| /* |
| 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. |
| */ |
| |
| /* |
| 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/platform_device.h> |
| #include <linux/kernel.h> |
| #include <linux/delay.h> |
| #include <linux/stddef.h> |
| #include <linux/ioport.h> |
| #include <linux/i2c.h> |
| #include <linux/io.h> |
| #include <linux/acpi.h> |
| |
| /* SCH SMBus address offsets */ |
| #define SMBHSTCNT (0 + sch_smba) |
| #define SMBHSTSTS (1 + sch_smba) |
| #define SMBHSTCLK (2 + 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) |
| |
| /* Other settings */ |
| #define MAX_RETRIES 5000 |
| |
| /* 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 i2c_adapter sch_adapter; |
| static int backbone_speed = 33000; /* backbone speed in kHz */ |
| module_param(backbone_speed, int, S_IRUSR | S_IWUSR); |
| MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)"); |
| |
| /* |
| * 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 retries = 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 { |
| usleep_range(100, 200); |
| temp = inb(SMBHSTSTS) & 0x0f; |
| } while ((temp & 0x08) && (retries++ < MAX_RETRIES)); |
| |
| /* If the SMBus is still busy, we give up */ |
| if (retries > MAX_RETRIES) { |
| 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 transferred 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; |
| } |
| temp = inw(SMBHSTCLK); |
| if (!temp) { |
| /* |
| * We can't determine if we have 33 or 25 MHz clock for |
| * SMBus, so expect 33 MHz and calculate a bus clock of |
| * 100 kHz. If we actually run at 25 MHz the bus will be |
| * run ~75 kHz instead which should do no harm. |
| */ |
| dev_notice(&sch_adapter.dev, |
| "Clock divider unitialized. Setting defaults\n"); |
| outw(backbone_speed / (4 * 100), SMBHSTCLK); |
| } |
| |
| 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 int smbus_sch_probe(struct platform_device *dev) |
| { |
| struct resource *res; |
| int retval; |
| |
| res = platform_get_resource(dev, IORESOURCE_IO, 0); |
| if (!res) |
| return -EBUSY; |
| |
| if (!devm_request_region(&dev->dev, res->start, resource_size(res), |
| dev->name)) { |
| dev_err(&dev->dev, "SMBus region 0x%x already in use!\n", |
| sch_smba); |
| return -EBUSY; |
| } |
| |
| sch_smba = res->start; |
| |
| 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"); |
| sch_smba = 0; |
| } |
| |
| return retval; |
| } |
| |
| static int smbus_sch_remove(struct platform_device *pdev) |
| { |
| if (sch_smba) { |
| i2c_del_adapter(&sch_adapter); |
| sch_smba = 0; |
| } |
| |
| return 0; |
| } |
| |
| static struct platform_driver smbus_sch_driver = { |
| .driver = { |
| .name = "isch_smbus", |
| .owner = THIS_MODULE, |
| }, |
| .probe = smbus_sch_probe, |
| .remove = smbus_sch_remove, |
| }; |
| |
| module_platform_driver(smbus_sch_driver); |
| |
| MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>"); |
| MODULE_DESCRIPTION("Intel SCH SMBus driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:isch_smbus"); |