mux.c
/*
* linux/arch/arm/plat-omap/mux.c
*
* Utility to set the Omap MUX and PULL_DWN registers from a table in mux.h
*
* Copyright (C) 2003 - 2005 Nokia Corporation
*
* Written by Tony Lindgren <tony.lindgren@nokia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <asm/system.h>
#include <asm/io.h>
#include <linux/spinlock.h>
#include <asm/arch/mux.h>
#ifdef CONFIG_OMAP_MUX
#define OMAP24XX_L4_BASE 0x48000000
#define OMAP24XX_PULL_ENA (1 << 3)
#define OMAP24XX_PULL_UP (1 << 4)
static struct pin_config * pin_table;
static unsigned long pin_table_sz;
extern struct pin_config * omap730_pins;
extern struct pin_config * omap1xxx_pins;
extern struct pin_config * omap24xx_pins;
int __init omap_mux_register(struct pin_config * pins, unsigned long size)
{
pin_table = pins;
pin_table_sz = size;
return 0;
}
/*
* Sets the Omap MUX and PULL_DWN registers based on the table
*/
int __init_or_module omap_cfg_reg(const unsigned long index)
{
static DEFINE_SPINLOCK(mux_spin_lock);
unsigned long flags;
struct pin_config *cfg;
unsigned int reg_orig = 0, reg = 0, pu_pd_orig = 0, pu_pd = 0,
pull_orig = 0, pull = 0;
unsigned int mask, warn = 0;
if (!pin_table)
BUG();
if (index >= pin_table_sz) {
printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
index, pin_table_sz);
dump_stack();
return -ENODEV;
}
cfg = (struct pin_config *)&pin_table[index];
if (cpu_is_omap24xx()) {
u8 reg = 0;
reg |= cfg->mask & 0x7;
if (cfg->pull_val)
reg |= OMAP24XX_PULL_ENA;
if(cfg->pu_pd_val)
reg |= OMAP24XX_PULL_UP;
#ifdef CONFIG_OMAP_MUX_DEBUG
printk("Muxing %s (0x%08x): 0x%02x -> 0x%02x\n",
cfg->name, OMAP24XX_L4_BASE + cfg->mux_reg,
omap_readb(OMAP24XX_L4_BASE + cfg->mux_reg), reg);
#endif
omap_writeb(reg, OMAP24XX_L4_BASE + cfg->mux_reg);
return 0;
}
/* Check the mux register in question */
if (cfg->mux_reg) {
unsigned tmp1, tmp2;
spin_lock_irqsave(&mux_spin_lock, flags);
reg_orig = omap_readl(cfg->mux_reg);
/* The mux registers always seem to be 3 bits long */
mask = (0x7 << cfg->mask_offset);
tmp1 = reg_orig & mask;
reg = reg_orig & ~mask;
tmp2 = (cfg->mask << cfg->mask_offset);
reg |= tmp2;
if (tmp1 != tmp2)
warn = 1;
omap_writel(reg, cfg->mux_reg);
spin_unlock_irqrestore(&mux_spin_lock, flags);
}
/* Check for pull up or pull down selection on 1610 */
if (!cpu_is_omap1510()) {
if (cfg->pu_pd_reg && cfg->pull_val) {
spin_lock_irqsave(&mux_spin_lock, flags);
pu_pd_orig = omap_readl(cfg->pu_pd_reg);
mask = 1 << cfg->pull_bit;
if (cfg->pu_pd_val) {
if (!(pu_pd_orig & mask))
warn = 1;
/* Use pull up */
pu_pd = pu_pd_orig | mask;
} else {
if (pu_pd_orig & mask)
warn = 1;
/* Use pull down */
pu_pd = pu_pd_orig & ~mask;
}
omap_writel(pu_pd, cfg->pu_pd_reg);
spin_unlock_irqrestore(&mux_spin_lock, flags);
}
}
/* Check for an associated pull down register */
if (cfg->pull_reg) {
spin_lock_irqsave(&mux_spin_lock, flags);
pull_orig = omap_readl(cfg->pull_reg);
mask = 1 << cfg->pull_bit;
if (cfg->pull_val) {
if (pull_orig & mask)
warn = 1;
/* Low bit = pull enabled */
pull = pull_orig & ~mask;
} else {
if (!(pull_orig & mask))
warn = 1;
/* High bit = pull disabled */
pull = pull_orig | mask;
}
omap_writel(pull, cfg->pull_reg);
spin_unlock_irqrestore(&mux_spin_lock, flags);
}
if (warn) {
#ifdef CONFIG_OMAP_MUX_WARNINGS
printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
#endif
}
#ifdef CONFIG_OMAP_MUX_DEBUG
if (cfg->debug || warn) {
printk("MUX: Setting register %s\n", cfg->name);
printk(" %s (0x%08x) = 0x%08x -> 0x%08x\n",
cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
if (!cpu_is_omap1510()) {
if (cfg->pu_pd_reg && cfg->pull_val) {
printk(" %s (0x%08x) = 0x%08x -> 0x%08x\n",
cfg->pu_pd_name, cfg->pu_pd_reg,
pu_pd_orig, pu_pd);
}
}
if (cfg->pull_reg)
printk(" %s (0x%08x) = 0x%08x -> 0x%08x\n",
cfg->pull_name, cfg->pull_reg, pull_orig, pull);
}
#endif
#ifdef CONFIG_OMAP_MUX_ERRORS
return warn ? -ETXTBSY : 0;
#else
return 0;
#endif
}
EXPORT_SYMBOL(omap_cfg_reg);
#else
#define omap_mux_init() do {} while(0)
#define omap_cfg_reg(x) do {} while(0)
#endif /* CONFIG_OMAP_MUX */