diff options
| author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
|---|---|---|
| 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 | } | ||
