i2c/busses/i2c-ali15x3.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003     Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
0004     Philip Edelbrock <phil@netroedge.com> and
0005     Mark D. Studebaker <mdsxyz123@yahoo.com>
0006
0007 */
0008
0009 /*
0010     This is the driver for the SMB Host controller on
0011     Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
0012
0013     The M1543C is a South bridge for desktop systems.
0014     The M1533 is a South bridge for portable systems.
0015     They are part of the following ALI chipsets:
0016        "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
0017        with AGP and 100MHz CPU Front Side bus
0018        "Aladdin V": Includes the M1541 Socket 7 North bridge
0019        with AGP and 100MHz CPU Front Side bus
0020        "Aladdin IV": Includes the M1541 Socket 7 North bridge
0021        with host bus up to 83.3 MHz.
0022     For an overview of these chips see http://www.acerlabs.com
0023
0024     The M1533/M1543C devices appear as FOUR separate devices
0025     on the PCI bus. An output of lspci will show something similar
0026     to the following:
0027
0028     00:02.0 USB Controller: Acer Laboratories Inc. M5237
0029     00:03.0 Bridge: Acer Laboratories Inc. M7101
0030     00:07.0 ISA bridge: Acer Laboratories Inc. M1533
0031     00:0f.0 IDE interface: Acer Laboratories Inc. M5229
0032
0033     The SMB controller is part of the 7101 device, which is an
0034     ACPI-compliant Power Management Unit (PMU).
0035
0036     The whole 7101 device has to be enabled for the SMB to work.
0037     You can't just enable the SMB alone.
0038     The SMB and the ACPI have separate I/O spaces.
0039     We make sure that the SMB is enabled. We leave the ACPI alone.
0040
0041     This driver controls the SMB Host only.
0042     The SMB Slave controller on the M15X3 is not enabled.
0043
0044     This driver does not use interrupts.
0045 */
0046
0047 /* Note: we assume there can only be one ALI15X3, with one SMBus interface */
0048
0049 #include <linux/module.h>
0050 #include <linux/pci.h>
0051 #include <linux/kernel.h>
0052 #include <linux/stddef.h>
0053 #include <linux/ioport.h>
0054 #include <linux/delay.h>
0055 #include <linux/i2c.h>
0056 #include <linux/acpi.h>
0057 #include <linux/io.h>
0058
0059 /* ALI15X3 SMBus address offsets */
0060 #define SMBHSTSTS   (0 + ali15x3_smba)
0061 #define SMBHSTCNT   (1 + ali15x3_smba)
0062 #define SMBHSTSTART (2 + ali15x3_smba)
0063 #define SMBHSTCMD   (7 + ali15x3_smba)
0064 #define SMBHSTADD   (3 + ali15x3_smba)
0065 #define SMBHSTDAT0  (4 + ali15x3_smba)
0066 #define SMBHSTDAT1  (5 + ali15x3_smba)
0067 #define SMBBLKDAT   (6 + ali15x3_smba)
0068
0069 /* PCI Address Constants */
0070 #define SMBCOM      0x004
0071 #define SMBBA       0x014
0072 #define SMBATPC     0x05B   /* used to unlock xxxBA registers */
0073 #define SMBHSTCFG   0x0E0
0074 #define SMBSLVC     0x0E1
0075 #define SMBCLK      0x0E2
0076 #define SMBREV      0x008
0077
0078 /* Other settings */
0079 #define MAX_TIMEOUT     200 /* times 1/100 sec */
0080 #define ALI15X3_SMB_IOSIZE  32
0081
0082 /* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
0083    We don't use these here. If the bases aren't set to some value we
0084    tell user to upgrade BIOS and we fail.
