1 /* 2 Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com> 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 19 /* 20 This module must be considered BETA unless and until 21 the chipset manufacturer releases a datasheet. 22 The register definitions are based on the SiS630. 23 24 This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c) 25 for just about every machine for which users have reported. 26 If this module isn't detecting your 96x south bridge, have a 27 look there. 28 29 We assume there can only be one SiS96x with one SMBus interface. 30 */ 31 32 #include <linux/module.h> 33 #include <linux/pci.h> 34 #include <linux/kernel.h> 35 #include <linux/delay.h> 36 #include <linux/stddef.h> 37 #include <linux/ioport.h> 38 #include <linux/i2c.h> 39 #include <linux/init.h> 40 #include <linux/acpi.h> 41 #include <linux/io.h> 42 43 /* base address register in PCI config space */ 44 #define SIS96x_BAR 0x04 45 46 /* SiS96x SMBus registers */ 47 #define SMB_STS 0x00 48 #define SMB_EN 0x01 49 #define SMB_CNT 0x02 50 #define SMB_HOST_CNT 0x03 51 #define SMB_ADDR 0x04 52 #define SMB_CMD 0x05 53 #define SMB_PCOUNT 0x06 54 #define SMB_COUNT 0x07 55 #define SMB_BYTE 0x08 56 #define SMB_DEV_ADDR 0x10 57 #define SMB_DB0 0x11 58 #define SMB_DB1 0x12 59 #define SMB_SAA 0x13 60 61 /* register count for request_region */ 62 #define SMB_IOSIZE 0x20 63 64 /* Other settings */ 65 #define MAX_TIMEOUT 500 66 67 /* SiS96x SMBus constants */ 68 #define SIS96x_QUICK 0x00 69 #define SIS96x_BYTE 0x01 70 #define SIS96x_BYTE_DATA 0x02 71 #define SIS96x_WORD_DATA 0x03 72 #define SIS96x_PROC_CALL 0x04 73 #define SIS96x_BLOCK_DATA 0x05 74 75 static struct pci_driver sis96x_driver; 76 static struct i2c_adapter sis96x_adapter; 77 static u16 sis96x_smbus_base; 78 79 static inline u8 sis96x_read(u8 reg) 80 { 81 return inb(sis96x_smbus_base + reg) ; 82 } 83 84 static inline void sis96x_write(u8 reg, u8 data) 85 { 86 outb(data, sis96x_smbus_base + reg) ; 87 } 88 89 /* Execute a SMBus transaction. 90 int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA 91 */ 92 static int sis96x_transaction(int size) 93 { 94 int temp; 95 int result = 0; 96 int timeout = 0; 97 98 dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size); 99 100 /* Make sure the SMBus host is ready to start transmitting */ 101 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) { 102 103 dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). " 104 "Resetting...\n", temp); 105 106 /* kill the transaction */ 107 sis96x_write(SMB_HOST_CNT, 0x20); 108 109 /* check it again */ 110 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) { 111 dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp); 112 return -EBUSY; 113 } else { 114 dev_dbg(&sis96x_adapter.dev, "Successful\n"); 115 } 116 } 117 118 /* Turn off timeout interrupts, set fast host clock */ 119 sis96x_write(SMB_CNT, 0x20); 120 121 /* clear all (sticky) status flags */ 122 temp = sis96x_read(SMB_STS); 123 sis96x_write(SMB_STS, temp & 0x1e); 124 125 /* start the transaction by setting bit 4 and size bits */ 126 sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07)); 127 128 /* We will always wait for a fraction of a second! */ 129 do { 130 msleep(1); 131 temp = sis96x_read(SMB_STS); 132 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT)); 133 134 /* If the SMBus is still busy, we give up */ 135 if (timeout > MAX_TIMEOUT) { 136 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp); 137 result = -ETIMEDOUT; 138 } 139 140 /* device error - probably missing ACK */ 141 if (temp & 0x02) { 142 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n"); 143 result = -ENXIO; 144 } 145 146 /* bus collision */ 147 if (temp & 0x04) { 148 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n"); 149 result = -EIO; 150 } 151 152 /* Finish up by resetting the bus */ 153 sis96x_write(SMB_STS, temp); 154 if ((temp = sis96x_read(SMB_STS))) { 155 dev_dbg(&sis96x_adapter.dev, "Failed reset at " 156 "end of transaction! (0x%02x)\n", temp); 157 } 158 159 return result; 160 } 161 162 /* Return negative errno on error. */ 163 static s32 sis96x_access(struct i2c_adapter * adap, u16 addr, 164 unsigned short flags, char read_write, 165 u8 command, int size, union i2c_smbus_data * data) 166 { 167 int status; 168 169 switch (size) { 170 case I2C_SMBUS_QUICK: 171 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); 172 size = SIS96x_QUICK; 173 