i2c-powermac.c

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/*
    i2c Support for Apple SMU Controller

    Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
                       <[email protected]>

    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.

    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.

*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <asm/prom.h>
#include <asm/pmac_low_i2c.h>

MODULE_AUTHOR("Benjamin Herrenschmidt <[email protected]>");
MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
MODULE_LICENSE("GPL");

/*
 * SMBUS-type transfer entrypoint
 */
static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap,
                    u16         addr,
                    unsigned short      flags,
                    char            read_write,
                    u8          command,
                    int         size,
                    union i2c_smbus_data*   data)
{
    struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
    int         rc = 0;
    int         read = (read_write == I2C_SMBUS_READ);
    int         addrdir = (addr << 1) | read;
    int         mode, subsize, len;
    u32         subaddr;
    u8          *buf;
    u8          local[2];

    if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
        mode = pmac_i2c_mode_std;
        subsize = 0;
        subaddr = 0;
    } else {
        mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
        subsize = 1;
        subaddr = command;
    }

    switch (size) {
        case I2C_SMBUS_QUICK:
        buf = NULL;
        len = 0;
            break;
        case I2C_SMBUS_BYTE:
        case I2C_SMBUS_BYTE_DATA:
        buf = &data->byte;
        len = 1;
            break;
        case I2C_SMBUS_WORD_DATA:
        if (!read) {
            local[0] = data->word & 0xff;
            local[1] = (data->word >> 8) & 0xff;
        }
        buf = local;
        len = 2;
            break;

    /* Note that these are broken vs. the expected smbus API where
     * on reads, the length is actually returned from the function,
     * but I think the current API makes no sense and I don't want
     * any driver that I haven't verified for correctness to go
     * anywhere near a pmac i2c bus anyway ...
     *
     * I'm also not completely sure what kind of phases to do between
     * the actual command and the data (what I am _supposed_ to do that
     * is). For now, I assume writes are a single stream and reads have
     * a repeat start/addr phase (but not stop in between)
     */
        case I2C_SMBUS_BLOCK_DATA:
        buf = data->block;
        len = data->block[0] + 1;
        break;
    case I2C_SMBUS_I2C_BLOCK_DATA:
        buf = &data->block[1];
        len = data->block[0];
        break;

        default:
        return -EINVAL;
    }

    rc = pmac_i2c_open(bus, 0);
    if (rc) {
        dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
        return rc;
    }

    rc = pmac_i2c_setmode(bus, mode);
    if (rc) {
        dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
            mode, rc);
        goto bail;
    }

    rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
    if (rc) {
        if (rc == -ENXIO)
            dev_dbg(&adap->dev,
                "I2C transfer at 0x%02x failed, size %d, "
                "err %d\n", addrdir >> 1, size, rc);
        else
            dev_err(&adap->dev,
                "I2C transfer at 0x%02x failed, size %d, "
                "err %d\n", addrdir >> 1, size, rc);
        goto bail;
    }

    if (size == I2C_SMBUS_WORD_DATA && read) {
        data->word = ((u16)local[1]) << 8;
        data->word |= local[0];
    }

 bail:
    pmac_i2c_close(bus);
    return rc;
}

/*
 * Generic i2c master transfer entrypoint. This driver only support single
 * messages (for "lame i2c" transfers). Anything else should use the smbus
 * entry point
 */
static int i2c_powermac_master_xfer(    struct i2c_adapter *adap,
                    struct i2c_msg *msgs,
                    int num)
{
    struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
    int         rc = 0;
    int         read;
    int         addrdir;

    if (num != 1) {
        dev_err(&adap->dev,
            "Multi-message I2C transactions not supported\n");
        return -EOPNOTSUPP;
    }

    if (msgs->flags & I2C_M_TEN)
        return -EINVAL;
    read = (msgs->flags & I2C_M_RD) != 0;
    addrdir = (msgs->addr << 1) | read;

    rc = pmac_i2c_open(bus, 0);
    if (rc) {
        dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
        return rc;
    }
    rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
    if (rc) {
        dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
            pmac_i2c_mode_std, rc);
        goto bail;
    }
    rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
    if (rc < 0) {
        if (rc == -ENXIO)
            dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
                addrdir & 1 ? "read from" : "write to",
                addrdir >> 1, rc);
        else
            dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
                addrdir & 1 ? "read from" : "write to",
                addrdir >> 1, rc);
    }
 bail:
    pmac_i2c_close(bus);
    return rc < 0 ? rc : 1;
}

static u32 i2c_powermac_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 | I2C_FUNC_I2C;
}

