xref: /openbmc/u-boot/arch/mips/mach-ath79/ar933x/ddr.c (revision dd1033e4)
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) & 0x3ff)
24 #define DDR_REFRESH_VAL_25M     (DDR_REFRESH_EN | DDR_REFRESH(390))
25 #define DDR_REFRESH_VAL_40M     (DDR_REFRESH_EN | DDR_REFRESH(624))
26 
27 #define DDR_TRAS_S              0
28 #define DDR_TRAS_M              0x1f
29 #define DDR_TRAS(x)             ((x) << DDR_TRAS_S)
30 #define DDR_TRCD_M              0xf
31 #define DDR_TRCD_S              5
32 #define DDR_TRCD(x)             ((x) << DDR_TRCD_S)
33 #define DDR_TRP_M               0xf
34 #define DDR_TRP_S               9
35 #define DDR_TRP(x)              ((x) << DDR_TRP_S)
36 #define DDR_TRRD_M              0xf
37 #define DDR_TRRD_S              13
38 #define DDR_TRRD(x)             ((x) << DDR_TRRD_S)
39 #define DDR_TRFC_M              0x7f
40 #define DDR_TRFC_S              17
41 #define DDR_TRFC(x)             ((x) << DDR_TRFC_S)
42 #define DDR_TMRD_M              0xf
43 #define DDR_TMRD_S              23
44 #define DDR_TMRD(x)             ((x) << DDR_TMRD_S)
45 #define DDR_CAS_L_M             0x17
46 #define DDR_CAS_L_S             27
47 #define DDR_CAS_L(x)            (((x) & DDR_CAS_L_M) << DDR_CAS_L_S)
48 #define DDR_OPEN                BIT(30)
49 #define DDR_CONF_REG_VAL        (DDR_TRAS(16) | DDR_TRCD(6) | \
50 				 DDR_TRP(6) | DDR_TRRD(4) | \
51 				 DDR_TRFC(30) | DDR_TMRD(15) | \
52 				 DDR_CAS_L(7) | DDR_OPEN)
53 
54 #define DDR_BURST_LEN_S         0
55 #define DDR_BURST_LEN_M         0xf
56 #define DDR_BURST_LEN(x)        ((x) << DDR_BURST_LEN_S)
57 #define DDR_BURST_TYPE          BIT(4)
58 #define DDR_CNTL_OE_EN          BIT(5)
59 #define DDR_PHASE_SEL           BIT(6)
60 #define DDR_CKE                 BIT(7)
61 #define DDR_TWR_S               8
62 #define DDR_TWR_M               0xf
63 #define DDR_TWR(x)              ((x) << DDR_TWR_S)
64 #define DDR_TRTW_S              12
65 #define DDR_TRTW_M              0x1f
66 #define DDR_TRTW(x)             ((x) << DDR_TRTW_S)
67 #define DDR_TRTP_S              17
68 #define DDR_TRTP_M              0xf
69 #define DDR_TRTP(x)             ((x) << DDR_TRTP_S)
70 #define DDR_TWTR_S              21
71 #define DDR_TWTR_M              0x1f
72 #define DDR_TWTR(x)             ((x) << DDR_TWTR_S)
73 #define DDR_G_OPEN_L_S          26
74 #define DDR_G_OPEN_L_M          0xf
75 #define DDR_G_OPEN_L(x)         ((x) << DDR_G_OPEN_L_S)
76 #define DDR_HALF_WIDTH_LOW      BIT(31)
77 #define DDR_CONF2_REG_VAL       (DDR_BURST_LEN(8) | DDR_CNTL_OE_EN | \
78 				 DDR_CKE | DDR_TWR(6) | DDR_TRTW(14) | \
79 				 DDR_TRTP(8) | DDR_TWTR(14) | \
80 				 DDR_G_OPEN_L(7) | DDR_HALF_WIDTH_LOW)
81 
82 #define DDR2_CONF_TWL_S         10
83 #define DDR2_CONF_TWL_M         0xf
84 #define DDR2_CONF_TWL(x)        (((x) & DDR2_CONF_TWL_M) << DDR2_CONF_TWL_S)
85 #define DDR2_CONF_ODT           BIT(9)
86 #define DDR2_CONF_TFAW_S        2
87 #define DDR2_CONF_TFAW_M        0x3f
88 #define DDR2_CONF_TFAW(x)       (((x) & DDR2_CONF_TFAW_M) << DDR2_CONF_TFAW_S)
89 #define DDR2_CONF_EN            BIT(0)
90 #define DDR2_CONF_VAL           (DDR2_CONF_TWL(2) | DDR2_CONF_ODT | \
91 				 DDR2_CONF_TFAW(22) | DDR2_CONF_EN)
92 
93 #define DDR1_EXT_MODE_VAL       0x02
94 #define DDR2_EXT_MODE_VAL       0x402
95 #define DDR2_EXT_MODE_OCD_VAL   0x382
96 #define DDR1_MODE_DLL_VAL       0x133
97 #define DDR2_MODE_DLL_VAL       0x100
