1/* leon_pmc.c: LEON Power-down cpu_idle() handler
 2 *
 3 * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
 4 */
 5
 6#include <linux/init.h>
 7#include <linux/pm.h>
 8
 9#include <asm/leon_amba.h>
 
10#include <asm/leon.h>
 
11
12/* List of Systems that need fixup instructions around power-down instruction */
13unsigned int pmc_leon_fixup_ids[] = {
14	AEROFLEX_UT699,
15	GAISLER_GR712RC,
16	LEON4_NEXTREME1,
17	0
18};
19
20int pmc_leon_need_fixup(void)
21{
22	unsigned int systemid = amba_system_id >> 16;
23	unsigned int *id;
24
25	id = &pmc_leon_fixup_ids[0];
26	while (*id != 0) {
27		if (*id == systemid)
28			return 1;
29		id++;
30	}
31
32	return 0;
33}
34
35/*
36 * CPU idle callback function for systems that need some extra handling
37 * See .../arch/sparc/kernel/process.c
38 */
39void pmc_leon_idle_fixup(void)
40{
41	/* Prepare an address to a non-cachable region. APB is always
42	 * none-cachable. One instruction is executed after the Sleep
43	 * instruction, we make sure to read the bus and throw away the
44	 * value by accessing a non-cachable area, also we make sure the
45	 * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
46	 */
47	register unsigned int address = (unsigned int)leon3_irqctrl_regs;
 
 
 
 
48	__asm__ __volatile__ (
49		"mov	%%g0, %%asr19\n"
50		"lda	[%0] %1, %%g0\n"
51		:
52		: "r"(address), "i"(ASI_LEON_BYPASS));
53}
54
55/*
56 * CPU idle callback function
57 * See .../arch/sparc/kernel/process.c
58 */
59void pmc_leon_idle(void)
60{
 
 
 
61	/* For systems without power-down, this will be no-op */
62	__asm__ __volatile__ ("mov	%g0, %asr19\n\t");
63}
64
65/* Install LEON Power Down function */
66static int __init leon_pmc_install(void)
67{
68	/* Assign power management IDLE handler */
69	if (pmc_leon_need_fixup())
70		pm_idle = pmc_leon_idle_fixup;
71	else
72		pm_idle = pmc_leon_idle;
 
73
74	printk(KERN_INFO "leon: power management initialized\n");
 
75
76	return 0;
77}
78
79/* This driver is not critical to the boot process, don't care
80 * if initialized late.
81 */
82late_initcall(leon_pmc_install);

 1/* leon_pmc.c: LEON Power-down cpu_idle() handler
 2 *
 3 * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
 4 */
 5
 6#include <linux/init.h>
 7#include <linux/pm.h>
 8
 9#include <asm/leon_amba.h>
10#include <asm/cpu_type.h>
11#include <asm/leon.h>
12#include <asm/processor.h>
13
14/* List of Systems that need fixup instructions around power-down instruction */
15unsigned int pmc_leon_fixup_ids[] = {
16	AEROFLEX_UT699,
17	GAISLER_GR712RC,
18	LEON4_NEXTREME1,
19	0
20};
21
22int pmc_leon_need_fixup(void)
23{
24	unsigned int systemid = amba_system_id >> 16;
25	unsigned int *id;
26
27	id = &pmc_leon_fixup_ids[0];
28	while (*id != 0) {
29		if (*id == systemid)
30			return 1;
31		id++;
32	}
33
34	return 0;
35}
36
37/*
38 * CPU idle callback function for systems that need some extra handling
39 * See .../arch/sparc/kernel/process.c
40 */
41void pmc_leon_idle_fixup(void)
42{
43	/* Prepare an address to a non-cachable region. APB is always
44	 * none-cachable. One instruction is executed after the Sleep
45	 * instruction, we make sure to read the bus and throw away the
46	 * value by accessing a non-cachable area, also we make sure the
47	 * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
48	 */
49	register unsigned int address = (unsigned int)leon3_irqctrl_regs;
50
51	/* Interrupts need to be enabled to not hang the CPU */
52	local_irq_enable();
53
54	__asm__ __volatile__ (
55		"wr	%%g0, %%asr19\n"
56		"lda	[%0] %1, %%g0\n"
57		:
58		: "r"(address), "i"(ASI_LEON_BYPASS));
59}
60
61/*
62 * CPU idle callback function
63 * See .../arch/sparc/kernel/process.c
64 */
65void pmc_leon_idle(void)
66{
67	/* Interrupts need to be enabled to not hang the CPU */
68	local_irq_enable();
69
70	/* For systems without power-down, this will be no-op */
71	__asm__ __volatile__ ("wr	%g0, %asr19\n\t");
72}
73
74/* Install LEON Power Down function */
75static int __init leon_pmc_install(void)
76{
77	if (sparc_cpu_model == sparc_leon) {
78		/* Assign power management IDLE handler */
79		if (pmc_leon_need_fixup())
80			sparc_idle = pmc_leon_idle_fixup;
81		else
82			sparc_idle = pmc_leon_idle;
83
84		printk(KERN_INFO "leon: power management initialized\n");
85	}
86
87	return 0;
88}
89
90/* This driver is not critical to the boot process, don't care
91 * if initialized late.
92 */
93late_initcall(leon_pmc_install);