/* For now, we only handle smbus */
static const struct i2c_algorithm i2c_powermac_algorithm = {
    .smbus_xfer = i2c_powermac_smbus_xfer,
    .master_xfer    = i2c_powermac_master_xfer,
    .functionality  = i2c_powermac_func,
};


static int __devexit i2c_powermac_remove(struct platform_device *dev)
{
    struct i2c_adapter  *adapter = platform_get_drvdata(dev);
    int         rc;

    rc = i2c_del_adapter(adapter);
    /* We aren't that prepared to deal with this... */
    if (rc)
        printk(KERN_WARNING
               "i2c-powermac.c: Failed to remove bus %s !\n",
               adapter->name);
    platform_set_drvdata(dev, NULL);
    memset(adapter, 0, sizeof(*adapter));

    return 0;
}

static u32 __devinit i2c_powermac_get_addr(struct i2c_adapter *adap,
                       struct pmac_i2c_bus *bus,
                       struct device_node *node)
{
    const __be32 *prop;
    int len;

    /* First check for valid "reg" */
    prop = of_get_property(node, "reg", &len);
    if (prop && (len >= sizeof(int)))
        return (be32_to_cpup(prop) & 0xff) >> 1;

    /* Then check old-style "i2c-address" */
    prop = of_get_property(node, "i2c-address", &len);
    if (prop && (len >= sizeof(int)))
        return (be32_to_cpup(prop) & 0xff) >> 1;

    /* Now handle some devices with missing "reg" properties */
    if (!strcmp(node->name, "cereal"))
        return 0x60;
    else if (!strcmp(node->name, "deq"))
        return 0x34;

    dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);

    return 0xffffffff;
}

static void __devinit i2c_powermac_create_one(struct i2c_adapter *adap,
                          const char *type,
                          u32 addr)
{
    struct i2c_board_info info = {};
    struct i2c_client *newdev;

    strncpy(info.type, type, sizeof(info.type));
    info.addr = addr;
    newdev = i2c_new_device(adap, &info);
    if (!newdev)
        dev_err(&adap->dev,
            "i2c-powermac: Failure to register missing %s\n",
            type);
}

static void __devinit i2c_powermac_add_missing(struct i2c_adapter *adap,
                           struct pmac_i2c_bus *bus,
                           bool found_onyx)
{
    struct device_node *busnode = pmac_i2c_get_bus_node(bus);
    int rc;

    /* Check for the onyx audio codec */
#define ONYX_REG_CONTROL        67
    if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
        union i2c_smbus_data data;

        rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
                    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
                    &data);
        if (rc >= 0)
            i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);

        rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
                    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
                    &data);
        if (rc >= 0)
            i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
    }
}

static bool __devinit i2c_powermac_get_type(struct i2c_adapter *adap,
                        struct device_node *node,
                        u32 addr, char *type, int type_size)
{
    char tmp[16];

    /* Note: we to _NOT_ want the standard
     * i2c drivers to match with any of our powermac stuff
     * unless they have been specifically modified to handle
     * it on a case by case basis. For example, for thermal
     * control, things like lm75 etc... shall match with their
     * corresponding windfarm drivers, _NOT_ the generic ones,
     * so we force a prefix of AAPL, onto the modalias to
     * make that happen
     */

    /* First try proper modalias */
    if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
        snprintf(type, type_size, "MAC,%s", tmp);
        return true;
    }

    /* Now look for known workarounds */
    if (!strcmp(node->name, "deq")) {
        /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
        if (addr == 0x34) {
            snprintf(type, type_size, "MAC,tas3001");
            return true;
        } else if (addr == 0x35) {
            snprintf(type, type_size, "MAC,tas3004");
            return true;
        }
    }

    dev_err(&adap->dev, "i2c-powermac: modalias failure"
        " on %s\n", node->full_name);
    return false;
}

static void __devinit i2c_powermac_register_devices(struct i2c_adapter *adap,
                            struct pmac_i2c_bus *bus)
{
    struct i2c_client *newdev;
    struct device_node *node;
    bool found_onyx = 0;

