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 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/pci.h> 20 #include <linux/ioport.h> 21 #include <linux/i2c.h> 22 #include <linux/i2c-algo-bit.h> 23 #include <linux/io.h> 24 25 /* Power management registers */ 26 #define PM_CFG_REVID 0x08 /* silicon revision code */ 27 #define PM_CFG_IOBASE0 0x20 28 #define PM_CFG_IOBASE1 0x48 29 30 #define I2C_DIR (pm_io_base+0x40) 31 #define I2C_OUT (pm_io_base+0x42) 32 #define I2C_IN (pm_io_base+0x44) 33 #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ 34 #define I2C_SDA 0x04 35 36 /* io-region reservation */ 37 #define IOSPACE 0x06 38 39 static struct pci_driver vt586b_driver; 40 static u16 pm_io_base; 41 42 /* 43 It does not appear from the datasheet that the GPIO pins are 44 open drain. So a we set a low value by setting the direction to 45 output and a high value by setting the direction to input and 46 relying on the required I2C pullup. The data value is initialized 47 to 0 in via_init() and never changed. 48 */ 49 static void bit_via_setscl(void *data, int state) 50 { 51 outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); 52 } 53 54 static void bit_via_setsda(void *data, int state) 55 { 56 outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); 57 } 58 59 static int bit_via_getscl(void *data) 60 { 61 return (0 != (inb(I2C_IN) & I2C_SCL)); 62 } 63 64 static int bit_via_getsda(void *data) 65 { 66 return (0 != (inb(I2C_IN) & I2C_SDA)); 67 } 68 69 70 static struct i2c_algo_bit_data bit_data = { 71 .setsda = bit_via_setsda, 72 .setscl = bit_via_setscl, 73 .getsda = bit_via_getsda, 74 .getscl = bit_via_getscl, 75 .udelay = 5, 76 .timeout = HZ 77 }; 78 79 static struct i2c_adapter vt586b_adapter = { 80 .owner = THIS_MODULE, 81 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 82 .name = "VIA i2c", 83 .algo_data = &bit_data, 84 }; 85 86 87 static const struct pci_device_id vt586b_ids[] = { 88 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, 89 { 0, } 90 }; 91 92 MODULE_DEVICE_TABLE (pci, vt586b_ids); 93 94 static int vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) 95 { 96 u16 base; 97 u8 rev; 98 int res; 99 100 if (pm_io_base) { 101 dev_err(&dev->dev, "i2c-via: Will only support one host\n"); 102 return -ENODEV; 103 } 104 105 pci_read_config_byte(dev, PM_CFG_REVID, &rev); 106 107 switch (rev) { 108 case 0x00: 109 base = PM_CFG_IOBASE0; 110 break; 111 case 0x01: 112 case 0x10: 113 base = PM_CFG_IOBASE1; 114 break; 115 116 default: 117 base = PM_CFG_IOBASE1; 118 /* later revision */ 119 } 120 121 pci_read_config_word(dev, base, &pm_io_base); 122 pm_io_base &= (0xff << 8); 123 124 if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) { 125 dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); 126 return -ENODEV; 127 } 128 129 outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); 130 outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); 131 132 /* set up the sysfs linkage to our parent device */ 133 vt586b_adapter.dev.parent = &dev->dev; 134 135 res = i2c_bit_add_bus(&vt586b_adapter); 136 if ( res < 0 ) { 137 release_region(I2C_DIR, IOSPACE); 138 pm_io_base = 0; 139 return res; 140 } 141 return 0; 142 } 143 144 static void vt586b_remove(struct pci_dev *dev) 145 { 146 i2c_del_adapter(&vt586b_adapter); 147 release_region(I2C_DIR, IOSPACE); 148 pm_io_base = 0; 149 } 150 151 152 static struct pci_driver vt586b_driver = { 153 .name = "vt586b_smbus", 154 .id_table = vt586b_ids, 155 .probe = vt586b_probe, 156 .remove = vt586b_remove, 157 }; 158 159 module_pci_driver(vt586b_driver); 160 161 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>"); 162 MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); 163 MODULE_LICENSE("GPL"); 164