--- /dev/null
+/*
+ i2c-isch.c - Linux kernel driver for Intel SCH chipset SMBus
+ - Based on i2c-piix4.c
+ Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
+ Philip Edelbrock <phil@netroedge.com>
+ - Intel SCH support
+ Copyright (c) 2007 - 2008 Jacob Jun Pan <jacob.jun.pan@intel.com>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License version 2 as
+ published by the Free Software Foundation.
+
+ 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.
+*/
+
+/*
+ Supports:
+ Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
+ Note: we assume there can only be one device, 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/io.h>
+
+/* SCH SMBus address offsets */
+#define SMBHSTCNT (0 + sch_smba)
+#define SMBHSTSTS (1 + sch_smba)
+#define SMBHSTADD (4 + sch_smba) /* TSA */
+#define SMBHSTCMD (5 + sch_smba)
+#define SMBHSTDAT0 (6 + sch_smba)
+#define SMBHSTDAT1 (7 + sch_smba)
+#define SMBBLKDAT (0x20 + sch_smba)
+
+/* count for request_region */
+#define SMBIOSIZE 64
+
+/* PCI Address Constants */
+#define SMBBA_SCH 0x40
+
+/* Other settings */
+#define MAX_TIMEOUT 500
+
+/* I2C constants */
+#define SCH_QUICK 0x00
+#define SCH_BYTE 0x01
+#define SCH_BYTE_DATA 0x02
+#define SCH_WORD_DATA 0x03
+#define SCH_BLOCK_DATA 0x05
+
+static unsigned short sch_smba;
+static struct pci_driver sch_driver;
+static struct i2c_adapter sch_adapter;
+
+/*
+ * Start the i2c transaction -- the i2c_access will prepare the transaction
+ * and this function will execute it.
+ * return 0 for success and others for failure.
+ */
+static int sch_transaction(void)
+{
+ int temp;
+ int result = 0;
+ int timeout = 0;
+
+ dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
+ "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
+ inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
+ inb(SMBHSTDAT1));
+
+ /* Make sure the SMBus host is ready to start transmitting */
+ temp = inb(SMBHSTSTS) & 0x0f;
+ if (temp) {
+ /* Can not be busy since we checked it in sch_access */
+ if (temp & 0x01) {
+ dev_dbg(&sch_adapter.dev, "Completion (%02x). "
+ "Clear...\n", temp);
+ }
+ if (temp & 0x06) {
+ dev_dbg(&sch_adapter.dev, "SMBus error (%02x). "
+ "Resetting...\n", temp);
+ }
+ outb(temp, SMBHSTSTS);
+ temp = inb(SMBHSTSTS) & 0x0f;
+ if (temp) {
+ dev_err(&sch_adapter.dev,
+ "SMBus is not ready: (%02x)\n", temp);
+ return -EAGAIN;
+ }
+ }
+
+ /* start the transaction by setting bit 4 */
+ outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT);
+
+ do {
+ msleep(1);
+ temp = inb(SMBHSTSTS) & 0x0f;
+ } while ((temp & 0x08) && (timeout++ < MAX_TIMEOUT));
+
+ /* If the SMBus is still busy, we give up */
+ if (timeout >= MAX_TIMEOUT) {
+ dev_err(&sch_adapter.dev, "SMBus Timeout!\n");
+ result = -ETIMEDOUT;
+ }
+ if (temp & 0x04) {
+ result = -EIO;
+ dev_dbg(&sch_adapter.dev, "Bus collision! SMBus may be "
+ "locked until next hard reset. (sorry!)\n");
+ /* Clock stops and slave is stuck in mid-transmission */
+ } else if (temp & 0x02) {
+ result = -EIO;
+ dev_err(&sch_adapter.dev, "Error: no response!\n");
+ } else if (temp & 0x01) {
+ dev_dbg(&sch_adapter.dev, "Post complete!\n");
+ outb(temp, SMBHSTSTS);
+ temp = inb(SMBHSTSTS) & 0x07;
+ if (temp & 0x06) {
+ /* Completion clear failed */
+ dev_dbg(&sch_adapter.dev, "Failed reset at end of "
+ "transaction (%02x), Bus error!\n", temp);
+ }
+ } else {
+ result = -ENXIO;
+ dev_dbg(&sch_adapter.dev, "No such address.\n");
+ }
+ dev_dbg(&sch_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
+ "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT),
+ inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
+ inb(SMBHSTDAT1));
+ return result;
+}
+
+/*
+ * This is the main access entry for i2c-sch access
+ * adap is i2c_adapter pointer, addr is the i2c device bus address, read_write
+ * (0 for read and 1 for write), size is i2c transaction type and data is the
+ * union of transaction for data to be transfered or data read from bus.
+ * return 0 for success and others for failure.
