diff options
author | Daniel Hellstrom <daniel@gaisler.com> | 2011-01-27 01:26:58 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2011-03-16 18:19:04 -0700 |
commit | 7279b82cb1975ba4e337a549757f17418cfdffad (patch) | |
tree | be97311b59bf95471ab2aa6e303e92c9a4427ac9 /arch/sparc/kernel/leon_pmc.c | |
parent | 684151a75bf25f5aeb8a23010da91a34e17b7353 (diff) | |
download | linux-7279b82cb1975ba4e337a549757f17418cfdffad.tar.bz2 |
SPARC/LEON: power down instruction different of different LEONs
The way a LEON is powered down is implemented differently depending
on CHIP type. The AMBA Plug&Play system ID tells revision of GRLIB
and CHIP.
This is for example needed by the GR-LEON4-ITX board and the UT699.
Previously the power down support for LEON was limited to SMP, now
both SMP and UP systems use the instruction.
Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/leon_pmc.c')
-rw-r--r-- | arch/sparc/kernel/leon_pmc.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/arch/sparc/kernel/leon_pmc.c b/arch/sparc/kernel/leon_pmc.c new file mode 100644 index 000000000000..519ca923f59f --- /dev/null +++ b/arch/sparc/kernel/leon_pmc.c @@ -0,0 +1,82 @@ +/* leon_pmc.c: LEON Power-down cpu_idle() handler + * + * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB + */ + +#include <linux/init.h> +#include <linux/pm.h> + +#include <asm/leon_amba.h> +#include <asm/leon.h> + +/* List of Systems that need fixup instructions around power-down instruction */ +unsigned int pmc_leon_fixup_ids[] = { + AEROFLEX_UT699, + GAISLER_GR712RC, + LEON4_NEXTREME1, + 0 +}; + +int pmc_leon_need_fixup(void) +{ + unsigned int systemid = amba_system_id >> 16; + unsigned int *id; + + id = &pmc_leon_fixup_ids[0]; + while (*id != 0) { + if (*id == systemid) + return 1; + id++; + } + + return 0; +} + +/* + * CPU idle callback function for systems that need some extra handling + * See .../arch/sparc/kernel/process.c + */ +void pmc_leon_idle_fixup(void) +{ + /* Prepare an address to a non-cachable region. APB is always + * none-cachable. One instruction is executed after the Sleep + * instruction, we make sure to read the bus and throw away the + * value by accessing a non-cachable area, also we make sure the + * MMU does not get a TLB miss here by using the MMU BYPASS ASI. + */ + register unsigned int address = (unsigned int)leon3_irqctrl_regs; + __asm__ __volatile__ ( + "mov %%g0, %%asr19\n" + "lda [%0] %1, %%g0\n" + : + : "r"(address), "i"(ASI_LEON_BYPASS)); +} + +/* + * CPU idle callback function + * See .../arch/sparc/kernel/process.c + */ +void pmc_leon_idle(void) +{ + /* For systems without power-down, this will be no-op */ + __asm__ __volatile__ ("mov %g0, %asr19\n\t"); +} + +/* Install LEON Power Down function */ +static int __init leon_pmc_install(void) +{ + /* Assign power management IDLE handler */ + if (pmc_leon_need_fixup()) + pm_idle = pmc_leon_idle_fixup; + else + pm_idle = pmc_leon_idle; + + printk(KERN_INFO "leon: power management initialized\n"); + + return 0; +} + +/* This driver is not critical to the boot process, don't care + * if initialized late. + */ +late_initcall(leon_pmc_install); |