drivers/i2c/busses/i2c-voodoo3.c

   1 /*
   2     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>,
   3     Philip Edelbrock <phil@netroedge.com>,
   4     Ralph Metzler <rjkm@thp.uni-koeln.de>, and
   5     Mark D. Studebaker <mdsxyz123@yahoo.com>
   6
   7     Based on code written by Ralph Metzler <rjkm@thp.uni-koeln.de> and
   8     Simon Vogl
   9
  10     This program is free software; you can redistribute it and/or modify
  11     it under the terms of the GNU General Public License as published by
  12     the Free Software Foundation; either version 2 of the License, or
  13     (at your option) any later version.
  14
  15     This program is distributed in the hope that it will be useful,
  16     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18     GNU General Public License for more details.
  19
  20     You should have received a copy of the GNU General Public License
  21     along with this program; if not, write to the Free Software
  22     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 /* This interfaces to the I2C bus of the Voodoo3 to gain access to
  26     the BT869 and possibly other I2C devices. */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/pci.h>
  32 #include <linux/i2c.h>
  33 #include <linux/i2c-algo-bit.h>
  34 #include <asm/io.h>
  35
  36 /* the only registers we use */
  37 #define REG             0x78
  38 #define REG2            0x70
  39
  40 /* bit locations in the register */
  41 #define DDC_ENAB        0x00040000
  42 #define DDC_SCL_OUT     0x00080000
  43 #define DDC_SDA_OUT     0x00100000
  44 #define DDC_SCL_IN      0x00200000
  45 #define DDC_SDA_IN      0x00400000
  46 #define I2C_ENAB        0x00800000
  47 #define I2C_SCL_OUT     0x01000000
  48 #define I2C_SDA_OUT     0x02000000
  49 #define I2C_SCL_IN      0x04000000
  50 #define I2C_SDA_IN      0x08000000
  51
  52 /* initialization states */
  53 #define INIT2           0x2
  54 #define INIT3           0x4
  55
  56 /* delays */
  57 #define CYCLE_DELAY     10
  58 #define TIMEOUT         (HZ / 2)
  59
  60
  61 static void __iomem *ioaddr;
  62
  63 /* The voo GPIO registers don't have individual masks for each bit
  64    so we always have to read before writing. */
  65
  66 static void bit_vooi2c_setscl(void *data, int val)
  67 {
  68         unsigned int r;
  69         r = readl(ioaddr + REG);
  70         if (val)
  71                 r |= I2C_SCL_OUT;
  72         else
  73                 r &= ~I2C_SCL_OUT;
  74         writel(r, ioaddr + REG);
  75         readl(ioaddr + REG);    /* flush posted write */
  76 }
  77
  78 static void bit_vooi2c_setsda(void *data, int val)
  79 {
  80         unsigned int r;
  81         r = readl(ioaddr + REG);
  82         if (val)
  83                 r |= I2C_SDA_OUT;
  84         else
  85                 r &= ~I2C_SDA_OUT;
  86         writel(r, ioaddr + REG);
  87         readl(ioaddr + REG);    /* flush posted write */
  88 }
  89
  90 /* The GPIO pins are open drain, so the pins always remain outputs.
  91    We rely on the i2c-algo-bit routines to set the pins high before
  92    reading the input from other chips. */
  93
  94 static int bit_vooi2c_getscl(void *data)
  95 {
  96         return (0 != (readl(ioaddr + REG) & I2C_SCL_IN));
  97 }
  98
  99 static int bit_vooi2c_getsda(void *data)
 100 {
 101         return (0 != (readl(ioaddr + REG) & I2C_SDA_IN));
 102 }
 103
 104 static void bit_vooddc_setscl(void *data, int val)
 105 {
 106         unsigned int r;
 107         r = readl(ioaddr + REG);
 108         if (val)
 109                 r |= DDC_SCL_OUT;
 110         else
 111                 r &= ~DDC_SCL_OUT;
 112         writel(r, ioaddr + REG);
 113         readl(ioaddr + REG);    /* flush posted write */
 114 }
 115
 116 static void bit_vooddc_setsda(void *data, int val)
 117 {
 118         unsigned int r;
 119         r = readl(ioaddr + REG);
 120         if (val)
 121                 r |= DDC_SDA_OUT;
 122         else
 123                 r &= ~DDC_SDA_OUT;
 124         writel(r, ioaddr + REG);
 125         readl(ioaddr + REG);    /* flush posted write */
 126 }
 127
 128 static int bit_vooddc_getscl(void *data)
