mpp.c

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/*
 * arch/arm/plat-orion/mpp.c
 *
 * MPP functions for Marvell orion SoCs
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mbus.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <mach/hardware.h>
#include <plat/orion-gpio.h>
#include <plat/mpp.h>

/* Address of the ith MPP control register */
static __init void __iomem *mpp_ctrl_addr(unsigned int i,
                      void __iomem *dev_bus)
{
    return dev_bus + (i) * 4;
}


void __init orion_mpp_conf(unsigned int *mpp_list, unsigned int variant_mask,
               unsigned int mpp_max, void __iomem *dev_bus)
{
    unsigned int mpp_nr_regs = (1 + mpp_max/8);
    u32 mpp_ctrl[mpp_nr_regs];
    int i;

    printk(KERN_DEBUG "initial MPP regs:");
    for (i = 0; i < mpp_nr_regs; i++) {
        mpp_ctrl[i] = readl(mpp_ctrl_addr(i, dev_bus));
        printk(" %08x", mpp_ctrl[i]);
    }
    printk("\n");

    for ( ; *mpp_list; mpp_list++) {
        unsigned int num = MPP_NUM(*mpp_list);
        unsigned int sel = MPP_SEL(*mpp_list);
        int shift, gpio_mode;

        if (num > mpp_max) {
            printk(KERN_ERR "orion_mpp_conf: invalid MPP "
                    "number (%u)\n", num);
            continue;
        }
        if (variant_mask & !(*mpp_list & variant_mask)) {
            printk(KERN_WARNING
                   "orion_mpp_conf: requested MPP%u config "
                   "unavailable on this hardware\n", num);
            continue;
        }

        shift = (num & 7) << 2;
        mpp_ctrl[num / 8] &= ~(0xf << shift);
        mpp_ctrl[num / 8] |= sel << shift;

        gpio_mode = 0;
        if (*mpp_list & MPP_INPUT_MASK)
            gpio_mode |= GPIO_INPUT_OK;
        if (*mpp_list & MPP_OUTPUT_MASK)
            gpio_mode |= GPIO_OUTPUT_OK;

        orion_gpio_set_valid(num, gpio_mode);
    }

    printk(KERN_DEBUG "  final MPP regs:");
    for (i = 0; i < mpp_nr_regs; i++) {
        writel(mpp_ctrl[i], mpp_ctrl_addr(i, dev_bus));
        printk(" %08x", mpp_ctrl[i]);
    }
    printk("\n");
}