1 /* 2 i2c-via.c - Part of lm_sensors, Linux kernel modules 3 for hardware monitoring 4 5 i2c Support for Via Technologies 82C586B South Bridge 6 7 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi> 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 2 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22 */ 23 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/pci.h> 27 #include <linux/ioport.h> 28 #include <linux/init.h> 29 #include <linux/i2c.h> 30 #include <linux/i2c-algo-bit.h> 31 #include <asm/io.h> 32 33 /* Power management registers */ 34 #define PM_CFG_REVID 0x08 /* silicon revision code */ 35 #define PM_CFG_IOBASE0 0x20 36 #define PM_CFG_IOBASE1 0x48 37 38 #define I2C_DIR (pm_io_base+0x40) 39 #define I2C_OUT (pm_io_base+0x42) 40 #define I2C_IN (pm_io_base+0x44) 41 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ 42 #define I2C_SDA 0x04 43 44 /* io-region reservation */ 45 #define IOSPACE 0x06 46 47 static struct pci_driver vt586b_driver; 48 static u16 pm_io_base; 49 50 /* 51 It does not appear from the datasheet that the GPIO pins are 52 open drain. So a we set a low value by setting the direction to 53 output and a high value by setting the direction to input and 54 relying on the required I2C pullup. The data value is initialized 55 to 0 in via_init() and never changed. 56 */ 57 static void bit_via_setscl(void *data, int state) 58 { 59 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); 60 } 61 62 static void bit_via_setsda(void *data, int state) 63 { 64 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); 65 } 66 67 static int bit_via_getscl(void *data) 68 { 69 return (0 != (inb(I2C_IN) & I2C_SCL)); 70 } 71 72 static int bit_via_getsda(void *data) 73 { 74 return (0 != (inb(I2C_IN) & I2C_SDA)); 75 } 76 77 78 static struct i2c_algo_bit_data bit_data = { 79 .setsda = bit_via_setsda, 80 .setscl = bit_via_setscl, 81 .getsda = bit_via_getsda, 82 .getscl = bit_via_getscl, 83 .udelay = 5, 84 .timeout = HZ 85 }; 86 87 static struct i2c_adapter vt586b_adapter = { 88 .owner = THIS_MODULE, 89 .id = I2C_HW_B_VIA, 90 .class = I2C_CLASS_HWMON, 91 .name = "VIA i2c", 92 .algo_data = &bit_data, 93 }; 94 95 96 static struct pci_device_id vt586b_ids[] __devinitdata = { 97 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, 98 { 0, } 99 }; 100 101 MODULE_DEVICE_TABLE (pci, vt586b_ids); 102 103 static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) 104 { 105 u16 base; 106 u8 rev; 107 int res; 108 109 if (pm_io_base) { 110 dev_err(&dev->dev, "i2c-via: Will only support one host\n"); 111 return -ENODEV; 112 } 113 114 pci_read_config_byte(dev, PM_CFG_REVID, &rev); 115 116 switch (rev) { 117 case 0x00: 118 base = PM_CFG_IOBASE0; 119 break; 120 case 0x01: 121 case 0x10: 122 base = PM_CFG_IOBASE1; 123 break; 124 125 default: 126 base = PM_CFG_IOBASE1; 127 /* later revision */ 128 } 129 130 pci_read_config_word(dev, base, &pm_io_base); 131 pm_io_base &= (0xff << 8); 132 133 if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) { 134 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); 135 return -ENODEV; 136 } 137 138 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); 139 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); 140 141 /* set up the sysfs linkage to our parent device */ 142 vt586b_adapter.dev.parent = &dev->dev; 143 144 res = i2c_bit_add_bus(&vt586b_adapter); 145 if ( res < 0 ) { 146 release_region(I2C_DIR, IOSPACE); 147 pm_io_base = 0; 148 return res; 149 } 150 return 0; 151 } 152 153 static void __devexit vt586b_remove(struct pci_dev *dev) 154 { 155 i2c_del_adapter(&vt586b_adapter); 156 release_region(I2C_DIR, IOSPACE); 157 pm_io_base = 0; 158 } 159 160 161 static struct pci_driver vt586b_driver = { 162 .name = "vt586b_smbus", 163 .id_table = vt586b_ids, 164 .probe = vt586b_probe, 165 .remove = __devexit_p(vt586b_remove), 166 }; 167 168 static int __init i2c_vt586b_init(void) 169 { 170 return pci_register_driver(&vt586b_driver); 171 } 172 173 static void __exit i2c_vt586b_exit(void) 174 { 175 pci_unregister_driver(&vt586b_driver); 176 } 177 178 179 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>"); 180 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); 181 MODULE_LICENSE("GPL"); 182 183 module_init(i2c_vt586b_init); 184 module_exit(i2c_vt586b_exit); 185