arch/arm/mach-omap/mux.c

   1 /*
   2  * linux/arch/arm/mach-omap/mux.c
   3  *
   4  * Utility to set the Omap MUX and PULL_DWN registers from a table in mux.h
   5  *
   6  * Copyright (C) 2003 Nokia Corporation
   7  *
   8  * Written by Tony Lindgren <tony.lindgren@nokia.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  */
  25 #include <linux/config.h>
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28 #include <asm/system.h>
  29 #include <asm/io.h>
  30 #include <linux/spinlock.h>
  31
  32 #define __MUX_C__
  33 #include <asm/arch/mux.h>
  34
  35 #ifdef CONFIG_OMAP_MUX
  36
  37 /*
  38  * Sets the Omap MUX and PULL_DWN registers based on the table
  39  */
  40 int __init_or_module
  41 omap_cfg_reg(const reg_cfg_t reg_cfg)
  42 {
  43         static DEFINE_SPINLOCK(mux_spin_lock);
  44
  45         unsigned long flags;
  46         reg_cfg_set *cfg;
  47         unsigned int reg_orig = 0, reg = 0, pu_pd_orig = 0, pu_pd = 0,
  48                 pull_orig = 0, pull = 0;
  49         unsigned int mask, warn = 0;
  50
  51         if (reg_cfg > ARRAY_SIZE(reg_cfg_table)) {
  52                 printk(KERN_ERR "MUX: reg_cfg %d\n", reg_cfg);
  53                 return -EINVAL;
  54         }
  55
  56         cfg = &reg_cfg_table[reg_cfg];
  57
  58         /*
  59          * We do a pretty long section here with lock on, but pin muxing
  60          * should only happen on driver init for each driver, so it's not time
  61          * critical.
  62          */
  63         spin_lock_irqsave(&mux_spin_lock, flags);
  64
  65         /* Check the mux register in question */
  66         if (cfg->mux_reg) {
  67                 unsigned        tmp1, tmp2;
  68
  69                 reg_orig = omap_readl(cfg->mux_reg);
  70
  71                 /* The mux registers always seem to be 3 bits long */
  72                 mask = (0x7 << cfg->mask_offset);
  73                 tmp1 = reg_orig & mask;
  74                 reg = reg_orig & ~mask;
  75
  76                 tmp2 = (cfg->mask << cfg->mask_offset);
  77                 reg |= tmp2;
  78
  79                 if (tmp1 != tmp2)
  80                         warn = 1;
  81
  82                 omap_writel(reg, cfg->mux_reg);
  83         }
  84
  85         /* Check for pull up or pull down selection on 1610 */
  86         if (!cpu_is_omap1510()) {
  87                 if (cfg->pu_pd_reg && cfg->pull_val) {
  88                         pu_pd_orig = omap_readl(cfg->pu_pd_reg);
  89                         mask = 1 << cfg->pull_bit;
  90
  91                         if (cfg->pu_pd_val) {
  92                                 if (!(pu_pd_orig & mask))
  93                                         warn = 1;
  94                                 /* Use pull up */
  95                                 pu_pd = pu_pd_orig | mask;
  96                         } else {
  97                                 if (pu_pd_orig & mask)
  98                                         warn = 1;
  99                                 /* Use pull down */
 100                                 pu_pd = pu_pd_orig & ~mask;
 101                         }
 102                         omap_writel(pu_pd, cfg->pu_pd_reg);
 103                 }
 104         }
 105
 106         /* Check for an associated pull down register */
 107         if (cfg->pull_reg) {
 108                 pull_orig = omap_readl(cfg->pull_reg);
 109                 mask = 1 << cfg->pull_bit;
 110
 111                 if (cfg->pull_val) {
 112                         if (pull_orig & mask)
 113                                 warn = 1;
 114                         /* Low bit = pull enabled */
 115                         pull = pull_orig & ~mask;
 116                 } else {
 117                         if (!(pull_orig & mask))
 118                                 warn = 1;
 119                         /* High bit = pull disabled */
 120                         pull = pull_orig | mask;
 121                 }
 122
 123                 omap_writel(pull, cfg->pull_reg);
 124         }
 125
 126         if (warn) {
 127 #ifdef CONFIG_OMAP_MUX_WARNINGS
 128                 printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
 129 #endif
 130         }
 131
 132 #ifdef CONFIG_OMAP_MUX_DEBUG
 133         if (cfg->debug || warn) {
 134                 printk("MUX: Setting register %s\n", cfg->name);
 135                 printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
 136                        cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
 137
 138                 if (!cpu_is_omap1510()) {
 139                         if (cfg->pu_pd_reg && cfg->pull_val) {
 140                                 printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
 141                                        cfg->pu_pd_name, cfg->pu_pd_reg,
 142                                        pu_pd_orig, pu_pd);
 143                         }
 144                 }
 145
 146                 if (cfg->pull_reg)
 147                         printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
 148                                cfg->pull_name, cfg->pull_reg, pull_orig, pull);
 149         }
 150 #endif
 151
 152         spin_unlock_irqrestore(&mux_spin_lock, flags);
 153
 154 #ifdef CONFIG_OMAP_MUX_ERRORS
 155         return warn ? -ETXTBSY : 0;
 156 #else
 157         return 0;
 158 #endif
 159 }
 160
 161 EXPORT_SYMBOL(omap_cfg_reg);
 162
 163 #endif  /* CONFIG_OMAP_MUX */