,
429 	EMC_XM2VTTGENPADCTRL3,
430 	EMC_XM2DQSPADCTRL3,
431 	EMC_XM2DQSPADCTRL4,
432 	EMC_XM2DQSPADCTRL5,
433 	EMC_XM2DQSPADCTRL6,
434 	EMC_DSR_VTTGEN_DRV,
435 	EMC_TXDSRVTTGEN,
436 	EMC_FBIO_SPARE,
437 	EMC_ZCAL_WAIT_CNT,
438 	EMC_MRS_WAIT_CNT2,
439 	EMC_CTT,
440 	EMC_CTT_DURATION,
441 	EMC_CFG_PIPE,
442 	EMC_DYN_SELF_REF_CONTROL,
443 	EMC_QPOP
444 };
445 
446 struct emc_timing {
447 	unsigned long rate;
448 
449 	u32 emc_burst_data[ARRAY_SIZE(emc_burst_regs)];
450 
451 	u32 emc_auto_cal_config;
452 	u32 emc_auto_cal_config2;
453 	u32 emc_auto_cal_config3;
454 	u32 emc_auto_cal_interval;
455 	u32 emc_bgbias_ctl0;
456 	u32 emc_cfg;
457 	u32 emc_cfg_2;
458 	u32 emc_ctt_term_ctrl;
459 	u32 emc_mode_1;
460 	u32 emc_mode_2;
461 	u32 emc_mode_4;
462 	u32 emc_mode_reset;
463 	u32 emc_mrs_wait_cnt;
464 	u32 emc_sel_dpd_ctrl;
465 	u32 emc_xm2dqspadctrl2;
466 	u32 emc_zcal_cnt_long;
467 	u32 emc_zcal_interval;
468 };
469 
470 enum emc_rate_request_type {
471 	EMC_RATE_DEBUG,
472 	EMC_RATE_ICC,
473 	EMC_RATE_TYPE_MAX,
474 };
475 
476 struct emc_rate_request {
477 	unsigned long min_rate;
478 	unsigned long max_rate;
479 };
480 
481 struct tegra_emc {
482 	struct device *dev;
483 
484 	struct tegra_mc *mc;
485 
486 	void __iomem *regs;
487 
488 	struct clk *clk;
489 
490 	enum emc_dram_type dram_type;
491 	unsigned int dram_bus_width;
492 	unsigned int dram_num;
493 
494 	struct emc_timing last_timing;
495 	struct emc_timing *timings;
496 	unsigned int num_timings;
497 
498 	struct {
499 		struct dentry *root;
500 		unsigned long min_rate;
501 		unsigned long max_rate;
502 	} debugfs;
503 
504 	struct icc_provider provider;
505 
506 	/*
507 	 * There are multiple sources in the EMC driver which could request
508 	 * a min/max clock rate, these rates are contained in this array.
509 	 */
510 	struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX];
511 
512 	/* protect shared rate-change code path */
513 	struct mutex rate_lock;
514 };
515 
516 /* Timing change sequence functions */
517 
518 static void emc_ccfifo_writel(struct tegra_emc *emc, u32 value,
519 			      unsigned long offset)
520 {
521 	writel(value, emc->regs + EMC_CCFIFO_DATA);
522 	writel(offset, emc->regs + EMC_CCFIFO_ADDR);
523 }
524 
525 static void emc_seq_update_timing(struct tegra_emc *emc)
526 {
527 	unsigned int i;
528 	u32 value;
529 
530 	writel(1, emc->regs + EMC_TIMING_CONTROL);
531 
532 	for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
533 		value = readl(emc->regs + EMC_STATUS);
534 		if ((value & EMC_STATUS_TIMING_UPDATE_STALLED) == 0)
535 			return;
536 		udelay(1);
537 	}
538 
539 	dev_err(emc->dev, "timing update timed out\n");
540 }
541 
542 static void emc_seq_disable_auto_cal(struct tegra_emc *emc)
543 {
544 	unsigned int i;
545 	u32 value;
546 
547 	writel(0, emc->regs + EMC_AUTO_CAL_INTERVAL);
548 
549 	for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
550 		value = readl(emc->regs + EMC_AUTO_CAL_STATUS);
551 		if ((value & EMC_AUTO_CAL_STATUS_ACTIVE) == 0)
552 			return;
553 		udelay(1);
554 	}
555 
556 	dev_err(emc->dev, "auto cal disable timed out\n");
557 }
558 
559 static void emc_seq_wait_clkchange(struct tegra_emc *emc)
560 {
561 	unsigned int i;
562 	u32 value;
563 
564 	for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
565 		value = readl(emc->regs + EMC_INTSTATUS);
566 		if (value & EMC_INTSTATUS_CLKCHANGE_COMPLETE)
567 			return;
568 		udelay(1);
569 	}
570 
571 	dev_err(emc->dev, "clock change timed out\n");
572 }
573 
574 static struct emc_timing *tegra_emc_find_timing(struct tegra_emc *emc,
575 						unsigned long rate)
576 {
577 	struct emc_timing *timing = NULL;
578 	unsigned int i;
579 
580 	for (i = 0; i < emc->num_timings; i++) {
581 		if (emc->timings[i].rate == rate) {
582 			timing = &emc->timings[i];
583 			break;
584 		}
585 	}
586 
587 	if (!timing) {
588 		dev_err(emc->dev, "no timing for rate %lu\n", rate);
589 		return NULL;
590 	}
591 
592 	return timing;
593 }
594 
595 static int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
