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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>4 5*/6 7/*8 This module must be considered BETA unless and until9 the chipset manufacturer releases a datasheet.10 The register definitions are based on the SiS630.11 12 This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c)13 for just about every machine for which users have reported.14 If this module isn't detecting your 96x south bridge, have a 15 look there.16 17 We assume there can only be one SiS96x with one SMBus interface.18*/19 20#include <linux/module.h>21#include <linux/pci.h>22#include <linux/kernel.h>23#include <linux/delay.h>24#include <linux/stddef.h>25#include <linux/ioport.h>26#include <linux/i2c.h>27#include <linux/acpi.h>28#include <linux/io.h>29 30/* base address register in PCI config space */31#define SIS96x_BAR 0x0432 33/* SiS96x SMBus registers */34#define SMB_STS 0x0035#define SMB_EN 0x0136#define SMB_CNT 0x0237#define SMB_HOST_CNT 0x0338#define SMB_ADDR 0x0439#define SMB_CMD 0x0540#define SMB_PCOUNT 0x0641#define SMB_COUNT 0x0742#define SMB_BYTE 0x0843#define SMB_DEV_ADDR 0x1044#define SMB_DB0 0x1145#define SMB_DB1 0x1246#define SMB_SAA 0x1347 48/* register count for request_region */49#define SMB_IOSIZE 0x2050 51/* Other settings */52#define MAX_TIMEOUT 50053 54/* SiS96x SMBus constants */55#define SIS96x_QUICK 0x0056#define SIS96x_BYTE 0x0157#define SIS96x_BYTE_DATA 0x0258#define SIS96x_WORD_DATA 0x0359#define SIS96x_PROC_CALL 0x0460#define SIS96x_BLOCK_DATA 0x0561 62static struct pci_driver sis96x_driver;63static struct i2c_adapter sis96x_adapter;64static u16 sis96x_smbus_base;65 66static inline u8 sis96x_read(u8 reg)67{68 return inb(sis96x_smbus_base + reg) ;69}70 71static inline void sis96x_write(u8 reg, u8 data)72{73 outb(data, sis96x_smbus_base + reg) ;74}75 76/* Execute a SMBus transaction.77 int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA78 */79static int sis96x_transaction(int size)80{81 int temp;82 int result = 0;83 int timeout = 0;84 85 dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);86 87 /* Make sure the SMBus host is ready to start transmitting */88 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {89 90 dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "91 "Resetting...\n", temp);92 93 /* kill the transaction */94 sis96x_write(SMB_HOST_CNT, 0x20);95 96 /* check it again */97 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {98 dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);99 return -EBUSY;100 } else {101 dev_dbg(&sis96x_adapter.dev, "Successful\n");102 }103 }104 105 /* Turn off timeout interrupts, set fast host clock */106 sis96x_write(SMB_CNT, 0x20);107 108 /* clear all (sticky) status flags */109 temp = sis96x_read(SMB_STS);110 sis96x_write(SMB_STS, temp & 0x1e);111 112 /* start the transaction by setting bit 4 and size bits */113 sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));114 115 /* We will always wait for a fraction of a second! */116 do {117 msleep(1);118 temp = sis96x_read(SMB_STS);119 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));120 121 /* If the SMBus is still busy, we give up */122 if (timeout > MAX_TIMEOUT) {123 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);124 result = -ETIMEDOUT;125 }126 127 /* device error - probably missing ACK */128 if (temp & 0x02) {129 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");130 result = -ENXIO;131 }132 133 /* bus collision */134 if (temp & 0x04) {135 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");136 result = -EIO;137 }138 139 /* Finish up by resetting the bus */140 sis96x_write(SMB_STS, temp);141 if ((temp = sis96x_read(SMB_STS))) {142 dev_dbg(&sis96x_adapter.dev, "Failed reset at "143 "end of transaction! (0x%02x)\n", temp);144 }145 146 return result;147}148 149/* Return negative errno on error. */150static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,151 unsigned short flags, char read_write,152 u8 command, int size, union i2c_smbus_data * data)153{154 int status;155 156 switch (size) {157 case I2C_SMBUS_QUICK:158 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));159 size = SIS96x_QUICK;160 break;161 162 case I2C_SMBUS_BYTE:163 