diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /arch/arm/mach-omap2/prcm.c | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'arch/arm/mach-omap2/prcm.c')
-rw-r--r-- | arch/arm/mach-omap2/prcm.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prcm.c b/arch/arm/mach-omap2/prcm.c new file mode 100644 index 00000000000..2e40a5cf016 --- /dev/null +++ b/arch/arm/mach-omap2/prcm.c | |||
@@ -0,0 +1,167 @@ | |||
1 | /* | ||
2 | * linux/arch/arm/mach-omap2/prcm.c | ||
3 | * | ||
4 | * OMAP 24xx Power Reset and Clock Management (PRCM) functions | ||
5 | * | ||
6 | * Copyright (C) 2005 Nokia Corporation | ||
7 | * | ||
8 | * Written by Tony Lindgren <tony.lindgren@nokia.com> | ||
9 | * | ||
10 | * Copyright (C) 2007 Texas Instruments, Inc. | ||
11 | * Rajendra Nayak <rnayak@ti.com> | ||
12 | * | ||
13 | * Some pieces of code Copyright (C) 2005 Texas Instruments, Inc. | ||
14 | * Upgraded with OMAP4 support by Abhijit Pagare <abhijitpagare@ti.com> | ||
15 | * | ||
16 | * This program is free software; you can redistribute it and/or modify | ||
17 | * it under the terms of the GNU General Public License version 2 as | ||
18 | * published by the Free Software Foundation. | ||
19 | */ | ||
20 | |||
21 | #include <linux/kernel.h> | ||
22 | #include <linux/init.h> | ||
23 | #include <linux/clk.h> | ||
24 | #include <linux/io.h> | ||
25 | #include <linux/delay.h> | ||
26 | |||
27 | #include <mach/system.h> | ||
28 | #include <plat/common.h> | ||
29 | #include <plat/prcm.h> | ||
30 | #include <plat/irqs.h> | ||
31 | |||
32 | #include "clock.h" | ||
33 | #include "clock2xxx.h" | ||
34 | #include "cm2xxx_3xxx.h" | ||
35 | #include "prm2xxx_3xxx.h" | ||
36 | #include "prm44xx.h" | ||
37 | #include "prminst44xx.h" | ||
38 | #include "prm-regbits-24xx.h" | ||
39 | #include "prm-regbits-44xx.h" | ||
40 | #include "control.h" | ||
41 | |||
42 | void __iomem *prm_base; | ||
43 | void __iomem *cm_base; | ||
44 | void __iomem *cm2_base; | ||
45 | |||
46 | #define MAX_MODULE_ENABLE_WAIT 100000 | ||
47 | |||
48 | u32 omap_prcm_get_reset_sources(void) | ||
49 | { | ||
50 | /* XXX This presumably needs modification for 34XX */ | ||
51 | if (cpu_is_omap24xx() || cpu_is_omap34xx()) | ||
52 | return omap2_prm_read_mod_reg(WKUP_MOD, OMAP2_RM_RSTST) & 0x7f; | ||
53 | if (cpu_is_omap44xx()) | ||
54 | return omap2_prm_read_mod_reg(WKUP_MOD, OMAP4_RM_RSTST) & 0x7f; | ||
55 | |||
56 | return 0; | ||
57 | } | ||
58 | EXPORT_SYMBOL(omap_prcm_get_reset_sources); | ||
59 | |||
60 | /* Resets clock rates and reboots the system. Only called from system.h */ | ||
61 | static void omap_prcm_arch_reset(char mode, const char *cmd) | ||
62 | { | ||
63 | s16 prcm_offs = 0; | ||
64 | |||
65 | if (cpu_is_omap24xx()) { | ||
66 | omap2xxx_clk_prepare_for_reboot(); | ||
67 | |||
68 | prcm_offs = WKUP_MOD; | ||
69 | } else if (cpu_is_omap34xx()) { | ||
70 | prcm_offs = OMAP3430_GR_MOD; | ||
71 | omap3_ctrl_write_boot_mode((cmd ? (u8)*cmd : 0)); | ||
72 | } else if (cpu_is_omap44xx()) { | ||
73 | omap4_prminst_global_warm_sw_reset(); /* never returns */ | ||
74 | } else { | ||
75 | WARN_ON(1); | ||
76 | } | ||
77 | |||
78 | /* | ||
79 | * As per Errata i520, in some cases, user will not be able to | ||
80 | * access DDR memory after warm-reset. | ||
81 | * This situation occurs while the warm-reset happens during a read | ||
82 | * access to DDR memory. In that particular condition, DDR memory | ||
83 | * does not respond to a corrupted read command due to the warm | ||