596 					   unsigned long rate)
597 {
598 	struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
599 	struct emc_timing *last = &emc->last_timing;
600 	enum emc_dll_change dll_change;
601 	unsigned int pre_wait = 0;
602 	u32 val, val2, mask;
603 	bool update = false;
604 	unsigned int i;
605 
606 	if (!timing)
607 		return -ENOENT;
608 
609 	if ((last->emc_mode_1 & 0x1) == (timing->emc_mode_1 & 0x1))
610 		dll_change = DLL_CHANGE_NONE;
611 	else if (timing->emc_mode_1 & 0x1)
612 		dll_change = DLL_CHANGE_ON;
613 	else
614 		dll_change = DLL_CHANGE_OFF;
615 
616 	/* Clear CLKCHANGE_COMPLETE interrupts */
617 	writel(EMC_INTSTATUS_CLKCHANGE_COMPLETE, emc->regs + EMC_INTSTATUS);
618 
619 	/* Disable dynamic self-refresh */
620 	val = readl(emc->regs + EMC_CFG);
621 	if (val & EMC_CFG_PWR_MASK) {
622 		val &= ~EMC_CFG_POWER_FEATURES_MASK;
623 		writel(val, emc->regs + EMC_CFG);
624 
625 		pre_wait = 5;
626 	}
627 
628 	/* Disable SEL_DPD_CTRL for clock change */
629 	if (emc->dram_type == DRAM_TYPE_DDR3)
630 		mask = EMC_SEL_DPD_CTRL_DDR3_MASK;
631 	else
632 		mask = EMC_SEL_DPD_CTRL_MASK;
633 
634 	val = readl(emc->regs + EMC_SEL_DPD_CTRL);
635 	if (val & mask) {
636 		val &= ~mask;
637 		writel(val, emc->regs + EMC_SEL_DPD_CTRL);
638 	}
639 
640 	/* Prepare DQ/DQS for clock change */
641 	val = readl(emc->regs + EMC_BGBIAS_CTL0);
642 	val2 = last->emc_bgbias_ctl0;
643 	if (!(timing->emc_bgbias_ctl0 &
644 	      EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX) &&
645 	    (val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX)) {
646 		val2 &= ~EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX;
647 		update = true;
648 	}
649 
650 	if ((val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD) ||
651 	    (val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN)) {
652 		update = true;
653 	}
654 
655 	if (update) {
656 		writel(val2, emc->regs + EMC_BGBIAS_CTL0);
657 		if (pre_wait < 5)
658 			pre_wait = 5;
659 	}
660 
661 	update = false;
662 	val = readl(emc->regs + EMC_XM2DQSPADCTRL2);
663 	if (timing->emc_xm2dqspadctrl2 & EMC_XM2DQSPADCTRL2_VREF_ENABLE &&
664 	    !(val & EMC_XM2DQSPADCTRL2_VREF_ENABLE)) {
665 		val |= EMC_XM2DQSPADCTRL2_VREF_ENABLE;
666 		update = true;
667 	}
668 
669 	if (timing->emc_xm2dqspadctrl2 & EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE &&
670 	    !(val & EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE)) {
671 		val |= EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE;
672 		update = true;
673 	}
674 
675 	if (update) {
676 		writel(val, emc->regs + EMC_XM2DQSPADCTRL2);
677 		if (pre_wait < 30)
678 			pre_wait = 30;
679 	}
680 
681 	/* Wait to settle */
682 	if (pre_wait) {
683 		emc_seq_update_timing(emc);
684 		udelay(pre_wait);
685 	}
686 
687 	/* Program CTT_TERM control */
688 	if (last->emc_ctt_term_ctrl != timing->emc_ctt_term_ctrl) {
689 		emc_seq_disable_auto_cal(emc);
690 		writel(timing->emc_ctt_term_ctrl,
691 		       emc->regs + EMC_CTT_TERM_CTRL);
692 		emc_seq_update_timing(emc);
693 	}
694 
695 	/* Program burst shadow registers */
696 	for (i = 0; i < ARRAY_SIZE(timing->emc_burst_data); ++i)
697 		writel(timing->emc_burst_data[i],
698 		       emc->regs + emc_burst_regs[i]);
699 
700 	writel(timing->emc_xm2dqspadctrl2, emc->regs + EMC_XM2DQSPADCTRL2);
701 	writel(timing->emc_zcal_interval, emc->regs + EMC_ZCAL_INTERVAL);
702 
703 	tegra_mc_write_emem_configuration(emc->mc, timing->rate);
704 
705 	val = timing->emc_cfg & ~EMC_CFG_POWER_FEATURES_MASK;
706 	emc_ccfifo_writel(emc, val, EMC_CFG);
707 
708 	/* Program AUTO_CAL_CONFIG */
709 	if (timing->emc_auto_cal_config2 != last->emc_auto_cal_config2)
710 		emc_ccfifo_writel(emc, timing->emc_auto_cal_config2,
711 				  EMC_AUTO_CAL_CONFIG2);
712 
713 	if (timing->emc_auto_cal_config3 != last->emc_auto_cal_config3)
714 		emc_ccfifo_writel(emc, timing->emc_auto_cal_config3,
715 				  EMC_AUTO_CAL_CONFIG3);
716 
717 	if (timing->emc_auto_cal_config != last->emc_auto_cal_config) {
