--- /dev/null
+/*
+ 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.
+*/
+
+/*
+ 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/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 const struct pci_device_id sis96x_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE (pci, sis96x_ids);
+
+static int 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 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 = sis96x_remove,
+};
+
+module_pci_driver(sis96x_driver);
+
+MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
+MODULE_DESCRIPTION("SiS96x SMBus driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff