drivers/i2c/busses/i2c-savage4.c

   1 /*
   2     i2c-savage4.c - Part of lm_sensors, Linux kernel modules for hardware
   3               monitoring
   4     Copyright (C) 1998-2003  The LM Sensors Team
   5     Alexander Wold <awold@bigfoot.com>
   6     Mark D. Studebaker <mdsxyz123@yahoo.com>
   7
   8     Based on i2c-voodoo3.c.
   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 Savage4 to gain access to
  26    the BT869 and possibly other I2C devices. The DDC bus is not
  27    yet supported because its register is not memory-mapped.
  28    However we leave the DDC code here, commented out, to make
  29    it easier to add later.
  30 */
  31
  32 #include <linux/config.h>
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/pci.h>
  37 #include <linux/i2c.h>
  38 #include <linux/i2c-algo-bit.h>
  39 #include <asm/io.h>
  40
  41 /* 3DFX defines */
  42 #define PCI_CHIP_SAVAGE3D       0x8A20
  43 #define PCI_CHIP_SAVAGE3D_MV    0x8A21
  44 #define PCI_CHIP_SAVAGE4        0x8A22
  45 #define PCI_CHIP_SAVAGE2000     0x9102
  46 #define PCI_CHIP_PROSAVAGE_PM   0x8A25
  47 #define PCI_CHIP_PROSAVAGE_KM   0x8A26
  48 #define PCI_CHIP_SAVAGE_MX_MV   0x8c10
  49 #define PCI_CHIP_SAVAGE_MX      0x8c11
  50 #define PCI_CHIP_SAVAGE_IX_MV   0x8c12
  51 #define PCI_CHIP_SAVAGE_IX      0x8c13
  52
  53 #define REG                     0xff20  /* Serial Port 1 Register */
  54
  55 /* bit locations in the register */
  56 #define DDC_ENAB                0x00040000
  57 #define DDC_SCL_OUT             0x00080000
  58 #define DDC_SDA_OUT             0x00100000
  59 #define DDC_SCL_IN              0x00200000
  60 #define DDC_SDA_IN              0x00400000
  61 #define I2C_ENAB                0x00000020
  62 #define I2C_SCL_OUT             0x00000001
  63 #define I2C_SDA_OUT             0x00000002
  64 #define I2C_SCL_IN              0x00000008
  65 #define I2C_SDA_IN              0x00000010
  66
  67 /* initialization states */
  68 #define INIT2                   0x20
  69 #define INIT3                   0x04
  70
  71 /* delays */
  72 #define CYCLE_DELAY             10
  73 #define TIMEOUT                 (HZ / 2)
  74
  75
  76 static void __iomem *ioaddr;
  77
  78 /* The sav GPIO registers don't have individual masks for each bit
  79    so we always have to read before writing. */
  80
  81 static void bit_savi2c_setscl(void *data, int val)
  82 {
  83         unsigned int r;
  84         r = readl(ioaddr + REG);
  85         if(val)
  86                 r |= I2C_SCL_OUT;
  87         else
  88                 r &= ~I2C_SCL_OUT;
  89         writel(r, ioaddr + REG);
  90         readl(ioaddr + REG);    /* flush posted write */
  91 }
  92
  93 static void bit_savi2c_setsda(void *data, int val)
  94 {
  95         unsigned int r;
  96         r = readl(ioaddr + REG);
  97         if(val)
  98                 r |= I2C_SDA_OUT;
  99         else
 100                 r &= ~I2C_SDA_OUT;
 101         writel(r, ioaddr + REG);
 102         readl(ioaddr + REG);    /* flush posted write */
 103 }
 104
 105 /* The GPIO pins are open drain, so the pins always remain outputs.
 106    We rely on the i2c-algo-bit routines to set the pins high before
 107    reading the input from other chips. */
 108
 109 static int bit_savi2c_getscl(void *data)
 110 {
 111         return (0 != (readl(ioaddr + REG) & I2C_SCL_IN));
 112 }
 113
 114 static int bit_savi2c_getsda(void *data)
 115 {
 116         return (0 != (readl(ioaddr + REG) & I2C_SDA_IN));
 117 }
 118
 119 /* Configures the chip */
 120
 121 static int config_s4(struct pci_dev *dev)
 122 {
 123         unsigned long cadr;
 124
 125         /* map memory */
 126         cadr = dev->resource[0].start;
 127         cadr &= PCI_BASE_ADDRESS_MEM_MASK;
 128         ioaddr = ioremap_nocache(cadr, 0x0080000);
 129         if (ioaddr) {
 130                 /* writel(0x8160, ioaddr + REG2); */
 131                 writel(0x00000020, ioaddr + REG);
 132                 dev_info(&dev->dev, "Using Savage4 at %p\n", ioaddr);
 133                 return 0;
 134         }
 135         return -ENODEV;
 136 }
 137
 138 static struct i2c_algo_bit_data sav_i2c_bit_data = {
 139         .setsda         = bit_savi2c_setsda,
 140         .setscl         = bit_savi2c_setscl,
 141         .getsda         = bit_savi2c_getsda,
 142         .getscl         = bit_savi2c_getscl,
 143         .udelay         = CYCLE_DELAY,
 144         .mdelay         = CYCLE_DELAY,
 145         .timeout        = TIMEOUT
 146 };
 147
 148 static struct i2c_adapter savage4_i2c_adapter = {
 149         .owner          = THIS_MODULE,
 150         .name           = "I2C Savage4 adapter",
 151         .algo_data      = &sav_i2c_bit_data,
 152 };
 153
 154 static struct pci_device_id savage4_ids[] __devinitdata = {
 155         { PCI_DEVICE(PCI_VENDOR_ID_S3, PCI_CHIP_SAVAGE4) },
 156         { PCI_DEVICE(PCI_VENDOR_ID_S3, PCI_CHIP_SAVAGE2000) },
 157         { 0, }
 158 };
 159
 160 MODULE_DEVICE_TABLE (pci, savage4_ids);
 161
 162 static int __devinit savage4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 163 {
 164         int retval;
 165
 166         retval = config_s4(dev);
 167         if (retval)
 168                 return retval;
 169
 170         /* set up the sysfs linkage to our parent device */
 171         savage4_i2c_adapter.dev.parent = &dev->dev;
 172
 173         return i2c_bit_add_bus(&savage4_i2c_adapter);
 174 }
 175
 176 static void __devexit savage4_remove(struct pci_dev *dev)
 177 {
 178         i2c_bit_del_bus(&savage4_i2c_adapter);
 179         iounmap(ioaddr);
 180 }
 181
 182 static struct pci_driver savage4_driver = {
 183         .name           = "savage4_smbus",
 184         .id_table       = savage4_ids,
 185         .probe          = savage4_probe,
 186         .remove         = __devexit_p(savage4_remove),
 187 };
 188
 189 static int __init i2c_savage4_init(void)
 190 {
 191         return pci_register_driver(&savage4_driver);
 192 }
 193
 194 static void __exit i2c_savage4_exit(void)
 195 {
 196         pci_unregister_driver(&savage4_driver);
 197 }
 198
 199 MODULE_AUTHOR("Alexander Wold <awold@bigfoot.com> "
 200                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
 201 MODULE_DESCRIPTION("Savage4 I2C/SMBus driver");
 202 MODULE_LICENSE("GPL");
 203
 204 module_init(i2c_savage4_init);
 205 module_exit(i2c_savage4_exit);