718 		val = timing->emc_auto_cal_config;
719 		val &= EMC_AUTO_CAL_CONFIG_AUTO_CAL_START;
720 		emc_ccfifo_writel(emc, val, EMC_AUTO_CAL_CONFIG);
721 	}
722 
723 	/* DDR3: predict MRS long wait count */
724 	if (emc->dram_type == DRAM_TYPE_DDR3 &&
725 	    dll_change == DLL_CHANGE_ON) {
726 		u32 cnt = 512;
727 
728 		if (timing->emc_zcal_interval != 0 &&
729 		    last->emc_zcal_interval == 0)
730 			cnt -= emc->dram_num * 256;
731 
732 		val = (timing->emc_mrs_wait_cnt
733 			& EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK)
734 			>> EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT;
735 		if (cnt < val)
736 			cnt = val;
737 
738 		val = timing->emc_mrs_wait_cnt
739 			& ~EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
740 		val |= (cnt << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
741 			& EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
742 
743 		writel(val, emc->regs + EMC_MRS_WAIT_CNT);
744 	}
745 
746 	val = timing->emc_cfg_2;
747 	val &= ~EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR;
748 	emc_ccfifo_writel(emc, val, EMC_CFG_2);
749 
750 	/* DDR3: Turn off DLL and enter self-refresh */
751 	if (emc->dram_type == DRAM_TYPE_DDR3 && dll_change == DLL_CHANGE_OFF)
752 		emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_EMRS);
753 
754 	/* Disable refresh controller */
755 	emc_ccfifo_writel(emc, EMC_REFCTRL_DEV_SEL(emc->dram_num),
756 			  EMC_REFCTRL);
757 	if (emc->dram_type == DRAM_TYPE_DDR3)
758 		emc_ccfifo_writel(emc, EMC_DRAM_DEV_SEL(emc->dram_num) |
759 				       EMC_SELF_REF_CMD_ENABLED,
760 				  EMC_SELF_REF);
761 
762 	/* Flow control marker */
763 	emc_ccfifo_writel(emc, 1, EMC_STALL_THEN_EXE_AFTER_CLKCHANGE);
764 
765 	/* DDR3: Exit self-refresh */
766 	if (emc->dram_type == DRAM_TYPE_DDR3)
767 		emc_ccfifo_writel(emc, EMC_DRAM_DEV_SEL(emc->dram_num),
768 				  EMC_SELF_REF);
769 	emc_ccfifo_writel(emc, EMC_REFCTRL_DEV_SEL(emc->dram_num) |
770 			       EMC_REFCTRL_ENABLE,
771 			  EMC_REFCTRL);
772 
773 	/* Set DRAM mode registers */
774 	if (emc->dram_type == DRAM_TYPE_DDR3) {
775 		if (timing->emc_mode_1 != last->emc_mode_1)
776 			emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_EMRS);
777 		if (timing->emc_mode_2 != last->emc_mode_2)
778 			emc_ccfifo_writel(emc, timing->emc_mode_2, EMC_EMRS2);
779 
780 		if ((timing->emc_mode_reset != last->emc_mode_reset) ||
781 		    dll_change == DLL_CHANGE_ON) {
782 			val = timing->emc_mode_reset;
783 			if (dll_change == DLL_CHANGE_ON) {
784 				val |= EMC_MODE_SET_DLL_RESET;
785 				val |= EMC_MODE_SET_LONG_CNT;
786 			} else {
787 				val &= ~EMC_MODE_SET_DLL_RESET;
788 			}
789 			emc_ccfifo_writel(emc, val, EMC_MRS);
790 		}
791 	} else {
792 		if (timing->emc_mode_2 != last->emc_mode_2)
793 			emc_ccfifo_writel(emc, timing->emc_mode_2, EMC_MRW2);
794 		if (timing->emc_mode_1 != last->emc_mode_1)
795 			emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_MRW);
796 		if (timing->emc_mode_4 != last->emc_mode_4)
797 			emc_ccfifo_writel(emc, timing->emc_mode_4, EMC_MRW4);
798 	}
799 
800 	/*  Issue ZCAL command if turning ZCAL on */
801 	if (timing->emc_zcal_interval != 0 && last->emc_zcal_interval == 0) {
802 		emc_ccfifo_writel(emc, EMC_ZQ_CAL_LONG_CMD_DEV0, EMC_ZQ_CAL);
803 		if (emc->dram_num > 1)
804 			emc_ccfifo_writel(emc, EMC_ZQ_CAL_LONG_CMD_DEV1,
805 					  EMC_ZQ_CAL);
806 	}
807 
808 	/*  Write to RO register to remove stall after change */
809 	emc_ccfifo_writel(emc, 0, EMC_CCFIFO_STATUS);
810 
811 	if (timing->emc_cfg_2 & EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR)
812 		emc_ccfifo_writel(emc, timing->emc_cfg_2, EMC_CFG_2);
813 
814 	/* Disable AUTO_CAL for clock change */
815 	emc_seq_disable_auto_cal(emc);
816 
817 	/* Read register to wait until programming has settled */
818 	readl(emc->regs + EMC_INTSTATUS);
819 
820 	return 0;
821 }
822 
823 static void tegra_emc_complete_timing_change(struct tegra_emc *emc,
824 					     unsigned long rate)
825 {