98 #define DDR1_MODE_VAL           0x33
99 #define DDR2_MODE_VAL           0xa33
100 #define DDR_TAP_VAL0            0x08
101 #define DDR_TAP_VAL1            0x09
102 
103 void ddr_init(void)
104 {
105 	void __iomem *regs;
106 	u32 val;
107 
108 	regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
109 			   MAP_NOCACHE);
110 
111 	writel(DDR_CONF_REG_VAL, regs + AR71XX_DDR_REG_CONFIG);
112 	writel(DDR_CONF2_REG_VAL, regs + AR71XX_DDR_REG_CONFIG2);
113 
114 	val = ath79_get_bootstrap();
115 	if (val & AR933X_BOOTSTRAP_DDR2) {
116 		/* AHB maximum timeout */
117 		writel(0xfffff, regs + AR933X_DDR_REG_TIMEOUT_MAX);
118 
119 		/* Enable DDR2 */
120 		writel(DDR2_CONF_VAL, regs + AR933X_DDR_REG_DDR2_CONFIG);
121 
122 		/* Precharge All */
123 		writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
124 
125 		/* Disable High Temperature Self-Refresh, Full Array */
126 		writel(0x00, regs + AR933X_DDR_REG_EMR2);
127 
128 		/* Extended Mode Register 2 Set (EMR2S) */
129 		writel(DDR_CTRL_UPD_EMR2S, regs + AR71XX_DDR_REG_CONTROL);
130 
131 		writel(0x00, regs + AR933X_DDR_REG_EMR3);
132 
133 		/* Extended Mode Register 3 Set (EMR3S) */
134 		writel(DDR_CTRL_UPD_EMR3S, regs + AR71XX_DDR_REG_CONTROL);
135 
136 		/* Enable DLL,  Full strength, ODT Disabled */
137 		writel(0x00, regs + AR71XX_DDR_REG_EMR);
138 
139 		/* Extended Mode Register Set (EMRS) */
140 		writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
141 
142 		/* Reset DLL */
143 		writel(DDR2_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
144 
145 		/* Mode Register Set (MRS) */
146 		writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
147 
148 		/* Precharge All */
149 		writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
150 
151 		/* Auto Refresh */
152 		writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
153 		writel(DDR_CTRL_AUTO_REFRESH, regs + AR71XX_DDR_REG_CONTROL);
154 
155 		/* Write recovery (WR) 6 clock, CAS Latency 3, Burst Length 8 */
156 		writel(DDR2_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
157 		/* Mode Register Set (MRS) */
158 		writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
159 
160 		/* Enable OCD defaults, Enable DLL, Reduced Drive Strength */
161 		writel(DDR2_EXT_MODE_OCD_VAL, regs + AR71XX_DDR_REG_EMR);
162 
163 		/* Extended Mode Register Set (EMRS) */
164 		writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
165 
166 		/* OCD exit, Enable DLL, Enable /DQS, Reduced Drive Strength */
167 		writel(DDR2_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
168 		/* Extended Mode Register Set (EMRS) */
169 		writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
170 
171 		/* Refresh time control */
172 		if (val & AR933X_BOOTSTRAP_REF_CLK_40)
173 			writel(DDR_REFRESH_VAL_40M, regs +
174 			       AR71XX_DDR_REG_REFRESH);
175 		else
176 			writel(DDR_REFRESH_VAL_25M, regs +
177 			       AR71XX_DDR_REG_REFRESH);
178 
179 		/* DQS 0 Tap Control */
180 		writel(DDR_TAP_VAL0, regs + AR71XX_DDR_REG_TAP_CTRL0);
181 
182 		/* DQS 1 Tap Control */
183 		writel(DDR_TAP_VAL1, regs + AR71XX_DDR_REG_TAP_CTRL1);
184 
185 		/* For 16-bit DDR */
186 		writel(0xff, regs + AR71XX_DDR_REG_RD_CYCLE);
187 	} else {
188 		/* AHB maximum timeout */
189 		writel(0xfffff, regs + AR933X_DDR_REG_TIMEOUT_MAX);
190 
191 		/* Precharge All */
192 		writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
193 
194 		/* Reset DLL, Burst Length 8, CAS Latency 3 */