+ */
+static s32 sch_access(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data)
+{
+ int i, len, temp, rc;
+
+ /* Make sure the SMBus host is not busy */
+ temp = inb(SMBHSTSTS) & 0x0f;
+ if (temp & 0x08) {
+ dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp);
+ return -EAGAIN;
+ }
+ dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size,
+ (read_write)?"READ":"WRITE");
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ outb((addr << 1) | read_write, SMBHSTADD);
+ size = SCH_QUICK;
+ break;
+ case I2C_SMBUS_BYTE:
+ outb((addr << 1) | read_write, SMBHSTADD);
+ if (read_write == I2C_SMBUS_WRITE)
+ outb(command, SMBHSTCMD);
+ size = SCH_BYTE;
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ outb((addr << 1) | read_write, SMBHSTADD);
+ outb(command, SMBHSTCMD);
+ if (read_write == I2C_SMBUS_WRITE)
+ outb(data->byte, SMBHSTDAT0);
+ size = SCH_BYTE_DATA;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ outb((addr << 1) | read_write, SMBHSTADD);
+ outb(command, SMBHSTCMD);
+ if (read_write == I2C_SMBUS_WRITE) {
+ outb(data->word & 0xff, SMBHSTDAT0);
+ outb((data->word & 0xff00) >> 8, SMBHSTDAT1);
+ }
+ size = SCH_WORD_DATA;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ outb((addr << 1) | read_write, SMBHSTADD);
+ outb(command, SMBHSTCMD);
+ if (read_write == I2C_SMBUS_WRITE) {
+ len = data->block[0];
+ if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
+ return -EINVAL;
+ outb(len, SMBHSTDAT0);
+ for (i = 1; i <= len; i++)
+ outb(data->block[i], SMBBLKDAT+i-1);
+ }
+ size = SCH_BLOCK_DATA;
+ break;
+ default:
+ dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
+ return -EOPNOTSUPP;
+ }
+ dev_dbg(&sch_adapter.dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);
+ outb((inb(SMBHSTCNT) & 0xb0) | (size & 0x7), SMBHSTCNT);
+
+ rc = sch_transaction();
+ if (rc) /* Error in transaction */
+ return rc;
+
+ if ((read_write == I2C_SMBUS_WRITE) || (size == SCH_QUICK))
+ return 0;
+
+ switch (size) {
+ case SCH_BYTE:
+ case SCH_BYTE_DATA:
+ data->byte = inb(SMBHSTDAT0);
+ break;
+ case SCH_WORD_DATA:
+ data->word = inb(SMBHSTDAT0) + (inb(SMBHSTDAT1) << 8);
+ break;
+ case SCH_BLOCK_DATA:
+ data->block[0] = inb(SMBHSTDAT0);
+ if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
+ return -EPROTO;
+ for (i = 1; i <= data->block[0]; i++)
+ data->block[i] = inb(SMBBLKDAT+i-1);
+ break;
+ }
+ return 0;
+}
+
+static u32 sch_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_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm smbus_algorithm = {
+ .smbus_xfer = sch_access,
+ .functionality = sch_func,
+};
+
+static struct i2c_adapter sch_adapter = {
+ .owner = THIS_MODULE,
+ .class = I2C_CLASS_HWMON,
+ .algo = &smbus_algorithm,
+};
+
+static struct pci_device_id sch_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, sch_ids);
+
+static int __devinit sch_probe(struct pci_dev *dev,
+ const struct pci_device_id *id)
+{
+ int retval;
+ unsigned int smba;
+
+ pci_read_config_dword(dev, SMBBA_SCH, &smba);
+ if (!(smba & (1 << 31))) {
+ dev_err(&dev->dev, "SMBus I/O space disabled!\n");
+ return -ENODEV;
+ }
+
+ sch_smba = (unsigned short)smba;
+ if (sch_smba == 0) {
+ dev_err(&dev->dev, "SMBus base address uninitialized!\n");
+ return -ENODEV;
+ }
+ if (!request_region(sch_smba, SMBIOSIZE, sch_driver.name)) {
+ dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
+ sch_smba);
+ return -EBUSY;
+ }
+ dev_dbg(&dev->dev, "SMBA = 0x%X\n", sch_smba);
+
+ /* set up the sysfs linkage to our parent device */
+ sch_adapter.dev.parent = &dev->dev;
+
+ snprintf(sch_adapter.name, sizeof(sch_adapter.name),
+ "SMBus SCH adapter at %04x", sch_smba);
+
+ retval = i2c_add_adapter(&sch_adapter);
+ if (retval) {
+ dev_err(&dev->dev, "Couldn't register adapter!\n");
+ release_region(sch_smba, SMBIOSIZE);
+ sch_smba = 0;
+ }
+
+ return retval;
+}
+
+static void __devexit sch_remove(struct pci_dev *dev)
+{
+ if (sch_smba) {
+ i2c_del_adapter(&sch_adapter);
+ release_region(sch_smba, SMBIOSIZE);
+ sch_smba = 0;
+ }
+}
+
+static struct pci_driver sch_driver = {
+ .name = "isch_smbus",
+ .id_table = sch_ids,
+ .probe = sch_probe,
+ .remove = __devexit_p(sch_remove),
+};
+
+static int __init i2c_sch_init(void)
+{
+ return pci_register_driver(&sch_driver);
+}
+
+static void __exit i2c_sch_exit(void)
+{
+ pci_unregister_driver(&sch_driver);
+}
+
+MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>");
+MODULE_DESCRIPTION("Intel SCH SMBus driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_sch_init);
+module_exit(i2c_sch_exit);
projects / cascardo / linux.git / commitdiff