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
  39 static DEFINE_SPINLOCK(gpio_mux_lock);
  40
  41 #define IOMUX_REG_MASK (IOMUX_PADNUM_MASK & ~0x3)
  42
  43 unsigned long mxc_pin_alloc_map[NB_PORTS * 32 / BITS_PER_LONG];
  44 /*
  45  * set the mode for a IOMUX pin.
  46  */
  47 int 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 }
  67 EXPORT_SYMBOL(mxc_iomux_mode);
  68
  69 /*
  70  * This function configures the pad value for a IOMUX pin.
  71  */
  72 void 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 }
  93 EXPORT_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  */
 100 int 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 }
 119 EXPORT_SYMBOL(mxc_iomux_alloc_pin);
 120
 121 int 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
 136 setup_error:
 137         mxc_iomux_release_multiple_pins(pin_list, i);
 138         return ret;
 139 }
 140 EXPORT_SYMBOL(mxc_iomux_setup_multiple_pins);
 141
 142 void 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 }
 149 EXPORT_SYMBOL(mxc_iomux_release_pin);
 150
 151 void 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 }
 161 EXPORT_SYMBOL(mxc_iomux_release_multiple_pins);
 162
 163 /*
 164  * This function enables/disables the general purpose function for a particular
 165  * signal.
 166  */
 167 void 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 }
 181 EXPORT_SYMBOL(mxc_iomux_set_gpr);