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【问题】4412开发板配置pcf8563时钟芯片驱动后,无法使用,是什么问题呢?

菜鸟
2017-08-28 14:33:20    评分


 

开发板:

图片1.jpg 

各位版主、工程师们你们好:

      请教你们一些问题:

             1)在内核中配置pcf8563时钟芯片启动完成,内核启动后 /dev/rtc/ 中没有pcf8563芯片对应的 rtc 节点;

             2)内核启动过程中打印 drivers/rtc/hctosys.c: unable to open rtc device (rtc0);

             3)pcf8563芯片驱动程序的 pcf8563_probe()在整个启动过程中没有被执行;

             4)请问这是怎么回事?该怎么修改???

             5)驱动程序代码如下:

驱动代码:
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>

#define DRV_VERSION "0.4.3"

#define PCF8563_REG_ST1                0x00 /* status */
#define PCF8563_REG_ST2                0x01

#define PCF8563_REG_SC                0x02 /* datetime */
#define PCF8563_REG_MN                0x03
#define PCF8563_REG_HR                0x04
#define PCF8563_REG_DM                0x05
#define PCF8563_REG_DW                0x06
#define PCF8563_REG_MO                0x07
#define PCF8563_REG_YR                0x08

#define PCF8563_REG_AMN                0x09 /* alarm */
#define PCF8563_REG_AHR                0x0A
#define PCF8563_REG_ADM                0x0B
#define PCF8563_REG_ADW                0x0C

#define PCF8563_REG_CLKO        0x0D /* clock out */
#define PCF8563_REG_TMRC        0x0E /* timer control */
#define PCF8563_REG_TMR                0x0F /* timer */

#define PCF8563_SC_LV                0x80 /* low voltage */
#define PCF8563_MO_C                0x80 /* century */

static struct i2c_driver pcf8563_driver;

struct pcf8563 {
        struct rtc_device *rtc;
        /*
         * The meaning of MO_C bit varies by the chip type.
         * From PCF8563 datasheet: this bit is toggled when the years
         * register overflows from 99 to 00
         *   0 indicates the century is 20xx
         *   1 indicates the century is 19xx
         * From RTC8564 datasheet: this bit indicates change of
         * century. When the year digit data overflows from 99 to 00,
         * this bit is set. By presetting it to 0 while still in the
         * 20th century, it will be set in year 2000, ...
         * There seems no reliable way to know how the system use this
         * bit.  So let's do it heuristically, assuming we are live in
         * 1970...2069.
         */
        int c_polarity;        /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
};

/*
* In the routines that deal directly with the pcf8563 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
        struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
        unsigned char buf[13] = { PCF8563_REG_ST1 };

        struct i2c_msg msgs[] = {
                { client->addr, 0, 1, buf },        /* setup read ptr */
                { client->addr, I2C_M_RD, 13, buf },        /* read status + date */
        };

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

        if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
                dev_info(&client->dev,
                        "low voltage detected, date/time is not reliable.\n");

        dev_dbg(&client->dev,
                "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
                "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
                __func__,
                buf[0], buf[1], buf[2], buf[3],
                buf[4], buf[5], buf[6], buf[7],
                buf[8]);


        tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
        tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
        tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
        tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
        tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
        tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
        tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
        if (tm->tm_year < 70)
                tm->tm_year += 100;        /* assume we are in 1970...2069 */
        /* detect the polarity heuristically. see note above. */
        pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
                (tm->tm_year >= 100) : (tm->tm_year < 100);

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

        /* the clock can give out invalid datetime, but we cannot return
         * -EINVAL otherwise hwclock will refuse to set the time on bootup.
         */
        if (rtc_valid_tm(tm) < 0)
                dev_err(&client->dev, "retrieved date/time is not valid.\n");

        return 0;
}

static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
        struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
        int i, err;
        unsigned char buf[9];

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

        /* hours, minutes and seconds */
        buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
        buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
        buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

        buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

        /* month, 1 - 12 */
        buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

        /* year and century */
        buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
        if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
                buf[PCF8563_REG_MO] |= PCF8563_MO_C;

        buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

        /* write register's data */
        for (i = 0; i < 7; i++) {
                unsigned char data[2] = { PCF8563_REG_SC + i,
                                                buf[PCF8563_REG_SC + i] };

                err = i2c_master_send(client, data, sizeof(data));
                if (err != sizeof(data)) {
                        dev_err(&client->dev,
                                "%s: err=%d addr=%02x, data=%02x\n",
                                __func__, err, data[0], data[1]);
                        return -EIO;
                }
        };

        return 0;
}

static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
        return pcf8563_get_datetime(to_i2c_client(dev), tm);
}

static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
        return pcf8563_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops pcf8563_rtc_ops = {
        .read_time        = pcf8563_rtc_read_time,
        .set_time        = pcf8563_rtc_set_time,
};

static int pcf8563_probe(struct i2c_client *client,
                                const struct i2c_device_id *id)
{
        struct pcf8563 *pcf8563;

        int err = 0;

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

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
                return -ENODEV;

        pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
        if (!pcf8563)
                return -ENOMEM;

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

        i2c_set_clientdata(client, pcf8563);

        pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
                                &client->dev, &pcf8563_rtc_ops, THIS_MODULE);

        if (IS_ERR(pcf8563->rtc)) {
                err = PTR_ERR(pcf8563->rtc);
                goto exit_kfree;
        }

        return 0;

exit_kfree:
        kfree(pcf8563);

        return err;
}

static int pcf8563_remove(struct i2c_client *client)
{
        struct pcf8563 *pcf8563 = i2c_get_clientdata(client);

        if (pcf8563->rtc)
                rtc_device_unregister(pcf8563->rtc);

        kfree(pcf8563);

        return 0;
}

static const struct i2c_device_id pcf8563_id[] = {
        { "pcf8563", 0 },
        { "rtc8564", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, pcf8563_id);

static struct i2c_driver pcf8563_driver = {
        .driver                = {
                .name        = "rtc-pcf8563",
        },
        .probe                = pcf8563_probe,
        .remove                = pcf8563_remove,
        .id_table        = pcf8563_id,
};

static int __init pcf8563_init(void)
{
        return i2c_add_driver(&pcf8563_driver);
}

static void __exit pcf8563_exit(void)
{
        i2c_del_driver(&pcf8563_driver);
}

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(pcf8563_init);
module_exit(pcf8563_exit);





关键词: 4412开发板    

专家
2017-08-29 06:25:19    评分
2楼

路过,打酱油


菜鸟
2017-11-24 16:51:10    评分
3楼

这是什么原因呢


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