arch/arm/mach-orion/gpio.c

   1 /*
   2  * arch/arm/mach-orion/gpio.c
   3  *
   4  * GPIO functions for Marvell Orion System On Chip
   5  *
   6  * Maintainer: Tzachi Perelstein <tzachi@marvell.com>
   7  *
   8  * This file is licensed under  the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/bitops.h>
  18 #include <asm/gpio.h>
  19 #include <asm/arch/orion.h>
  20 #include "common.h"
  21
  22 static DEFINE_SPINLOCK(gpio_lock);
  23 static unsigned long gpio_valid[BITS_TO_LONGS(GPIO_MAX)];
  24 static const char *gpio_label[GPIO_MAX];  /* non null for allocated GPIOs */
  25
  26 void __init orion_gpio_set_valid_pins(u32 pins)
  27 {
  28         gpio_valid[0] = pins;
  29 }
  30
  31 /*
  32  * GENERIC_GPIO primitives
  33  */
  34 int gpio_direction_input(unsigned pin)
  35 {
  36         unsigned long flags;
  37
  38         if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
  39                 pr_debug("%s: invalid GPIO %d\n", __func__, pin);
  40                 return -EINVAL;
  41         }
  42
  43         spin_lock_irqsave(&gpio_lock, flags);
  44
  45         /*
  46          * Some callers might have not used the gpio_request(),
  47          * so flag this pin as requested now.
  48          */
  49         if (!gpio_label[pin])
  50                 gpio_label[pin] = "?";
  51
  52         orion_setbits(GPIO_IO_CONF, 1 << pin);
  53
  54         spin_unlock_irqrestore(&gpio_lock, flags);
  55         return 0;
  56 }
  57 EXPORT_SYMBOL(gpio_direction_input);
  58
  59 int gpio_direction_output(unsigned pin, int value)
  60 {
  61         unsigned long flags;
  62         int mask;
  63
  64         if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
  65                 pr_debug("%s: invalid GPIO %d\n", __func__, pin);
  66                 return -EINVAL;
  67         }
  68
  69         spin_lock_irqsave(&gpio_lock, flags);
  70
  71         /*
  72          * Some callers might have not used the gpio_request(),
  73          * so flag this pin as requested now.
  74          */
  75         if (!gpio_label[pin])
  76                 gpio_label[pin] = "?";
  77
  78         mask = 1 << pin;
  79         orion_clrbits(GPIO_BLINK_EN, mask);
  80         if (value)
  81                 orion_setbits(GPIO_OUT, mask);
  82         else
  83                 orion_clrbits(GPIO_OUT, mask);
  84         orion_clrbits(GPIO_IO_CONF, mask);
  85
  86         spin_unlock_irqrestore(&gpio_lock, flags);
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(gpio_direction_output);
  90
  91 int gpio_get_value(unsigned pin)
  92 {
  93         int val, mask = 1 << pin;
  94
  95         if (orion_read(GPIO_IO_CONF) & mask)
  96                 val = orion_read(GPIO_DATA_IN) ^ orion_read(GPIO_IN_POL);
  97         else
  98                 val = orion_read(GPIO_OUT);
  99
 100         return val & mask;
 101 }
 102 EXPORT_SYMBOL(gpio_get_value);
 103
 104 void gpio_set_value(unsigned pin, int value)
 105 {
 106         unsigned long flags;
 107         int mask = 1 << pin;
 108
 109         spin_lock_irqsave(&gpio_lock, flags);
 110
 111         orion_clrbits(GPIO_BLINK_EN, mask);
 112         if (value)
 113                 orion_setbits(GPIO_OUT, mask);
 114         else
 115                 orion_clrbits(GPIO_OUT, mask);
 116
 117         spin_unlock_irqrestore(&gpio_lock, flags);
 118 }
 119 EXPORT_SYMBOL(gpio_set_value);
 120
 121 void orion_gpio_set_blink(unsigned pin, int blink)
 122 {
 123         unsigned long flags;
 124         int mask = 1 << pin;
 125
 126         spin_lock_irqsave(&gpio_lock, flags);
 127
 128         orion_clrbits(GPIO_OUT, mask);
 129         if (blink)
 130                 orion_setbits(GPIO_BLINK_EN, mask);
 131         else
 132                 orion_clrbits(GPIO_BLINK_EN, mask);
 133
 134         spin_unlock_irqrestore(&gpio_lock, flags);
 135 }
 136 EXPORT_SYMBOL(orion_gpio_set_blink);
 137
 138 int gpio_request(unsigned pin, const char *label)
 139 {
 140         int ret = 0;
 141         unsigned long flags;
 142
