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/ioport.h>
  29 #include <linux/module.h>
  30 #include <linux/kernel.h>
  31 #include <linux/gpio/driver.h>
  32 #include <linux/pci.h>
  33 #include <linux/spinlock.h>
  34
  35 #define PMBASE_OFFSET 0xb0
  36 #define PMBASE_SIZE   0x30
  37
  38 #define AMD_REG_GPIO(i) (0x10 + (i))
  39
  40 #define AMD_GPIO_LTCH_STS       0x40 /* Latch status, w1 */
  41 #define AMD_GPIO_RTIN           0x20 /* Real Time in, ro */
  42 #define AMD_GPIO_DEBOUNCE       0x10 /* Debounce, rw */
  43 #define AMD_GPIO_MODE_MASK      0x0c /* Pin Mode Select, rw */
  44 #define AMD_GPIO_MODE_IN        0x00
  45 #define AMD_GPIO_MODE_OUT       0x04
  46 /* Enable alternative (e.g. clkout, IRQ, etc) function of the pin */
  47 #define AMD_GPIO_MODE_ALTFN     0x08 /* Or 0x09 */
  48 #define AMD_GPIO_X_MASK         0x03 /* In/Out specific, rw */
  49 #define AMD_GPIO_X_IN_ACTIVEHI  0x01 /* Active High */
  50 #define AMD_GPIO_X_IN_LATCH     0x02 /* Latched version is selected */
  51 #define AMD_GPIO_X_OUT_LOW      0x00
  52 #define AMD_GPIO_X_OUT_HI       0x01
  53 #define AMD_GPIO_X_OUT_CLK0     0x02
  54 #define AMD_GPIO_X_OUT_CLK1     0x03
  55
  56 /*
  57  * Data for PCI driver interface
  58  *
  59  * This data only exists for exporting the supported
  60  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
  61  * register a pci_driver, because someone else might one day
  62  * want to register another driver on the same PCI id.
  63  */
  64 static const struct pci_device_id pci_tbl[] = {
  65         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS), 0 },
  66         { 0, }, /* terminate list */
  67 };
  68 MODULE_DEVICE_TABLE(pci, pci_tbl);
  69
  70 struct amd_gpio {
  71         struct gpio_chip        chip;
  72         u32                     pmbase;
  73         void __iomem            *pm;
  74         struct pci_dev          *pdev;
  75         spinlock_t              lock; /* guards hw registers and orig table */
  76         u8                      orig[32];
  77 };
  78
  79 static int amd_gpio_request(struct gpio_chip *chip, unsigned offset)
  80 {
  81         struct amd_gpio *agp = gpiochip_get_data(chip);
  82
  83         agp->orig[offset] = ioread8(agp->pm + AMD_REG_GPIO(offset)) &
  84                 (AMD_GPIO_DEBOUNCE | AMD_GPIO_MODE_MASK | AMD_GPIO_X_MASK);
  85
  86         dev_dbg(&agp->pdev->dev, "Requested gpio %d, data %x\n", offset, agp->orig[offset]);
  87
  88         return 0;
  89 }
  90
  91 static void amd_gpio_free(struct gpio_chip *chip, unsigned offset)
  92 {
  93         struct amd_gpio *agp = gpiochip_get_data(chip);
  94
  95         dev_dbg(&agp->pdev->dev, "Freed gpio %d, data %x\n", offset, agp->orig[offset]);
  96
  97         iowrite8(agp->orig[offset], agp->pm + AMD_REG_GPIO(offset));
  98 }
  99
 100 static void amd_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 101 {
 102         struct amd_gpio *agp = gpiochip_get_data(chip);
 103         u8 temp;
 104         unsigned long flags;
 105
 106         spin_lock_irqsave(&agp->lock, flags);
 107         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 108         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
 109         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 110         spin_unlock_irqrestore(&agp->lock, flags);
 111
 112         dev_dbg(&agp->pdev->dev, "Setting gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
 113 }
 114
 115 static int amd_gpio_get(struct gpio_chip *chip, unsigned offset)
 116 {
 117         struct amd_gpio *agp = gpiochip_get_data(chip);
 118         u8 temp;
 119
 120         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 121
 122         dev_dbg(&agp->pdev->dev, "Getting gpio %d, reg=%02x\n", offset, temp);
 123
 124         return (temp & AMD_GPIO_RTIN) ? 1 : 0;
 125 }
 126
 127 static int amd_gpio_dirout(struct gpio_chip *chip, unsigned offset, int value)
 128 {
 129         struct amd_gpio *agp = gpiochip_get_data(chip);
 130         u8 temp;
 131         unsigned long flags;