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));164 if (read_write == I2C_SMBUS_WRITE)165 sis96x_write(SMB_CMD, command);166 size = SIS96x_BYTE;167 break;168 169 case I2C_SMBUS_BYTE_DATA:170 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));171 sis96x_write(SMB_CMD, command);172 if (read_write == I2C_SMBUS_WRITE)173 sis96x_write(SMB_BYTE, data->byte);174 size = SIS96x_BYTE_DATA;175 break;176 177 case I2C_SMBUS_PROC_CALL:178 case I2C_SMBUS_WORD_DATA:179 sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));180 sis96x_write(SMB_CMD, command);181 if (read_write == I2C_SMBUS_WRITE) {182 sis96x_write(SMB_BYTE, data->word & 0xff);183 sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);184 }185 size = (size == I2C_SMBUS_PROC_CALL ? 186 SIS96x_PROC_CALL : SIS96x_WORD_DATA);187 break;188 189 default:190 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);191 return -EOPNOTSUPP;192 }193 194 status = sis96x_transaction(size);195 if (status)196 return status;197 198 if ((size != SIS96x_PROC_CALL) &&199 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))200 return 0;201 202 switch (size) {203 case SIS96x_BYTE:204 case SIS96x_BYTE_DATA:205 data->byte = sis96x_read(SMB_BYTE);206 break;207 208 case SIS96x_WORD_DATA:209 case SIS96x_PROC_CALL:210 data->word = sis96x_read(SMB_BYTE) +211 (sis96x_read(SMB_BYTE + 1) << 8);212 break;213 }214 return 0;215}216 217static u32 sis96x_func(struct i2c_adapter *adapter)218{219 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |220 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |221 I2C_FUNC_SMBUS_PROC_CALL;222}223 224static const struct i2c_algorithm smbus_algorithm = {225 .smbus_xfer = sis96x_access,226 .functionality = sis96x_func,227};228 229static struct i2c_adapter sis96x_adapter = {230 .owner = THIS_MODULE,231 .class = I2C_CLASS_HWMON,232 .algo = &smbus_algorithm,233};234 235static const struct pci_device_id sis96x_ids[] = {236 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },237 { 0, }238};239 240MODULE_DEVICE_TABLE (pci, sis96x_ids);241 242static int sis96x_probe(struct pci_dev *dev,243 const struct pci_device_id *id)244{245 u16 ww = 0;246 int retval;247 248 if (sis96x_smbus_base) {249 dev_err(&dev->dev, "Only one device supported.\n");250 return -EBUSY;251 }252 253 pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww);254 if (PCI_CLASS_SERIAL_SMBUS != ww) {255 dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww);256 return -ENODEV;257 }258 259 sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR);260 if (!sis96x_smbus_base) {261 dev_err(&dev->dev, "SiS96x SMBus base address "262 "not initialized!\n");263 return -EINVAL;264 }265 dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n",266 sis96x_smbus_base);267 268 retval = acpi_check_resource_conflict(&dev->resource[SIS96x_BAR]);269 if (retval)270 return -ENODEV;271 272 /* Everything is happy, let's grab the memory and set things up. */273 if (!request_region(sis96x_smbus_base, SMB_IOSIZE,274 sis96x_driver.name)) {275 dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x "276 "already in use!\n", sis96x_smbus_base,277 sis96x_smbus_base + SMB_IOSIZE - 1);278 279 sis96x_smbus_base = 0;280 return -EINVAL;281 }282 283 /* set up the sysfs linkage to our parent device */284 sis96x_adapter.dev.parent = &dev->dev;285 286 snprintf(sis96x_adapter.name, sizeof(sis96x_adapter.name),287 "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base);288 289 if ((retval = i2c_add_adapter(&sis96x_adapter))) {290 dev_err(&dev->dev, "Couldn't register adapter!\n");291 release_region(sis96x_smbus_base, SMB_IOSIZE);292 sis96x_smbus_base = 0;293 }294 295 return retval;296}297 298static void sis96x_remove(struct pci_dev *dev)299{300 if (sis96x_smbus_base) {301 i2c_del_adapter(&sis96x_adapter);302 release_region(sis96x_smbus_base, SMB_IOSIZE);303 sis96x_smbus_base = 0;304 }305}306 307static struct pci_driver sis96x_driver = {308 .name = "sis96x_smbus",309 .id_table = sis96x_ids,310 .probe = sis96x_probe,311 .remove = sis96x_remove,312};313 314module_pci_driver(sis96x_driver);315 316MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");317MODULE_DESCRIPTION("SiS96x SMBus driver");318MODULE_LICENSE("GPL");319