826 	struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
827 	struct emc_timing *last = &emc->last_timing;
828 	u32 val;
829 
830 	if (!timing)
831 		return;
832 
833 	/* Wait until the state machine has settled */
834 	emc_seq_wait_clkchange(emc);
835 
836 	/* Restore AUTO_CAL */
837 	if (timing->emc_ctt_term_ctrl != last->emc_ctt_term_ctrl)
838 		writel(timing->emc_auto_cal_interval,
839 		       emc->regs + EMC_AUTO_CAL_INTERVAL);
840 
841 	/* Restore dynamic self-refresh */
842 	if (timing->emc_cfg & EMC_CFG_PWR_MASK)
843 		writel(timing->emc_cfg, emc->regs + EMC_CFG);
844 
845 	/* Set ZCAL wait count */
846 	writel(timing->emc_zcal_cnt_long, emc->regs + EMC_ZCAL_WAIT_CNT);
847 
848 	/* LPDDR3: Turn off BGBIAS if low frequency */
849 	if (emc->dram_type == DRAM_TYPE_LPDDR3 &&
850 	    timing->emc_bgbias_ctl0 &
851 	      EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX) {
852 		val = timing->emc_bgbias_ctl0;
853 		val |= EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN;
854 		val |= EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD;
855 		writel(val, emc->regs + EMC_BGBIAS_CTL0);
856 	} else {
857 		if (emc->dram_type == DRAM_TYPE_DDR3 &&
858 		    readl(emc->regs + EMC_BGBIAS_CTL0) !=
859 		      timing->emc_bgbias_ctl0) {
860 			writel(timing->emc_bgbias_ctl0,
861 			       emc->regs + EMC_BGBIAS_CTL0);
862 		}
863 
864 		writel(timing->emc_auto_cal_interval,
865 		       emc->regs + EMC_AUTO_CAL_INTERVAL);
866 	}
867 
868 	/* Wait for timing to settle */
869 	udelay(2);
870 
871 	/* Reprogram SEL_DPD_CTRL */
872 	writel(timing->emc_sel_dpd_ctrl, emc->regs + EMC_SEL_DPD_CTRL);
873 	emc_seq_update_timing(emc);
874 
875 	emc->last_timing = *timing;
876 }
877 
878 /* Initialization and deinitialization */
879 
880 static void emc_read_current_timing(struct tegra_emc *emc,
881 				    struct emc_timing *timing)
882 {
883 	unsigned int i;
884 
885 	for (i = 0; i < ARRAY_SIZE(emc_burst_regs); ++i)
886 		timing->emc_burst_data[i] =
887 			readl(emc->regs + emc_burst_regs[i]);
888 
889 	timing->emc_cfg = readl(emc->regs + EMC_CFG);
890 
891 	timing->emc_auto_cal_interval = 0;
892 	timing->emc_zcal_cnt_long = 0;
893 	timing->emc_mode_1 = 0;
894 	timing->emc_mode_2 = 0;
895 	timing->emc_mode_4 = 0;
896 	timing->emc_mode_reset = 0;
897 }
898 
899 static int emc_init(struct tegra_emc *emc)
900 {
901 	emc->dram_type = readl(emc->regs + EMC_FBIO_CFG5);
902 
903 	if (emc->dram_type & EMC_FBIO_CFG5_DRAM_WIDTH_X64)
904 		emc->dram_bus_width = 64;
905 	else
906 		emc->dram_bus_width = 32;
907 
908 	dev_info_once(emc->dev, "%ubit DRAM bus\n", emc->dram_bus_width);
909 
910 	emc->dram_type &= EMC_FBIO_CFG5_DRAM_TYPE_MASK;
911 	emc->dram_type >>= EMC_FBIO_CFG5_DRAM_TYPE_SHIFT;
912 
913 	emc->dram_num = tegra_mc_get_emem_device_count(emc->mc);
914 
915 	emc_read_current_timing(emc, &emc->last_timing);
916 
917 	return 0;
918 }
919 
920 static int load_one_timing_from_dt(struct tegra_emc *emc,
921 				   struct emc_timing *timing,
922 				   struct device_node *node)
923 {
924 	u32 value;
925 	int err;
926 
927 	err = of_property_read_u32(node, "clock-frequency", &value);
928 	if (err) {
929 		dev_err(emc->dev, "timing %pOFn: failed to read rate: %d\n",
930 			node, err);
931 		return err;
932 	}
933 
934 	timing->rate = value;
935 
936 	err = of_property_read_u32_array(node, "nvidia,emc-configuration",
937 					 timing->emc_burst_data,
938 					 ARRAY_SIZE(timing->emc_burst_data));
939 	if (err) {
940 		dev_err(emc->dev,
941 			"timing %pOFn: failed to read emc burst data: %d\n",
942 			node, err);
943 		return err;
944 	}
945 
946 #define EMC_READ_PROP(prop, dtprop) { \
947 	err = of_property_read_u32(node, dtprop, &timing->prop); \
948 	if (err) { \
949 		dev_err(emc->dev, "timing %pOFn: failed to read " #prop ": %d\n", \
950 			node, err); \
951 		return err; \
952 	} \
953 }
954 
955 	EMC_READ_PROP(emc_auto_cal_config, "nvidia,emc-auto-cal-config")
956 	EMC_READ_PROP(emc_auto_cal_config2, "nvidia,emc-auto-cal-config2")
