summaryrefslogtreecommitdiff
path: root/cpu/bf533/init_sdram.S
blob: 1aae9e30f96b95fa36a073383a2150826b51463f (plain)
1
2
3
4
5
6
7
8
9
10
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
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
#define ASSEMBLY

#include <linux/config.h>
#include <config.h>
#include <asm/blackfin.h>
#include <asm/mem_init.h>
.global init_sdram;

#if (CONFIG_CCLK_DIV == 1)
#define CONFIG_CCLK_ACT_DIV   CCLK_DIV1
#endif
#if (CONFIG_CCLK_DIV == 2)
#define CONFIG_CCLK_ACT_DIV   CCLK_DIV2
#endif
#if (CONFIG_CCLK_DIV == 4)
#define CONFIG_CCLK_ACT_DIV   CCLK_DIV4
#endif
#if (CONFIG_CCLK_DIV == 8)
#define CONFIG_CCLK_ACT_DIV   CCLK_DIV8
#endif
#ifndef CONFIG_CCLK_ACT_DIV
#define CONFIG_CCLK_ACT_DIV   CONFIG_CCLK_DIV_not_defined_properly
#endif

init_sdram:
	[--SP] = ASTAT;
	[--SP] = RETS;
	[--SP] = (R7:0);
	[--SP] = (P5:0);

#if (BFIN_BOOT_MODE == BF533_SPI_BOOT)
	p0.h = hi(SPI_BAUD);
	p0.l = lo(SPI_BAUD);
	r0.l = CONFIG_SPI_BAUD;
	w[p0] = r0.l;
	SSYNC;
#endif

	/*
	 * PLL_LOCKCNT - how many SCLK Cycles to delay while PLL becomes stable
	 */
	p0.h = hi(PLL_LOCKCNT);
	p0.l = lo(PLL_LOCKCNT);
	r0 = 0x300(Z);
	w[p0] = r0.l;
	ssync;

	/*
	 * Put SDRAM in self-refresh, incase anything is running
	 */
	P2.H = hi(EBIU_SDGCTL);
	P2.L = lo(EBIU_SDGCTL);
	R0 = [P2];
	BITSET (R0, 24);
	[P2] = R0;
	SSYNC;

	/*
	 *  Set PLL_CTL with the value that we calculate in R0
	 *   - [14:09] = MSEL[5:0] : CLKIN / VCO multiplication factors
	 *   - [8]     = BYPASS    : BYPASS the PLL, run CLKIN into CCLK/SCLK
	 *   - [7]     = output delay (add 200ps of delay to mem signals)
	 *   - [6]     = input delay (add 200ps of input delay to mem signals)
	 *   - [5]     = PDWN      : 1=All Clocks off
	 *   - [3]     = STOPCK    : 1=Core Clock off
	 *   - [1]     = PLL_OFF   : 1=Disable Power to PLL
	 *   - [0]     = DF        : 1=Pass CLKIN/2 to PLL / 0=Pass CLKIN to PLL
	 *   all other bits set to zero
	 */

	r0 = CONFIG_VCO_MULT & 63;	/* Load the VCO multiplier         */
	r0 = r0 << 9;			/* Shift it over,                  */
	r1 = CONFIG_CLKIN_HALF;		/* Do we need to divide CLKIN by 2?*/
	r0 = r1 | r0;
	r1 = CONFIG_PLL_BYPASS;		/* Bypass the PLL?                 */
	r1 = r1 << 8;			/* Shift it over                   */
	r0 = r1 | r0;			/* add them all together           */

	p0.h = hi(PLL_CTL);
	p0.l = lo(PLL_CTL);		/* Load the address                */
	cli r2;				/* Disable interrupts              */
	ssync;
	w[p0] = r0.l;			/* Set the value                   */
	idle;				/* Wait for the PLL to stablize    */
	sti r2;				/* Enable interrupts               */

check_again:
	p0.h = hi(PLL_STAT);
	p0.l = lo(PLL_STAT);
	R0 = W[P0](Z);
	CC = BITTST(R0,5);
	if ! CC jump check_again;

	/* Configure SCLK & CCLK Dividers */
	r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
	p0.h = hi(PLL_DIV);
	p0.l = lo(PLL_DIV);
	w[p0] = r0.l;
	ssync;

	/*
	 * We now are running at speed, time to set the Async mem bank wait states
	 * This will speed up execution, since we are normally running from FLASH.
	 */

	p2.h = (EBIU_AMBCTL1 >> 16);
	p2.l = (EBIU_AMBCTL1 & 0xFFFF);
	r0.h = (AMBCTL1VAL >> 16);
	r0.l = (AMBCTL1VAL & 0xFFFF);
	[p2] = r0;
	ssync;
	
	p2.h = (EBIU_AMBCTL0 >> 16);
	p2.l = (EBIU_AMBCTL0 & 0xFFFF);
	r0.h = (AMBCTL0VAL >> 16);
	r0.l = (AMBCTL0VAL & 0xFFFF);
	[p2] = r0;
	ssync;
	
	p2.h = (EBIU_AMGCTL >> 16);
	p2.l = (EBIU_AMGCTL & 0xffff);
	r0 = AMGCTLVAL;
	w[p2] = r0;
	ssync;

	/*
	 * Now, Initialize the SDRAM,
	 * start with the SDRAM Refresh Rate Control Register
	 */
	p0.l = lo(EBIU_SDRRC);
	p0.h = hi(EBIU_SDRRC);
	r0 = mem_SDRRC;
	w[p0] = r0.l;
	ssync;

	/*
	 * SDRAM Memory Bank Control Register - bank specific parameters
	 */
	p0.l = (EBIU_SDBCTL & 0xFFFF);
	p0.h = (EBIU_SDBCTL >> 16);
	r0 = mem_SDBCTL;
	w[p0] = r0.l;
	ssync;

	/*
	 * SDRAM Global Control Register - global programmable parameters
	 * Disable self-refresh
	 */
	P2.H = hi(EBIU_SDGCTL);
	P2.L = lo(EBIU_SDGCTL);
	R0 = [P2];
	BITCLR (R0, 24);

	/*
	 * Check if SDRAM is already powered up, if it is, enable self-refresh
	 */
	p0.h = hi(EBIU_SDSTAT);
	p0.l = lo(EBIU_SDSTAT);
	r2.l = w[p0];
	cc = bittst(r2,3);
	if !cc jump skip;
	NOP;
	BITSET (R0, 23);
skip:
	[P2] = R0;
	SSYNC;

	/* Write in the new value in the register */
	R0.L = lo(mem_SDGCTL);
	R0.H = hi(mem_SDGCTL);
	[P2] = R0;
	SSYNC;
	nop;

	(P5:0) = [SP++];
	(R7:0) = [SP++];
	RETS   = [SP++];
	ASTAT  = [SP++];
	RTS;