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 "../w1.h"
  38 #include "../w1_int.h"
  39 #include "../w1_log.h"
  40
  41 MODULE_LICENSE("GPL");
  42 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
  43 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
  44
  45 static struct pci_device_id matrox_w1_tbl[] = {
  46         { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
  47         { },
  48 };
  49 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
  50
  51 static int matrox_w1_probe(struct pci_dev *, const struct pci_device_id *);
  52 static void matrox_w1_remove(struct pci_dev *);
  53
  54 static struct pci_driver matrox_w1_pci_driver = {
  55         .name = "matrox_w1",
  56         .id_table = matrox_w1_tbl,
  57         .probe = matrox_w1_probe,
  58         .remove = matrox_w1_remove,
  59 };
  60
  61 /*
  62  * Matrox G400 DDC registers.
  63  */
  64
  65 #define MATROX_G400_DDC_CLK             (1<<4)
  66 #define MATROX_G400_DDC_DATA            (1<<1)
  67
  68 #define MATROX_BASE                     0x3C00
  69 #define MATROX_STATUS                   0x1e14
  70
  71 #define MATROX_PORT_INDEX_OFFSET        0x00
  72 #define MATROX_PORT_DATA_OFFSET         0x0A
  73
  74 #define MATROX_GET_CONTROL              0x2A
  75 #define MATROX_GET_DATA                 0x2B
  76 #define MATROX_CURSOR_CTL               0x06
  77
  78 struct matrox_device
  79 {
  80         void __iomem *base_addr;
  81         void __iomem *port_index;
  82         void __iomem *port_data;
  83         u8 data_mask;
  84
  85         unsigned long phys_addr;
  86         void __iomem *virt_addr;
  87         unsigned long found;
  88
  89         struct w1_bus_master *bus_master;
  90 };
  91
  92 static u8 matrox_w1_read_ddc_bit(void *);
  93 static void matrox_w1_write_ddc_bit(void *, u8);
  94
  95 /*
  96  * These functions read and write DDC Data bit.
  97  *
  98  * Using tristate pins, since i can't find any open-drain pin in whole motherboard.
  99  * Unfortunately we can't connect to Intel's 82801xx IO controller
 100  * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
 101  *
 102  * I've heard that PIIX also has open drain pin.
 103  *
 104  * Port mapping.
 105  */
 106 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
 107 {
 108         u8 ret;
 109
 110         writeb(reg, dev->port_index);
 111         ret = readb(dev->port_data);
 112         barrier();
 113
 114         return ret;
 115 }
 116
 117 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
 118 {
 119         writeb(reg, dev->port_index);
 120         writeb(val, dev->port_data);
 121         wmb();
 122 }
 123
 124 static void matrox_w1_write_ddc_bit(void *data, u8 bit)
 125 {
 126         u8 ret;
 127         struct matrox_device *dev = data;
 128
 129         if (bit)
 130                 bit = 0;
 131         else
 132                 bit = dev->data_mask;
 133
 134         ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
 135         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
 136         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
 137 }
 138
 139 static u8 matrox_w1_read_ddc_bit(void *data)
 140 {
 141         u8 ret;
 142         struct matrox_device *dev = data;
 143
 144         ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
 145
 146         return ret;
 147 }
 148
 149 static void matrox_w1_hw_init(struct matrox_device *dev)
 150 {
 151         matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
 152         matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
 153 }
 154
 155 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 156 {
 157         struct matrox_device *dev;
 158         int err;
 159
 160         assert(pdev != NULL);
 161         assert(ent != NULL);
 162
 163         if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
 164                 return -ENODEV;
 165
 166         dev = kzalloc(sizeof(struct matrox_device) +
 167                        sizeof(struct w1_bus_master), GFP_KERNEL);
 168         if (!dev) {
 169                 dev_err(&pdev->dev,
 170                         "%s: Failed to create new matrox_device object.\n",
 171                         __func__);
 172                 return -ENOMEM;
 173         }
 174
 175
 176         dev->bus_master = (struct w1_bus_master *)(dev + 1);
 177
 178         /*
 179          * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
 180          */
 181
 182         dev->phys_addr = pci_resource_start(pdev, 1);
 183
 184         dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384);
 185         if (!dev->virt_addr) {
 186                 dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
 187                         __func__, dev->phys_addr, 16384);
 188                 err = -EIO;
 189                 goto err_out_free_device;
 190         }
 191
 192         dev->base_addr = dev->virt_addr + MATROX_BASE;
 193         dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
 194         dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
 195         dev->data_mask = (MATROX_G400_DDC_DATA);
 196
 197         matrox_w1_hw_init(dev);
 198
 199         dev->bus_master->data = dev;
 200         dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
 201         dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
 202
 203         err = w1_add_master_device(dev->bus_master);
 204         if (err)
 205                 goto err_out_free_device;
 206
 207         pci_set_drvdata(pdev, dev);
 208
 209         dev->found = 1;
 210
 211         dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
 212
 213         return 0;
 214
 215 err_out_free_device:
 216         if (dev->virt_addr)
 217                 iounmap(dev->virt_addr);
 218         kfree(dev);
 219
 220         return err;
 221 }
 222
 223 static void 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 module_pci_driver(matrox_w1_pci_driver);