957 	EMC_READ_PROP(emc_auto_cal_config3, "nvidia,emc-auto-cal-config3")
958 	EMC_READ_PROP(emc_auto_cal_interval, "nvidia,emc-auto-cal-interval")
959 	EMC_READ_PROP(emc_bgbias_ctl0, "nvidia,emc-bgbias-ctl0")
960 	EMC_READ_PROP(emc_cfg, "nvidia,emc-cfg")
961 	EMC_READ_PROP(emc_cfg_2, "nvidia,emc-cfg-2")
962 	EMC_READ_PROP(emc_ctt_term_ctrl, "nvidia,emc-ctt-term-ctrl")
963 	EMC_READ_PROP(emc_mode_1, "nvidia,emc-mode-1")
964 	EMC_READ_PROP(emc_mode_2, "nvidia,emc-mode-2")
965 	EMC_READ_PROP(emc_mode_4, "nvidia,emc-mode-4")
966 	EMC_READ_PROP(emc_mode_reset, "nvidia,emc-mode-reset")
967 	EMC_READ_PROP(emc_mrs_wait_cnt, "nvidia,emc-mrs-wait-cnt")
968 	EMC_READ_PROP(emc_sel_dpd_ctrl, "nvidia,emc-sel-dpd-ctrl")
969 	EMC_READ_PROP(emc_xm2dqspadctrl2, "nvidia,emc-xm2dqspadctrl2")
970 	EMC_READ_PROP(emc_zcal_cnt_long, "nvidia,emc-zcal-cnt-long")
971 	EMC_READ_PROP(emc_zcal_interval, "nvidia,emc-zcal-interval")
972 
973 #undef EMC_READ_PROP
974 
975 	return 0;
976 }
977 
978 static int cmp_timings(const void *_a, const void *_b)
979 {
980 	const struct emc_timing *a = _a;
981 	const struct emc_timing *b = _b;
982 
983 	if (a->rate < b->rate)
984 		return -1;
985 	else if (a->rate == b->rate)
986 		return 0;
987 	else
988 		return 1;
989 }
990 
991 static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
992 					  struct device_node *node)
993 {
994 	int child_count = of_get_child_count(node);
995 	struct device_node *child;
996 	struct emc_timing *timing;
997 	unsigned int i = 0;
998 	int err;
999 
1000 	emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing),
1001 				    GFP_KERNEL);
1002 	if (!emc->timings)
1003 		return -ENOMEM;
1004 
1005 	emc->num_timings = child_count;
1006 
1007 	for_each_child_of_node(node, child) {
1008 		timing = &emc->timings[i++];
1009 
1010 		err = load_one_timing_from_dt(emc, timing, child);
1011 		if (err) {
1012 			of_node_put(child);
1013 			return err;
1014 		}
1015 	}
1016 
1017 	sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
1018 	     NULL);
1019 
1020 	return 0;
1021 }
1022 
1023 static const struct of_device_id tegra_emc_of_match[] = {
1024 	{ .compatible = "nvidia,tegra124-emc" },
1025 	{ .compatible = "nvidia,tegra132-emc" },
1026 	{}
1027 };
1028 MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
1029 
1030 static struct device_node *
1031 tegra_emc_find_node_by_ram_code(struct device_node *node, u32 ram_code)
1032 {
1033 	struct device_node *np;
1034 	int err;
1035 
1036 	for_each_child_of_node(node, np) {
1037 		u32 value;
1038 
1039 		err = of_property_read_u32(np, "nvidia,ram-code", &value);
1040 		if (err || (value != ram_code))
1041 			continue;
1042 
1043 		return np;
1044 	}
1045 
1046 	return NULL;
1047 }
1048 
1049 static void tegra_emc_rate_requests_init(struct tegra_emc *emc)
1050 {
1051 	unsigned int i;
1052 
1053 	for (i = 0; i < EMC_RATE_TYPE_MAX; i++) {
1054 		emc->requested_rate[i].min_rate = 0;
1055 		emc->requested_rate[i].max_rate = ULONG_MAX;
1056 	}
1057 }
1058 
1059 static int emc_request_rate(struct tegra_emc *emc,
1060 			    unsigned long new_min_rate,
1061 			    unsigned long new_max_rate,
1062 			    enum emc_rate_request_type type)
1063 {
1064 	struct emc_rate_request *req = emc->requested_rate;
1065 	unsigned long min_rate = 0, max_rate = ULONG_MAX;
1066 	unsigned int i;
1067 	int err;
1068 
1069 	/* select minimum and maximum rates among the requested rates */
1070 	for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) {
1071 		if (i == type) {
1072 			min_rate = max(new_min_rate, min_rate);
1073 			max_rate = min(new_max_rate, max_rate);
1074 		} else {
1075 			min_rate = max(req->min_rate, min_rate);
1076 			max_rate = min(req->max_rate, max_rate);
1077 		}
1078 	}
1079 
1080 	if (min_rate > max_rate) {
1081 		dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n",
1082 				    __func__, type, min_rate, max_rate);
1083 		return -ERANGE;
1084 	}
1085 
1086 	/*
1087 	 * EMC rate-changes should go via OPP API because it manages voltage
1088 	 * changes.
