drivers/i2c/busses/i2c-i810.c

   1 /*
   2     i2c-i810.c - Part of lm_sensors, Linux kernel modules for hardware
   3               monitoring
   4     Copyright (c) 1998, 1999, 2000  Frodo Looijaard <frodol@dds.nl>,
   5     Philip Edelbrock <phil@netroedge.com>,
   6     Ralph Metzler <rjkm@thp.uni-koeln.de>, and
   7     Mark D. Studebaker <mdsxyz123@yahoo.com>
   8
   9     Based on code written by Ralph Metzler <rjkm@thp.uni-koeln.de> and
  10     Simon Vogl
  11
  12     This program is free software; you can redistribute it and/or modify
  13     it under the terms of the GNU General Public License as published by
  14     the Free Software Foundation; either version 2 of the License, or
  15     (at your option) any later version.
  16
  17     This program is distributed in the hope that it will be useful,
  18     but WITHOUT ANY WARRANTY; without even the implied warranty of
  19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20     GNU General Public License for more details.
  21
  22     You should have received a copy of the GNU General Public License
  23     along with this program; if not, write to the Free Software
  24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25 */
  26 /*
  27    This interfaces to the I810/I815 to provide access to
  28    the DDC Bus and the I2C Bus.
  29
  30    SUPPORTED DEVICES    PCI ID
  31    i810AA               7121
  32    i810AB               7123
  33    i810E                7125
  34    i815                 1132
  35    i845G                2562
  36 */
  37
  38 #include <linux/kernel.h>
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/pci.h>
  42 #include <linux/i2c.h>
  43 #include <linux/i2c-algo-bit.h>
  44 #include <asm/io.h>
  45
  46 /* GPIO register locations */
  47 #define I810_IOCONTROL_OFFSET   0x5000
  48 #define I810_HVSYNC             0x00    /* not used */
  49 #define I810_GPIOA              0x10
  50 #define I810_GPIOB              0x14
  51
  52 /* bit locations in the registers */
  53 #define SCL_DIR_MASK            0x0001
  54 #define SCL_DIR                 0x0002
  55 #define SCL_VAL_MASK            0x0004
  56 #define SCL_VAL_OUT             0x0008
  57 #define SCL_VAL_IN              0x0010
  58 #define SDA_DIR_MASK            0x0100
  59 #define SDA_DIR                 0x0200
  60 #define SDA_VAL_MASK            0x0400
  61 #define SDA_VAL_OUT             0x0800
  62 #define SDA_VAL_IN              0x1000
  63
  64 /* initialization states */
  65 #define INIT1                   0x1
  66 #define INIT2                   0x2
  67 #define INIT3                   0x4
  68
  69 /* delays */
  70 #define CYCLE_DELAY             10
  71 #define TIMEOUT                 (HZ / 2)
  72
  73 static void __iomem *ioaddr;
  74
  75 /* The i810 GPIO registers have individual masks for each bit
  76    so we never have to read before writing. Nice. */
  77
  78 static void bit_i810i2c_setscl(void *data, int val)
  79 {
  80         writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,
  81              ioaddr + I810_GPIOB);
  82         readl(ioaddr + I810_GPIOB);     /* flush posted write */
  83 }
  84
  85 static void bit_i810i2c_setsda(void *data, int val)
  86 {
  87         writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,
  88              ioaddr + I810_GPIOB);
  89         readl(ioaddr + I810_GPIOB);     /* flush posted write */
  90 }
  91
  92 /* The GPIO pins are open drain, so the pins could always remain outputs.
  93    However, some chip versions don't latch the inputs unless they
  94    are set as inputs.
  95    We rely on the i2c-algo-bit routines to set the pins high before
  96    reading the input from other chips. Following guidance in the 815
  97    prog. ref. guide, we do a "dummy write" of 0 to the register before
  98    reading which forces the input value to be latched. We presume this
  99    applies to the 810 as well; shouldn't hurt anyway. This is necessary to get
 100    i2c_algo_bit bit_test=1 to pass. */
 101
 102 static int bit_i810i2c_getscl(void *data)
 103 {
 104         writel(SCL_DIR_MASK, ioaddr + I810_GPIOB);
 105         writel(0, ioaddr + I810_GPIOB);
 106         return (0 != (readl(ioaddr + I810_GPIOB) & SCL_VAL_IN));
 107 }
 108
 109 static int bit_i810i2c_getsda(void *data)
 110 {
 111         writel(SDA_DIR_MASK, ioaddr + I810_GPIOB);
 112         writel(0, ioaddr + I810_GPIOB);
 113         return (0 != (readl(ioaddr + I810_GPIOB) & SDA_VAL_IN));
 114 }
 115
 116 static void bit_i810ddc_setscl(void *data, int val)
 117 {
 118         writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,
 119              ioaddr + I810_GPIOA);
 120         readl(ioaddr + I810_GPIOA);     /* flush posted write */
 121 }
 122
 123 static void bit_i810ddc_setsda(void *data, int val)
 124 {
 125         writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,
