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/hardware.h>
  23 #include <mach/mux.h>
  24 #include <mach/common.h>
  25
  26 /*
  27  * Sets the DAVINCI MUX register based on the table
  28  */
  29 int __init_or_module davinci_cfg_reg(const unsigned long index)
  30 {
  31         static DEFINE_SPINLOCK(mux_spin_lock);
  32         struct davinci_soc_info *soc_info = &davinci_soc_info;
  33         void __iomem *base = soc_info->pinmux_base;
  34         unsigned long flags;
  35         const struct mux_config *cfg;
  36         unsigned int reg_orig = 0, reg = 0;
  37         unsigned int mask, warn = 0;
  38
  39         if (!soc_info->pinmux_pins)
  40                 BUG();
  41
  42         if (index >= soc_info->pinmux_pins_num) {
  43                 printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
  44                        index, soc_info->pinmux_pins_num);
  45                 dump_stack();
  46                 return -ENODEV;
  47         }
  48
  49         cfg = &soc_info->pinmux_pins[index];
  50
  51         if (cfg->name == NULL) {
  52                 printk(KERN_ERR "No entry for the specified index\n");
  53                 return -ENODEV;
  54         }
  55
  56         /* Update the mux register in question */
  57         if (cfg->mask) {
  58                 unsigned        tmp1, tmp2;
  59
  60                 spin_lock_irqsave(&mux_spin_lock, flags);
  61                 reg_orig = __raw_readl(base + cfg->mux_reg);
  62
  63                 mask = (cfg->mask << cfg->mask_offset);
  64                 tmp1 = reg_orig & mask;
  65                 reg = reg_orig & ~mask;
  66
  67                 tmp2 = (cfg->mode << cfg->mask_offset);
  68                 reg |= tmp2;
  69
  70                 if (tmp1 != tmp2)
  71                         warn = 1;
  72
  73                 __raw_writel(reg, base + cfg->mux_reg);
  74                 spin_unlock_irqrestore(&mux_spin_lock, flags);
  75         }
  76
  77         if (warn) {
  78 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
  79                 printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
  80 #endif
  81         }
  82
  83 #ifdef CONFIG_DAVINCI_MUX_DEBUG
  84         if (cfg->debug || warn) {
  85                 printk(KERN_WARNING "MUX: Setting register %s\n", cfg->name);
  86                 printk(KERN_WARNING "      %s (0x%08x) = 0x%08x -> 0x%08x\n",
  87                        cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
  88         }
  89 #endif
  90
  91         return 0;
  92 }
  93 EXPORT_SYMBOL(davinci_cfg_reg);