0085 */
0086 #define ALI15X3_SMB_DEFAULTBASE 0xE800
0087
0088 /* ALI15X3 address lock bits */
0089 #define ALI15X3_LOCK        0x06
0090
0091 /* ALI15X3 command constants */
0092 #define ALI15X3_ABORT       0x02
0093 #define ALI15X3_T_OUT       0x04
0094 #define ALI15X3_QUICK       0x00
0095 #define ALI15X3_BYTE        0x10
0096 #define ALI15X3_BYTE_DATA   0x20
0097 #define ALI15X3_WORD_DATA   0x30
0098 #define ALI15X3_BLOCK_DATA  0x40
0099 #define ALI15X3_BLOCK_CLR   0x80
0100
0101 /* ALI15X3 status register bits */
0102 #define ALI15X3_STS_IDLE    0x04
0103 #define ALI15X3_STS_BUSY    0x08
0104 #define ALI15X3_STS_DONE    0x10
0105 #define ALI15X3_STS_DEV     0x20    /* device error */
0106 #define ALI15X3_STS_COLL    0x40    /* collision or no response */
0107 #define ALI15X3_STS_TERM    0x80    /* terminated by abort */
0108 #define ALI15X3_STS_ERR     0xE0    /* all the bad error bits */
0109
0110
0111 /* If force_addr is set to anything different from 0, we forcibly enable
0112    the device at the given address. */
0113 static u16 force_addr;
0114 module_param_hw(force_addr, ushort, ioport, 0);
0115 MODULE_PARM_DESC(force_addr,
0116          "Initialize the base address of the i2c controller");
0117
0118 static struct pci_driver ali15x3_driver;
0119 static unsigned short ali15x3_smba;
0120
0121 static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
0122 {
0123     u16 a;
0124     unsigned char temp;
0125
0126     /* Check the following things:
0127         - SMB I/O address is initialized
0128         - Device is enabled
0129         - We can use the addresses
0130     */
0131
0132     /* Unlock the register.
0133        The data sheet says that the address registers are read-only
0134        if the lock bits are 1, but in fact the address registers
0135        are zero unless you clear the lock bits.
0136     */
0137     pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
0138     if (temp & ALI15X3_LOCK) {
0139         temp &= ~ALI15X3_LOCK;
0140         pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
0141     }
0142
0143     /* Determine the address of the SMBus area */
0144     pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
0145     ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
0146     if (ali15x3_smba == 0 && force_addr == 0) {
0147         dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
0148             "- upgrade BIOS or use force_addr=0xaddr\n");
0149         return -ENODEV;
0150     }
0151
0152     if(force_addr)
0153         ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
0154
0155     if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
0156                   ali15x3_driver.name))
0157         return -EBUSY;
0158
0159     if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
0160                 ali15x3_driver.name)) {
0161         dev_err(&ALI15X3_dev->dev,
0162             "ALI15X3_smb region 0x%x already in use!\n",
0163             ali15x3_smba);
0164         return -ENODEV;
0165     }
0166
0167     if(force_addr) {
0168         dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
0169             ali15x3_smba);
0170         if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
0171                                 SMBBA,
0172                                 ali15x3_smba))
0173             goto error;
0174         if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
0175                                 SMBBA, &a))
0176             goto error;
0177         if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
0178             /* make sure it works */
0179             dev_err(&ALI15X3_dev->dev,
0180                 "force address failed - not supported?\n");
0181             goto error;
0182         }
0183     }
0184     /* check if whole device is enabled */
0185     pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
0186     if ((temp & 1) == 0) {
0187         dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
0188         pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
0189     }
0190
0191     /* Is SMB Host controller enabled? */
0192     pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
0193     if ((temp & 1) == 0) {
0194         dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
0195         pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
0196     }
0197
0198     /* set SMB clock to 74KHz as recommended in data sheet */
0199     pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
0200
0201     /*
0202       The interrupt routing for SMB is set up in register 0x77 in the
0203       1533 ISA Bridge device, NOT in the 7101 device.
0204       Don't bother with finding the 1533 device and reading the register.
0205     if ((....... & 0x0F) == 1)
0206         dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
0207     */
0208     pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
0209     dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
0210     dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
0211
0212     return 0;
0213 error:
0214     release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
0215     return -ENODEV;
0216 }
0217
0218 /* Another internally used function */
0219 static int ali15x3_transaction(struct i2c_adapter *adap)
0220 {
0221     int temp;
0222     int result = 0;
0223     int timeout = 0;
0224
0225     dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
0226         "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
0227         inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
0228         inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
0229
0230     /* get status */
0231     temp = inb_p(SMBHSTSTS);
0232
0233     /* Make sure the SMBus host is ready to start transmitting */
0234     /* Check the busy bit first */
0235     if (temp & ALI15X3_STS_BUSY) {
0236     /*
0237        If the host controller is still busy, it may have timed out in the
0238        previous transaction, resulting in a "SMBus Timeout" Dev.
0239        I've tried the following to reset a stuck busy bit.
0240         1. Reset the controller with an ABORT command.
