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git01.mediatek.com / filogic / uboot / 2028012e4a55eb348d358e17756c809a87912a3b / . / arch / mips / mach-ath79 / qca953x / ddr.c
blob: c6049d8958a47fa288f9e4155f963991cf7a9dd3 [file] [log] [blame]
Wills Wang6b83b442016-03-16 16:59:54 +0800[diff] [blame]1/*
2 * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
3 * Based on Atheros LSDK/QSDK
4 *
5 * SPDX-License-Identifier: GPL-2.0+
6 */
7
8#include <common.h>
9#include <asm/io.h>
10#include <asm/addrspace.h>
11#include <asm/types.h>
12#include <mach/ar71xx_regs.h>
Wills Wangddc05522016-05-30 22:54:50 +0800[diff] [blame]13#include <mach/ath79.h>
Wills Wang6b83b442016-03-16 16:59:54 +0800[diff] [blame]14
15DECLARE_GLOBAL_DATA_PTR;
16
17#define DDR_CTRL_UPD_EMR3S BIT(5)
18#define DDR_CTRL_UPD_EMR2S BIT(4)
19#define DDR_CTRL_PRECHARGE BIT(3)
20#define DDR_CTRL_AUTO_REFRESH BIT(2)
21#define DDR_CTRL_UPD_EMRS BIT(1)
22#define DDR_CTRL_UPD_MRS BIT(0)
23
24#define DDR_REFRESH_EN BIT(14)
25#define DDR_REFRESH_M 0x3ff
26#define DDR_REFRESH(x) ((x) & DDR_REFRESH_M)
27#define DDR_REFRESH_VAL (DDR_REFRESH_EN | DDR_REFRESH(312))
28
29#define DDR_TRAS_S 0
30#define DDR_TRAS_M 0x1f
31#define DDR_TRAS(x) (((x) & DDR_TRAS_M) << DDR_TRAS_S)
32#define DDR_TRCD_M 0xf
33#define DDR_TRCD_S 5
34#define DDR_TRCD(x) (((x) & DDR_TRCD_M) << DDR_TRCD_S)
35#define DDR_TRP_M 0xf
36#define DDR_TRP_S 9
37#define DDR_TRP(x) (((x) & DDR_TRP_M) << DDR_TRP_S)
38#define DDR_TRRD_M 0xf
39#define DDR_TRRD_S 13
40#define DDR_TRRD(x) (((x) & DDR_TRRD_M) << DDR_TRRD_S)
41#define DDR_TRFC_M 0x7f
42#define DDR_TRFC_S 17
43#define DDR_TRFC(x) (((x) & DDR_TRFC_M) << DDR_TRFC_S)
44#define DDR_TMRD_M 0xf
45#define DDR_TMRD_S 23
46#define DDR_TMRD(x) (((x) & DDR_TMRD_M) << DDR_TMRD_S)
47#define DDR_CAS_L_M 0x17
48#define DDR_CAS_L_S 27
49#define DDR_CAS_L(x) (((x) & DDR_CAS_L_M) << DDR_CAS_L_S)
50#define DDR_OPEN BIT(30)
51#define DDR1_CONF_REG_VAL (DDR_TRAS(16) | DDR_TRCD(6) | \
52 DDR_TRP(6) | DDR_TRRD(4) | \
53 DDR_TRFC(7) | DDR_TMRD(5) | \
54 DDR_CAS_L(7) | DDR_OPEN)
55#define DDR2_CONF_REG_VAL (DDR_TRAS(27) | DDR_TRCD(9) | \
56 DDR_TRP(9) | DDR_TRRD(7) | \
57 DDR_TRFC(21) | DDR_TMRD(15) | \
58 DDR_CAS_L(17) | DDR_OPEN)
59
60#define DDR_BURST_LEN_S 0
61#define DDR_BURST_LEN_M 0xf
62#define DDR_BURST_LEN(x) ((x) << DDR_BURST_LEN_S)
63#define DDR_BURST_TYPE BIT(4)
64#define DDR_CNTL_OE_EN BIT(5)
65#define DDR_PHASE_SEL BIT(6)
66#define DDR_CKE BIT(7)
67#define DDR_TWR_S 8
68#define DDR_TWR_M 0xf
69#define DDR_TWR(x) (((x) & DDR_TWR_M) << DDR_TWR_S)
70#define DDR_TRTW_S 12
71#define DDR_TRTW_M 0x1f
72#define DDR_TRTW(x) (((x) & DDR_TRTW_M) << DDR_TRTW_S)