 126              ioaddr + I810_GPIOA);
 127         readl(ioaddr + I810_GPIOA);     /* flush posted write */
 128 }
 129
 130 static int bit_i810ddc_getscl(void *data)
 131 {
 132         writel(SCL_DIR_MASK, ioaddr + I810_GPIOA);
 133         writel(0, ioaddr + I810_GPIOA);
 134         return (0 != (readl(ioaddr + I810_GPIOA) & SCL_VAL_IN));
 135 }
 136
 137 static int bit_i810ddc_getsda(void *data)
 138 {
 139         writel(SDA_DIR_MASK, ioaddr + I810_GPIOA);
 140         writel(0, ioaddr + I810_GPIOA);
 141         return (0 != (readl(ioaddr + I810_GPIOA) & SDA_VAL_IN));
 142 }
 143
 144 static int config_i810(struct pci_dev *dev)
 145 {
 146         unsigned long cadr;
 147
 148         /* map I810 memory */
 149         cadr = dev->resource[1].start;
 150         cadr += I810_IOCONTROL_OFFSET;
 151         cadr &= PCI_BASE_ADDRESS_MEM_MASK;
 152         ioaddr = ioremap_nocache(cadr, 0x1000);
 153         if (ioaddr) {
 154                 bit_i810i2c_setscl(NULL, 1);
 155                 bit_i810i2c_setsda(NULL, 1);
 156                 bit_i810ddc_setscl(NULL, 1);
 157                 bit_i810ddc_setsda(NULL, 1);
 158                 return 0;
 159         }
 160         return -ENODEV;
 161 }
 162
 163 static struct i2c_algo_bit_data i810_i2c_bit_data = {
 164         .setsda         = bit_i810i2c_setsda,
 165         .setscl         = bit_i810i2c_setscl,
 166         .getsda         = bit_i810i2c_getsda,
 167         .getscl         = bit_i810i2c_getscl,
 168         .udelay         = CYCLE_DELAY,
 169         .timeout        = TIMEOUT,
 170 };
 171
 172 static struct i2c_adapter i810_i2c_adapter = {
 173         .owner          = THIS_MODULE,
 174         .id             = I2C_HW_B_I810,
 175         .name           = "I810/I815 I2C Adapter",
 176         .algo_data      = &i810_i2c_bit_data,
 177 };
 178
 179 static struct i2c_algo_bit_data i810_ddc_bit_data = {
 180         .setsda         = bit_i810ddc_setsda,
 181         .setscl         = bit_i810ddc_setscl,
 182         .getsda         = bit_i810ddc_getsda,
 183         .getscl         = bit_i810ddc_getscl,
 184         .udelay         = CYCLE_DELAY,
 185         .timeout        = TIMEOUT,
 186 };
 187
 188 static struct i2c_adapter i810_ddc_adapter = {
 189         .owner          = THIS_MODULE,
 190         .id             = I2C_HW_B_I810,
 191         .name           = "I810/I815 DDC Adapter",
 192         .algo_data      = &i810_ddc_bit_data,
 193 };
 194
 195 static struct pci_device_id i810_ids[] __devinitdata = {
 196         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG1) },
 197         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG3) },
 198         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810E_IG) },
 199         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82815_CGC) },
 200         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82845G_IG) },
 201         { 0, },
 202 };
 203
 204 MODULE_DEVICE_TABLE (pci, i810_ids);
 205
 206 static int __devinit i810_probe(struct pci_dev *dev, const struct pci_device_id *id)
 207 {
 208         int retval;
 209
 210         retval = config_i810(dev);
 211         if (retval)
 212                 return retval;
 213         dev_info(&dev->dev, "i810/i815 i2c device found.\n");
 214
 215         /* set up the sysfs linkage to our parent device */
 216         i810_i2c_adapter.dev.parent = &dev->dev;
 217         i810_ddc_adapter.dev.parent = &dev->dev;
 218
 219         retval = i2c_bit_add_bus(&i810_i2c_adapter);
 220         if (retval)
 221                 return retval;
 222         retval = i2c_bit_add_bus(&i810_ddc_adapter);
 223         if (retval)
 224                 i2c_del_adapter(&i810_i2c_adapter);
 225         return retval;
 226 }
 227
 228 static void __devexit i810_remove(struct pci_dev *dev)
 229 {
 230         i2c_del_adapter(&i810_ddc_adapter);
 231         i2c_del_adapter(&i810_i2c_adapter);
 232         iounmap(ioaddr);
 233 }
 234
 235 static struct pci_driver i810_driver = {
 236         .name           = "i810_smbus",
 237         .id_table       = i810_ids,
 238         .probe          = i810_probe,
 239         .remove         = __devexit_p(i810_remove),
 240 };
 241
 242 static int __init i2c_i810_init(void)
 243 {
 244         return pci_register_driver(&i810_driver);
 245 }
 246
 247 static void __exit i2c_i810_exit(void)
 248 {
 249         pci_unregister_driver(&i810_driver);
 250 }
 251
 252 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 253                 "Philip Edelbrock <phil@netroedge.com>, "
 254                 "Ralph Metzler <rjkm@thp.uni-koeln.de>, "
 255                 "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
 256 MODULE_DESCRIPTION("I810/I815 I2C/DDC driver");
 257 MODULE_LICENSE("GPL");
 258
 259 module_init(i2c_i810_init);
 260 module_exit(i2c_i810_exit);