 129 {
 130         return (0 != (readl(ioaddr + REG) & DDC_SCL_IN));
 131 }
 132
 133 static int bit_vooddc_getsda(void *data)
 134 {
 135         return (0 != (readl(ioaddr + REG) & DDC_SDA_IN));
 136 }
 137
 138 static int config_v3(struct pci_dev *dev)
 139 {
 140         unsigned long cadr;
 141
 142         /* map Voodoo3 memory */
 143         cadr = dev->resource[0].start;
 144         cadr &= PCI_BASE_ADDRESS_MEM_MASK;
 145         ioaddr = ioremap_nocache(cadr, 0x1000);
 146         if (ioaddr) {
 147                 writel(0x8160, ioaddr + REG2);
 148                 writel(0xcffc0020, ioaddr + REG);
 149                 dev_info(&dev->dev, "Using Banshee/Voodoo3 I2C device at %p\n", ioaddr);
 150                 return 0;
 151         }
 152         return -ENODEV;
 153 }
 154
 155 static struct i2c_algo_bit_data voo_i2c_bit_data = {
 156         .setsda         = bit_vooi2c_setsda,
 157         .setscl         = bit_vooi2c_setscl,
 158         .getsda         = bit_vooi2c_getsda,
 159         .getscl         = bit_vooi2c_getscl,
 160         .udelay         = CYCLE_DELAY,
 161         .timeout        = TIMEOUT
 162 };
 163
 164 static struct i2c_adapter voodoo3_i2c_adapter = {
 165         .owner          = THIS_MODULE,
 166         .name           = "I2C Voodoo3/Banshee adapter",
 167         .algo_data      = &voo_i2c_bit_data,
 168 };
 169
 170 static struct i2c_algo_bit_data voo_ddc_bit_data = {
 171         .setsda         = bit_vooddc_setsda,
 172         .setscl         = bit_vooddc_setscl,
 173         .getsda         = bit_vooddc_getsda,
 174         .getscl         = bit_vooddc_getscl,
 175         .udelay         = CYCLE_DELAY,
 176         .timeout        = TIMEOUT
 177 };
 178
 179 static struct i2c_adapter voodoo3_ddc_adapter = {
 180         .owner          = THIS_MODULE,
 181         .class          = I2C_CLASS_DDC,
 182         .name           = "DDC Voodoo3/Banshee adapter",
 183         .algo_data      = &voo_ddc_bit_data,
 184 };
 185
 186 static struct pci_device_id voodoo3_ids[] __devinitdata = {
 187         { PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO3) },
 188         { PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_BANSHEE) },
 189         { 0, }
 190 };
 191
 192 MODULE_DEVICE_TABLE (pci, voodoo3_ids);
 193
 194 static int __devinit voodoo3_probe(struct pci_dev *dev, const struct pci_device_id *id)
 195 {
 196         int retval;
 197
 198         retval = config_v3(dev);
 199         if (retval)
 200                 return retval;
 201
 202         /* set up the sysfs linkage to our parent device */
 203         voodoo3_i2c_adapter.dev.parent = &dev->dev;
 204         voodoo3_ddc_adapter.dev.parent = &dev->dev;
 205
 206         retval = i2c_bit_add_bus(&voodoo3_i2c_adapter);
 207         if (retval)
 208                 return retval;
 209         retval = i2c_bit_add_bus(&voodoo3_ddc_adapter);
 210         if (retval)
 211                 i2c_del_adapter(&voodoo3_i2c_adapter);
 212         return retval;
 213 }
 214
 215 static void __devexit voodoo3_remove(struct pci_dev *dev)
 216 {
 217         i2c_del_adapter(&voodoo3_i2c_adapter);
 218         i2c_del_adapter(&voodoo3_ddc_adapter);
 219         iounmap(ioaddr);
 220 }
 221
 222 static struct pci_driver voodoo3_driver = {
 223         .name           = "voodoo3_smbus",
 224         .id_table       = voodoo3_ids,
 225         .probe          = voodoo3_probe,
 226         .remove         = __devexit_p(voodoo3_remove),
 227 };
 228
 229 static int __init i2c_voodoo3_init(void)
 230 {
 231         return pci_register_driver(&voodoo3_driver);
 232 }
 233
 234 static void __exit i2c_voodoo3_exit(void)
 235 {
 236         pci_unregister_driver(&voodoo3_driver);
 237 }
 238
 239
 240 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 241                 "Philip Edelbrock <phil@netroedge.com>, "
 242                 "Ralph Metzler <rjkm@thp.uni-koeln.de>, "
 243                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
 244 MODULE_DESCRIPTION("Voodoo3 I2C/SMBus driver");
 245 MODULE_LICENSE("GPL");
 246
 247 module_init(i2c_voodoo3_init);
 248 module_exit(i2c_voodoo3_exit);