[PATCH] i2c: Drop i2c_driver.{owner,name}, 2 of 11

[linux-2.6/linux-loongson.git] / drivers / i2c / chips / x1205.c

/*
 *  x1205.c - An i2c driver for the Xicor X1205 RTC
 *  Copyright 2004 Karen Spearel
 *  Copyright 2005 Alessandro Zummo
 *
 *  please send all reports to:
 *      kas11 at tampabay dot rr dot com
 *      a dot zummo at towertech dot it
 *
 *  based on the other drivers in this same directory.
 *
 *  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.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/string.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/list.h>

#include <linux/x1205.h>

#define DRV_VERSION "0.9.9"

/* Addresses to scan: none. This chip is located at
 * 0x6f and uses a two bytes register addressing.
 * Two bytes need to be written to read a single register,
 * while most other chips just require one and take the second
 * one as the data to be written. To prevent corrupting
 * unknown chips, the user must explicitely set the probe parameter.
 */

static unsigned short normal_i2c[] = { I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD;
I2C_CLIENT_MODULE_PARM(hctosys,
        "Set the system time from the hardware clock upon initialization");

/* offsets into CCR area */

#define CCR_SEC                 0
#define CCR_MIN                 1
#define CCR_HOUR                2
#define CCR_MDAY                3
#define CCR_MONTH               4
#define CCR_YEAR                5
#define CCR_WDAY                6
#define CCR_Y2K                 7

#define X1205_REG_SR            0x3F    /* status register */
#define X1205_REG_Y2K           0x37
#define X1205_REG_DW            0x36
#define X1205_REG_YR            0x35
#define X1205_REG_MO            0x34
#define X1205_REG_DT            0x33
#define X1205_REG_HR            0x32
#define X1205_REG_MN            0x31
#define X1205_REG_SC            0x30
#define X1205_REG_DTR           0x13
#define X1205_REG_ATR           0x12
#define X1205_REG_INT           0x11
#define X1205_REG_0             0x10
#define X1205_REG_Y2K1          0x0F
#define X1205_REG_DWA1          0x0E
#define X1205_REG_YRA1          0x0D
#define X1205_REG_MOA1          0x0C
#define X1205_REG_DTA1          0x0B
#define X1205_REG_HRA1          0x0A
#define X1205_REG_MNA1          0x09
#define X1205_REG_SCA1          0x08
#define X1205_REG_Y2K0          0x07
#define X1205_REG_DWA0          0x06
#define X1205_REG_YRA0          0x05
#define X1205_REG_MOA0          0x04
#define X1205_REG_DTA0          0x03
#define X1205_REG_HRA0          0x02
#define X1205_REG_MNA0          0x01
#define X1205_REG_SCA0          0x00

#define X1205_CCR_BASE          0x30    /* Base address of CCR */
#define X1205_ALM0_BASE         0x00    /* Base address of ALARM0 */

#define X1205_SR_RTCF           0x01    /* Clock failure */
#define X1205_SR_WEL            0x02    /* Write Enable Latch */
#define X1205_SR_RWEL           0x04    /* Register Write Enable */

#define X1205_DTR_DTR0          0x01
#define X1205_DTR_DTR1          0x02
#define X1205_DTR_DTR2          0x04

#define X1205_HR_MIL            0x80    /* Set in ccr.hour for 24 hr mode */

/* Prototypes */
static int x1205_attach(struct i2c_adapter *adapter);
static int x1205_detach(struct i2c_client *client);
static int x1205_probe(struct i2c_adapter *adapter, int address, int kind);
static int x1205_command(struct i2c_client *client, unsigned int cmd,
        void *arg);

static struct i2c_driver x1205_driver = {
        .driver = {
                .owner  = THIS_MODULE,
                .name   = "x1205",
        },
        .attach_adapter = &x1205_attach,
        .detach_client  = &x1205_detach,
};

struct x1205_data {
        struct i2c_client client;
        struct list_head list;
        unsigned int epoch;
};

static const unsigned char days_in_mo[] =
        { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static LIST_HEAD(x1205_clients);

/* Workaround until the I2C subsytem will allow to send
 * commands to a specific client. This function will send the command
 * to the first client.
 */
int x1205_do_command(unsigned int cmd, void *arg)
{
        struct list_head *walk;
        struct list_head *tmp;
        struct x1205_data *data;

        list_for_each_safe(walk, tmp, &x1205_clients) {
                data = list_entry(walk, struct x1205_data, list);
                return x1205_command(&data->client, cmd, arg);
        }

        return -ENODEV;
}

#define is_leap(year) \
        ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))

