1 /*
2  * (C) Copyright 2000-2003
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * Copyright (C) 2004-2007, 2012 Freescale Semiconductor, Inc.
6  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <config.h>
12 #include <common.h>
13 #include <asm/immap.h>
14 #include <asm/io.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 int checkboard(void)
19 {
20 	puts("Board: ");
21 	puts("Freescale M5235 EVB\n");
22 	return 0;
23 };
24 
25 int dram_init(void)
26 {
27 	sdram_t *sdram = (sdram_t *)(MMAP_SDRAM);
28 	gpio_t *gpio = (gpio_t *)(MMAP_GPIO);
29 	u32 dramsize, i, dramclk;
30 
31 	/*
32 	 * When booting from external Flash, the port-size is less than
33 	 * the port-size of SDRAM.  In this case it is necessary to enable
34 	 * Data[15:0] on Port Address/Data.
35 	 */
36 	out_8(&gpio->par_ad,
37 		GPIO_PAR_AD_ADDR23 | GPIO_PAR_AD_ADDR22 | GPIO_PAR_AD_ADDR21 |
38 		GPIO_PAR_AD_DATAL);
39 
40 	/* Initialize PAR to enable SDRAM signals */
41 	out_8(&gpio->par_sdram,
42 		GPIO_PAR_SDRAM_SDWE | GPIO_PAR_SDRAM_SCAS |
43 		GPIO_PAR_SDRAM_SRAS | GPIO_PAR_SDRAM_SCKE |
44 		GPIO_PAR_SDRAM_SDCS(3));
45 
46 	dramsize = CONFIG_SYS_SDRAM_SIZE * 0x100000;
47 	for (i = 0x13; i < 0x20; i++) {
48 		if (dramsize == (1 << i))
49 			break;
50 	}
51 	i--;
52 
53 	if (!(in_be32(&sdram->dacr0) & SDRAMC_DARCn_RE)) {
54 		dramclk = gd->bus_clk / (CONFIG_SYS_HZ * CONFIG_SYS_HZ);
55 
56 		/* Initialize DRAM Control Register: DCR */
57 		out_be16(&sdram->dcr, SDRAMC_DCR_RTIM_9CLKS |
58 			SDRAMC_DCR_RTIM_6CLKS |
59 			SDRAMC_DCR_RC((15 * dramclk) >> 4));
60 
61 		/* Initialize DACR0 */
62 		out_be32(&sdram->dacr0,
63 			SDRAMC_DARCn_BA(CONFIG_SYS_SDRAM_BASE) |
64 			SDRAMC_DARCn_CASL_C1 | SDRAMC_DARCn_CBM_CMD20 |
65 			SDRAMC_DARCn_PS_32);
66 		asm("nop");
67 
68 		/* Initialize DMR0 */
69 		out_be32(&sdram->dmr0,
70 			((dramsize - 1) & 0xFFFC0000) | SDRAMC_DMRn_V);
71 		asm("nop");
72 
73 		/* Set IP (bit 3) in DACR */
74 		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_IP);
75 
76 		/* Wait 30ns to allow banks to precharge */
77 		for (i = 0; i < 5; i++) {
78 			asm("nop");
79 		}
80 
81 		/* Write to this block to initiate precharge */
82 		*(u32 *) (CONFIG_SYS_SDRAM_BASE) = 0xA5A59696;
83 
84 		/*  Set RE (bit 15) in DACR */
85 		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_RE);
86 
87 		/* Wait for at least 8 auto refresh cycles to occur */
88 		for (i = 0; i < 0x2000; i++) {
89 			asm("nop");
90 		}
91 
92 		/* Finish the configuration by issuing the MRS. */
93 		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_IMRS);
94 		asm("nop");
95 
96 		/* Write to the SDRAM Mode Register */
97 		*(u32 *) (CONFIG_SYS_SDRAM_BASE + 0x400) = 0xA5A59696;
98 	}
99 
100 	gd->ram_size = dramsize;
101 
102 	return 0;
103 };
104 
105 int testdram(void)
106 {
107 	/* TODO: XXX XXX XXX */
108 	printf("DRAM test not implemented!\n");
109 
110 	return (0);
111 }
112