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