diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-isch.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-isch.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c new file mode 100644 index 0000000..b9c01aa --- /dev/null +++ b/drivers/i2c/busses/i2c-isch.c @@ -0,0 +1,339 @@ +/* + 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> +#include <linux/acpi.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 | I2C_CLASS_SPD, + .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 (acpi_check_region(sch_smba, SMBIOSIZE, sch_driver.name)) + return -EBUSY; + 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); |
