arch/arm/mach-davinci/mux.c

   1 /*
   2  * Utility to set the DAVINCI MUX register from a table in mux.h
   3  *
   4  * Author: Vladimir Barinov, MontaVista Software, Inc. <source@mvista.com>
   5  *
   6  * Based on linux/arch/arm/plat-omap/mux.c:
   7  * Copyright (C) 2003 - 2005 Nokia Corporation
   8  *
   9  * Written by Tony Lindgren
  10  *
  11  * 2007 (c) MontaVista Software, Inc. This file is licensed under
  12  * the terms of the GNU General Public License version 2. This program
  13  * is licensed "as is" without any warranty of any kind, whether express
  14  * or implied.
  15  *
  16  * Copyright (C) 2008 Texas Instruments.
  17  */
  18 #include <linux/io.h>
  19 #include <linux/module.h>
  20 #include <linux/spinlock.h>
  21
  22 #include <mach/mux.h>
  23 #include <mach/common.h>
  24
  25 /*
  26  * Sets the DAVINCI MUX register based on the table
  27  */
  28 int __init_or_module davinci_cfg_reg(const unsigned long index)
  29 {
  30         static DEFINE_SPINLOCK(mux_spin_lock);
  31         struct davinci_soc_info *soc_info = &davinci_soc_info;
  32         void __iomem *base = soc_info->pinmux_base;
  33         unsigned long flags;
  34         const struct mux_config *cfg;
  35         unsigned int reg_orig = 0, reg = 0;
  36         unsigned int mask, warn = 0;
  37
  38         if (!soc_info->pinmux_pins)
  39                 BUG();
  40
  41         if (index >= soc_info->pinmux_pins_num) {
  42                 printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
  43                        index, soc_info->pinmux_pins_num);
  44                 dump_stack();
  45                 return -ENODEV;
  46         }
  47
  48         cfg = &soc_info->pinmux_pins[index];
  49
  50         if (cfg->name == NULL) {
  51                 printk(KERN_ERR "No entry for the specified index\n");
  52                 return -ENODEV;
  53         }
  54
  55         /* Update the mux register in question */
  56         if (cfg->mask) {
  57                 unsigned        tmp1, tmp2;
  58
  59                 spin_lock_irqsave(&mux_spin_lock, flags);
  60                 reg_orig = __raw_readl(base + cfg->mux_reg);
  61
  62                 mask = (cfg->mask << cfg->mask_offset);
  63                 tmp1 = reg_orig & mask;
  64                 reg = reg_orig & ~mask;
  65
  66                 tmp2 = (cfg->mode << cfg->mask_offset);
  67                 reg |= tmp2;
  68
  69                 if (tmp1 != tmp2)
  70                         warn = 1;
  71
  72                 __raw_writel(reg, base + cfg->mux_reg);
  73                 spin_unlock_irqrestore(&mux_spin_lock, flags);
  74         }
  75
  76         if (warn) {
  77 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
  78                 printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
  79 #endif
  80         }
  81
  82 #ifdef CONFIG_DAVINCI_MUX_DEBUG
  83         if (cfg->debug || warn) {
  84                 printk(KERN_WARNING "MUX: Setting register %s\n", cfg->name);
  85                 printk(KERN_WARNING "      %s (0x%08x) = 0x%08x -> 0x%08x\n",
  86                        cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
  87         }
  88 #endif
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL(davinci_cfg_reg);
  93
  94 int da8xx_pinmux_setup(const short pins[])
  95 {
  96         int i, error = -EINVAL;
  97
  98         if (pins)
  99                 for (i = 0; pins[i] >= 0; i++) {
 100                         error = davinci_cfg_reg(pins[i]);
 101                         if (error)
 102                                 break;
 103                 }
 104
 105         return error;
 106 }