[deliverable/linux.git] / arch / sparc / kernel / leon_pmc.c

/* 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/cpu_type.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)
{
	if (sparc_cpu_model == sparc_leon) {
		/* 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);
Commit	Line	Data
7279b82c DH	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>
556626ad	10	#include <asm/cpu_type.h>
7279b82c DH	11	#include <asm/leon.h>
	12
	13	/* List of Systems that need fixup instructions around power-down instruction */
	14	unsigned int pmc_leon_fixup_ids[] = {
	15	AEROFLEX_UT699,
	16	GAISLER_GR712RC,
	17	LEON4_NEXTREME1,
	18	0
	19	};
	20
	21	int 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	*/
	40	void 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	*/
	60	void 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 */
	67	static int __init leon_pmc_install(void)
	68	{
556626ad SR	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;
7279b82c	75
556626ad SR	76	printk(KERN_INFO "leon: power management initialized\n");
556626ad SR	77	}
7279b82c DH	78
	79	return 0;
	80	}
	81
	82	/* This driver is not critical to the boot process, don't care
	83	* if initialized late.
	84	*/
	85	late_initcall(leon_pmc_install);