LXR linux/drivers/w1/masters/matrox

   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
  41MODULE_LICENSE("GPL");
  42MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
  43MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
  44
  45static struct pci_device_id matrox_w1_tbl[] = {
  46        { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
  47        { },
  48};
  49MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
  50
  51static int matrox_w1_probe(struct pci_dev *, const struct pci_device_id *);
  52static void matrox_w1_remove(struct pci_dev *);
  53
  54static 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
  78struct 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
  92static u8 matrox_w1_read_ddc_bit(void *);
  93static 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 */
 106static __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
 117static __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
 124static 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
 139static 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
 149static 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
 155static 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
 215err_out_free_device:
 216        if (dev->virt_addr)
 217                iounmap(dev->virt_addr);
 218        kfree(dev);
 219
 220        return err;
 221}
 222
 223static 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}
 235module_pci_driver(matrox_w1_pci_driver);
 236