arch/arm/mach-imx/iomux-imx31.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
   4  * Copyright (C) 2008 by Sascha Hauer <kernel@pengutronix.de>
   5  * Copyright (C) 2009 by Valentin Longchamp <valentin.longchamp@epfl.ch>
   6  */
   7 #include <linux/gpio.h>
   8 #include <linux/module.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/io.h>
  11 #include <linux/kernel.h>
  12
  13 #include "hardware.h"
  14 #include "iomux-mx3.h"
  15
  16 /*
  17  * IOMUX register (base) addresses
  18  */
  19 #define IOMUX_BASE      MX31_IO_ADDRESS(MX31_IOMUXC_BASE_ADDR)
  20 #define IOMUXINT_OBS1   (IOMUX_BASE + 0x000)
  21 #define IOMUXINT_OBS2   (IOMUX_BASE + 0x004)
  22 #define IOMUXGPR        (IOMUX_BASE + 0x008)
  23 #define IOMUXSW_MUX_CTL (IOMUX_BASE + 0x00C)
  24 #define IOMUXSW_PAD_CTL (IOMUX_BASE + 0x154)
  25
  26 static DEFINE_SPINLOCK(gpio_mux_lock);
  27
  28 #define IOMUX_REG_MASK (IOMUX_PADNUM_MASK & ~0x3)
  29
  30 static DECLARE_BITMAP(mxc_pin_alloc_map, NB_PORTS * 32);
  31 /*
  32  * set the mode for a IOMUX pin.
  33  */
  34 void mxc_iomux_mode(unsigned int pin_mode)
  35 {
  36         u32 field;
  37         u32 l;
  38         u32 mode;
  39         void __iomem *reg;
  40
  41         reg = IOMUXSW_MUX_CTL + (pin_mode & IOMUX_REG_MASK);
  42         field = pin_mode & 0x3;
  43         mode = (pin_mode & IOMUX_MODE_MASK) >> IOMUX_MODE_SHIFT;
  44
  45         spin_lock(&gpio_mux_lock);
  46
  47         l = imx_readl(reg);
  48         l &= ~(0xff << (field * 8));
  49         l |= mode << (field * 8);
  50         imx_writel(l, reg);
  51
  52         spin_unlock(&gpio_mux_lock);
  53 }
  54
  55 /*
  56  * This function configures the pad value for a IOMUX pin.
  57  */
  58 void mxc_iomux_set_pad(enum iomux_pins pin, u32 config)
  59 {
  60         u32 field, l;
  61         void __iomem *reg;
  62
  63         pin &= IOMUX_PADNUM_MASK;
  64         reg = IOMUXSW_PAD_CTL + (pin + 2) / 3 * 4;
  65         field = (pin + 2) % 3;
  66
  67         pr_debug("%s: reg offset = 0x%x, field = %d\n",
  68                         __func__, (pin + 2) / 3, field);
  69
  70         spin_lock(&gpio_mux_lock);
  71
  72         l = imx_readl(reg);
  73         l &= ~(0x1ff << (field * 10));
  74         l |= config << (field * 10);
  75         imx_writel(l, reg);
  76
  77         spin_unlock(&gpio_mux_lock);
  78 }
  79
  80 /*
  81  * allocs a single pin:
  82  *      - reserves the pin so that it is not claimed by another driver
  83  *      - setups the iomux according to the configuration
  84  */
  85 int mxc_iomux_alloc_pin(unsigned int pin, const char *label)
  86 {
  87         unsigned pad = pin & IOMUX_PADNUM_MASK;
  88
  89         if (pad >= (PIN_MAX + 1)) {
  90                 printk(KERN_ERR "mxc_iomux: Attempt to request nonexistent pin %u for \"%s\"\n",
  91                         pad, label ? label : "?");
  92                 return -EINVAL;
  93         }
  94
  95         if (test_and_set_bit(pad, mxc_pin_alloc_map)) {
  96                 printk(KERN_ERR "mxc_iomux: pin %u already used. Allocation for \"%s\" failed\n",
  97                         pad, label ? label : "?");
  98                 return -EBUSY;
  99         }
 100         mxc_iomux_mode(pin);
 101
 102         return 0;
 103 }
 104
 105 int mxc_iomux_setup_multiple_pins(const unsigned int *pin_list, unsigned count,
 106                 const char *label)
 107 {
 108         const unsigned int *p = pin_list;
 109         int i;
 110         int ret = -EINVAL;
 111
 112         for (i = 0; i < count; i++) {
 113                 ret = mxc_iomux_alloc_pin(*p, label);
 114                 if (ret)
 115                         goto setup_error;
 116                 p++;
 117         }
 118         return 0;
 119
 120 setup_error:
 121         mxc_iomux_release_multiple_pins(pin_list, i);
 122         return ret;
 123 }
 124
 125 void mxc_iomux_release_pin(unsigned int pin)
 126 {
 127         unsigned pad = pin & IOMUX_PADNUM_MASK;
 128
 129         if (pad < (PIN_MAX + 1))
 130                 clear_bit(pad, mxc_pin_alloc_map);
 131 }
 132
 133 void mxc_iomux_release_multiple_pins(const unsigned int *pin_list, int count)
 134 {
 135         const unsigned int *p = pin_list;
 136         int i;
 137
 138         for (i = 0; i < count; i++) {
 139                 mxc_iomux_release_pin(*p);
 140                 p++;
 141         }
 142 }
 143
 144 /*
 145  * This function enables/disables the general purpose function for a particular
 146  * signal.
 147  */
 148 void mxc_iomux_set_gpr(enum iomux_gp_func gp, bool en)
 149 {
 150         u32 l;
 151
 152         spin_lock(&gpio_mux_lock);
 153         l = imx_readl(IOMUXGPR);
 154         if (en)
 155                 l |= gp;
 156         else
 157                 l &= ~gp;
 158
 159         imx_writel(l, IOMUXGPR);
 160         spin_unlock(&gpio_mux_lock);
 161 }