drivers/gpio/gpio-amd8111.c

   1 /*
   2  * GPIO driver for AMD 8111 south bridges
   3  *
   4  * Copyright (c) 2012 Dmitry Eremin-Solenikov
   5  *
   6  * Based on the AMD RNG driver:
   7  * Copyright 2005 (c) MontaVista Software, Inc.
   8  * with the majority of the code coming from:
   9  *
  10  * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
  11  * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
  12  *
  13  * derived from
  14  *
  15  * Hardware driver for the AMD 768 Random Number Generator (RNG)
  16  * (c) Copyright 2001 Red Hat Inc
  17  *
  18  * derived from
  19  *
  20  * Hardware driver for Intel i810 Random Number Generator (RNG)
  21  * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
  22  * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
  23  *
  24  * This file is licensed under  the terms of the GNU General Public
  25  * License version 2. This program is licensed "as is" without any
  26  * warranty of any kind, whether express or implied.
  27  */
  28 #include <linux/module.h>
  29 #include <linux/kernel.h>
  30 #include <linux/gpio.h>
  31 #include <linux/pci.h>
  32 #include <linux/spinlock.h>
  33
  34 #define PMBASE_OFFSET 0xb0
  35 #define PMBASE_SIZE   0x30
  36
  37 #define AMD_REG_GPIO(i) (0x10 + (i))
  38
  39 #define AMD_GPIO_LTCH_STS       0x40 /* Latch status, w1 */
  40 #define AMD_GPIO_RTIN           0x20 /* Real Time in, ro */
  41 #define AMD_GPIO_DEBOUNCE       0x10 /* Debounce, rw */
  42 #define AMD_GPIO_MODE_MASK      0x0c /* Pin Mode Select, rw */
  43 #define AMD_GPIO_MODE_IN        0x00
  44 #define AMD_GPIO_MODE_OUT       0x04
  45 /* Enable alternative (e.g. clkout, IRQ, etc) function of the pin */
  46 #define AMD_GPIO_MODE_ALTFN     0x08 /* Or 0x09 */
  47 #define AMD_GPIO_X_MASK         0x03 /* In/Out specific, rw */
  48 #define AMD_GPIO_X_IN_ACTIVEHI  0x01 /* Active High */
  49 #define AMD_GPIO_X_IN_LATCH     0x02 /* Latched version is selected */
  50 #define AMD_GPIO_X_OUT_LOW      0x00
  51 #define AMD_GPIO_X_OUT_HI       0x01
  52 #define AMD_GPIO_X_OUT_CLK0     0x02
  53 #define AMD_GPIO_X_OUT_CLK1     0x03
  54
  55 /*
  56  * Data for PCI driver interface
  57  *
  58  * This data only exists for exporting the supported
  59  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
  60  * register a pci_driver, because someone else might one day
  61  * want to register another driver on the same PCI id.
  62  */
  63 static const struct pci_device_id pci_tbl[] = {
  64         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS), 0 },
  65         { 0, }, /* terminate list */
  66 };
  67 MODULE_DEVICE_TABLE(pci, pci_tbl);
  68
  69 struct amd_gpio {
  70         struct gpio_chip        chip;
  71         u32                     pmbase;
  72         void __iomem            *pm;
  73         struct pci_dev          *pdev;
  74         spinlock_t              lock; /* guards hw registers and orig table */
  75         u8                      orig[32];
  76 };
  77
  78 #define to_agp(chip)    container_of(chip, struct amd_gpio, chip)
  79
  80 static int amd_gpio_request(struct gpio_chip *chip, unsigned offset)
  81 {
  82         struct amd_gpio *agp = to_agp(chip);
  83
  84         agp->orig[offset] = ioread8(agp->pm + AMD_REG_GPIO(offset)) &
  85                 (AMD_GPIO_DEBOUNCE | AMD_GPIO_MODE_MASK | AMD_GPIO_X_MASK);
  86
  87         dev_dbg(&agp->pdev->dev, "Requested gpio %d, data %x\n", offset, agp->orig[offset]);
  88
  89         return 0;
  90 }
  91
  92 static void amd_gpio_free(struct gpio_chip *chip, unsigned offset)
  93 {
  94         struct amd_gpio *agp = to_agp(chip);
  95
  96         dev_dbg(&agp->pdev->dev, "Freed gpio %d, data %x\n", offset, agp->orig[offset]);
  97
  98         iowrite8(agp->orig[offset], agp->pm + AMD_REG_GPIO(offset));
  99 }
 100
 101 static void amd_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 102 {
 103         struct amd_gpio *agp = to_agp(chip);
 104         u8 temp;
 105         unsigned long flags;
 106
 107         spin_lock_irqsave(&agp->lock, flags);
 108         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 109         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
 110         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 111         spin_unlock_irqrestore(&agp->lock, flags);
 112
 113         dev_dbg(&agp->pdev->dev, "Setting gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
 114 }
 115
 116 static int amd_gpio_get(struct gpio_chip *chip, unsigned offset)
 117 {
 118         struct amd_gpio *agp = to_agp(chip);
 119         u8 temp;
 120