break; 174 175 case I2C_SMBUS_BYTE: 176 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); 177 if (read_write == I2C_SMBUS_WRITE) 178 sis96x_write(SMB_CMD, command); 179 size = SIS96x_BYTE; 180 break; 181 182 case I2C_SMBUS_BYTE_DATA: 183 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); 184 sis96x_write(SMB_CMD, command); 185 if (read_write == I2C_SMBUS_WRITE) 186 sis96x_write(SMB_BYTE, data->byte); 187 size = SIS96x_BYTE_DATA; 188 break; 189 190 case I2C_SMBUS_PROC_CALL: 191 case I2C_SMBUS_WORD_DATA: 192 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); 193 sis96x_write(SMB_CMD, command); 194 if (read_write == I2C_SMBUS_WRITE) { 195 sis96x_write(SMB_BYTE, data->word & 0xff); 196 sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8); 197 } 198 size = (size == I2C_SMBUS_PROC_CALL ? 199 SIS96x_PROC_CALL : SIS96x_WORD_DATA); 200 break; 201 202 default: 203 dev_warn(&adap->dev, "Unsupported transaction %d\n", size); 204 return -EOPNOTSUPP; 205 } 206 207 status = sis96x_transaction(size); 208 if (status) 209 return status; 210 211 if ((size != SIS96x_PROC_CALL) && 212 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK))) 213 return 0; 214 215 switch (size) { 216 case SIS96x_BYTE: 217 case SIS96x_BYTE_DATA: 218 data->byte = sis96x_read(SMB_BYTE); 219 break; 220 221 case SIS96x_WORD_DATA: 222 case SIS96x_PROC_CALL: 223 data->word = sis96x_read(SMB_BYTE) + 224 (sis96x_read(SMB_BYTE + 1) << 8); 225 break; 226 } 227 return 0; 228 } 229 230 static u32 sis96x_func(struct i2c_adapter *adapter) 231 { 232 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 233 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 234 I2C_FUNC_SMBUS_PROC_CALL; 235 } 236 237 static const struct i2c_algorithm smbus_algorithm = { 238 .smbus_xfer = sis96x_access, 239 .functionality = sis96x_func, 240 }; 241 242 static struct i2c_adapter sis96x_adapter = { 243 .owner = THIS_MODULE, 244 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 245 .algo = &smbus_algorithm, 246 }; 247 248 static DEFINE_PCI_DEVICE_TABLE(sis96x_ids) = { 249 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) }, 250 { 0, } 251 }; 252 253 MODULE_DEVICE_TABLE (pci, sis96x_ids); 254 255 static int sis96x_probe(struct pci_dev *dev, 256 const struct pci_device_id *id) 257 { 258 u16 ww = 0; 259 int retval; 260 261 if (sis96x_smbus_base) { 262 dev_err(&dev->dev, "Only one device supported.\n"); 263 return -EBUSY; 264 } 265 266 pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww); 267 if (PCI_CLASS_SERIAL_SMBUS != ww) { 268 dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww); 269 return -ENODEV; 270 } 271 272 sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR); 273 if (!sis96x_smbus_base) { 274 dev_err(&dev->dev, "SiS96x SMBus base address " 275 "not initialized!\n"); 276 return -EINVAL; 277 } 278 dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n", 279 sis96x_smbus_base); 280 281 retval = acpi_check_resource_conflict(&dev->resource[SIS96x_BAR]); 282 if (retval) 283 return -ENODEV; 284 285 /* Everything is happy, let's grab the memory and set things up. */ 286 if (!request_region(sis96x_smbus_base, SMB_IOSIZE, 287 sis96x_driver.name)) { 288 dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x " 289 "already in use!\n", sis96x_smbus_base, 290 sis96x_smbus_base + SMB_IOSIZE - 1); 291 292 sis96x_smbus_base = 0; 293 return -EINVAL; 294 } 295 296 /* set up the sysfs linkage to our parent device */ 297 sis96x_adapter.dev.parent = &dev->dev; 298 299 snprintf(sis96x_adapter.name, sizeof(sis96x_adapter.name), 300 "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base); 301 302 if ((retval = i2c_add_adapter(&sis96x_adapter))) { 303 dev_err(&dev->dev, "Couldn't register adapter!\n"); 304 release_region(sis96x_smbus_base, SMB_IOSIZE); 305 sis96x_smbus_base = 0; 306 } 307 308 return retval; 309 } 310 311 static void sis96x_remove(struct pci_dev *dev) 312 { 313 if (sis96x_smbus_base) { 314 i2c_del_adapter(&sis96x_adapter); 315 release_region(sis96x_smbus_base, SMB_IOSIZE); 316 sis96x_smbus_base = 0; 317 } 318 } 319 320 static struct pci_driver sis96x_driver = { 321 .name = "sis96x_smbus", 322 .id_table = sis96x_ids, 323 .probe = sis96x_probe, 324 .remove = sis96x_remove, 325 }; 326 327 module_pci_driver(sis96x_driver); 328 329 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); 330 MODULE_DESCRIPTION("SiS96x SMBus driver"); 331 MODULE_LICENSE("GPL"); 332