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
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/io.h>
  22 #include <linux/module.h>
  23 #include <linux/spinlock.h>
  24
  25 #include <mach/mux.h>
  26 #include <mach/common.h>
  27
  28 static void __iomem *pinmux_base;
  29
  30 /*
  31  * Sets the DAVINCI MUX register based on the table
  32  */
  33 int davinci_cfg_reg(const unsigned long index)
  34 {
  35         static DEFINE_SPINLOCK(mux_spin_lock);
  36         struct davinci_soc_info *soc_info = &davinci_soc_info;
  37         unsigned long flags;
  38         const struct mux_config *cfg;
  39         unsigned int reg_orig = 0, reg = 0;
  40         unsigned int mask, warn = 0;
  41
  42         if (WARN_ON(!soc_info->pinmux_pins))
  43                 return -ENODEV;
  44
  45         if (!pinmux_base) {
  46                 pinmux_base = ioremap(soc_info->pinmux_base, SZ_4K);
  47                 if (WARN_ON(!pinmux_base))
  48                         return -ENOMEM;
  49         }
  50
  51         if (index >= soc_info->pinmux_pins_num) {
  52                 pr_err("Invalid pin mux index: %lu (%lu)\n",
  53                        index, soc_info->pinmux_pins_num);
  54                 dump_stack();
  55                 return -ENODEV;
  56         }
  57
  58         cfg = &soc_info->pinmux_pins[index];
  59
  60         if (cfg->name == NULL) {
  61                 pr_err("No entry for the specified index\n");
  62                 return -ENODEV;
  63         }
  64
  65         /* Update the mux register in question */
  66         if (cfg->mask) {
  67                 unsigned        tmp1, tmp2;
  68
  69                 spin_lock_irqsave(&mux_spin_lock, flags);
  70                 reg_orig = __raw_readl(pinmux_base + cfg->mux_reg);
  71
  72                 mask = (cfg->mask << cfg->mask_offset);
  73                 tmp1 = reg_orig & mask;
  74                 reg = reg_orig & ~mask;
  75
  76                 tmp2 = (cfg->mode << cfg->mask_offset);
  77                 reg |= tmp2;
  78
  79                 if (tmp1 != tmp2)
  80                         warn = 1;
  81
  82                 __raw_writel(reg, pinmux_base + cfg->mux_reg);
  83                 spin_unlock_irqrestore(&mux_spin_lock, flags);
  84         }
  85
  86         if (warn) {
  87 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
  88                 pr_warn("initialized %s\n", cfg->name);
  89 #endif
  90         }
  91
  92 #ifdef CONFIG_DAVINCI_MUX_DEBUG
  93         if (cfg->debug || warn) {
  94                 pr_warn("Setting register %s\n", cfg->name);
  95                 pr_warn("   %s (0x%08x) = 0x%08x -> 0x%08x\n",
  96                         cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
  97         }
  98 #endif
  99
 100         return 0;
 101 }
 102 EXPORT_SYMBOL(davinci_cfg_reg);
 103
 104 int davinci_cfg_reg_list(const short pins[])
 105 {
 106         int i, error = -EINVAL;
 107
 108         if (pins)
 109                 for (i = 0; pins[i] >= 0; i++) {
 110                         error = davinci_cfg_reg(pins[i]);
 111                         if (error)
 112                                 break;
 113                 }
 114
 115         return error;
 116 }