73#define DDR_TRTP_S 17
74#define DDR_TRTP_M 0xf
75#define DDR_TRTP(x) (((x) & DDR_TRTP_M) << DDR_TRTP_S)
76#define DDR_TWTR_S 21
77#define DDR_TWTR_M 0x1f
78#define DDR_TWTR(x) (((x) & DDR_TWTR_M) << DDR_TWTR_S)
79#define DDR_G_OPEN_L_S 26
80#define DDR_G_OPEN_L_M 0xf
81#define DDR_G_OPEN_L(x) ((x) << DDR_G_OPEN_L_S)
82#define DDR_HALF_WIDTH_LOW BIT(31)
83#define DDR1_CONF2_REG_VAL (DDR_BURST_LEN(8) | DDR_CNTL_OE_EN | \
84 DDR_CKE | DDR_TWR(13) | DDR_TRTW(14) | \
85 DDR_TRTP(8) | DDR_TWTR(14) | \
86 DDR_G_OPEN_L(6) | DDR_HALF_WIDTH_LOW)
87#define DDR2_CONF2_REG_VAL (DDR_BURST_LEN(8) | DDR_CNTL_OE_EN | \
88 DDR_CKE | DDR_TWR(1) | DDR_TRTW(14) | \
89 DDR_TRTP(9) | DDR_TWTR(21) | \
90 DDR_G_OPEN_L(8) | DDR_HALF_WIDTH_LOW)
91
92#define DDR_TWR_MSB BIT(3)
93#define DDR_TRAS_MSB BIT(2)
94#define DDR_TRFC_MSB_M 0x3
95#define DDR_TRFC_MSB(x) (x)
96#define DDR1_CONF3_REG_VAL 0
97#define DDR2_CONF3_REG_VAL (DDR_TWR_MSB | DDR_TRFC_MSB(2))
98
99#define DDR_CTL_SRAM_TSEL BIT(30)
100#define DDR_CTL_SRAM_GE0_SYNC BIT(20)
101#define DDR_CTL_SRAM_GE1_SYNC BIT(19)
102#define DDR_CTL_SRAM_USB_SYNC BIT(18)
103#define DDR_CTL_SRAM_PCIE_SYNC BIT(17)
104#define DDR_CTL_SRAM_WMAC_SYNC BIT(16)
105#define DDR_CTL_SRAM_MISC1_SYNC BIT(15)
106#define DDR_CTL_SRAM_MISC2_SYNC BIT(14)
107#define DDR_CTL_PAD_DDR2_SEL BIT(6)
108#define DDR_CTL_HALF_WIDTH BIT(1)
109#define DDR_CTL_CONFIG_VAL (DDR_CTL_SRAM_TSEL | \
110 DDR_CTL_SRAM_GE0_SYNC | \
111 DDR_CTL_SRAM_GE1_SYNC | \
112 DDR_CTL_SRAM_USB_SYNC | \
113 DDR_CTL_SRAM_PCIE_SYNC | \
114 DDR_CTL_SRAM_WMAC_SYNC | \
115 DDR_CTL_HALF_WIDTH)
116
117#define DDR_BURST_GE0_MAX_BL_S 0
118#define DDR_BURST_GE0_MAX_BL_M 0xf
119#define DDR_BURST_GE0_MAX_BL(x) \
120 (((x) & DDR_BURST_GE0_MAX_BL_M) << DDR_BURST_GE0_MAX_BL_S)
121#define DDR_BURST_GE1_MAX_BL_S 4
122#define DDR_BURST_GE1_MAX_BL_M 0xf
123#define DDR_BURST_GE1_MAX_BL(x) \
124 (((x) & DDR_BURST_GE1_MAX_BL_M) << DDR_BURST_GE1_MAX_BL_S)
125#define DDR_BURST_PCIE_MAX_BL_S 8
126#define DDR_BURST_PCIE_MAX_BL_M 0xf
127#define DDR_BURST_PCIE_MAX_BL(x) \
128 (((x) & DDR_BURST_PCIE_MAX_BL_M) << DDR_BURST_PCIE_MAX_BL_S)
129#define DDR_BURST_USB_MAX_BL_S 12
130#define DDR_BURST_USB_MAX_BL_M 0xf
131#define DDR_BURST_USB_MAX_BL(x) \
132 (((x) & DDR_BURST_USB_MAX_BL_M) << DDR_BURST_USB_MAX_BL_S)
133#define DDR_BURST_CPU_MAX_BL_S 16
134#define DDR_BURST_CPU_MAX_BL_M 0xf
135#define DDR_BURST_CPU_MAX_BL(x) \
136 (((x) & DDR_BURST_CPU_MAX_BL_M) << DDR_BURST_CPU_MAX_BL_S)
137#define DDR_BURST_RD_MAX_BL_S 20
138#define DDR_BURST_RD_MAX_BL_M 0xf
139#define DDR_BURST_RD_MAX_BL(x) \
140 (((x) & DDR_BURST_RD_MAX_BL_M) << DDR_BURST_RD_MAX_BL_S)