0241            (this doesn't seem to clear the controller if an external
0242            device is hung)
0243         2. Reset the controller and the other SMBus devices with a
0244            T_OUT command.  (this clears the host busy bit if an
0245            external device is hung, but it comes back upon a new access
0246            to a device)
0247         3. Disable and reenable the controller in SMBHSTCFG
0248        Worst case, nothing seems to work except power reset.
0249     */
0250     /* Abort - reset the host controller */
0251     /*
0252        Try resetting entire SMB bus, including other devices -
0253        This may not work either - it clears the BUSY bit but
0254        then the BUSY bit may come back on when you try and use the chip again.
0255        If that's the case you are stuck.
0256     */
0257         dev_info(&adap->dev, "Resetting entire SMB Bus to "
0258             "clear busy condition (%02x)\n", temp);
0259         outb_p(ALI15X3_T_OUT, SMBHSTCNT);
0260         temp = inb_p(SMBHSTSTS);
0261     }
0262
0263     /* now check the error bits and the busy bit */
0264     if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
0265         /* do a clear-on-write */
0266         outb_p(0xFF, SMBHSTSTS);
0267         if ((temp = inb_p(SMBHSTSTS)) &
0268             (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
0269             /* this is probably going to be correctable only by a power reset
0270                as one of the bits now appears to be stuck */
0271             /* This may be a bus or device with electrical problems. */
0272             dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
0273                 "controller or device on bus is probably hung\n",
0274                 temp);
0275             return -EBUSY;
0276         }
0277     } else {
0278         /* check and clear done bit */
0279         if (temp & ALI15X3_STS_DONE) {
0280             outb_p(temp, SMBHSTSTS);
0281         }
0282     }
0283
0284     /* start the transaction by writing anything to the start register */
0285     outb_p(0xFF, SMBHSTSTART);
0286
0287     /* We will always wait for a fraction of a second! */
0288     timeout = 0;
0289     do {
0290         msleep(1);
0291         temp = inb_p(SMBHSTSTS);
0292     } while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
0293          && (timeout++ < MAX_TIMEOUT));
0294
0295     /* If the SMBus is still busy, we give up */
0296     if (timeout > MAX_TIMEOUT) {
0297         result = -ETIMEDOUT;
0298         dev_err(&adap->dev, "SMBus Timeout!\n");
0299     }
0300
0301     if (temp & ALI15X3_STS_TERM) {
0302         result = -EIO;
0303         dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
0304     }
0305
0306     /*
0307       Unfortunately the ALI SMB controller maps "no response" and "bus
0308       collision" into a single bit. No response is the usual case so don't
0309       do a printk.
0310       This means that bus collisions go unreported.
0311     */
0312     if (temp & ALI15X3_STS_COLL) {
0313         result = -ENXIO;
0314         dev_dbg(&adap->dev,
0315             "Error: no response or bus collision ADD=%02x\n",
0316             inb_p(SMBHSTADD));
0317     }
0318
0319     /* haven't ever seen this */
0320     if (temp & ALI15X3_STS_DEV) {
0321         result = -EIO;
0322         dev_err(&adap->dev, "Error: device error\n");
0323     }
0324     dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
0325         "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
0326         inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
0327         inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
0328     return result;
0329 }
0330
0331 /* Return negative errno on error. */
0332 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
0333            unsigned short flags, char read_write, u8 command,
0334            int size, union i2c_smbus_data * data)
0335 {
0336     int i, len;
0337     int temp;
0338     int timeout;
0339
0340     /* clear all the bits (clear-on-write) */
0341     outb_p(0xFF, SMBHSTSTS);
0342     /* make sure SMBus is idle */
0343     temp = inb_p(SMBHSTSTS);
0344     for (timeout = 0;
0345          (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
0346          timeout++) {
0347         msleep(1);
0348         temp = inb_p(SMBHSTSTS);
0349     }
0350     if (timeout >= MAX_TIMEOUT) {
0351         dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
0352     }
0353
0354     switch (size) {
0355     case I2C_SMBUS_QUICK:
0356         outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
0357                SMBHSTADD);
0358         size = ALI15X3_QUICK;
0359         break;
0360     case I2C_SMBUS_BYTE:
0361         outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
0362                SMBHSTADD);
0363         if (read_write == I2C_SMBUS_WRITE)
0364             outb_p(command, SMBHSTCMD);
0365         size = ALI15X3_BYTE;
0366         break;
