Newer
Older
/*
* (C) Copyright 2017
* Vikas Manocha, <vikas.manocha@st.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <ram.h>
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
#include <asm/io.h>
#include <asm/arch/fmc.h>
#include <asm/arch/stm32.h>
static inline u32 _ns2clk(u32 ns, u32 freq)
{
u32 tmp = freq/1000000;
return (tmp * ns) / 1000;
}
#define NS2CLK(ns) (_ns2clk(ns, freq))
/*
* Following are timings for IS42S16400J, from corresponding datasheet
*/
#define SDRAM_CAS 3 /* 3 cycles */
#define SDRAM_NB 1 /* Number of banks */
#define SDRAM_MWID 1 /* 16 bit memory */
#define SDRAM_NR 0x1 /* 12-bit row */
#define SDRAM_NC 0x0 /* 8-bit col */
#define SDRAM_RBURST 0x1 /* Single read requests always as bursts */
#define SDRAM_RPIPE 0x0 /* No HCLK clock cycle delay */
#define SDRAM_TRRD NS2CLK(12)
#define SDRAM_TRCD NS2CLK(18)
#define SDRAM_TRP NS2CLK(18)
#define SDRAM_TRAS NS2CLK(42)
#define SDRAM_TRC NS2CLK(60)
#define SDRAM_TRFC NS2CLK(60)
#define SDRAM_TCDL (1 - 1)
#define SDRAM_TRDL NS2CLK(12)
#define SDRAM_TBDL (1 - 1)
#define SDRAM_TREF (NS2CLK(64000000 / 8192) - 20)
#define SDRAM_TCCD (1 - 1)
#define SDRAM_TXSR SDRAM_TRFC /* Row cycle time after precharge */
#define SDRAM_TMRD 1 /* Page 10, Mode Register Set */
/* Last data in to row precharge, need also comply ineq on page 1648 */
#define SDRAM_TWR max(\
(int)max((int)SDRAM_TRDL, (int)(SDRAM_TRAS - SDRAM_TRCD)), \
(int)(SDRAM_TRC - SDRAM_TRCD - SDRAM_TRP)\
)
#define SDRAM_MODE_BL_SHIFT 0
#define SDRAM_MODE_CAS_SHIFT 4
#define SDRAM_MODE_BL 0
#define SDRAM_MODE_CAS SDRAM_CAS
int stm32_sdram_init(void)
{
u32 freq;
/*
* Get frequency for NS2CLK calculation.
*/
freq = clock_get(CLOCK_AHB) / CONFIG_SYS_RAM_FREQ_DIV;
writel(CONFIG_SYS_RAM_FREQ_DIV << FMC_SDCR_SDCLK_SHIFT
| SDRAM_CAS << FMC_SDCR_CAS_SHIFT
| SDRAM_NB << FMC_SDCR_NB_SHIFT
| SDRAM_MWID << FMC_SDCR_MWID_SHIFT
| SDRAM_NR << FMC_SDCR_NR_SHIFT
| SDRAM_NC << FMC_SDCR_NC_SHIFT
| SDRAM_RPIPE << FMC_SDCR_RPIPE_SHIFT
| SDRAM_RBURST << FMC_SDCR_RBURST_SHIFT,
&STM32_SDRAM_FMC->sdcr1);
writel(SDRAM_TRCD << FMC_SDTR_TRCD_SHIFT
| SDRAM_TRP << FMC_SDTR_TRP_SHIFT
| SDRAM_TWR << FMC_SDTR_TWR_SHIFT
| SDRAM_TRC << FMC_SDTR_TRC_SHIFT
| SDRAM_TRAS << FMC_SDTR_TRAS_SHIFT
| SDRAM_TXSR << FMC_SDTR_TXSR_SHIFT
| SDRAM_TMRD << FMC_SDTR_TMRD_SHIFT,
&STM32_SDRAM_FMC->sdtr1);
writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_START_CLOCK,
&STM32_SDRAM_FMC->sdcmr);
udelay(200); /* 200 us delay, page 10, "Power-Up" */
FMC_BUSY_WAIT();
writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_PRECHARGE,
&STM32_SDRAM_FMC->sdcmr);
udelay(100);
FMC_BUSY_WAIT();
writel((FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_AUTOREFRESH
| 7 << FMC_SDCMR_NRFS_SHIFT), &STM32_SDRAM_FMC->sdcmr);
udelay(100);
FMC_BUSY_WAIT();
writel(FMC_SDCMR_BANK_1 | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
| SDRAM_MODE_CAS << SDRAM_MODE_CAS_SHIFT)
<< FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
&STM32_SDRAM_FMC->sdcmr);
udelay(100);
FMC_BUSY_WAIT();
writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_NORMAL,
&STM32_SDRAM_FMC->sdcmr);
FMC_BUSY_WAIT();
/* Refresh timer */
writel(SDRAM_TREF, &STM32_SDRAM_FMC->sdrtr);
return 0;
}
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
static int stm32_fmc_probe(struct udevice *dev)
{
stm32_sdram_init();
return 0;
}
static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
{
info->size = CONFIG_SYS_RAM_SIZE;
return 0;
}
static struct ram_ops stm32_fmc_ops = {
.get_info = stm32_fmc_get_info,
};
static const struct udevice_id stm32_fmc_ids[] = {
{ .compatible = "st,stm32-fmc" },
{ }
};
U_BOOT_DRIVER(stm32_fmc) = {
.name = "stm32_fmc",
.id = UCLASS_RAM,
.of_match = stm32_fmc_ids,
.ops = &stm32_fmc_ops,
.probe = stm32_fmc_probe,
};