141#define DDR_BURST_WR_MAX_BL_S 24
142#define DDR_BURST_WR_MAX_BL_M 0xf
143#define DDR_BURST_WR_MAX_BL(x) \
144 (((x) & DDR_BURST_WR_MAX_BL_M) << DDR_BURST_WR_MAX_BL_S)
145#define DDR_BURST_RWP_MASK_EN_S 28
146#define DDR_BURST_RWP_MASK_EN_M 0x3
147#define DDR_BURST_RWP_MASK_EN(x) \
148 (((x) & DDR_BURST_RWP_MASK_EN_M) << DDR_BURST_RWP_MASK_EN_S)
149#define DDR_BURST_CPU_PRI_BE BIT(30)
150#define DDR_BURST_CPU_PRI BIT(31)
151#define DDR_BURST_VAL (DDR_BURST_CPU_PRI_BE | \
152 DDR_BURST_RWP_MASK_EN(3) | \
153 DDR_BURST_WR_MAX_BL(4) | \
154 DDR_BURST_RD_MAX_BL(4) | \
155 DDR_BURST_CPU_MAX_BL(4) | \
156 DDR_BURST_USB_MAX_BL(4) | \
157 DDR_BURST_PCIE_MAX_BL(4) | \
158 DDR_BURST_GE1_MAX_BL(4) | \
159 DDR_BURST_GE0_MAX_BL(4))
160
161#define DDR_BURST_WMAC_MAX_BL_S 0
162#define DDR_BURST_WMAC_MAX_BL_M 0xf
163#define DDR_BURST_WMAC_MAX_BL(x) \
164 (((x) & DDR_BURST_WMAC_MAX_BL_M) << DDR_BURST_WMAC_MAX_BL_S)
165#define DDR_BURST2_VAL DDR_BURST_WMAC_MAX_BL(4)
166
167#define DDR2_CONF_TWL_S 10
168#define DDR2_CONF_TWL_M 0xf
169#define DDR2_CONF_TWL(x) \
170 (((x) & DDR2_CONF_TWL_M) << DDR2_CONF_TWL_S)
171#define DDR2_CONF_ODT BIT(9)
172#define DDR2_CONF_TFAW_S 2
173#define DDR2_CONF_TFAW_M 0x3f
174#define DDR2_CONF_TFAW(x) \
175 (((x) & DDR2_CONF_TFAW_M) << DDR2_CONF_TFAW_S)
176#define DDR2_CONF_EN BIT(0)
177#define DDR2_CONF_VAL (DDR2_CONF_TWL(5) | \
178 DDR2_CONF_TFAW(31) | \
179 DDR2_CONF_ODT | \
180 DDR2_CONF_EN)
181
182#define DDR1_EXT_MODE_VAL 0
183#define DDR2_EXT_MODE_VAL 0x402
184#define DDR2_EXT_MODE_OCD_VAL 0x782
185#define DDR1_MODE_DLL_VAL 0x133
186#define DDR2_MODE_DLL_VAL 0x143
187#define DDR1_MODE_VAL 0x33
188#define DDR2_MODE_VAL 0x43
189#define DDR1_TAP_VAL 0x20
190#define DDR2_TAP_VAL 0x10
191
192#define DDR_REG_BIST_MASK_ADDR_0 0x2c
193#define DDR_REG_BIST_MASK_ADDR_1 0x30
194#define DDR_REG_BIST_MASK_AHB_GE0_0 0x34
195#define DDR_REG_BIST_COMP_AHB_GE0_0 0x38
196#define DDR_REG_BIST_MASK_AHB_GE1_0 0x3c
197#define DDR_REG_BIST_COMP_AHB_GE1_0 0x40
198#define DDR_REG_BIST_COMP_ADDR_0 0x64
199#define DDR_REG_BIST_COMP_ADDR_1 0x68
200#define DDR_REG_BIST_MASK_AHB_GE0_1 0x6c
201#define DDR_REG_BIST_COMP_AHB_GE0_1 0x70
202#define DDR_REG_BIST_MASK_AHB_GE1_1 0x74
203#define DDR_REG_BIST_COMP_AHB_GE1_1 0x78
204#define DDR_REG_BIST 0x11c
205#define DDR_REG_BIST_STATUS 0x120
206
207#define DDR_BIST_COMP_CNT_S 1
208#define DDR_BIST_COMP_CNT_M 0xff
209#define DDR_BIST_COMP_CNT(x) \
210 (((x) & DDR_BIST_COMP_CNT_M) << DDR_BIST_COMP_CNT_S)
211#define DDR_BIST_COMP_CNT_MASK \
212 (DDR_BIST_COMP_CNT_M << DDR_BIST_COMP_CNT_S)
213#define DDR_BIST_TEST_START BIT(0)
