xref: /openbmc/u-boot/arch/arm/mach-at91/mpddrc.c (revision 8f695232)
1 /*
2  * Copyright (C) 2013 Atmel Corporation
3  *		      Bo Shen <voice.shen@atmel.com>
4  *
5  * Copyright (C) 2015 Atmel Corporation
6  *		      Wenyou Yang <wenyou.yang@atmel.com>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <asm/io.h>
13 #include <asm/arch/atmel_mpddrc.h>
14 
15 #define SAMA5D3_MPDDRC_VERSION		0x140
16 
17 static inline void atmel_mpddr_op(const struct atmel_mpddr *mpddr,
18 	      int mode,
19 	      u32 ram_address)
20 {
21 	writel(mode, &mpddr->mr);
22 	writel(0, ram_address);
23 }
24 
25 static int ddr2_decodtype_is_seq(const unsigned int base, u32 cr)
26 {
27 	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
28 	u16 version = readl(&mpddr->version) & 0xffff;
29 
30 	if ((version >= SAMA5D3_MPDDRC_VERSION) &&
31 	    (cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED))
32 		return 0;
33 
34 	return 1;
35 }
36 
37 
38 int ddr2_init(const unsigned int base,
39 	      const unsigned int ram_address,
40 	      const struct atmel_mpddrc_config *mpddr_value)
41 {
42 	const struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
43 
44 	u32 ba_off, cr;
45 
46 	/* Compute bank offset according to NC in configuration register */
47 	ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
48 	if (ddr2_decodtype_is_seq(base, mpddr_value->cr))
49 		ba_off += ((mpddr_value->cr & ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;
50 
51 	ba_off += (mpddr_value->md & ATMEL_MPDDRC_MD_DBW_MASK) ? 1 : 2;
52 
53 	/* Program the memory device type into the memory device register */
54 	writel(mpddr_value->md, &mpddr->md);
55 
56 	/* Program the configuration register */
57 	writel(mpddr_value->cr, &mpddr->cr);
58 
59 	/* Program the timing register */
60 	writel(mpddr_value->tpr0, &mpddr->tpr0);
61 	writel(mpddr_value->tpr1, &mpddr->tpr1);
62 	writel(mpddr_value->tpr2, &mpddr->tpr2);
63 
64 	/* Issue a NOP command */
65 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
66 
67 	/* A 200 us is provided to precede any signal toggle */
68 	udelay(200);
69 
70 	/* Issue a NOP command */
71 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
72 
73 	/* Issue an all banks precharge command */
74 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
75 
76 	/* Issue an extended mode register set(EMRS2) to choose operation */
77 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
78 		       ram_address + (0x2 << ba_off));
79 
80 	/* Issue an extended mode register set(EMRS3) to set EMSR to 0 */
81 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
82 		       ram_address + (0x3 << ba_off));
83 
84 	/*
85 	 * Issue an extended mode register set(EMRS1) to enable DLL and
86 	 * program D.I.C (output driver impedance control)
87 	 */
88 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
89 		       ram_address + (0x1 << ba_off));
90 
91 	/* Enable DLL reset */
92 	cr = readl(&mpddr->cr);
93 	writel(cr | ATMEL_MPDDRC_CR_DLL_RESET_ENABLED, &mpddr->cr);
94 
95 	/* A mode register set(MRS) cycle is issued to reset DLL */
96 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
97 
98 	/* Issue an all banks precharge command */
99 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
100 
101 	/* Two auto-refresh (CBR) cycles are provided */
102 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
103 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
104 
105 	/* Disable DLL reset */
106 	cr = readl(&mpddr->cr);
107 	writel(cr & (~ATMEL_MPDDRC_CR_DLL_RESET_ENABLED), &mpddr->cr);
108 
109 	/* A mode register set (MRS) cycle is issued to disable DLL reset */
110 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
111 
112 	/* Set OCD calibration in default state */
113 	cr = readl(&mpddr->cr);
114 	writel(cr | ATMEL_MPDDRC_CR_OCD_DEFAULT, &mpddr->cr);
115 