    /*
     * In some cases we end up with the via-pmu node itself, in this
     * case we skip this function completely as the device-tree will
     * not contain anything useful.
     */
    if (!strcmp(adap->dev.of_node->name, "via-pmu"))
        return;

    for_each_child_of_node(adap->dev.of_node, node) {
        struct i2c_board_info info = {};
        u32 addr;

        /* Get address & channel */
        addr = i2c_powermac_get_addr(adap, bus, node);
        if (addr == 0xffffffff)
            continue;

        /* Multibus setup, check channel */
        if (!pmac_i2c_match_adapter(node, adap))
            continue;

        dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
            node->full_name);

        /*
         * Keep track of some device existence to handle
         * workarounds later.
         */
        if (of_device_is_compatible(node, "pcm3052"))
            found_onyx = true;

        /* Make up a modalias */
        if (!i2c_powermac_get_type(adap, node, addr,
                       info.type, sizeof(info.type))) {
            continue;
        }

        /* Fill out the rest of the info structure */
        info.addr = addr;
        info.irq = irq_of_parse_and_map(node, 0);
        info.of_node = of_node_get(node);

        newdev = i2c_new_device(adap, &info);
        if (!newdev) {
            dev_err(&adap->dev, "i2c-powermac: Failure to register"
                " %s\n", node->full_name);
            of_node_put(node);
            /* We do not dispose of the interrupt mapping on
             * purpose. It's not necessary (interrupt cannot be
             * re-used) and somebody else might have grabbed it
             * via direct DT lookup so let's not bother
             */
            continue;
        }
    }

    /* Additional workarounds */
    i2c_powermac_add_missing(adap, bus, found_onyx);
}

static int __devinit i2c_powermac_probe(struct platform_device *dev)
{
    struct pmac_i2c_bus *bus = dev->dev.platform_data;
    struct device_node *parent = NULL;
    struct i2c_adapter *adapter;
    const char *basename;
    int rc;

    if (bus == NULL)
        return -EINVAL;
    adapter = pmac_i2c_get_adapter(bus);

    /* Ok, now we need to make up a name for the interface that will
     * match what we used to do in the past, that is basically the
     * controller's parent device node for keywest. PMU didn't have a
     * naming convention and SMU has a different one
     */
    switch(pmac_i2c_get_type(bus)) {
    case pmac_i2c_bus_keywest:
        parent = of_get_parent(pmac_i2c_get_controller(bus));
        if (parent == NULL)
            return -EINVAL;
        basename = parent->name;
        break;
    case pmac_i2c_bus_pmu:
        basename = "pmu";
        break;
    case pmac_i2c_bus_smu:
        /* This is not what we used to do but I'm fixing drivers at
         * the same time as this change
         */
        basename = "smu";
        break;
    default:
        return -EINVAL;
    }
    snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
         pmac_i2c_get_channel(bus));
    of_node_put(parent);

    platform_set_drvdata(dev, adapter);
    adapter->algo = &i2c_powermac_algorithm;
    i2c_set_adapdata(adapter, bus);
    adapter->dev.parent = &dev->dev;
    adapter->dev.of_node = dev->dev.of_node;
    rc = i2c_add_adapter(adapter);
    if (rc) {
        printk(KERN_ERR "i2c-powermac: Adapter %s registration "
               "failed\n", adapter->name);
        memset(adapter, 0, sizeof(*adapter));
    }

    printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);

    /* Cannot use of_i2c_register_devices() due to Apple device-tree
     * funkyness
     */
    i2c_powermac_register_devices(adapter, bus);

    return rc;
}

static struct platform_driver i2c_powermac_driver = {
    .probe = i2c_powermac_probe,
    .remove = __devexit_p(i2c_powermac_remove),
    .driver = {
        .name = "i2c-powermac",
        .bus = &platform_bus_type,
    },
};

module_platform_driver(i2c_powermac_driver);

MODULE_ALIAS("platform:i2c-powermac");