WSL2-Linux-Kernel/arch/arm/mach-pxa/mfp-pxa3xx.c

256 строки
6.0 KiB
C

/*
* linux/arch/arm/mach-pxa/mfp.c
*
* PXA3xx Multi-Function Pin Support
*
* Copyright (C) 2007 Marvell Internation Ltd.
*
* 2007-08-21: eric miao <eric.miao@marvell.com>
* initial version
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/sysdev.h>
#include <asm/hardware.h>
#include <asm/arch/mfp.h>
#include <asm/arch/mfp-pxa3xx.h>
#include <asm/arch/pxa3xx-regs.h>
/* mfp_spin_lock is used to ensure that MFP register configuration
* (most likely a read-modify-write operation) is atomic, and that
* mfp_table[] is consistent
*/
static DEFINE_SPINLOCK(mfp_spin_lock);
static void __iomem *mfpr_mmio_base = (void __iomem *)&__REG(MFPR_BASE);
struct pxa3xx_mfp_pin {
unsigned long config; /* -1 for not configured */
unsigned long mfpr_off; /* MFPRxx Register offset */
unsigned long mfpr_run; /* Run-Mode Register Value */
unsigned long mfpr_lpm; /* Low Power Mode Register Value */
};
static struct pxa3xx_mfp_pin mfp_table[MFP_PIN_MAX];
/* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
static const unsigned long mfpr_lpm[] = {
MFPR_LPM_INPUT,
MFPR_LPM_DRIVE_LOW,
MFPR_LPM_DRIVE_HIGH,
MFPR_LPM_PULL_LOW,
MFPR_LPM_PULL_HIGH,
MFPR_LPM_FLOAT,
};
/* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
static const unsigned long mfpr_pull[] = {
MFPR_PULL_NONE,
MFPR_PULL_LOW,
MFPR_PULL_HIGH,
MFPR_PULL_BOTH,
};
/* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
static const unsigned long mfpr_edge[] = {
MFPR_EDGE_NONE,
MFPR_EDGE_RISE,
MFPR_EDGE_FALL,
MFPR_EDGE_BOTH,
};
#define mfpr_readl(off) \
__raw_readl(mfpr_mmio_base + (off))
#define mfpr_writel(off, val) \
__raw_writel(val, mfpr_mmio_base + (off))
#define mfp_configured(p) ((p)->config != -1)
/*
* perform a read-back of any MFPR register to make sure the
* previous writings are finished
*/
#define mfpr_sync() (void)__raw_readl(mfpr_mmio_base + 0)
static inline void __mfp_config_run(struct pxa3xx_mfp_pin *p)
{
if (mfp_configured(p))
mfpr_writel(p->mfpr_off, p->mfpr_run);
}
static inline void __mfp_config_lpm(struct pxa3xx_mfp_pin *p)
{
if (mfp_configured(p)) {
unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
if (mfpr_clr != p->mfpr_run)
mfpr_writel(p->mfpr_off, mfpr_clr);
if (p->mfpr_lpm != mfpr_clr)
mfpr_writel(p->mfpr_off, p->mfpr_lpm);
}
}
void pxa3xx_mfp_config(unsigned long *mfp_cfgs, int num)
{
unsigned long flags;
int i;
spin_lock_irqsave(&mfp_spin_lock, flags);
for (i = 0; i < num; i++, mfp_cfgs++) {
unsigned long tmp, c = *mfp_cfgs;
struct pxa3xx_mfp_pin *p;
int pin, af, drv, lpm, edge, pull;
pin = MFP_PIN(c);
BUG_ON(pin >= MFP_PIN_MAX);
p = &mfp_table[pin];
af = MFP_AF(c);
drv = MFP_DS(c);
lpm = MFP_LPM_STATE(c);
edge = MFP_LPM_EDGE(c);
pull = MFP_PULL(c);
/* run-mode pull settings will conflict with MFPR bits of
* low power mode state, calculate mfpr_run and mfpr_lpm
* individually if pull != MFP_PULL_NONE
*/
tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
if (likely(pull == MFP_PULL_NONE)) {
p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
p->mfpr_lpm = p->mfpr_run;
} else {
p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
p->mfpr_run = tmp | mfpr_pull[pull];
}
p->config = c; __mfp_config_run(p);
}
mfpr_sync();
spin_unlock_irqrestore(&mfp_spin_lock, flags);
}
unsigned long pxa3xx_mfp_read(int mfp)
{
unsigned long val, flags;
BUG_ON(mfp >= MFP_PIN_MAX);
spin_lock_irqsave(&mfp_spin_lock, flags);
val = mfpr_readl(mfp_table[mfp].mfpr_off);
spin_unlock_irqrestore(&mfp_spin_lock, flags);
return val;
}
void pxa3xx_mfp_write(int mfp, unsigned long val)
{
unsigned long flags;
BUG_ON(mfp >= MFP_PIN_MAX);
spin_lock_irqsave(&mfp_spin_lock, flags);
mfpr_writel(mfp_table[mfp].mfpr_off, val);
mfpr_sync();
spin_unlock_irqrestore(&mfp_spin_lock, flags);
}
void __init pxa3xx_mfp_init_addr(struct pxa3xx_mfp_addr_map *map)
{
struct pxa3xx_mfp_addr_map *p;
unsigned long offset, flags;
int i;
spin_lock_irqsave(&mfp_spin_lock, flags);
for (p = map; p->start != MFP_PIN_INVALID; p++) {
offset = p->offset;
i = p->start;
do {
mfp_table[i].mfpr_off = offset;
mfp_table[i].mfpr_run = 0;
mfp_table[i].mfpr_lpm = 0;
offset += 4; i++;
} while ((i <= p->end) && (p->end != -1));
}
spin_unlock_irqrestore(&mfp_spin_lock, flags);
}
void __init pxa3xx_init_mfp(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
mfp_table[i].config = -1;
}
#ifdef CONFIG_PM
/*
* Configure the MFPs appropriately for suspend/resume.
* FIXME: this should probably depend on which system state we're
* entering - for instance, we might not want to place MFP pins in
* a pull-down mode if they're an active low chip select, and we're
* just entering standby.
*/
static int pxa3xx_mfp_suspend(struct sys_device *d, pm_message_t state)
{
int pin;
for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) {
struct pxa3xx_mfp_pin *p = &mfp_table[pin];
__mfp_config_lpm(p);
}
return 0;
}
static int pxa3xx_mfp_resume(struct sys_device *d)
{
int pin;
for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) {
struct pxa3xx_mfp_pin *p = &mfp_table[pin];
__mfp_config_run(p);
}
/* clear RDH bit when MFP settings are restored
*
* NOTE: the last 3 bits DxS are write-1-to-clear so carefully
* preserve them here in case they will be referenced later
*/
ASCR &= ~(ASCR_RDH | ASCR_D1S | ASCR_D2S | ASCR_D3S);
return 0;
}
#else
#define pxa3xx_mfp_suspend NULL
#define pxa3xx_mfp_resume NULL
#endif
struct sysdev_class pxa3xx_mfp_sysclass = {
.name = "mfp",
.suspend = pxa3xx_mfp_suspend,
.resume = pxa3xx_mfp_resume,
};
static int __init mfp_init_devicefs(void)
{
if (cpu_is_pxa3xx())
return sysdev_class_register(&pxa3xx_mfp_sysclass);
return 0;
}
postcore_initcall(mfp_init_devicefs);