116 	/*
117 	 * An extended mode register set (EMRS1) cycle is issued
118 	 * to OCD default value
119 	 */
120 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
121 		       ram_address + (0x1 << ba_off));
122 
123 	 /* OCD calibration mode exit */
124 	cr = readl(&mpddr->cr);
125 	writel(cr & (~ATMEL_MPDDRC_CR_OCD_DEFAULT), &mpddr->cr);
126 
127 	/*
128 	 * An extended mode register set (EMRS1) cycle is issued
129 	 * to enable OCD exit
130 	 */
131 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
132 		       ram_address + (0x1 << ba_off));
133 
134 	/* A nornal mode command is provided */
135 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
136 
137 	/* Perform a write access to any DDR2-SDRAM address */
138 	writel(0, ram_address);
139 
140 	/* Write the refresh rate */
141 	writel(mpddr_value->rtr, &mpddr->rtr);
142 
143 	return 0;
144 }
145 
146 int ddr3_init(const unsigned int base,
147 	      const unsigned int ram_address,
148 	      const struct atmel_mpddrc_config *mpddr_value)
149 {
150 	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
151 	u32 ba_off;
152 
153 	/* Compute bank offset according to NC in configuration register */
154 	ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
155 	if (ddr2_decodtype_is_seq(base, mpddr_value->cr))
156 		ba_off += ((mpddr_value->cr &
157 			   ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;
158 
159 	ba_off += (mpddr_value->md & ATMEL_MPDDRC_MD_DBW_MASK) ? 1 : 2;
160 
161 	/* Program the memory device type */
162 	writel(mpddr_value->md, &mpddr->md);
163 
164 	/*
165 	 * Program features of the DDR3-SDRAM device and timing parameters
166 	 */
167 	writel(mpddr_value->cr, &mpddr->cr);
168 
169 	writel(mpddr_value->tpr0, &mpddr->tpr0);
170 	writel(mpddr_value->tpr1, &mpddr->tpr1);
171 	writel(mpddr_value->tpr2, &mpddr->tpr2);
172 
173 	/* A NOP command is issued to the DDR3-SRAM */
174 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
175 
176 	/* A pause of at least 500us must be observed before a single toggle. */
177 	udelay(500);
178 
179 	/* A NOP command is issued to the DDR3-SDRAM */
180 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
181 
182 	/*
183 	 * An Extended Mode Register Set (EMRS2) cycle is issued to choose
184 	 * between commercial or high temperature operations.
185 	 */
186 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
187 		       ram_address + (0x2 << ba_off));
188 	/*
189 	 * Step 7: An Extended Mode Register Set (EMRS3) cycle is issued to set
190 	 * the Extended Mode Register to 0.
191 	 */
192 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
193 		       ram_address + (0x3 << ba_off));
194 	/*
195 	 * An Extended Mode Register Set (EMRS1) cycle is issued to disable and
196 	 * to program O.D.S. (Output Driver Strength).
197 	 */
198 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
199 		       ram_address + (0x1 << ba_off));
200 
201 	/*
202 	 * Write a one to the DLL bit (enable DLL reset) in the MPDDRC
203 	 * Configuration Register.
204 	 */
205 
206 	/* A Mode Register Set (MRS) cycle is issued to reset DLL. */
207 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
208 
209 	udelay(50);
210 
211 	/*
212 	 * A Calibration command (MRS) is issued to calibrate RTT and RON
213 	 * values for the Process Voltage Temperature (PVT).
214 	 */
215 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_DEEP_CMD, ram_address);
216 
217 	/* A Normal Mode command is provided. */
218 	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
219 
220 	/* Perform a write access to any DDR3-SDRAM address. */
221 	writel(0, ram_address);
222 
223 	/*
224 	 * Write the refresh rate into the COUNT field in the MPDDRC
225 	 * Refresh Timer Register (MPDDRC_RTR):
226 	 */
227 	writel(mpddr_value->rtr, &mpddr->rtr);
228 
229 	return 0;
230 }
231