/* make sure the rtc_time values are in bounds */
static int x1205_validate_tm(struct rtc_time *tm)
{
        int year = tm->tm_year + 1900;

        if ((tm->tm_year < 70) || (tm->tm_year > 255))
                return -EINVAL;

        if ((tm->tm_mon > 11) || (tm->tm_mday == 0))
                return -EINVAL;

        if (tm->tm_mday > days_in_mo[tm->tm_mon]
                + ((tm->tm_mon == 1) && is_leap(year)))
                return -EINVAL;

        if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) || (tm->tm_sec >= 60))
                return -EINVAL;

        return 0;
}

/*
 * In the routines that deal directly with the x1205 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
 * Epoch is initialized as 2000. Time is set to UTC.
 */
static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
                                u8 reg_base)
{
        unsigned char dt_addr[2] = { 0, reg_base };
        static unsigned char sr_addr[2] = { 0, X1205_REG_SR };

        unsigned char buf[8], sr;

        struct i2c_msg msgs[] = {
                { client->addr, 0, 2, sr_addr },        /* setup read ptr */
                { client->addr, I2C_M_RD, 1, &sr },     /* read status */
                { client->addr, 0, 2, dt_addr },        /* setup read ptr */
                { client->addr, I2C_M_RD, 8, buf },     /* read date */
        };

        struct x1205_data *data = i2c_get_clientdata(client);

        /* read status register */
        if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
                dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
                return -EIO;
        }

        /* check for battery failure */
        if (sr & X1205_SR_RTCF) {
                dev_warn(&client->dev,
                        "Clock had a power failure, you must set the date.\n");
                return -EINVAL;
        }

        /* read date registers */
        if ((i2c_transfer(client->adapter, &msgs[2], 2)) != 2) {
                dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
                return -EIO;
        }

        dev_dbg(&client->dev,
                "%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
                "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
                __FUNCTION__,
                buf[0], buf[1], buf[2], buf[3],
                buf[4], buf[5], buf[6], buf[7]);

        tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
        tm->tm_min = BCD2BIN(buf[CCR_MIN]);
        tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
        tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
        tm->tm_mon = BCD2BIN(buf[CCR_MONTH]);
        data->epoch = BCD2BIN(buf[CCR_Y2K]) * 100;
        tm->tm_year = BCD2BIN(buf[CCR_YEAR]) + data->epoch - 1900;
        tm->tm_wday = buf[CCR_WDAY];

        dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __FUNCTION__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

        return 0;
}

static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
                                int datetoo, u8 reg_base)
{
        int i, err, xfer;

        unsigned char buf[8];

        static const unsigned char wel[3] = { 0, X1205_REG_SR,
                                                X1205_SR_WEL };

        static const unsigned char rwel[3] = { 0, X1205_REG_SR,
                                                X1205_SR_WEL | X1205_SR_RWEL };

        static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };

        struct x1205_data *data = i2c_get_clientdata(client);

        /* check if all values in the tm struct are correct */
        if ((err = x1205_validate_tm(tm)) < 0)
                return err;

        dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __FUNCTION__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

        buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
        buf[CCR_MIN] = BIN2BCD(tm->tm_min);

        /* set hour and 24hr bit */
        buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;

        /* should we also set the date? */
        if (datetoo) {
                buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);

                /* month, 0 - 11 */
                buf[CCR_MONTH] = BIN2BCD(tm->tm_mon);

                /* year, since 1900 */
                buf[CCR_YEAR] = BIN2BCD(tm->tm_year + 1900 - data->epoch);
                buf[CCR_WDAY] = tm->tm_wday & 0x07;
                buf[CCR_Y2K] = BIN2BCD(data->epoch / 100);
        }

        /* this sequence is required to unlock the chip */
        xfer = i2c_master_send(client, wel, 3);
        if (xfer != 3) {
                dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);
                return -EIO;
        }

        xfer = i2c_master_send(client, rwel, 3);
        if (xfer != 3) {
                dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer);
                return -EIO;
        }

        /* write register's data */
        for (i = 0; i < (datetoo ? 8 : 3); i++) {
                unsigned char rdata[3] = { 0, reg_base + i, buf[i] };

                xfer = i2c_master_send(client, rdata, 3);
                if (xfer != 3) {
                        dev_err(&client->dev,
                                "%s: xfer=%d addr=%02x, data=%02x\n",
                                __FUNCTION__,
                                 xfer, rdata[1], rdata[2]);
                        return -EIO;
                }
        };

        /* disable further writes */
        xfer = i2c_master_send(client, diswe, 3);
        if (xfer != 3) {
                dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);
                return -EIO;
        }

        return 0;
}

static int x1205_get_dtrim(struct i2c_client *client, int *trim)
{
        unsigned char dtr;
        static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };

        struct i2c_msg msgs[] = {
                { client->addr, 0, 2, dtr_addr },       /* setup read ptr */
                { client->addr, I2C_M_RD, 1, &dtr },    /* read dtr */
        };

