1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mach-omap2/sdrc2xxx.c
4 *
5 * SDRAM timing related functions for OMAP2xxx
6 *
7 * Copyright (C) 2005, 2008 Texas Instruments Inc.
8 * Copyright (C) 2005, 2008 Nokia Corporation
9 *
10 * Tony Lindgren <tony@atomide.com>
11 * Paul Walmsley
12 * Richard Woodruff <r-woodruff2@ti.com>
13 */
14
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/device.h>
18 #include <linux/list.h>
19 #include <linux/errno.h>
20 #include <linux/delay.h>
21 #include <linux/clk.h>
22 #include <linux/io.h>
23
24 #include "soc.h"
25 #include "iomap.h"
26 #include "common.h"
27 #include "prm2xxx.h"
28 #include "clock.h"
29 #include "sdrc.h"
30 #include "sram.h"
31
32 /* Memory timing, DLL mode flags */
33 #define M_DDR 1
34 #define M_LOCK_CTRL (1 << 2)
35 #define M_UNLOCK 0
36 #define M_LOCK 1
37
38
39 static struct memory_timings mem_timings;
40 static u32 curr_perf_level = CORE_CLK_SRC_DPLL_X2;
41
omap2xxx_sdrc_get_slow_dll_ctrl(void)42 static u32 omap2xxx_sdrc_get_slow_dll_ctrl(void)
43 {
44 return mem_timings.slow_dll_ctrl;
45 }
46
omap2xxx_sdrc_get_fast_dll_ctrl(void)47 static u32 omap2xxx_sdrc_get_fast_dll_ctrl(void)
48 {
49 return mem_timings.fast_dll_ctrl;
50 }
51
omap2xxx_sdrc_get_type(void)52 static u32 omap2xxx_sdrc_get_type(void)
53 {
54 return mem_timings.m_type;
55 }
56
57 /*
58 * Check the DLL lock state, and return tue if running in unlock mode.
59 * This is needed to compensate for the shifted DLL value in unlock mode.
60 */
omap2xxx_sdrc_dll_is_unlocked(void)61 u32 omap2xxx_sdrc_dll_is_unlocked(void)
62 {
63 /* dlla and dllb are a set */
64 u32 dll_state = sdrc_read_reg(SDRC_DLLA_CTRL);
65
66 if ((dll_state & (1 << 2)) == (1 << 2))
67 return 1;
68 else
69 return 0;
70 }
71
72 /*
73 * 'level' is the value to store to CM_CLKSEL2_PLL.CORE_CLK_SRC.
74 * Practical values are CORE_CLK_SRC_DPLL (for CORE_CLK = DPLL_CLK) or
75 * CORE_CLK_SRC_DPLL_X2 (for CORE_CLK = * DPLL_CLK * 2)
76 *
77 * Used by the clock framework during CORE DPLL changes
78 */
omap2xxx_sdrc_reprogram(u32 level,u32 force)79 u32 omap2xxx_sdrc_reprogram(u32 level, u32 force)
80 {
81 u32 dll_ctrl, m_type;
82 u32 prev = curr_perf_level;
83 unsigned long flags;
84
85 if ((curr_perf_level == level) && !force)
86 return prev;
87
88 if (level == CORE_CLK_SRC_DPLL)
89 dll_ctrl = omap2xxx_sdrc_get_slow_dll_ctrl();
90 else if (level == CORE_CLK_SRC_DPLL_X2)
91 dll_ctrl = omap2xxx_sdrc_get_fast_dll_ctrl();
92 else
93 return prev;
94
95 m_type = omap2xxx_sdrc_get_type();
96
97 local_irq_save(flags);
98 /*
99 * XXX These calls should be abstracted out through a
100 * prm2xxx.c function
101 */
102 if (cpu_is_omap2420())
103 writel_relaxed(0xffff, OMAP2420_PRCM_VOLTSETUP);
104 else
105 writel_relaxed(0xffff, OMAP2430_PRCM_VOLTSETUP);
106 omap2_sram_reprogram_sdrc(level, dll_ctrl, m_type);
107 curr_perf_level = level;
108 local_irq_restore(flags);
109
110 return prev;
111 }
112
113 /* Used by the clock framework during CORE DPLL changes */
omap2xxx_sdrc_init_params(u32 force_lock_to_unlock_mode)114 void omap2xxx_sdrc_init_params(u32 force_lock_to_unlock_mode)
115 {
116 unsigned long dll_cnt;
117 u32 fast_dll = 0;
118
119 /* DDR = 1, SDR = 0 */
120 mem_timings.m_type = !((sdrc_read_reg(SDRC_MR_0) & 0x3) == 0x1);
121
122 /* 2422 es2.05 and beyond has a single SIP DDR instead of 2 like others.
123 * In the case of 2422, its ok to use CS1 instead of CS0.
124 */
125 if (cpu_is_omap2422())
126 mem_timings.base_cs = 1;
127 else
128 mem_timings.base_cs = 0;
129
130 if (mem_timings.m_type != M_DDR)
131 return;
132
133 /* With DDR we need to determine the low frequency DLL value */
134 if (((mem_timings.fast_dll_ctrl & (1 << 2)) == M_LOCK_CTRL))
135 mem_timings.dll_mode = M_UNLOCK;
136 else
137 mem_timings.dll_mode = M_LOCK;
138
139 if (mem_timings.base_cs == 0) {
140 fast_dll = sdrc_read_reg(SDRC_DLLA_CTRL);
141 dll_cnt = sdrc_read_reg(SDRC_DLLA_STATUS) & 0xff00;
142 } else {
143 fast_dll = sdrc_read_reg(SDRC_DLLB_CTRL);
144 dll_cnt = sdrc_read_reg(SDRC_DLLB_STATUS) & 0xff00;
145 }
146 if (force_lock_to_unlock_mode) {
147 fast_dll &= ~0xff00;
148 fast_dll |= dll_cnt; /* Current lock mode */
149 }
150 /* set fast timings with DLL filter disabled */
151 mem_timings.fast_dll_ctrl = (fast_dll | (3 << 8));
152
153 /* No disruptions, DDR will be offline & C-ABI not followed */
154 omap2_sram_ddr_init(&mem_timings.slow_dll_ctrl,
155 mem_timings.fast_dll_ctrl,
156 mem_timings.base_cs,
157 force_lock_to_unlock_mode);
158 mem_timings.slow_dll_ctrl &= 0xff00; /* Keep lock value */
159
160 /* Turn status into unlock ctrl */
161 mem_timings.slow_dll_ctrl |=
162 ((mem_timings.fast_dll_ctrl & 0xF) | (1 << 2));
163
164 /* 90 degree phase for anything below 133MHz + disable DLL filter */
165 mem_timings.slow_dll_ctrl |= ((1 << 1) | (3 << 8));
166 }
167