1 /* 2 i2c Support for Via Technologies 82C586B South Bridge 3 4 Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi> 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/pci.h> 24 #include <linux/ioport.h> 25 #include <linux/init.h> 26 #include <linux/i2c.h> 27 #include <linux/i2c-algo-bit.h> 28 #include <linux/io.h> 29 30 /* Power management registers */ 31 #define PM_CFG_REVID 0x08 /* silicon revision code */ 32 #define PM_CFG_IOBASE0 0x20 33 #define PM_CFG_IOBASE1 0x48 34 35 #define I2C_DIR (pm_io_base+0x40) 36 #define I2C_OUT (pm_io_base+0x42) 37 #define I2C_IN (pm_io_base+0x44) 38 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ 39 #define I2C_SDA 0x04 40 41 /* io-region reservation */ 42 #define IOSPACE 0x06 43 44 static struct pci_driver vt586b_driver; 45 static u16 pm_io_base; 46 47 /* 48 It does not appear from the datasheet that the GPIO pins are 49 open drain. So a we set a low value by setting the direction to 50 output and a high value by setting the direction to input and 51 relying on the required I2C pullup. The data value is initialized 52 to 0 in via_init() and never changed. 53 */ 54 static void bit_via_setscl(void *data, int state) 55 { 56 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); 57 } 58 59 static void bit_via_setsda(void *data, int state) 60 { 61 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); 62 } 63 64 static int bit_via_getscl(void *data) 65 { 66 return (0 != (inb(I2C_IN) & I2C_SCL)); 67 } 68 69 static int bit_via_getsda(void *data) 70 { 71 return (0 != (inb(I2C_IN) & I2C_SDA)); 72 } 73 74 75 static struct i2c_algo_bit_data bit_data = { 76 .setsda = bit_via_setsda, 77 .setscl = bit_via_setscl, 78 .getsda = bit_via_getsda, 79 .getscl = bit_via_getscl, 80 .udelay = 5, 81 .timeout = HZ 82 }; 83 84 static struct i2c_adapter vt586b_adapter = { 85 .owner = THIS_MODULE, 86 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 87 .name = "VIA i2c", 88 .algo_data = &bit_data, 89 }; 90 91 92 static DEFINE_PCI_DEVICE_TABLE(vt586b_ids) = { 93 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, 94 { 0, } 95 }; 96 97 MODULE_DEVICE_TABLE (pci, vt586b_ids); 98 99 static int vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) 100 { 101 u16 base; 102 u8 rev; 103 int res; 104 105 if (pm_io_base) { 106 dev_err(&dev->dev, "i2c-via: Will only support one host\n"); 107 return -ENODEV; 108 } 109 110 pci_read_config_byte(dev, PM_CFG_REVID, &rev); 111 112 switch (rev) { 113 case 0x00: 114 base = PM_CFG_IOBASE0; 115 break; 116 case 0x01: 117 case 0x10: 118 base = PM_CFG_IOBASE1; 119 break; 120 121 default: 122 base = PM_CFG_IOBASE1; 123 /* later revision */ 124 } 125 126 pci_read_config_word(dev, base, &pm_io_base); 127 pm_io_base &= (0xff << 8); 128 129 if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) { 130 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); 131 return -ENODEV; 132 } 133 134 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); 135 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); 136 137 /* set up the sysfs linkage to our parent device */ 138 vt586b_adapter.dev.parent = &dev->dev; 139 140 res = i2c_bit_add_bus(&vt586b_adapter); 141 if ( res < 0 ) { 142 release_region(I2C_DIR, IOSPACE); 143 pm_io_base = 0; 144 return res; 145 } 146 return 0; 147 } 148 149 static void vt586b_remove(struct pci_dev *dev) 150 { 151 i2c_del_adapter(&vt586b_adapter); 152 release_region(I2C_DIR, IOSPACE); 153 pm_io_base = 0; 154 } 155 156 157 static struct pci_driver vt586b_driver = { 158 .name = "vt586b_smbus", 159 .id_table = vt586b_ids, 160 .probe = vt586b_probe, 161 .remove = vt586b_remove, 162 }; 163 164 module_pci_driver(vt586b_driver); 165 166 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>"); 167 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); 168 MODULE_LICENSE("GPL"); 169