1089 	 */
1090 	err = dev_pm_opp_set_rate(emc->dev, min_rate);
1091 	if (err)
1092 		return err;
1093 
1094 	emc->requested_rate[type].min_rate = new_min_rate;
1095 	emc->requested_rate[type].max_rate = new_max_rate;
1096 
1097 	return 0;
1098 }
1099 
1100 static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate,
1101 			    enum emc_rate_request_type type)
1102 {
1103 	struct emc_rate_request *req = &emc->requested_rate[type];
1104 	int ret;
1105 
1106 	mutex_lock(&emc->rate_lock);
1107 	ret = emc_request_rate(emc, rate, req->max_rate, type);
1108 	mutex_unlock(&emc->rate_lock);
1109 
1110 	return ret;
1111 }
1112 
1113 static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate,
1114 			    enum emc_rate_request_type type)
1115 {
1116 	struct emc_rate_request *req = &emc->requested_rate[type];
1117 	int ret;
1118 
1119 	mutex_lock(&emc->rate_lock);
1120 	ret = emc_request_rate(emc, req->min_rate, rate, type);
1121 	mutex_unlock(&emc->rate_lock);
1122 
1123 	return ret;
1124 }
1125 
1126 /*
1127  * debugfs interface
1128  *
1129  * The memory controller driver exposes some files in debugfs that can be used
1130  * to control the EMC frequency. The top-level directory can be found here:
1131  *
1132  *   /sys/kernel/debug/emc
1133  *
1134  * It contains the following files:
1135  *
1136  *   - available_rates: This file contains a list of valid, space-separated
1137  *     EMC frequencies.
1138  *
1139  *   - min_rate: Writing a value to this file sets the given frequency as the
1140  *       floor of the permitted range. If this is higher than the currently
1141  *       configured EMC frequency, this will cause the frequency to be
1142  *       increased so that it stays within the valid range.
1143  *
1144  *   - max_rate: Similarily to the min_rate file, writing a value to this file
1145  *       sets the given frequency as the ceiling of the permitted range. If
1146  *       the value is lower than the currently configured EMC frequency, this
1147  *       will cause the frequency to be decreased so that it stays within the
1148  *       valid range.
1149  */
1150 
1151 static bool tegra_emc_validate_rate(struct tegra_emc *emc, unsigned long rate)
1152 {
1153 	unsigned int i;
1154 
1155 	for (i = 0; i < emc->num_timings; i++)
1156 		if (rate == emc->timings[i].rate)
1157 			return true;
1158 
1159 	return false;
1160 }
1161 
1162 static int tegra_emc_debug_available_rates_show(struct seq_file *s,
1163 						void *data)
1164 {
1165 	struct tegra_emc *emc = s->private;
1166 	const char *prefix = "";
1167 	unsigned int i;
1168 
1169 	for (i = 0; i < emc->num_timings; i++) {
1170 		seq_printf(s, "%s%lu", prefix, emc->timings[i].rate);
1171 		prefix = " ";
1172 	}
1173 
1174 	seq_puts(s, "\n");
1175 
1176 	return 0;
1177 }
1178 
1179 DEFINE_SHOW_ATTRIBUTE(tegra_emc_debug_available_rates);
1180 
1181 static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
1182 {
1183 	struct tegra_emc *emc = data;
1184 
1185 	*rate = emc->debugfs.min_rate;
1186 
1187 	return 0;
1188 }
1189 
1190 static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
1191 {
1192 	struct tegra_emc *emc = data;
1193 	int err;
1194 
1195 	if (!tegra_emc_validate_rate(emc, rate))
1196 		return -EINVAL;
1197 
1198 	err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
1199 	if (err < 0)
1200 		return err;
1201 
1202 	emc->debugfs.min_rate = rate;
1203 
1204 	return 0;
1205 }
1206 
1207 DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
1208 			tegra_emc_debug_min_rate_get,
1209 			tegra_emc_debug_min_rate_set, "%llu\n");
1210 
1211 static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
1212 {
1213 	struct tegra_emc *emc = data;
1214 
1215 	*rate = emc->debugfs.max_rate;
1216 
1217 	return 0;
1218 }
1219 
1220 static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
1221 {
1222 	struct tegra_emc *emc = data;
1223 	int err;
1224 
1225 	if (!tegra_emc_validate_rate(emc, rate))
1226 		return -EINVAL;
1227 
1228 	err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
1229 	if (err < 0)
1230 		return err;
1231 
1232 	emc->debugfs.max_rate = rate;
1233 
1234 	return 0;
1235 }
1236 
1237 DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
1238 			tegra_emc_debug_max_rate_get,
1239 			tegra_emc_debug_max_rate_set, "%llu\n");
1240 
1241 static void emc_debugfs_init(struct device *dev, struct tegra_emc *emc)
