drivers/w1/matrox_w1.c

   1 /*
   2  *      matrox_w1.c
   3  *
   4  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <asm/atomic.h>
  23 #include <asm/types.h>
  24 #include <asm/io.h>
  25
  26 #include <linux/delay.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/list.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/timer.h>
  33 #include <linux/slab.h>
  34 #include <linux/pci_ids.h>
  35 #include <linux/pci.h>
  36 #include <linux/timer.h>
  37
  38 #include "w1.h"
  39 #include "w1_int.h"
  40 #include "w1_log.h"
  41
  42 MODULE_LICENSE("GPL");
  43 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
  44 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire prtocol) over VGA DDC(matrox gpio).");
  45
  46 static struct pci_device_id matrox_w1_tbl[] = {
  47         { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
  48         { },
  49 };
  50 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
  51
  52 static int __devinit matrox_w1_probe(struct pci_dev *, const struct pci_device_id *);
  53 static void __devexit matrox_w1_remove(struct pci_dev *);
  54
  55 static struct pci_driver matrox_w1_pci_driver = {
  56         .name = "matrox_w1",
  57         .id_table = matrox_w1_tbl,
  58         .probe = matrox_w1_probe,
  59         .remove = __devexit_p(matrox_w1_remove),
  60 };
  61
  62 /*
  63  * Matrox G400 DDC registers.
  64  */
  65
  66 #define MATROX_G400_DDC_CLK             (1<<4)
  67 #define MATROX_G400_DDC_DATA            (1<<1)
  68
  69 #define MATROX_BASE                     0x3C00
  70 #define MATROX_STATUS                   0x1e14
  71
  72 #define MATROX_PORT_INDEX_OFFSET        0x00
  73 #define MATROX_PORT_DATA_OFFSET         0x0A
  74
  75 #define MATROX_GET_CONTROL              0x2A
  76 #define MATROX_GET_DATA                 0x2B
  77 #define MATROX_CURSOR_CTL               0x06
  78
  79 struct matrox_device
  80 {
  81         void __iomem *base_addr;
  82         void __iomem *port_index;
  83         void __iomem *port_data;
  84         u8 data_mask;
  85
  86         unsigned long phys_addr;
  87         void __iomem *virt_addr;
  88         unsigned long found;
  89
  90         struct w1_bus_master *bus_master;
  91 };
  92
  93 static u8 matrox_w1_read_ddc_bit(unsigned long);
  94 static void matrox_w1_write_ddc_bit(unsigned long, u8);
  95
  96 /*
  97  * These functions read and write DDC Data bit.
  98  *
  99  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
 100  * Unfortunately we can't connect to Intel's 82801xx IO controller
 101  * since we don't know motherboard schema, wich has pretty unused(may be not) GPIO.
 102  *
 103  * I've heard that PIIX also has open drain pin.
 104  *
 105  * Port mapping.
 106  */
 107 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
 108 {
 109         u8 ret;
 110
 111         writeb(reg, dev->port_index);
 112         ret = readb(dev->port_data);
 113         barrier();
 114
 115         return ret;
 116 }
 117
 118 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
 119 {
 120         writeb(reg, dev->port_index);
 121         writeb(val, dev->port_data);
 122         wmb();
 123 }
 124
 125 static void matrox_w1_write_ddc_bit(unsigned long data, u8 bit)
 126 {
 127         u8 ret;
 128         struct matrox_device *dev = (struct matrox_device *) data;
 129
 130         if (bit)
 131                 bit = 0;
 132         else
 133                 bit = dev->data_mask;
 134
 135         ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
 136         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
 137         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
 138 }
 139
 140 static u8 matrox_w1_read_ddc_bit(unsigned long data)
 141 {
 142         u8 ret;
 143         struct matrox_device *dev = (struct matrox_device *) data;
 144
 145         ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
 146
 147         return ret;
 148 }
 149
 150 static void matrox_w1_hw_init(struct matrox_device *dev)
 151 {
 152         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
 153         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
 154 }
 155
 156 static int __devinit matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 157 {
 158         struct matrox_device *dev;
 159         int err;
 160
 161         assert(pdev != NULL);
 162         assert(ent != NULL);
 163
 164         if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
 165                 return -ENODEV;
 166
 167         dev = kmalloc(sizeof(struct matrox_device) +
 168                        sizeof(struct w1_bus_master), GFP_KERNEL);
 169         if (!dev) {
 170                 dev_err(&pdev->dev,
 171                         "%s: Failed to create new matrox_device object.\n",
 172                         __func__);
 173                 return -ENOMEM;
 174         }
 175
 176         memset(dev, 0, sizeof(struct matrox_device) + sizeof(struct w1_bus_master));
 177
 178         dev->bus_master = (struct w1_bus_master *)(dev + 1);
 179
 180         /*
 181          * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
 182          */
 183
 184         dev->phys_addr = pci_resource_start(pdev, 1);
 185
 186         dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
 187         if (!dev->virt_addr) {
 188                 dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
 189                         __func__, dev->phys_addr, 16384);
 190                 err = -EIO;
 191                 goto err_out_free_device;
 192         }
 193
 194         dev->base_addr = dev->virt_addr + MATROX_BASE;
 195         dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
 196         dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
 197         dev->data_mask = (MATROX_G400_DDC_DATA);
 198
 199         matrox_w1_hw_init(dev);
 200
 201         dev->bus_master->data = (unsigned long) dev;
 202         dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
 203         dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
 204
 205         err = w1_add_master_device(dev->bus_master);
 206         if (err)
 207                 goto err_out_free_device;
 208
 209         pci_set_drvdata(pdev, dev);
 210
 211         dev->found = 1;
 212
 213         dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
 214
 215         return 0;
 216
 217 err_out_free_device:
 218         kfree(dev);
 219
 220         return err;
 221 }
 222
 223 static void __devexit matrox_w1_remove(struct pci_dev *pdev)
 224 {
 225         struct matrox_device *dev = pci_get_drvdata(pdev);
 226
 227         assert(dev != NULL);
 228
 229         if (dev->found) {
 230                 w1_remove_master_device(dev->bus_master);
 231                 iounmap(dev->virt_addr);
 232         }
 233         kfree(dev);
 234 }
 235
 236 static int __init matrox_w1_init(void)
 237 {
 238         return pci_register_driver(&matrox_w1_pci_driver);
 239 }
 240
 241 static void __exit matrox_w1_fini(void)
 242 {
 243         pci_unregister_driver(&matrox_w1_pci_driver);
 244 }
 245
 246 module_init(matrox_w1_init);
 247 module_exit(matrox_w1_fini);