195 		writel(DDR1_MODE_DLL_VAL, regs + AR71XX_DDR_REG_MODE);
196 
197 		/* Forces an MRS update cycle in DDR */
198 		writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
199 
200 		/* Enable DLL, Full strength */
201 		writel(DDR1_EXT_MODE_VAL, regs + AR71XX_DDR_REG_EMR);
202 
203 		/* Extended Mode Register Set (EMRS) */
204 		writel(DDR_CTRL_UPD_EMRS, regs + AR71XX_DDR_REG_CONTROL);
205 
206 		/* Precharge All */
207 		writel(DDR_CTRL_PRECHARGE, regs + AR71XX_DDR_REG_CONTROL);
208 
209 		/* Normal DLL, Burst Length 8, CAS Latency 3 */
210 		writel(DDR1_MODE_VAL, regs + AR71XX_DDR_REG_MODE);
211 
212 		/* Mode Register Set (MRS) */
213 		writel(DDR_CTRL_UPD_MRS, regs + AR71XX_DDR_REG_CONTROL);
214 
215 		/* Refresh time control */
216 		if (val & AR933X_BOOTSTRAP_REF_CLK_40)
217 			writel(DDR_REFRESH_VAL_40M, regs +
218 			       AR71XX_DDR_REG_REFRESH);
219 		else
220 			writel(DDR_REFRESH_VAL_25M, regs +
221 			       AR71XX_DDR_REG_REFRESH);
222 
223 		/* DQS 0 Tap Control */
224 		writel(DDR_TAP_VAL0, regs + AR71XX_DDR_REG_TAP_CTRL0);
225 
226 		/* DQS 1 Tap Control */
227 		writel(DDR_TAP_VAL1, regs + AR71XX_DDR_REG_TAP_CTRL1);
228 
229 		/* For 16-bit DDR */
230 		writel(0xff, regs + AR71XX_DDR_REG_RD_CYCLE);
231 	}
232 }
233 
234 void ddr_tap_tuning(void)
235 {
236 	void __iomem *regs;
237 	u32 *addr_k0, *addr_k1, *addr;
238 	u32 val, tap, upper, lower;
239 	int i, j, dir, err, done;
240 
241 	regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
242 			   MAP_NOCACHE);
243 
244 	/* Init memory pattern */
245 	addr = (void *)CKSEG0ADDR(0x2000);
246 	for (i = 0; i < 256; i++) {
247 		val = 0;
248 		for (j = 0; j < 8; j++) {
249 			if (i & (1 << j)) {
250 				if (j % 2)
251 					val |= 0xffff0000;
252 				else
253 					val |= 0x0000ffff;
254 			}
255 
256 			if (j % 2) {
257 				*addr++ = val;
258 				val = 0;
259 			}
260 		}
261 	}
262 
263 	err = 0;
264 	done = 0;
265 	dir = 1;
266 	tap = readl(regs + AR71XX_DDR_REG_TAP_CTRL0);
267 	val = tap;
268 	upper = tap;
269 	lower = tap;
270 	while (!done) {
271 		err = 0;
272 
273 		/* Update new DDR tap value */
274 		writel(val, regs + AR71XX_DDR_REG_TAP_CTRL0);
275 		writel(val, regs + AR71XX_DDR_REG_TAP_CTRL1);
276 
277 		/* Compare DDR with cache */
278 		for (i = 0; i < 2; i++) {
279 			addr_k1 = (void *)CKSEG1ADDR(0x2000);
280 			addr_k0 = (void *)CKSEG0ADDR(0x2000);
281 			addr = (void *)CKSEG0ADDR(0x3000);
282 
283 			while (addr_k0 < addr) {
284 				if (*addr_k1++ != *addr_k0++) {
285 					err = 1;
286 					break;
287 				}
288 			}
289 
290 			if (err)
291 				break;
292 		}
293 
294 		if (err) {
295 			/* Save upper/lower threshold if error  */
296 			if (dir) {
297 				dir = 0;
298 				val--;
299 				upper = val;
300 				val = tap;
301 			} else {
302 				val++;
303 				lower = val;
304 				done = 1;
305 			}
306 		} else {
307 			/* Try the next value until limitation */
308 			if (dir) {
309 				if (val < 0x20) {
310 					val++;
311 				} else {
312 					dir = 0;
313 					upper = val;
314 					val = tap;
315 				}
316 			} else {
317 				if (!val) {
318 					lower = val;
319 					done = 1;
320 				} else {
321 					val--;
322 				}
323 			}
324 		}
325 	}
326 
327 	/* compute an intermediate value and write back */
328 	val = (upper + lower) / 2;
329 	writel(val, regs + AR71XX_DDR_REG_TAP_CTRL0);
330 	val++;
331 	writel(val, regs + AR71XX_DDR_REG_TAP_CTRL1);
332 }
333