1242 {
1243 	unsigned int i;
1244 	int err;
1245 
1246 	emc->debugfs.min_rate = ULONG_MAX;
1247 	emc->debugfs.max_rate = 0;
1248 
1249 	for (i = 0; i < emc->num_timings; i++) {
1250 		if (emc->timings[i].rate < emc->debugfs.min_rate)
1251 			emc->debugfs.min_rate = emc->timings[i].rate;
1252 
1253 		if (emc->timings[i].rate > emc->debugfs.max_rate)
1254 			emc->debugfs.max_rate = emc->timings[i].rate;
1255 	}
1256 
1257 	if (!emc->num_timings) {
1258 		emc->debugfs.min_rate = clk_get_rate(emc->clk);
1259 		emc->debugfs.max_rate = emc->debugfs.min_rate;
1260 	}
1261 
1262 	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
1263 				 emc->debugfs.max_rate);
1264 	if (err < 0) {
1265 		dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
1266 			emc->debugfs.min_rate, emc->debugfs.max_rate,
1267 			emc->clk);
1268 		return;
1269 	}
1270 
1271 	emc->debugfs.root = debugfs_create_dir("emc", NULL);
1272 
1273 	debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc,
1274 			    &tegra_emc_debug_available_rates_fops);
1275 	debugfs_create_file("min_rate", 0644, emc->debugfs.root,
1276 			    emc, &tegra_emc_debug_min_rate_fops);
1277 	debugfs_create_file("max_rate", 0644, emc->debugfs.root,
1278 			    emc, &tegra_emc_debug_max_rate_fops);
1279 }
1280 
1281 static inline struct tegra_emc *
1282 to_tegra_emc_provider(struct icc_provider *provider)
1283 {
1284 	return container_of(provider, struct tegra_emc, provider);
1285 }
1286 
1287 static struct icc_node_data *
1288 emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
1289 {
1290 	struct icc_provider *provider = data;
1291 	struct icc_node_data *ndata;
1292 	struct icc_node *node;
1293 
1294 	/* External Memory is the only possible ICC route */
1295 	list_for_each_entry(node, &provider->nodes, node_list) {
1296 		if (node->id != TEGRA_ICC_EMEM)
1297 			continue;
1298 
1299 		ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
1300 		if (!ndata)
1301 			return ERR_PTR(-ENOMEM);
1302 
1303 		/*
1304 		 * SRC and DST nodes should have matching TAG in order to have
1305 		 * it set by default for a requested path.
1306 		 */
1307 		ndata->tag = TEGRA_MC_ICC_TAG_ISO;
1308 		ndata->node = node;
1309 
1310 		return ndata;
1311 	}
1312 
1313 	return ERR_PTR(-EPROBE_DEFER);
1314 }
1315 
1316 static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
1317 {
1318 	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
1319 	unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
1320 	unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
1321 	unsigned long long rate = max(avg_bw, peak_bw);
1322 	unsigned int dram_data_bus_width_bytes;
1323 	const unsigned int ddr = 2;
1324 	int err;
1325 
1326 	/*
1327 	 * Tegra124 EMC runs on a clock rate of SDRAM bus. This means that
1328 	 * EMC clock rate is twice smaller than the peak data rate because
1329 	 * data is sampled on both EMC clock edges.
1330 	 */
1331 	dram_data_bus_width_bytes = emc->dram_bus_width / 8;
1332 	do_div(rate, ddr * dram_data_bus_width_bytes);
1333 	rate = min_t(u64, rate, U32_MAX);
1334 
1335 	err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
1336 	if (err)
1337 		return err;
1338 
1339 	return 0;
1340 }
1341 
1342 static int tegra_emc_interconnect_init(struct tegra_emc *emc)
1343 {
1344 	const struct tegra_mc_soc *soc = emc->mc->soc;
1345 	struct icc_node *node;
1346 	int err;
1347 
1348 	emc->provider.dev = emc->dev;
1349 	emc->provider.set = emc_icc_set;
1350 	emc->provider.data = &emc->provider;
1351 	emc->provider.aggregate = soc->icc_ops->aggregate;
1352 	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
1353 
1354 	icc_provider_init(&emc->provider);
1355 
1356 	/* create External Memory Controller node */
1357 	node = icc_node_create(TEGRA_ICC_EMC);
1358 	if (IS_ERR(node)) {
1359 		err = PTR_ERR(node);
1360 		goto err_msg;
1361 	}
1362 
1363 	node->name = "External Memory Controller";
1364 	icc_node_add(node, &emc->provider);
1365 
1366 	/* link External Memory Controller to External Memory (DRAM) */
1367 	err = icc_link_create(node, TEGRA_ICC_EMEM);
1368 	if (err)
1369 		goto remove_nodes;
1370 
1371 	/* create External Memory node */
1372 	node = icc_node_create(TEGRA_ICC_EMEM);
1373 	if (IS_ERR(node)) {
1374 		err = PTR_ERR(node);
1375 		goto remove_nodes;
1376 	}
1377 
1378 	node->name = "External Memory (DRAM)";
1379 	icc_node_add(node, &emc->provider);