 132
 133         spin_lock_irqsave(&agp->lock, flags);
 134         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 135         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
 136         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 137         spin_unlock_irqrestore(&agp->lock, flags);
 138
 139         dev_dbg(&agp->pdev->dev, "Dirout gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
 140
 141         return 0;
 142 }
 143
 144 static int amd_gpio_dirin(struct gpio_chip *chip, unsigned offset)
 145 {
 146         struct amd_gpio *agp = gpiochip_get_data(chip);
 147         u8 temp;
 148         unsigned long flags;
 149
 150         spin_lock_irqsave(&agp->lock, flags);
 151         temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
 152         temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_IN;
 153         iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
 154         spin_unlock_irqrestore(&agp->lock, flags);
 155
 156         dev_dbg(&agp->pdev->dev, "Dirin gpio %d, reg=%02x\n", offset, temp);
 157
 158         return 0;
 159 }
 160
 161 static struct amd_gpio gp = {
 162         .chip = {
 163                 .label          = "AMD GPIO",
 164                 .owner          = THIS_MODULE,
 165                 .base           = -1,
 166                 .ngpio          = 32,
 167                 .request        = amd_gpio_request,
 168                 .free           = amd_gpio_free,
 169                 .set            = amd_gpio_set,
 170                 .get            = amd_gpio_get,
 171                 .direction_output = amd_gpio_dirout,
 172                 .direction_input = amd_gpio_dirin,
 173         },
 174 };
 175
 176 static int __init amd_gpio_init(void)
 177 {
 178         int err = -ENODEV;
 179         struct pci_dev *pdev = NULL;
 180         const struct pci_device_id *ent;
 181
 182
 183         /* We look for our device - AMD South Bridge
 184          * I don't know about a system with two such bridges,
 185          * so we can assume that there is max. one device.
 186          *
 187          * We can't use plain pci_driver mechanism,
 188          * as the device is really a multiple function device,
 189          * main driver that binds to the pci_device is an smbus
 190          * driver and have to find & bind to the device this way.
 191          */
 192         for_each_pci_dev(pdev) {
 193                 ent = pci_match_id(pci_tbl, pdev);
 194                 if (ent)
 195                         goto found;
 196         }
 197         /* Device not found. */
 198         goto out;
 199
 200 found:
 201         err = pci_read_config_dword(pdev, 0x58, &gp.pmbase);
 202         if (err)
 203                 goto out;
 204         err = -EIO;
 205         gp.pmbase &= 0x0000FF00;
 206         if (gp.pmbase == 0)
 207                 goto out;
 208         if (!devm_request_region(&pdev->dev, gp.pmbase + PMBASE_OFFSET,
 209                 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         if (!gp.pm) {
 217                 dev_err(&pdev->dev, "Couldn't map io port into io memory\n");
 218                 err = -ENOMEM;
 219                 goto out;
 220         }
 221         gp.pdev = pdev;
 222         gp.chip.parent = &pdev->dev;
 223
 224         spin_lock_init(&gp.lock);
 225
 226         printk(KERN_INFO "AMD-8111 GPIO detected\n");
 227         err = gpiochip_add_data(&gp.chip, &gp);
 228         if (err) {
 229                 printk(KERN_ERR "GPIO registering failed (%d)\n",
 230                        err);
 231                 ioport_unmap(gp.pm);
 232                 goto out;
 233         }
 234 out:
 235         return err;
 236 }
 237
 238 static void __exit amd_gpio_exit(void)
 239 {
 240         gpiochip_remove(&gp.chip);
 241         ioport_unmap(gp.pm);
 242 }
 243
 244 module_init(amd_gpio_init);
 245 module_exit(amd_gpio_exit);
 246
 247 MODULE_AUTHOR("The Linux Kernel team");
 248 MODULE_DESCRIPTION("GPIO driver for AMD chipsets");
 249 MODULE_LICENSE("GPL");