84 | * reset occurrence but SDRC is waiting for read completion. | ||
85 | * SDRC is not sensitive to the warm reset, but the interconnect is | ||
86 | * reset on the fly, thus causing a misalignment between SDRC logic, | ||
87 | * interconnect logic and DDR memory state. | ||
88 | * WORKAROUND: | ||
89 | * Steps to perform before a Warm reset is trigged: | ||
90 | * 1. enable self-refresh on idle request | ||
91 | * 2. put SDRC in idle | ||
92 | * 3. wait until SDRC goes to idle | ||
93 | * 4. generate SW reset (Global SW reset) | ||
94 | * | ||
95 | * Steps to be performed after warm reset occurs (in bootloader): | ||
96 | * if HW warm reset is the source, apply below steps before any | ||
97 | * accesses to SDRAM: | ||
98 | * 1. Reset SMS and SDRC and wait till reset is complete | ||
99 | * 2. Re-initialize SMS, SDRC and memory | ||
100 | * | ||
101 | * NOTE: Above work around is required only if arch reset is implemented | ||
102 | * using Global SW reset(GLOBAL_SW_RST). DPLL3 reset does not need | ||
103 | * the WA since it resets SDRC as well as part of cold reset. | ||
104 | */ | ||
105 | |||
106 | /* XXX should be moved to some OMAP2/3 specific code */ | ||
107 | omap2_prm_set_mod_reg_bits(OMAP_RST_DPLL3_MASK, prcm_offs, | ||
108 | OMAP2_RM_RSTCTRL); | ||
109 | omap2_prm_read_mod_reg(prcm_offs, OMAP2_RM_RSTCTRL); /* OCP barrier */ | ||
110 | } | ||
111 | |||
112 | void (*arch_reset)(char, const char *) = omap_prcm_arch_reset; | ||
113 | |||
114 | /** | ||
115 | * omap2_cm_wait_idlest - wait for IDLEST bit to indicate module readiness | ||
116 | * @reg: physical address of module IDLEST register | ||
117 | * @mask: value to mask against to determine if the module is active | ||
118 | * @idlest: idle state indicator (0 or 1) for the clock | ||
119 | * @name: name of the clock (for printk) | ||
120 | * | ||
121 | * Returns 1 if the module indicated readiness in time, or 0 if it | ||
122 | * failed to enable in roughly MAX_MODULE_ENABLE_WAIT microseconds. | ||
123 | * | ||
124 | * XXX This function is deprecated. It should be removed once the | ||
125 | * hwmod conversion is complete. | ||
126 | */ | ||
127 | int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, u8 idlest, | ||
128 | const char *name) | ||
129 | { | ||
130 | int i = 0; | ||
131 | int ena = 0; | ||
132 | |||
133 | if (idlest) | ||
134 | ena = 0; | ||
135 | else | ||
136 | ena = mask; | ||
137 | |||
138 | /* Wait for lock */ | ||
139 | omap_test_timeout(((__raw_readl(reg) & mask) == ena), | ||
140 | MAX_MODULE_ENABLE_WAIT, i); | ||
141 | |||
142 | if (i < MAX_MODULE_ENABLE_WAIT) | ||
143 | pr_debug("cm: Module associated with clock %s ready after %d " | ||
144 | "loops\n", name, i); | ||
145 | else | ||
146 | pr_err("cm: Module associated with clock %s didn't enable in " | ||
147 | "%d tries\n", name, MAX_MODULE_ENABLE_WAIT); | ||
148 | |||
149 | return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0; | ||
150 | }; | ||
151 | |||
152 | void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals) | ||
153 | { | ||
154 | /* Static mapping, never released */ | ||
155 | if (omap2_globals->prm) { | ||
156 | prm_base = ioremap(omap2_globals->prm, SZ_8K); | ||
157 | WARN_ON(!prm_base); | ||
158 | } | ||
159 | if (omap2_globals->cm) { | ||
160 | cm_base = ioremap(omap2_globals->cm, SZ_8K); | ||
161 | WARN_ON(!cm_base); | ||
162 | } | ||
163 | if (omap2_globals->cm2) { | ||
164 | cm2_base = ioremap(omap2_globals->cm2, SZ_8K); | ||
165 | WARN_ON(!cm2_base); | ||
166 | } | ||
167 | } | ||