1380 
1381 	err = icc_provider_register(&emc->provider);
1382 	if (err)
1383 		goto remove_nodes;
1384 
1385 	return 0;
1386 
1387 remove_nodes:
1388 	icc_nodes_remove(&emc->provider);
1389 err_msg:
1390 	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
1391 
1392 	return err;
1393 }
1394 
1395 static int tegra_emc_opp_table_init(struct tegra_emc *emc)
1396 {
1397 	u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
1398 	int opp_token, err;
1399 
1400 	err = dev_pm_opp_set_supported_hw(emc->dev, &hw_version, 1);
1401 	if (err < 0) {
1402 		dev_err(emc->dev, "failed to set OPP supported HW: %d\n", err);
1403 		return err;
1404 	}
1405 	opp_token = err;
1406 
1407 	err = dev_pm_opp_of_add_table(emc->dev);
1408 	if (err) {
1409 		if (err == -ENODEV)
1410 			dev_err(emc->dev, "OPP table not found, please update your device tree\n");
1411 		else
1412 			dev_err(emc->dev, "failed to add OPP table: %d\n", err);
1413 
1414 		goto put_hw_table;
1415 	}
1416 
1417 	dev_info_once(emc->dev, "OPP HW ver. 0x%x, current clock rate %lu MHz\n",
1418 		      hw_version, clk_get_rate(emc->clk) / 1000000);
1419 
1420 	/* first dummy rate-set initializes voltage state */
1421 	err = dev_pm_opp_set_rate(emc->dev, clk_get_rate(emc->clk));
1422 	if (err) {
1423 		dev_err(emc->dev, "failed to initialize OPP clock: %d\n", err);
1424 		goto remove_table;
1425 	}
1426 
1427 	return 0;
1428 
1429 remove_table:
1430 	dev_pm_opp_of_remove_table(emc->dev);
1431 put_hw_table:
1432 	dev_pm_opp_put_supported_hw(opp_token);
1433 
1434 	return err;
1435 }
1436 
1437 static void devm_tegra_emc_unset_callback(void *data)
1438 {
1439 	tegra124_clk_set_emc_callbacks(NULL, NULL);
1440 }
1441 
1442 static int tegra_emc_probe(struct platform_device *pdev)
1443 {
1444 	struct device_node *np;
1445 	struct tegra_emc *emc;
1446 	u32 ram_code;
1447 	int err;
1448 
1449 	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
1450 	if (!emc)
1451 		return -ENOMEM;
1452 
1453 	mutex_init(&emc->rate_lock);
1454 	emc->dev = &pdev->dev;
1455 
1456 	emc->regs = devm_platform_ioremap_resource(pdev, 0);
1457 	if (IS_ERR(emc->regs))
1458 		return PTR_ERR(emc->regs);
1459 
1460 	emc->mc = devm_tegra_memory_controller_get(&pdev->dev);
1461 	if (IS_ERR(emc->mc))
1462 		return PTR_ERR(emc->mc);
1463 
1464 	ram_code = tegra_read_ram_code();
1465 
1466 	np = tegra_emc_find_node_by_ram_code(pdev->dev.of_node, ram_code);
1467 	if (np) {
1468 		err = tegra_emc_load_timings_from_dt(emc, np);
1469 		of_node_put(np);
1470 		if (err)
1471 			return err;
1472 	} else {
1473 		dev_info_once(&pdev->dev,
1474 			      "no memory timings for RAM code %u found in DT\n",
1475 			      ram_code);
1476 	}
1477 
1478 	err = emc_init(emc);
1479 	if (err) {
1480 		dev_err(&pdev->dev, "EMC initialization failed: %d\n", err);
1481 		return err;
1482 	}
1483 
1484 	platform_set_drvdata(pdev, emc);
1485 
1486 	tegra124_clk_set_emc_callbacks(tegra_emc_prepare_timing_change,
1487 				       tegra_emc_complete_timing_change);
1488 
1489 	err = devm_add_action_or_reset(&pdev->dev, devm_tegra_emc_unset_callback,
1490 				       NULL);
1491 	if (err)
1492 		return err;
1493 
1494 	emc->clk = devm_clk_get(&pdev->dev, "emc");
1495 	if (IS_ERR(emc->clk)) {
1496 		err = PTR_ERR(emc->clk);
1497 		dev_err(&pdev->dev, "failed to get EMC clock: %d\n", err);
1498 		return err;
1499 	}
1500 
1501 	err = tegra_emc_opp_table_init(emc);
1502 	if (err)
1503 		return err;
1504 
1505 	tegra_emc_rate_requests_init(emc);
1506 
1507 	if (IS_ENABLED(CONFIG_DEBUG_FS))
1508 		emc_debugfs_init(&pdev->dev, emc);
1509 
1510 	tegra_emc_interconnect_init(emc);
1511 
1512 	/*
1513 	 * Don't allow the kernel module to be unloaded. Unloading adds some
1514 	 * extra complexity which doesn't really worth the effort in a case of
1515 	 * this driver.
1516 	 */
1517 	try_module_get(THIS_MODULE);
1518 
1519 	return 0;
1520 };
1521 
1522 static struct platform_driver tegra_emc_driver = {
1523 	.probe = tegra_emc_probe,
1524 	.driver = {
1525 		.name = "tegra-emc",
1526 		.of_match_table = tegra_emc_of_match,
1527 		.suppress_bind_attrs = true,
1528 		.sync_state = icc_sync_state,
1529 	},
1530 };
1531 module_platform_driver(tegra_emc_driver);
1532 
1533 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
1534 MODULE_DESCRIPTION("NVIDIA Tegra124 EMC driver");
1535 MODULE_LICENSE("GPL v2");
1536