214#define DDR_BIST_STATUS_DONE BIT(0)
215
216/* 4 Row Address Bits, 4 Column Address Bits, 2 BA bits */
217#define DDR_BIST_MASK_ADDR_VAL 0xfa5de83f
218
219#define DDR_TAP_MAGIC_VAL 0xaa55aa55
220#define DDR_TAP_MAX_VAL 0x40
221
222void ddr_init(void)
223{
224 void __iomem *regs;
225 u32 val;
226
227 regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
228 MAP_NOCACHE);
Wills Wangddc05522016-05-30 22:54:50 +0800[diff] [blame]229 val = ath79_get_bootstrap();
Wills Wang6b83b442016-03-16 16:59:54 +0800[diff] [blame]230 if (val & QCA953X_BOOTSTRAP_DDR1) {
231 writel(DDR_CTL_CONFIG_VAL, regs + QCA953X_DDR_REG_CTL_CONF);
232 udelay(10);
233
234 /* For 16-bit DDR */
235 writel(0xffff, regs + AR71XX_DDR_REG_RD_CYCLE);
236 udelay(100);
237
238 /* Burst size */
239 writel(DDR_BURST_VAL, regs + QCA953X_DDR_REG_BURST);
240 udelay(100);
241 writel(DDR_BURST2_VAL, regs + QCA953X_DDR_REG_BURST2);
242 udelay(100);
243
244 /* AHB maximum timeout */
245 writel(0xfffff, regs + QCA953X_DDR_REG_TIMEOUT_MAX);
246 udelay(100);
247
248 /* DRAM timing */
249 writel(DDR1_CONF_REG_VAL, regs + AR71XX_DDR_REG_CONFIG);
250 udelay(100);
251 writel(DDR1_CONF2_REG_VAL, regs + AR71XX_DDR_REG_CONFIG2);
252 udelay(100);
253 writel(DDR1_CONF3_REG_VAL, regs + QCA953X_DDR_REG_CONFIG3);
254 udelay(100);
255
256 /* Precharge All */
257 writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
258 udelay(100);
259
260 /* ODT disable, Full strength, Enable DLL */
261 writel(DDR1_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
262 udelay(100);
263
264 /* Update Extended Mode Register Set (EMRS) */
265 writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
266 udelay(100);
267
268 /* Reset DLL, CAS Latency 3, Burst Length 8 */
269 writel(DDR1_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
270 udelay(100);
271
272 /* Update Mode Register Set (MRS) */
273 writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
274 udelay(100);
275
276 /* Precharge All */
277 writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
278 udelay(100);
279
280 /* Auto Refresh */
281 writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
282 udelay(100);
283 writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
284 udelay(100);
285
286 /* Normal DLL, CAS Latency 3, Burst Length 8 */
287 writel(DDR1_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
288 udelay(100);
289
290 /* Update Mode Register Set (MRS) */
291 writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
292 udelay(100);
293
294 /* Refresh time control */
295 writel(DDR_REFRESH_VAL, regs + AR71XX_DDR_REG_REFRESH);
296 udelay(100);
297
298 /* DQS 0 Tap Control */