        /* read dtr register */
        if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
                dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
                return -EIO;
        }

        dev_dbg(&client->dev, "%s: raw dtr=%x\n", __FUNCTION__, dtr);

        *trim = 0;

        if (dtr & X1205_DTR_DTR0)
                *trim += 20;

        if (dtr & X1205_DTR_DTR1)
                *trim += 10;

        if (dtr & X1205_DTR_DTR2)
                *trim = -*trim;

        return 0;
}

static int x1205_get_atrim(struct i2c_client *client, int *trim)
{
        s8 atr;
        static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };

        struct i2c_msg msgs[] = {
                { client->addr, 0, 2, atr_addr },       /* setup read ptr */
                { client->addr, I2C_M_RD, 1, &atr },    /* read atr */
        };

        /* read atr register */
        if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
                dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
                return -EIO;
        }

        dev_dbg(&client->dev, "%s: raw atr=%x\n", __FUNCTION__, atr);

        /* atr is a two's complement value on 6 bits,
         * perform sign extension. The formula is
         * Catr = (atr * 0.25pF) + 11.00pF.
         */
        if (atr & 0x20)
                atr |= 0xC0;

        dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __FUNCTION__, atr, atr);

        *trim = (atr * 250) + 11000;

        dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim);

        return 0;
}

static int x1205_hctosys(struct i2c_client *client)
{
        int err;

        struct rtc_time tm;
        struct timespec tv;

        err = x1205_command(client, X1205_CMD_GETDATETIME, &tm);

        if (err) {
                dev_err(&client->dev,
                        "Unable to set the system clock\n");
                return err;
        }

        /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
         * whether it stores the most close value or the value with partial
         * seconds truncated. However, it is important that we use it to store
         * the truncated value. This is because otherwise it is necessary,
         * in an rtc sync function, to read both xtime.tv_sec and
         * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
         * of >32bits is not possible. So storing the most close value would
         * slow down the sync API. So here we have the truncated value and
         * the best guess is to add 0.5s.
         */

        tv.tv_nsec = NSEC_PER_SEC >> 1;

        /* WARNING: this is not the C library 'mktime' call, it is a built in
         * inline function from include/linux/time.h.  It expects (requires)
         * the month to be in the range 1-12
         */

        tv.tv_sec  = mktime(tm.tm_year + 1900, tm.tm_mon + 1,
                                tm.tm_mday, tm.tm_hour,
                                tm.tm_min, tm.tm_sec);

        do_settimeofday(&tv);

        dev_info(&client->dev,
                "setting the system clock to %d-%d-%d %d:%d:%d\n",
                tm.tm_year + 1900, tm.tm_mon + 1,
                tm.tm_mday, tm.tm_hour, tm.tm_min,
                tm.tm_sec);

        return 0;
}

struct x1205_limit
{
        unsigned char reg;
        unsigned char mask;
        unsigned char min;
        unsigned char max;
};

static int x1205_validate_client(struct i2c_client *client)
{
        int i, xfer;

        /* Probe array. We will read the register at the specified
         * address and check if the given bits are zero.
         */
        static const unsigned char probe_zero_pattern[] = {
                /* register, mask */
                X1205_REG_SR,   0x18,
                X1205_REG_DTR,  0xF8,
                X1205_REG_ATR,  0xC0,
                X1205_REG_INT,  0x18,
                X1205_REG_0,    0xFF,
        };

        static const struct x1205_limit probe_limits_pattern[] = {
                /* register, mask, min, max */
                { X1205_REG_Y2K,        0xFF,   19,     20      },
                { X1205_REG_DW,         0xFF,   0,      6       },
                { X1205_REG_YR,         0xFF,   0,      99      },
                { X1205_REG_MO,         0xFF,   0,      12      },
                { X1205_REG_DT,         0xFF,   0,      31      },
                { X1205_REG_HR,         0x7F,   0,      23      },
                { X1205_REG_MN,         0xFF,   0,      59      },
                { X1205_REG_SC,         0xFF,   0,      59      },
                { X1205_REG_Y2K1,       0xFF,   19,     20      },
                { X1205_REG_Y2K0,       0xFF,   19,     20      },
        };

        /* check that registers have bits a 0 where expected */
        for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
                unsigned char buf;

                unsigned char addr[2] = { 0, probe_zero_pattern[i] };

                struct i2c_msg msgs[2] = {
                        { client->addr, 0, 2, addr },
                        { client->addr, I2C_M_RD, 1, &buf },
                };

                xfer = i2c_transfer(client->adapter, msgs, 2);
                if (xfer != 2) {
                        dev_err(&client->adapter->dev,
                                "%s: could not read register %x\n",
                                __FUNCTION__, addr[1]);

                        return -EIO;
                }

                if ((buf & probe_zero_pattern[i+1]) != 0) {
                        dev_err(&client->adapter->dev,
                                "%s: register=%02x, zero pattern=%d, value=%x\n",
                                __FUNCTION__, addr[1], i, buf);

