/* Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* This module must be considered BETA unless and until the chipset manufacturer releases a datasheet. The register definitions are based on the SiS630. This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c) for just about every machine for which users have reported. If this module isn't detecting your 96x south bridge, have a look there. We assume there can only be one SiS96x with one SMBus interface. */ #include <linux/module.h> #include <linux/pci.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/stddef.h> #include <linux/ioport.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/acpi.h> #include <linux/io.h> /* base address register in PCI config space */ #define SIS96x_BAR 0x04 /* SiS96x SMBus registers */ #define SMB_STS 0x00 #define SMB_EN 0x01 #define SMB_CNT 0x02 #define SMB_HOST_CNT 0x03 #define SMB_ADDR 0x04 #define SMB_CMD 0x05 #define SMB_PCOUNT 0x06 #define SMB_COUNT 0x07 #define SMB_BYTE 0x08 #define SMB_DEV_ADDR 0x10 #define SMB_DB0 0x11 #define SMB_DB1 0x12 #define SMB_SAA 0x13 /* register count for request_region */ #define SMB_IOSIZE 0x20 /* Other settings */ #define MAX_TIMEOUT 500 /* SiS96x SMBus constants */ #define SIS96x_QUICK 0x00 #define SIS96x_BYTE 0x01 #define SIS96x_BYTE_DATA 0x02 #define SIS96x_WORD_DATA 0x03 #define SIS96x_PROC_CALL 0x04 #define SIS96x_BLOCK_DATA 0x05 static struct pci_driver sis96x_driver; static struct i2c_adapter sis96x_adapter; static u16 sis96x_smbus_base; static inline u8 sis96x_read(u8 reg) { return inb(sis96x_smbus_base + reg) ; } static inline void sis96x_write(u8 reg, u8 data) { outb(data, sis96x_smbus_base + reg) ; } /* Execute a SMBus transaction. int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA */ static int sis96x_transaction(int size) { int temp; int result = 0; int timeout = 0; dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size); /* Make sure the SMBus host is ready to start transmitting */ if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) { dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). " "Resetting...\n", temp); /* kill the transaction */ sis96x_write(SMB_HOST_CNT, 0x20); /* check it again */ if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) { dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp); return -EBUSY; } else { dev_dbg(&sis96x_adapter.dev, "Successful\n"); } } /* Turn off timeout interrupts, set fast host clock */ sis96x_write(SMB_CNT, 0x20); /* clear all (sticky) status flags */ temp = sis96x_read(SMB_STS); sis96x_write(SMB_STS, temp & 0x1e); /* start the transaction by setting bit 4 and size bits */ sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07)); /* We will always wait for a fraction of a second! */ do { msleep(1); temp = sis96x_read(SMB_STS); } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT)); /* If the SMBus is still busy, we give up */ if (timeout > MAX_TIMEOUT) { dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp); result = -ETIMEDOUT; } /* device error - probably missing ACK */ if (temp & 0x02) { dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n"); result = -ENXIO; } /* bus collision */ if (temp & 0x04) { dev_dbg(&sis96x_adapter.dev, "Bus collision!\n"); result = -EIO; } /* Finish up by resetting the bus */ sis96x_write(SMB_STS, temp); if ((temp = sis96x_read(SMB_STS))) { dev_dbg(&sis96x_adapter.dev, "Failed reset at " "end of transaction! (0x%02x)\n", temp); } return result; } /* Return negative errno on error. */ static s32 sis96x_access(struct i2c_adapter * adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data * data) { int status; switch (size) { case I2C_SMBUS_QUICK: sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); size = SIS96x_QUICK; break; case I2C_SMBUS_BYTE: sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); if (read_write == I2C_SMBUS_WRITE) sis96x_write(SMB_CMD, command); size = SIS96x_BYTE; break; case I2C_SMBUS_BYTE_DATA: sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); sis96x_write(SMB_CMD, command); if (read_write == I2C_SMBUS_WRITE) sis96x_write(SMB_BYTE, data->byte); size = SIS96x_BYTE_DATA; break; case I2C_SMBUS_PROC_CALL: case I2C_SMBUS_WORD_DATA: sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01)); sis96x_write(SMB_CMD, command); if (read_write == I2C_SMBUS_WRITE) { sis96x_write(SMB_BYTE, data->word & 0xff); sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8); } size = (size == I2C_SMBUS_PROC_CALL ? SIS96x_PROC_CALL : SIS96x_WORD_DATA); break; default: dev_warn(&adap->dev, "Unsupported transaction %d\n", size); return -EOPNOTSUPP; } status = sis96x_transaction(size); if (status) return status; if ((size != SIS96x_PROC_CALL) && ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK))) return 0; switch (size) { case SIS96x_BYTE: case SIS96x_BYTE_DATA: data->byte = sis96x_read(SMB_BYTE); break; case SIS96x_WORD_DATA: case SIS96x_PROC_CALL: data->word = sis96x_read(SMB_BYTE) + (sis96x_read(SMB_BYTE + 1) << 8); break; } return 0; } static u32 sis96x_func(struct i2c_adapter *adapter) { return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL; } static const struct i2c_algorithm smbus_algorithm = { .smbus_xfer = sis96x_access, .functionality = sis96x_func, }; static struct i2c_adapter sis96x_adapter = { .owner = THIS_MODULE, .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, .algo = &smbus_algorithm, }; static DEFINE_PCI_DEVICE_TABLE(sis96x_ids) = { { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) }, { 0, } }; MODULE_DEVICE_TABLE (pci, sis96x_ids); static int __devinit sis96x_probe(struct pci_dev *dev, const struct pci_device_id *id) { u16 ww = 0; int retval; if (sis96x_smbus_base) { dev_err(&dev->dev, "Only one device supported.\n"); return -EBUSY; } pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww); if (PCI_CLASS_SERIAL_SMBUS != ww) { dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww); return -ENODEV; } sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR); if (!sis96x_smbus_base) { dev_err(&dev->dev, "SiS96x SMBus base address " "not initialized!\n"); return -EINVAL; } dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n", sis96x_smbus_base); retval = acpi_check_resource_conflict(&dev->resource[SIS96x_BAR]); if (retval) return -ENODEV; /* Everything is happy, let's grab the memory and set things up. */ if (!request_region(sis96x_smbus_base, SMB_IOSIZE, sis96x_driver.name)) { dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x " "already in use!\n", sis96x_smbus_base, sis96x_smbus_base + SMB_IOSIZE - 1); sis96x_smbus_base = 0; return -EINVAL; } /* set up the sysfs linkage to our parent device */ sis96x_adapter.dev.parent = &dev->dev; snprintf(sis96x_adapter.name, sizeof(sis96x_adapter.name), "SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base); if ((retval = i2c_add_adapter(&sis96x_adapter))) { dev_err(&dev->dev, "Couldn't register adapter!\n"); release_region(sis96x_smbus_base, SMB_IOSIZE); sis96x_smbus_base = 0; } return retval; } static void __devexit sis96x_remove(struct pci_dev *dev) { if (sis96x_smbus_base) { i2c_del_adapter(&sis96x_adapter); release_region(sis96x_smbus_base, SMB_IOSIZE); sis96x_smbus_base = 0; } } static struct pci_driver sis96x_driver = { .name = "sis96x_smbus", .id_table = sis96x_ids, .probe = sis96x_probe, .remove = __devexit_p(sis96x_remove), }; static int __init i2c_sis96x_init(void) { return pci_register_driver(&sis96x_driver); } static void __exit i2c_sis96x_exit(void) { pci_unregister_driver(&sis96x_driver); } MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); MODULE_DESCRIPTION("SiS96x SMBus driver"); MODULE_LICENSE("GPL"); /* Register initialization functions using helper macros */ module_init(i2c_sis96x_init); module_exit(i2c_sis96x_exit);