2 * Copyright (C) 2013 Atmel Corporation
3 * Bo Shen <voice.shen@atmel.com>
5 * SPDX-License-Identifier: GPL-2.0+
10 #include <asm/arch/atmel_mpddrc.h>
12 static inline void atmel_mpddr_op(int mode, u32 ram_address)
14 struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
16 writel(mode, &mpddr->mr);
17 writel(0, ram_address);
20 static int ddr2_decodtype_is_seq(u32 cr)
22 #if defined(CONFIG_SAMA5D3) || defined(CONFIG_SAMA5D4) || \
23 defined(CONFIG_AT91SAM9X5)
24 if (cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED)
30 int ddr2_init(const unsigned int ram_address,
31 const struct atmel_mpddr *mpddr_value)
33 struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
36 /* Compute bank offset according to NC in configuration register */
37 ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
38 if (ddr2_decodtype_is_seq(mpddr_value->cr))
39 ba_off += ((mpddr_value->cr & ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;
41 ba_off += (mpddr_value->md & ATMEL_MPDDRC_MD_DBW_MASK) ? 1 : 2;
43 /* Program the memory device type into the memory device register */
44 writel(mpddr_value->md, &mpddr->md);
46 /* Program the configuration register */
47 writel(mpddr_value->cr, &mpddr->cr);
49 /* Program the timing register */
50 writel(mpddr_value->tpr0, &mpddr->tpr0);
51 writel(mpddr_value->tpr1, &mpddr->tpr1);
52 writel(mpddr_value->tpr2, &mpddr->tpr2);
54 /* Issue a NOP command */
55 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
57 /* A 200 us is provided to precede any signal toggle */
60 /* Issue a NOP command */
61 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
63 /* Issue an all banks precharge command */
64 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
66 /* Issue an extended mode register set(EMRS2) to choose operation */
67 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
68 ram_address + (0x2 << ba_off));
70 /* Issue an extended mode register set(EMRS3) to set EMSR to 0 */
71 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
72 ram_address + (0x3 << ba_off));
75 * Issue an extended mode register set(EMRS1) to enable DLL and
76 * program D.I.C (output driver impedance control)
78 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
79 ram_address + (0x1 << ba_off));
81 /* Enable DLL reset */
82 cr = readl(&mpddr->cr);
83 writel(cr | ATMEL_MPDDRC_CR_DLL_RESET_ENABLED, &mpddr->cr);
85 /* A mode register set(MRS) cycle is issued to reset DLL */
86 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
88 /* Issue an all banks precharge command */
89 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
91 /* Two auto-refresh (CBR) cycles are provided */
92 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
93 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
95 /* Disable DLL reset */
96 cr = readl(&mpddr->cr);
97 writel(cr & (~ATMEL_MPDDRC_CR_DLL_RESET_ENABLED), &mpddr->cr);
99 /* A mode register set (MRS) cycle is issued to disable DLL reset */
100 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
102 /* Set OCD calibration in default state */
103 cr = readl(&mpddr->cr);
104 writel(cr | ATMEL_MPDDRC_CR_OCD_DEFAULT, &mpddr->cr);
107 * An extended mode register set (EMRS1) cycle is issued
108 * to OCD default value
110 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
111 ram_address + (0x1 << ba_off));
113 /* OCD calibration mode exit */
114 cr = readl(&mpddr->cr);
115 writel(cr & (~ATMEL_MPDDRC_CR_OCD_DEFAULT), &mpddr->cr);
118 * An extended mode register set (EMRS1) cycle is issued
121 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
122 ram_address + (0x1 << ba_off));
124 /* A nornal mode command is provided */
125 atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
127 /* Perform a write access to any DDR2-SDRAM address */
128 writel(0, ram_address);
130 /* Write the refresh rate */
131 writel(mpddr_value->rtr, &mpddr->rtr);