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 Ky�sti M�lkki <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/config.h> 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/pci.h> 28 #include <linux/ioport.h> 29 #include <linux/init.h> 30 #include <linux/i2c.h> 31 #include <linux/i2c-algo-bit.h> 32 #include <asm/io.h> 33 34 /* Power management registers */ 35 #define PM_CFG_REVID 0x08 /* silicon revision code */ 36 #define PM_CFG_IOBASE0 0x20 37 #define PM_CFG_IOBASE1 0x48 38 39 #define I2C_DIR (pm_io_base+0x40) 40 #define I2C_OUT (pm_io_base+0x42) 41 #define I2C_IN (pm_io_base+0x44) 42 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ 43 #define I2C_SDA 0x04 44 45 /* io-region reservation */ 46 #define IOSPACE 0x06 47 #define IOTEXT "via-i2c" 48 49 static u16 pm_io_base = 0; 50 51 /* 52 It does not appear from the datasheet that the GPIO pins are 53 open drain. So a we set a low value by setting the direction to 54 output and a high value by setting the direction to input and 55 relying on the required I2C pullup. The data value is initialized 56 to 0 in via_init() and never changed. 57 */ 58 static void bit_via_setscl(void *data, int state) 59 { 60 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); 61 } 62 63 static void bit_via_setsda(void *data, int state) 64 { 65 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); 66 } 67 68 static int bit_via_getscl(void *data) 69 { 70 return (0 != (inb(I2C_IN) & I2C_SCL)); 71 } 72 73 static int bit_via_getsda(void *data) 74 { 75 return (0 != (inb(I2C_IN) & I2C_SDA)); 76 } 77 78 79 static struct i2c_algo_bit_data bit_data = { 80 .setsda = bit_via_setsda, 81 .setscl = bit_via_setscl, 82 .getsda = bit_via_getsda, 83 .getscl = bit_via_getscl, 84 .udelay = 5, 85 .mdelay = 5, 86 .timeout = HZ 87 }; 88 89 static struct i2c_adapter vt586b_adapter = { 90 .owner = THIS_MODULE, 91 .class = I2C_CLASS_HWMON, 92 .name = "VIA i2c", 93 .algo_data = &bit_data, 94 }; 95 96 97 static struct pci_device_id vt586b_ids[] __devinitdata = { 98 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, 99 { 0, } 100 }; 101 102 MODULE_DEVICE_TABLE (pci, vt586b_ids); 103 104 static int __devinit vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) 105 { 106 u16 base; 107 u8 rev; 108 int res; 109 110 if (pm_io_base) { 111 dev_err(&dev->dev, "i2c-via: Will only support one host\n"); 112 return -ENODEV; 113 } 114 115 pci_read_config_byte(dev, PM_CFG_REVID, &rev); 116 117 switch (rev) { 118 case 0x00: 119 base = PM_CFG_IOBASE0; 120 break; 121 case 0x01: 122 case 0x10: 123 base = PM_CFG_IOBASE1; 124 break; 125 126 default: 127 base = PM_CFG_IOBASE1; 128 /* later revision */ 129 } 130 131 pci_read_config_word(dev, base, &pm_io_base); 132 pm_io_base &= (0xff << 8); 133 134 if (!request_region(I2C_DIR, IOSPACE, IOTEXT)) { 135 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); 136 return -ENODEV; 137 } 138 139 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); 140 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); 141 142 /* set up the driverfs linkage to our parent device */ 143 vt586b_adapter.dev.parent = &dev->dev; 144 145 res = i2c_bit_add_bus(&vt586b_adapter); 146 if ( res < 0 ) { 147 release_region(I2C_DIR, IOSPACE); 148 pm_io_base = 0; 149 return res; 150 } 151 return 0; 152 } 153 154 static void __devexit vt586b_remove(struct pci_dev *dev) 155 { 156 i2c_bit_del_bus(&vt586b_adapter); 157 release_region(I2C_DIR, IOSPACE); 158 pm_io_base = 0; 159 } 160 161 162 static struct pci_driver vt586b_driver = { 163 .name = "vt586b_smbus", 164 .id_table = vt586b_ids, 165 .probe = vt586b_probe, 166 .remove = __devexit_p(vt586b_remove), 167 }; 168 169 static int __init i2c_vt586b_init(void) 170 { 171 return pci_register_driver(&vt586b_driver); 172 } 173 174 static void __exit i2c_vt586b_exit(void) 175 { 176 pci_unregister_driver(&vt586b_driver); 177 } 178 179 180 MODULE_AUTHOR("Ky�sti M�lkki <kmalkki@cc.hut.fi>"); 181 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); 182 MODULE_LICENSE("GPL"); 183 184 module_init(i2c_vt586b_init); 185 module_exit(i2c_vt586b_exit); 186