 121         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 122
 123         dev_dbg(&agp->pdev->dev, "Getting gpio %d, reg=%02x\n", offset, temp);
 124
 125         return (temp & AMD_GPIO_RTIN) ? 1 : 0;
 126 }
 127
 128 static int amd_gpio_dirout(struct gpio_chip *chip, unsigned offset, int value)
 129 {
 130         struct amd_gpio *agp = to_agp(chip);
 131         u8 temp;
 132         unsigned long flags;
 133
 134         spin_lock_irqsave(&agp->lock, flags);
 135         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 136         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
 137         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 138         spin_unlock_irqrestore(&agp->lock, flags);
 139
 140         dev_dbg(&agp->pdev->dev, "Dirout gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
 141
 142         return 0;
 143 }
 144
 145 static int amd_gpio_dirin(struct gpio_chip *chip, unsigned offset)
 146 {
 147         struct amd_gpio *agp = to_agp(chip);
 148         u8 temp;
 149         unsigned long flags;
 150
 151         spin_lock_irqsave(&agp->lock, flags);
 152         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 153         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_IN;
 154         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 155         spin_unlock_irqrestore(&agp->lock, flags);
 156
 157         dev_dbg(&agp->pdev->dev, "Dirin gpio %d, reg=%02x\n", offset, temp);
 158
 159         return 0;
 160 }
 161
 162 static struct amd_gpio gp = {
 163         .chip = {
 164                 .label          = "AMD GPIO",
 165                 .owner          = THIS_MODULE,
 166                 .base           = -1,
 167                 .ngpio          = 32,
 168                 .request        = amd_gpio_request,
 169                 .free           = amd_gpio_free,
 170                 .set            = amd_gpio_set,
 171                 .get            = amd_gpio_get,
 172                 .direction_output = amd_gpio_dirout,
 173                 .direction_input = amd_gpio_dirin,
 174         },
 175 };
 176
 177 static int __init amd_gpio_init(void)
 178 {
 179         int err = -ENODEV;
 180         struct pci_dev *pdev = NULL;
 181         const struct pci_device_id *ent;
 182
 183
 184         /* We look for our device - AMD South Bridge
 185          * I don't know about a system with two such bridges,
 186          * so we can assume that there is max. one device.
 187          *
 188          * We can't use plain pci_driver mechanism,
 189          * as the device is really a multiple function device,
 190          * main driver that binds to the pci_device is an smbus
 191          * driver and have to find & bind to the device this way.
 192          */
 193         for_each_pci_dev(pdev) {
 194                 ent = pci_match_id(pci_tbl, pdev);
 195                 if (ent)
 196                         goto found;
 197         }
 198         /* Device not found. */
 199         goto out;
 200
 201 found:
 202         err = pci_read_config_dword(pdev, 0x58, &gp.pmbase);
 203         if (err)
 204                 goto out;
 205         err = -EIO;
 206         gp.pmbase &= 0x0000FF00;
 207         if (gp.pmbase == 0)
 208                 goto out;
 209         if (!request_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE, "AMD GPIO")) {
 210                 dev_err(&pdev->dev, "AMD GPIO region 0x%x already in use!\n",
 211                         gp.pmbase + PMBASE_OFFSET);
 212                 err = -EBUSY;
 213                 goto out;
 214         }
 215         gp.pm = ioport_map(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
 216         gp.pdev = pdev;
 217         gp.chip.dev = &pdev->dev;
 218
 219         spin_lock_init(&gp.lock);
 220
 221         printk(KERN_INFO "AMD-8111 GPIO detected\n");
 222         err = gpiochip_add(&gp.chip);
 223         if (err) {
 224                 printk(KERN_ERR "GPIO registering failed (%d)\n",
 225                        err);
 226                 release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
 227                 goto out;
 228         }
 229 out:
 230         return err;
 231 }
 232
 233 static void __exit amd_gpio_exit(void)
 234 {
 235         int err = gpiochip_remove(&gp.chip);
 236         WARN_ON(err);
 237         ioport_unmap(gp.pm);
 238         release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
 239 }
 240
 241 module_init(amd_gpio_init);
 242 module_exit(amd_gpio_exit);
 243
 244 MODULE_AUTHOR("The Linux Kernel team");
 245 MODULE_DESCRIPTION("GPIO driver for AMD chipsets");
 246 MODULE_LICENSE("GPL");