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