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Diffstat (limited to 'arch/arm/mach-omap/mux.c')
| -rw-r--r-- | arch/arm/mach-omap/mux.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/arm/mach-omap/mux.c b/arch/arm/mach-omap/mux.c new file mode 100644 index 000000000000..bcf3c6e5ecd0 --- /dev/null +++ b/arch/arm/mach-omap/mux.c @@ -0,0 +1,163 @@ +/* + * linux/arch/arm/mach-omap/mux.c + * + * Utility to set the Omap MUX and PULL_DWN registers from a table in mux.h + * + * Copyright (C) 2003 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 <asm/system.h> +#include <asm/io.h> +#include <linux/spinlock.h> + +#define __MUX_C__ +#include <asm/arch/mux.h> + +#ifdef CONFIG_OMAP_MUX + +/* + * Sets the Omap MUX and PULL_DWN registers based on the table + */ +int __init_or_module +omap_cfg_reg(const reg_cfg_t reg_cfg) +{ + static DEFINE_SPINLOCK(mux_spin_lock); + + unsigned long flags; + reg_cfg_set *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 (reg_cfg > ARRAY_SIZE(reg_cfg_table)) { + printk(KERN_ERR "MUX: reg_cfg %d\n", reg_cfg); + return -EINVAL; + } + + cfg = ®_cfg_table[reg_cfg]; + + /* + * We do a pretty long section here with lock on, but pin muxing + * should only happen on driver init for each driver, so it's not time + * critical. + */ + spin_lock_irqsave(&mux_spin_lock, flags); + + /* Check the mux register in question */ + if (cfg->mux_reg) { + unsigned tmp1, tmp2; + + 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); + } + + /* Check for pull up or pull down selection on 1610 */ + if (!cpu_is_omap1510()) { + if (cfg->pu_pd_reg && cfg->pull_val) { + 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); + } + } + + /* Check for an associated pull down register */ + if (cfg->pull_reg) { + 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); + } + + 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 + + spin_unlock_irqrestore(&mux_spin_lock, flags); + +#ifdef CONFIG_OMAP_MUX_ERRORS + return warn ? -ETXTBSY : 0; +#else + return 0; +#endif +} + +EXPORT_SYMBOL(omap_cfg_reg); + +#endif /* CONFIG_OMAP_MUX */ |