mux.c

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/*
 * Utility to set the DAVINCI MUX register from a table in mux.h
 *
 * Author: Vladimir Barinov, MontaVista Software, Inc. <[email protected]>
 *
 * Based on linux/arch/arm/plat-omap/mux.c:
 * Copyright (C) 2003 - 2005 Nokia Corporation
 *
 * Written by Tony Lindgren
 *
 * 2007 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 *
 * Copyright (C) 2008 Texas Instruments.
 */
#include <linux/io.h>
#include <linux/module.h>
#include <linux/spinlock.h>

#include <mach/mux.h>
#include <mach/common.h>

static void __iomem *pinmux_base;

/*
 * Sets the DAVINCI MUX register based on the table
 */
int __init_or_module davinci_cfg_reg(const unsigned long index)
{
    static DEFINE_SPINLOCK(mux_spin_lock);
    struct davinci_soc_info *soc_info = &davinci_soc_info;
    unsigned long flags;
    const struct mux_config *cfg;
    unsigned int reg_orig = 0, reg = 0;
    unsigned int mask, warn = 0;

    if (WARN_ON(!soc_info->pinmux_pins))
        return -ENODEV;

    if (!pinmux_base) {
        pinmux_base = ioremap(soc_info->pinmux_base, SZ_4K);
        if (WARN_ON(!pinmux_base))
            return -ENOMEM;
    }

    if (index >= soc_info->pinmux_pins_num) {
        printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
               index, soc_info->pinmux_pins_num);
        dump_stack();
        return -ENODEV;
    }

    cfg = &soc_info->pinmux_pins[index];

    if (cfg->name == NULL) {
        printk(KERN_ERR "No entry for the specified index\n");
        return -ENODEV;
    }

    /* Update the mux register in question */
    if (cfg->mask) {
        unsigned    tmp1, tmp2;

        spin_lock_irqsave(&mux_spin_lock, flags);
        reg_orig = __raw_readl(pinmux_base + cfg->mux_reg);

        mask = (cfg->mask << cfg->mask_offset);
        tmp1 = reg_orig & mask;
        reg = reg_orig & ~mask;

        tmp2 = (cfg->mode << cfg->mask_offset);
        reg |= tmp2;

        if (tmp1 != tmp2)
            warn = 1;

        __raw_writel(reg, pinmux_base + cfg->mux_reg);
        spin_unlock_irqrestore(&mux_spin_lock, flags);
    }

    if (warn) {
#ifdef CONFIG_DAVINCI_MUX_WARNINGS
        printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
#endif
    }

#ifdef CONFIG_DAVINCI_MUX_DEBUG
    if (cfg->debug || warn) {
        printk(KERN_WARNING "MUX: Setting register %s\n", cfg->name);
        printk(KERN_WARNING "      %s (0x%08x) = 0x%08x -> 0x%08x\n",
               cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
    }
#endif

    return 0;
}
EXPORT_SYMBOL(davinci_cfg_reg);

int __init_or_module davinci_cfg_reg_list(const short pins[])
{
    int i, error = -EINVAL;

    if (pins)
        for (i = 0; pins[i] >= 0; i++) {
            error = davinci_cfg_reg(pins[i]);
            if (error)
                break;
        }

    return error;
}