                        return -ENODEV;
                }
        }

        /* check limits (only registers with bcd values) */
        for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
                unsigned char reg, value;

                unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };

                struct i2c_msg msgs[2] = {
                        { client->addr, 0, 2, addr },
                        { client->addr, I2C_M_RD, 1, &reg },
                };

                xfer = i2c_transfer(client->adapter, msgs, 2);

                if (xfer != 2) {
                        dev_err(&client->adapter->dev,
                                "%s: could not read register %x\n",
                                __FUNCTION__, addr[1]);

                        return -EIO;
                }

                value = BCD2BIN(reg & probe_limits_pattern[i].mask);

                if (value > probe_limits_pattern[i].max ||
                        value < probe_limits_pattern[i].min) {
                        dev_dbg(&client->adapter->dev,
                                "%s: register=%x, lim pattern=%d, value=%d\n",
                                __FUNCTION__, addr[1], i, value);

                        return -ENODEV;
                }
        }

        return 0;
}

static int x1205_attach(struct i2c_adapter *adapter)
{
        dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);

        return i2c_probe(adapter, &addr_data, x1205_probe);
}

int x1205_direct_attach(int adapter_id,
        struct i2c_client_address_data *address_data)
{
        int err;
        struct i2c_adapter *adapter = i2c_get_adapter(adapter_id);

        if (adapter) {
                err = i2c_probe(adapter,
                        address_data, x1205_probe);

                i2c_put_adapter(adapter);

                return err;
        }

        return -ENODEV;
}

static int x1205_probe(struct i2c_adapter *adapter, int address, int kind)
{
        struct i2c_client *client;
        struct x1205_data *data;

        int err = 0;

        dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);

        if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
                err = -ENODEV;
                goto exit;
        }

        if (!(data = kzalloc(sizeof(struct x1205_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto exit;
        }

        /* Initialize our structures */
        data->epoch = 2000;

        client = &data->client;
        client->addr = address;
        client->driver = &x1205_driver;
        client->adapter = adapter;

        strlcpy(client->name, "x1205", I2C_NAME_SIZE);

        i2c_set_clientdata(client, data);

        /* Verify the chip is really an X1205 */
        if (kind < 0) {
                if (x1205_validate_client(client) < 0) {
                        err = -ENODEV;
                        goto exit_kfree;
                }
        }

        /* Inform the i2c layer */
        if ((err = i2c_attach_client(client)))
                goto exit_kfree;

        list_add(&data->list, &x1205_clients);

        dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");

        /* If requested, set the system time */
        if (hctosys)
                x1205_hctosys(client);

        return 0;

exit_kfree:
        kfree(data);

exit:
        return err;
}

static int x1205_detach(struct i2c_client *client)
{
        int err;
        struct x1205_data *data = i2c_get_clientdata(client);

        dev_dbg(&client->dev, "%s\n", __FUNCTION__);

        if ((err = i2c_detach_client(client)))
                return err;

        list_del(&data->list);

        kfree(data);

        return 0;
}

static int x1205_command(struct i2c_client *client, unsigned int cmd,
        void *param)
{
        if (param == NULL)
                return -EINVAL;

        if (!capable(CAP_SYS_TIME))
                return -EACCES;

        dev_dbg(&client->dev, "%s: cmd=%d\n", __FUNCTION__, cmd);

        switch (cmd) {
        case X1205_CMD_GETDATETIME:
                return x1205_get_datetime(client, param, X1205_CCR_BASE);

        case X1205_CMD_SETTIME:
                return x1205_set_datetime(client, param, 0,
                                X1205_CCR_BASE);

        case X1205_CMD_SETDATETIME:
                return x1205_set_datetime(client, param, 1,
                                X1205_CCR_BASE);

        case X1205_CMD_GETALARM:
                return x1205_get_datetime(client, param, X1205_ALM0_BASE);

        case X1205_CMD_SETALARM:
                return x1205_set_datetime(client, param, 1,
                                X1205_ALM0_BASE);

        case X1205_CMD_GETDTRIM:
                return x1205_get_dtrim(client, param);

        case X1205_CMD_GETATRIM:
                return x1205_get_atrim(client, param);

        default:
                return -EINVAL;
        }
}

static int __init x1205_init(void)
{
        return i2c_add_driver(&x1205_driver);
}

static void __exit x1205_exit(void)
{
        i2c_del_driver(&x1205_driver);
}

MODULE_AUTHOR(
        "Karen Spearel <kas11@tampabay.rr.com>, "
        "Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Xicor X1205 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

EXPORT_SYMBOL_GPL(x1205_do_command);
EXPORT_SYMBOL_GPL(x1205_direct_attach);

module_init(x1205_init);
module_exit(x1205_exit);