0367     case I2C_SMBUS_BYTE_DATA:
0368         outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
0369                SMBHSTADD);
0370         outb_p(command, SMBHSTCMD);
0371         if (read_write == I2C_SMBUS_WRITE)
0372             outb_p(data->byte, SMBHSTDAT0);
0373         size = ALI15X3_BYTE_DATA;
0374         break;
0375     case I2C_SMBUS_WORD_DATA:
0376         outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
0377                SMBHSTADD);
0378         outb_p(command, SMBHSTCMD);
0379         if (read_write == I2C_SMBUS_WRITE) {
0380             outb_p(data->word & 0xff, SMBHSTDAT0);
0381             outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
0382         }
0383         size = ALI15X3_WORD_DATA;
0384         break;
0385     case I2C_SMBUS_BLOCK_DATA:
0386         outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
0387                SMBHSTADD);
0388         outb_p(command, SMBHSTCMD);
0389         if (read_write == I2C_SMBUS_WRITE) {
0390             len = data->block[0];
0391             if (len < 0) {
0392                 len = 0;
0393                 data->block[0] = len;
0394             }
0395             if (len > 32) {
0396                 len = 32;
0397                 data->block[0] = len;
0398             }
0399             outb_p(len, SMBHSTDAT0);
0400             /* Reset SMBBLKDAT */
0401             outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
0402             for (i = 1; i <= len; i++)
0403                 outb_p(data->block[i], SMBBLKDAT);
0404         }
0405         size = ALI15X3_BLOCK_DATA;
0406         break;
0407     default:
0408         dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
0409         return -EOPNOTSUPP;
0410     }
0411
0412     outb_p(size, SMBHSTCNT);    /* output command */
0413
0414     temp = ali15x3_transaction(adap);
0415     if (temp)
0416         return temp;
0417
0418     if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
0419         return 0;
0420
0421
0422     switch (size) {
0423     case ALI15X3_BYTE:  /* Result put in SMBHSTDAT0 */
0424         data->byte = inb_p(SMBHSTDAT0);
0425         break;
0426     case ALI15X3_BYTE_DATA:
0427         data->byte = inb_p(SMBHSTDAT0);
0428         break;
0429     case ALI15X3_WORD_DATA:
0430         data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
0431         break;
0432     case ALI15X3_BLOCK_DATA:
0433         len = inb_p(SMBHSTDAT0);
0434         if (len > 32)
0435             len = 32;
0436         data->block[0] = len;
0437         /* Reset SMBBLKDAT */
0438         outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
0439         for (i = 1; i <= data->block[0]; i++) {
0440             data->block[i] = inb_p(SMBBLKDAT);
0441             dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
0442                 len, i, data->block[i]);
0443         }
0444         break;
0445     }
0446     return 0;
0447 }
0448
0449 static u32 ali15x3_func(struct i2c_adapter *adapter)
0450 {
0451     return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
0452         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
0453         I2C_FUNC_SMBUS_BLOCK_DATA;
0454 }
0455
0456 static const struct i2c_algorithm smbus_algorithm = {
0457     .smbus_xfer = ali15x3_access,
0458     .functionality  = ali15x3_func,
0459 };
0460
0461 static struct i2c_adapter ali15x3_adapter = {
0462     .owner      = THIS_MODULE,
0463     .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
0464     .algo       = &smbus_algorithm,
0465 };
0466
0467 static const struct pci_device_id ali15x3_ids[] = {
0468     { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
0469     { 0, }
0470 };
0471
0472 MODULE_DEVICE_TABLE (pci, ali15x3_ids);
0473
0474 static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
0475 {
0476     if (ali15x3_setup(dev)) {
0477         dev_err(&dev->dev,
0478             "ALI15X3 not detected, module not inserted.\n");
0479         return -ENODEV;
0480     }
0481
0482     /* set up the sysfs linkage to our parent device */
0483     ali15x3_adapter.dev.parent = &dev->dev;
0484
0485     snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
0486         "SMBus ALI15X3 adapter at %04x", ali15x3_smba);
0487     return i2c_add_adapter(&ali15x3_adapter);
0488 }
0489
0490 static void ali15x3_remove(struct pci_dev *dev)
0491 {
0492     i2c_del_adapter(&ali15x3_adapter);
0493     release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
0494 }
0495
0496 static struct pci_driver ali15x3_driver = {
0497     .name       = "ali15x3_smbus",
0498     .id_table   = ali15x3_ids,
0499     .probe      = ali15x3_probe,
0500     .remove     = ali15x3_remove,
0501 };
0502
0503 module_pci_driver(ali15x3_driver);
0504
0505 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
0506 MODULE_AUTHOR("Philip Edelbrock <phil@netroedge.com>");
0507 MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
0508 MODULE_DESCRIPTION("ALI15X3 SMBus driver");
0509 MODULE_LICENSE("GPL");