299 writel(DDR1_TAP_VAL, regs + AR71XX_DDR_REG_TAP_CTRL0);
300
301 /* DQS 1 Tap Control */
302 writel(DDR1_TAP_VAL, regs + AR71XX_DDR_REG_TAP_CTRL1);
303 } else {
304 writel(DDR_CTRL_UPD_EMR2S, regs + AR71XX_DDR_REG_CONTROL);
305 udelay(10);
306 writel(DDR_CTRL_UPD_EMR3S, regs + AR71XX_DDR_REG_CONTROL);
307 udelay(10);
308 writel(DDR_CTL_CONFIG_VAL | DDR_CTL_PAD_DDR2_SEL,
309 regs + QCA953X_DDR_REG_CTL_CONF);
310 udelay(10);
311
312 /* For 16-bit DDR */
313 writel(0xffff, regs + AR71XX_DDR_REG_RD_CYCLE);
314 udelay(100);
315
316 /* Burst size */
317 writel(DDR_BURST_VAL, regs + QCA953X_DDR_REG_BURST);
318 udelay(100);
319 writel(DDR_BURST2_VAL, regs + QCA953X_DDR_REG_BURST2);
320 udelay(100);
321
322 /* AHB maximum timeout */
323 writel(0xfffff, regs + QCA953X_DDR_REG_TIMEOUT_MAX);
324 udelay(100);
325
326 /* DRAM timing */
327 writel(DDR2_CONF_REG_VAL, regs + AR71XX_DDR_REG_CONFIG);
328 udelay(100);
329 writel(DDR2_CONF2_REG_VAL, regs + AR71XX_DDR_REG_CONFIG2);
330 udelay(100);
331 writel(DDR2_CONF3_REG_VAL, regs + QCA953X_DDR_REG_CONFIG3);
332 udelay(100);
333
334 /* Enable DDR2 */
335 writel(DDR2_CONF_VAL, regs + QCA953X_DDR_REG_DDR2_CONFIG);
336 udelay(100);
337
338 /* Precharge All */
339 writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
340 udelay(100);
341
342 /* Update Extended Mode Register 2 Set (EMR2S) */
343 writel(DDR_CTRL_UPD_EMR2S, regs + AR71XX_DDR_REG_CONTROL);
344 udelay(100);
345
346 /* Update Extended Mode Register 3 Set (EMR3S) */
347 writel(DDR_CTRL_UPD_EMR3S, regs + AR71XX_DDR_REG_CONTROL);
348 udelay(100);
349
350 /* 150 ohm, Reduced strength, Enable DLL */
351 writel(DDR2_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
352 udelay(100);
353
354 /* Update Extended Mode Register Set (EMRS) */
355 writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
356 udelay(100);
357
358 /* Reset DLL, CAS Latency 4, Burst Length 8 */
359 writel(DDR2_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
360 udelay(100);
361
362 /* Update Mode Register Set (MRS) */
363 writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
364 udelay(100);
365
366 /* Precharge All */
367 writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
368 udelay(100);
369
370 /* Auto Refresh */
371 writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
372 udelay(100);
373 writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
374 udelay(100);
375
376 /* Normal DLL, CAS Latency 4, Burst Length 8 */
377 writel(DDR2_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
378 udelay(100);
379
380 /* Mode Register Set (MRS) */
381 writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
