drivers/w1/masters/matrox_w1.c

   1 /*
   2  *      matrox_w1.c
   3  *
   4  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
   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/types.h>
  23 #include <linux/atomic.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
  37 #include <linux/w1.h>
  38
  39 /*
  40  * Matrox G400 DDC registers.
  41  */
  42
  43 #define MATROX_G400_DDC_CLK             (1<<4)
  44 #define MATROX_G400_DDC_DATA            (1<<1)
  45
  46 #define MATROX_BASE                     0x3C00
  47 #define MATROX_STATUS                   0x1e14
  48
  49 #define MATROX_PORT_INDEX_OFFSET        0x00
  50 #define MATROX_PORT_DATA_OFFSET         0x0A
  51
  52 #define MATROX_GET_CONTROL              0x2A
  53 #define MATROX_GET_DATA                 0x2B
  54 #define MATROX_CURSOR_CTL               0x06
  55
  56 struct matrox_device
  57 {
  58         void __iomem *base_addr;
  59         void __iomem *port_index;
  60         void __iomem *port_data;
  61         u8 data_mask;
  62
  63         unsigned long phys_addr;
  64         void __iomem *virt_addr;
  65         unsigned long found;
  66
  67         struct w1_bus_master *bus_master;
  68 };
  69
  70 /*
  71  * These functions read and write DDC Data bit.
  72  *
  73  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
  74  * Unfortunately we can't connect to Intel's 82801xx IO controller
  75  * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
  76  *
  77  * I've heard that PIIX also has open drain pin.
  78  *
  79  * Port mapping.
  80  */
  81 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
  82 {
  83         u8 ret;
  84
  85         writeb(reg, dev->port_index);
  86         ret = readb(dev->port_data);
  87         barrier();
  88
  89         return ret;
  90 }
  91
  92 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
  93 {
  94         writeb(reg, dev->port_index);
  95         writeb(val, dev->port_data);
  96         wmb();
  97 }
  98
  99 static void matrox_w1_write_ddc_bit(void *data, u8 bit)
 100 {
 101         u8 ret;
 102         struct matrox_device *dev = data;
 103
 104         if (bit)
 105                 bit = 0;
 106         else
 107                 bit = dev->data_mask;
 108
 109         ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
 110         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
 111         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
 112 }
 113
 114 static u8 matrox_w1_read_ddc_bit(void *data)
 115 {
 116         u8 ret;
 117         struct matrox_device *dev = data;
 118
 119         ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
 120
 121         return ret;
 122 }
 123
 124 static void matrox_w1_hw_init(struct matrox_device *dev)
 125 {
 126         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
 127         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
 128 }
 129
 130 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 131 {
 132         struct matrox_device *dev;
 133         int err;
 134
 135         if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
 136                 return -ENODEV;
 137
 138         dev = kzalloc(sizeof(struct matrox_device) +
 139                        sizeof(struct w1_bus_master), GFP_KERNEL);
 140         if (!dev) {
 141                 dev_err(&pdev->dev,
 142                         "%s: Failed to create new matrox_device object.\n",
 143                         __func__);
 144                 return -ENOMEM;
 145         }
 146
 147
 148         dev->bus_master = (struct w1_bus_master *)(dev + 1);
 149
 150         /*
 151          * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
 152          */
 153
 154         dev->phys_addr = pci_resource_start(pdev, 1);
 155
 156         dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
 157         if (!dev->virt_addr) {
 158                 dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
 159                         __func__, dev->phys_addr, 16384);
 160                 err = -EIO;
 161                 goto err_out_free_device;
 162         }
 163
 164         dev->base_addr = dev->virt_addr + MATROX_BASE;
 165         dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
 166         dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
 167         dev->data_mask = (MATROX_G400_DDC_DATA);
 168
 169         matrox_w1_hw_init(dev);
 170
 171         dev->bus_master->data = dev;
 172         dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
 173         dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
 174
 175         err = w1_add_master_device(dev->bus_master);
 176         if (err)
 177                 goto err_out_free_device;
 178
 179         pci_set_drvdata(pdev, dev);
 180
 181         dev->found = 1;
 182
 183         dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
 184
 185         return 0;
 186
 187 err_out_free_device:
 188         if (dev->virt_addr)
 189                 iounmap(dev->virt_addr);
 190         kfree(dev);
 191
 192         return err;
 193 }
 194
 195 static void matrox_w1_remove(struct pci_dev *pdev)
 196 {
 197         struct matrox_device *dev = pci_get_drvdata(pdev);
 198
 199         if (dev->found) {
 200                 w1_remove_master_device(dev->bus_master);
 201                 iounmap(dev->virt_addr);
 202         }
 203         kfree(dev);
 204 }
 205
 206 static struct pci_device_id matrox_w1_tbl[] = {
 207         { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
 208         { },
 209 };
 210 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
 211
 212 static struct pci_driver matrox_w1_pci_driver = {
 213         .name = "matrox_w1",
 214         .id_table = matrox_w1_tbl,
 215         .probe = matrox_w1_probe,
 216         .remove = matrox_w1_remove,
 217 };
 218 module_pci_driver(matrox_w1_pci_driver);
 219
 220 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
 221 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
 222 MODULE_LICENSE("GPL");