xref: /linux/arch/arm/mach-omap2/sdrc.c (revision 9a87ffc99ec8eb8d35eed7c4f816d75f5cc9662e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SMS/SDRC (SDRAM controller) common code for OMAP2/3
4  *
5  * Copyright (C) 2005, 2008 Texas Instruments Inc.
6  * Copyright (C) 2005, 2008 Nokia Corporation
7  *
8  * Tony Lindgren <tony@atomide.com>
9  * Paul Walmsley
10  * Richard Woodruff <r-woodruff2@ti.com>
11  */
12 #undef DEBUG
13 
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/device.h>
17 #include <linux/list.h>
18 #include <linux/errno.h>
19 #include <linux/delay.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 
23 #include "common.h"
24 #include "clock.h"
25 #include "sdrc.h"
26 
27 static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;
28 
29 void __iomem *omap2_sdrc_base;
30 void __iomem *omap2_sms_base;
31 
32 struct omap2_sms_regs {
33 	u32	sms_sysconfig;
34 };
35 
36 static struct omap2_sms_regs sms_context;
37 
38 /* SDRC_POWER register bits */
39 #define SDRC_POWER_EXTCLKDIS_SHIFT		3
40 #define SDRC_POWER_PWDENA_SHIFT			2
41 #define SDRC_POWER_PAGEPOLICY_SHIFT		0
42 
43 /**
44  * omap2_sms_save_context - Save SMS registers
45  *
46  * Save SMS registers that need to be restored after off mode.
47  */
omap2_sms_save_context(void)48 static void omap2_sms_save_context(void)
49 {
50 	sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
51 }
52 
53 /**
54  * omap2_sms_restore_context - Restore SMS registers
55  *
56  * Restore SMS registers that need to be Restored after off mode.
57  */
omap2_sms_restore_context(void)58 void omap2_sms_restore_context(void)
59 {
60 	sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
61 }
62 
omap2_set_globals_sdrc(void __iomem * sdrc,void __iomem * sms)63 void __init omap2_set_globals_sdrc(void __iomem *sdrc, void __iomem *sms)
64 {
65 	omap2_sdrc_base = sdrc;
66 	omap2_sms_base = sms;
67 }
68 
69 /**
70  * omap2_sdrc_init - initialize SMS, SDRC devices on boot
71  * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
72  *  Support for 2 chip selects timings
73  *
74  * Turn on smart idle modes for SDRAM scheduler and controller.
75  * Program a known-good configuration for the SDRC to deal with buggy
76  * bootloaders.
77  */
omap2_sdrc_init(struct omap_sdrc_params * sdrc_cs0,struct omap_sdrc_params * sdrc_cs1)78 void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
79 			    struct omap_sdrc_params *sdrc_cs1)
80 {
81 	u32 l;
82 
83 	l = sms_read_reg(SMS_SYSCONFIG);
84 	l &= ~(0x3 << 3);
85 	l |= (0x2 << 3);
86 	sms_write_reg(l, SMS_SYSCONFIG);
87 
88 	l = sdrc_read_reg(SDRC_SYSCONFIG);
89 	l &= ~(0x3 << 3);
90 	l |= (0x2 << 3);
91 	sdrc_write_reg(l, SDRC_SYSCONFIG);
92 
93 	sdrc_init_params_cs0 = sdrc_cs0;
94 	sdrc_init_params_cs1 = sdrc_cs1;
95 
96 	/* XXX Enable SRFRONIDLEREQ here also? */
97 	/*
98 	 * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
99 	 * can cause random memory corruption
100 	 */
101 	l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
102 		(1 << SDRC_POWER_PAGEPOLICY_SHIFT);
103 	sdrc_write_reg(l, SDRC_POWER);
104 	omap2_sms_save_context();
105 }
106