xref: /openbmc/linux/arch/arm/mach-omap2/sdrc.c (revision 615c36f5)
1 /*
2  * SMS/SDRC (SDRAM controller) common code for OMAP2/3
3  *
4  * Copyright (C) 2005, 2008 Texas Instruments Inc.
5  * Copyright (C) 2005, 2008 Nokia Corporation
6  *
7  * Tony Lindgren <tony@atomide.com>
8  * Paul Walmsley
9  * Richard Woodruff <r-woodruff2@ti.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 #undef DEBUG
16 
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/list.h>
21 #include <linux/errno.h>
22 #include <linux/delay.h>
23 #include <linux/clk.h>
24 #include <linux/io.h>
25 
26 #include <plat/common.h>
27 #include <plat/clock.h>
28 #include <plat/sram.h>
29 
30 #include <plat/sdrc.h>
31 #include "sdrc.h"
32 
33 static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;
34 
35 void __iomem *omap2_sdrc_base;
36 void __iomem *omap2_sms_base;
37 
38 struct omap2_sms_regs {
39 	u32	sms_sysconfig;
40 };
41 
42 static struct omap2_sms_regs sms_context;
43 
44 /* SDRC_POWER register bits */
45 #define SDRC_POWER_EXTCLKDIS_SHIFT		3
46 #define SDRC_POWER_PWDENA_SHIFT			2
47 #define SDRC_POWER_PAGEPOLICY_SHIFT		0
48 
49 /**
50  * omap2_sms_save_context - Save SMS registers
51  *
52  * Save SMS registers that need to be restored after off mode.
53  */
54 void omap2_sms_save_context(void)
55 {
56 	sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
57 }
58 
59 /**
60  * omap2_sms_restore_context - Restore SMS registers
61  *
62  * Restore SMS registers that need to be Restored after off mode.
63  */
64 void omap2_sms_restore_context(void)
65 {
66 	sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
67 }
68 
69 /**
70  * omap2_sdrc_get_params - return SDRC register values for a given clock rate
71  * @r: SDRC clock rate (in Hz)
72  * @sdrc_cs0: chip select 0 ram timings **
73  * @sdrc_cs1: chip select 1 ram timings **
74  *
75  * Return pre-calculated values for the SDRC_ACTIM_CTRLA,
76  *  SDRC_ACTIM_CTRLB, SDRC_RFR_CTRL and SDRC_MR registers in sdrc_cs[01]
77  *  structs,for a given SDRC clock rate 'r'.
78  * These parameters control various timing delays in the SDRAM controller
79  *  that are expressed in terms of the number of SDRC clock cycles to
80  *  wait; hence the clock rate dependency.
81  *
82  * Supports 2 different timing parameters for both chip selects.
83  *
84  * Note 1: the sdrc_init_params_cs[01] must be sorted rate descending.
85  * Note 2: If sdrc_init_params_cs_1 is not NULL it must be of same size
86  *  as sdrc_init_params_cs_0.
87  *
88  * Fills in the struct omap_sdrc_params * for each chip select.
89  * Returns 0 upon success or -1 upon failure.
90  */
91 int omap2_sdrc_get_params(unsigned long r,
92 			  struct omap_sdrc_params **sdrc_cs0,
93 			  struct omap_sdrc_params **sdrc_cs1)
94 {
95 	struct omap_sdrc_params *sp0, *sp1;
96 
97 	if (!sdrc_init_params_cs0)
98 		return -1;
99 
100 	sp0 = sdrc_init_params_cs0;
101 	sp1 = sdrc_init_params_cs1;
102 
103 	while (sp0->rate && sp0->rate != r) {
104 		sp0++;
105 		if (sdrc_init_params_cs1)
106 			sp1++;
107 	}
108 
109 	if (!sp0->rate)
110 		return -1;
111 
112 	*sdrc_cs0 = sp0;
113 	*sdrc_cs1 = sp1;
114 	return 0;
115 }
116 
117 
118 void __init omap2_set_globals_sdrc(struct omap_globals *omap2_globals)
119 {
120 	if (omap2_globals->sdrc)
121 		omap2_sdrc_base = omap2_globals->sdrc;
122 	if (omap2_globals->sms)
123 		omap2_sms_base = omap2_globals->sms;
124 }
125 
126 /**
127  * omap2_sdrc_init - initialize SMS, SDRC devices on boot
128  * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
129  *  Support for 2 chip selects timings
130  *
131  * Turn on smart idle modes for SDRAM scheduler and controller.
132  * Program a known-good configuration for the SDRC to deal with buggy
133  * bootloaders.
134  */
135 void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
136 			    struct omap_sdrc_params *sdrc_cs1)
137 {
138 	u32 l;
139 
140 	l = sms_read_reg(SMS_SYSCONFIG);
141 	l &= ~(0x3 << 3);
142 	l |= (0x2 << 3);
143 	sms_write_reg(l, SMS_SYSCONFIG);
144 
145 	l = sdrc_read_reg(SDRC_SYSCONFIG);
146 	l &= ~(0x3 << 3);
147 	l |= (0x2 << 3);
148 	sdrc_write_reg(l, SDRC_SYSCONFIG);
149 
150 	sdrc_init_params_cs0 = sdrc_cs0;
151 	sdrc_init_params_cs1 = sdrc_cs1;
152 
153 	/* XXX Enable SRFRONIDLEREQ here also? */
154 	/*
155 	 * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
156 	 * can cause random memory corruption
157 	 */
158 	l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
159 		(1 << SDRC_POWER_PAGEPOLICY_SHIFT);
160 	sdrc_write_reg(l, SDRC_POWER);
161 	omap2_sms_save_context();
162 }
163 
164 void omap2_sms_write_rot_control(u32 val, unsigned ctx)
165 {
166 	sms_write_reg(val, SMS_ROT_CONTROL(ctx));
167 }
168 
169 void omap2_sms_write_rot_size(u32 val, unsigned ctx)
170 {
171 	sms_write_reg(val, SMS_ROT_SIZE(ctx));
172 }
173 
174 void omap2_sms_write_rot_physical_ba(u32 val, unsigned ctx)
175 {
176 	sms_write_reg(val, SMS_ROT_PHYSICAL_BA(ctx));
177 }
178 
179