382 udelay(100);
383
384 /* Enable OCD, Enable DLL, Reduced Drive Strength */
385 writel(DDR2_EXT_MODE_OCD_VAL, regs + AR71XX_DDR_REG_EMR);
386 udelay(100);
387
388 /* Update Extended Mode Register Set (EMRS) */
389 writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
390 udelay(100);
391
392 /* OCD diable, Enable DLL, Reduced Drive Strength */
393 writel(DDR2_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
394 udelay(100);
395
396 /* Update Extended Mode Register Set (EMRS) */
397 writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
398 udelay(100);
399
400 /* Refresh time control */
401 writel(DDR_REFRESH_VAL, regs + AR71XX_DDR_REG_REFRESH);
402 udelay(100);
403
404 /* DQS 0 Tap Control */
405 writel(DDR2_TAP_VAL, regs + AR71XX_DDR_REG_TAP_CTRL0);
406
407 /* DQS 1 Tap Control */
408 writel(DDR2_TAP_VAL, regs + AR71XX_DDR_REG_TAP_CTRL1);
409 }
410}
411
412void ddr_tap_tuning(void)
413{
414 void __iomem *regs;
415 u32 val, pass, tap, cnt, tap_val, last, first;
416
417 regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
418 MAP_NOCACHE);
419
420 tap_val = readl(regs + AR71XX_DDR_REG_TAP_CTRL0);
421 first = DDR_TAP_MAGIC_VAL;
422 last = 0;
423 cnt = 0;
424 tap = 0;
425
426 do {
427 writel(tap, regs + AR71XX_DDR_REG_TAP_CTRL0);
428 writel(tap, regs + AR71XX_DDR_REG_TAP_CTRL1);
429
430 writel(DDR_BIST_COMP_CNT(8), regs + DDR_REG_BIST_COMP_ADDR_1);
431 writel(DDR_BIST_MASK_ADDR_VAL, regs + DDR_REG_BIST_MASK_ADDR_0);
432 writel(0xffff, regs + DDR_REG_BIST_COMP_AHB_GE0_1);
433 writel(0xffff, regs + DDR_REG_BIST_COMP_AHB_GE1_0);
434 writel(0xffff, regs + DDR_REG_BIST_COMP_AHB_GE1_1);
435 writel(0xffff, regs + DDR_REG_BIST_MASK_AHB_GE0_0);
436 writel(0xffff, regs + DDR_REG_BIST_MASK_AHB_GE0_1);
437 writel(0xffff, regs + DDR_REG_BIST_MASK_AHB_GE1_0);
438 writel(0xffff, regs + DDR_REG_BIST_MASK_AHB_GE1_1);
439 writel(0xffff, regs + DDR_REG_BIST_COMP_AHB_GE0_0);
440
441 /* Start BIST test */
442 writel(DDR_BIST_TEST_START, regs + DDR_REG_BIST);
443
444 do {
445 val = readl(regs + DDR_REG_BIST_STATUS);
446 } while (!(val & DDR_BIST_STATUS_DONE));
447
448 /* Stop BIST test */
449 writel(0, regs + DDR_REG_BIST);
450
451 pass = val & DDR_BIST_COMP_CNT_MASK;
452 pass ^= DDR_BIST_COMP_CNT(8);
453 if (!pass) {
454 if (first != DDR_TAP_MAGIC_VAL) {
455 last = tap;
456 } else {
457 first = tap;
458 last = tap;
459 }
460 cnt++;
461 }
462 tap++;
463 } while (tap < DDR_TAP_MAX_VAL);
464
465 if (cnt) {
466 tap_val = (first + last) / 2;
467 tap_val %= DDR_TAP_MAX_VAL;
468 }
469
470 writel(tap_val, regs + AR71XX_DDR_REG_TAP_CTRL0);
471 writel(tap_val, regs + AR71XX_DDR_REG_TAP_CTRL1);
472}