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 */
48 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 */
58 void omap2_sms_restore_context(void)
59 {
60 sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
61 }
62
63 /**
64 * omap2_sdrc_get_params - return SDRC register values for a given clock rate
65 * @r: SDRC clock rate (in Hz)
66 * @sdrc_cs0: chip select 0 ram timings **
67 * @sdrc_cs1: chip select 1 ram timings **
68 *
69 * Return pre-calculated values for the SDRC_ACTIM_CTRLA,
70 * SDRC_ACTIM_CTRLB, SDRC_RFR_CTRL and SDRC_MR registers in sdrc_cs[01]
71 * structs,for a given SDRC clock rate 'r'.
72 * These parameters control various timing delays in the SDRAM controller
73 * that are expressed in terms of the number of SDRC clock cycles to
74 * wait; hence the clock rate dependency.
75 *
76 * Supports 2 different timing parameters for both chip selects.
77 *
78 * Note 1: the sdrc_init_params_cs[01] must be sorted rate descending.
79 * Note 2: If sdrc_init_params_cs_1 is not NULL it must be of same size
80 * as sdrc_init_params_cs_0.
81 *
82 * Fills in the struct omap_sdrc_params * for each chip select.
83 * Returns 0 upon success or -1 upon failure.
84 */
85 int omap2_sdrc_get_params(unsigned long r,
86 struct omap_sdrc_params **sdrc_cs0,
87 struct omap_sdrc_params **sdrc_cs1)
88 {
89 struct omap_sdrc_params *sp0, *sp1;
90
91 if (!sdrc_init_params_cs0)
92 return -1;
93
94 sp0 = sdrc_init_params_cs0;
95 sp1 = sdrc_init_params_cs1;
96
97 while (sp0->rate && sp0->rate != r) {
98 sp0++;
99 if (sdrc_init_params_cs1)
100 sp1++;
101 }
102
103 if (!sp0->rate)
104 return -1;
105
106 *sdrc_cs0 = sp0;
107 *sdrc_cs1 = sp1;
108 return 0;
109 }
110
111
112 void __init omap2_set_globals_sdrc(void __iomem *sdrc, void __iomem *sms)
113 {
114 omap2_sdrc_base = sdrc;
115 omap2_sms_base = sms;
116 }
117
118 /**
119 * omap2_sdrc_init - initialize SMS, SDRC devices on boot
120 * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
121 * Support for 2 chip selects timings
122 *
123 * Turn on smart idle modes for SDRAM scheduler and controller.
124 * Program a known-good configuration for the SDRC to deal with buggy
125 * bootloaders.
126 */
127 void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
128 struct omap_sdrc_params *sdrc_cs1)
129 {
130 u32 l;
131
132 l = sms_read_reg(SMS_SYSCONFIG);
133 l &= ~(0x3 << 3);
134 l |= (0x2 << 3);
135 sms_write_reg(l, SMS_SYSCONFIG);
136
137 l = sdrc_read_reg(SDRC_SYSCONFIG);
138 l &= ~(0x3 << 3);
139 l |= (0x2 << 3);
140 sdrc_write_reg(l, SDRC_SYSCONFIG);
141
142 sdrc_init_params_cs0 = sdrc_cs0;
143 sdrc_init_params_cs1 = sdrc_cs1;
144
145 /* XXX Enable SRFRONIDLEREQ here also? */
146 /*
147 * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
148 * can cause random memory corruption
149 */
150 l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
151 (1 << SDRC_POWER_PAGEPOLICY_SHIFT);
152 sdrc_write_reg(l, SDRC_POWER);
153 omap2_sms_save_context();
154 }