 143         if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
 144                 pr_debug("%s: invalid GPIO %d\n", __func__, pin);
 145                 return -EINVAL;
 146         }
 147
 148         spin_lock_irqsave(&gpio_lock, flags);
 149
 150         if (gpio_label[pin]) {
 151                 pr_debug("%s: GPIO %d already used as %s\n",
 152                          __func__, pin, gpio_label[pin]);
 153                 ret = -EBUSY;
 154         } else
 155                 gpio_label[pin] = label ? label : "?";
 156
 157         spin_unlock_irqrestore(&gpio_lock, flags);
 158         return ret;
 159 }
 160 EXPORT_SYMBOL(gpio_request);
 161
 162 void gpio_free(unsigned pin)
 163 {
 164         if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
 165                 pr_debug("%s: invalid GPIO %d\n", __func__, pin);
 166                 return;
 167         }
 168
 169         if (!gpio_label[pin])
 170                 pr_warning("%s: GPIO %d already freed\n", __func__, pin);
 171         else
 172                 gpio_label[pin] = NULL;
 173 }
 174 EXPORT_SYMBOL(gpio_free);
 175
 176 /* Debug helper */
 177 void gpio_display(void)
 178 {
 179         int i;
 180
 181         for (i = 0; i < GPIO_MAX; i++) {
 182                 printk(KERN_DEBUG "Pin-%d: ", i);
 183
 184                 if (!test_bit(i, gpio_valid)) {
 185                         printk("non-GPIO\n");
 186                 } else if (!gpio_label[i]) {
 187                         printk("GPIO, free\n");
 188                 } else {
 189                         printk("GPIO, used by %s, ", gpio_label[i]);
 190                         if (orion_read(GPIO_IO_CONF) & (1 << i)) {
 191                                 printk("input, active %s, level %s, edge %s\n",
 192                                 ((orion_read(GPIO_IN_POL) >> i) & 1) ? "low" : "high",
 193                                 ((orion_read(GPIO_LEVEL_MASK) >> i) & 1) ? "enabled" : "masked",
 194                                 ((orion_read(GPIO_EDGE_MASK) >> i) & 1) ? "enabled" : "masked");
 195                         } else {
 196                                 printk("output, val=%d\n", (orion_read(GPIO_OUT) >> i) & 1);
 197                         }
 198                 }
 199         }
 200
 201         printk(KERN_DEBUG "MPP_0_7_CTRL (0x%08x) = 0x%08x\n",
 202                                 MPP_0_7_CTRL, orion_read(MPP_0_7_CTRL));
 203         printk(KERN_DEBUG "MPP_8_15_CTRL (0x%08x) = 0x%08x\n",
 204                                 MPP_8_15_CTRL, orion_read(MPP_8_15_CTRL));
 205         printk(KERN_DEBUG "MPP_16_19_CTRL (0x%08x) = 0x%08x\n",
 206                                 MPP_16_19_CTRL, orion_read(MPP_16_19_CTRL));
 207         printk(KERN_DEBUG "MPP_DEV_CTRL (0x%08x) = 0x%08x\n",
 208                                 MPP_DEV_CTRL, orion_read(MPP_DEV_CTRL));
 209         printk(KERN_DEBUG "GPIO_OUT (0x%08x) = 0x%08x\n",
 210                                 GPIO_OUT, orion_read(GPIO_OUT));
 211         printk(KERN_DEBUG "GPIO_IO_CONF (0x%08x) = 0x%08x\n",
 212                                 GPIO_IO_CONF, orion_read(GPIO_IO_CONF));
 213         printk(KERN_DEBUG "GPIO_BLINK_EN (0x%08x) = 0x%08x\n",
 214                                 GPIO_BLINK_EN, orion_read(GPIO_BLINK_EN));
 215         printk(KERN_DEBUG "GPIO_IN_POL (0x%08x) = 0x%08x\n",
 216                                 GPIO_IN_POL, orion_read(GPIO_IN_POL));
 217         printk(KERN_DEBUG "GPIO_DATA_IN (0x%08x) = 0x%08x\n",
 218                                 GPIO_DATA_IN, orion_read(GPIO_DATA_IN));
 219         printk(KERN_DEBUG "GPIO_LEVEL_MASK (0x%08x) = 0x%08x\n",
 220                                 GPIO_LEVEL_MASK, orion_read(GPIO_LEVEL_MASK));
 221         printk(KERN_DEBUG "GPIO_EDGE_CAUSE (0x%08x) = 0x%08x\n",
 222                                 GPIO_EDGE_CAUSE, orion_read(GPIO_EDGE_CAUSE));
 223         printk(KERN_DEBUG "GPIO_EDGE_MASK (0x%08x) = 0x%08x\n",
 224                                 GPIO_EDGE_MASK, orion_read(GPIO_EDGE_MASK));
 225 }