LXR linux/arch/arm/mach-mx3/iomux.c

   1/*
   2 * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
   3 * Copyright (C) 2008 by Sascha Hauer <kernel@pengutronix.de>
   4 * Copyright (C) 2009 by Valentin Longchamp <valentin.longchamp@epfl.ch>
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version 2
   9 * of the License, or (at your option) any later version.
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  18 * MA 02110-1301, USA.
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/spinlock.h>
  23#include <linux/io.h>
  24#include <linux/kernel.h>
  25#include <mach/hardware.h>
  26#include <mach/gpio.h>
  27#include <mach/iomux-mx3.h>
  28
  29/*
  30 * IOMUX register (base) addresses
  31 */
  32#define IOMUX_BASE      IO_ADDRESS(IOMUXC_BASE_ADDR)
  33#define IOMUXINT_OBS1   (IOMUX_BASE + 0x000)
  34#define IOMUXINT_OBS2   (IOMUX_BASE + 0x004)
  35#define IOMUXGPR        (IOMUX_BASE + 0x008)
  36#define IOMUXSW_MUX_CTL (IOMUX_BASE + 0x00C)
  37#define IOMUXSW_PAD_CTL (IOMUX_BASE + 0x154)
  38
  39static DEFINE_SPINLOCK(gpio_mux_lock);
  40
  41#define IOMUX_REG_MASK (IOMUX_PADNUM_MASK & ~0x3)
  42
  43unsigned long mxc_pin_alloc_map[NB_PORTS * 32 / BITS_PER_LONG];
  44/*
  45 * set the mode for a IOMUX pin.
  46 */
  47int mxc_iomux_mode(unsigned int pin_mode)
  48{
  49        u32 field, l, mode, ret = 0;
  50        void __iomem *reg;
  51
  52        reg = IOMUXSW_MUX_CTL + (pin_mode & IOMUX_REG_MASK);
  53        field = pin_mode & 0x3;
  54        mode = (pin_mode & IOMUX_MODE_MASK) >> IOMUX_MODE_SHIFT;
  55
  56        spin_lock(&gpio_mux_lock);
  57
  58        l = __raw_readl(reg);
  59        l &= ~(0xff << (field * 8));
  60        l |= mode << (field * 8);
  61        __raw_writel(l, reg);
  62
  63        spin_unlock(&gpio_mux_lock);
  64
  65        return ret;
  66}
  67EXPORT_SYMBOL(mxc_iomux_mode);
  68
  69/*
  70 * This function configures the pad value for a IOMUX pin.
  71 */
  72void mxc_iomux_set_pad(enum iomux_pins pin, u32 config)
  73{
  74        u32 field, l;
  75        void __iomem *reg;
  76
  77        pin &= IOMUX_PADNUM_MASK;
  78        reg = IOMUXSW_PAD_CTL + (pin + 2) / 3 * 4;
  79        field = (pin + 2) % 3;
  80
  81        pr_debug("%s: reg offset = 0x%x, field = %d\n",
  82                        __func__, (pin + 2) / 3, field);
  83
  84        spin_lock(&gpio_mux_lock);
  85
  86        l = __raw_readl(reg);
  87        l &= ~(0x1ff << (field * 10));
  88        l |= config << (field * 10);
  89        __raw_writel(l, reg);
  90
  91        spin_unlock(&gpio_mux_lock);
  92}
  93EXPORT_SYMBOL(mxc_iomux_set_pad);
  94
  95/*
  96 * allocs a single pin:
  97 *      - reserves the pin so that it is not claimed by another driver
  98 *      - setups the iomux according to the configuration
  99 */
 100int mxc_iomux_alloc_pin(const unsigned int pin, const char *label)
 101{
 102        unsigned pad = pin & IOMUX_PADNUM_MASK;
 103
 104        if (pad >= (PIN_MAX + 1)) {
 105                printk(KERN_ERR "mxc_iomux: Attempt to request nonexistant pin %u for \"%s\"\n",
 106                        pad, label ? label : "?");
 107                return -EINVAL;
 108        }
 109
 110        if (test_and_set_bit(pad, mxc_pin_alloc_map)) {
 111                printk(KERN_ERR "mxc_iomux: pin %u already used. Allocation for \"%s\" failed\n",
 112                        pad, label ? label : "?");
 113                return -EBUSY;
 114        }
 115        mxc_iomux_mode(pin);
 116
 117        return 0;
 118}
 119EXPORT_SYMBOL(mxc_iomux_alloc_pin);
 120
 121int mxc_iomux_setup_multiple_pins(unsigned int *pin_list, unsigned count,
 122                const char *label)
 123{
 124        unsigned int *p = pin_list;
 125        int i;
 126        int ret = -EINVAL;
 127
 128        for (i = 0; i < count; i++) {
 129                ret = mxc_iomux_alloc_pin(*p, label);
 130                if (ret)
 131                        goto setup_error;
 132                p++;
 133        }
 134        return 0;
 135
 136setup_error:
 137        mxc_iomux_release_multiple_pins(pin_list, i);
 138        return ret;
 139}
 140EXPORT_SYMBOL(mxc_iomux_setup_multiple_pins);
 141
 142void mxc_iomux_release_pin(const unsigned int pin)
 143{
 144        unsigned pad = pin & IOMUX_PADNUM_MASK;
 145
 146        if (pad < (PIN_MAX + 1))
 147                clear_bit(pad, mxc_pin_alloc_map);
 148}
 149EXPORT_SYMBOL(mxc_iomux_release_pin);
 150
 151void mxc_iomux_release_multiple_pins(unsigned int *pin_list, int count)
 152{
 153        unsigned int *p = pin_list;
 154        int i;
 155
 156        for (i = 0; i < count; i++) {
 157                mxc_iomux_release_pin(*p);
 158                p++;
 159        }
 160}
 161EXPORT_SYMBOL(mxc_iomux_release_multiple_pins);
 162
 163/*
 164 * This function enables/disables the general purpose function for a particular
 165 * signal.
 166 */
 167void mxc_iomux_set_gpr(enum iomux_gp_func gp, bool en)
 168{
 169        u32 l;
 170
 171        spin_lock(&gpio_mux_lock);
 172        l = __raw_readl(IOMUXGPR);
 173        if (en)
 174                l |= gp;
 175        else
 176                l &= ~gp;
 177
 178        __raw_writel(l, IOMUXGPR);
 179        spin_unlock(&gpio_mux_lock);
 180}
 181EXPORT_SYMBOL(mxc_iomux_set_gpr);
 182