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    SubjectRe: [rtc-linux] [PATCH] isl12022: added Intersil ISL12022 RTC
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    Hi Roman Fietze ,

    Some minor comments inline.

    2010/6/17 Roman Fietze <roman.fietze@telemotive.de>:
    > Hello,
    >
    > We are using this on our MPC5200B board. Any comments on the code are
    > welcome.
    >
    > From 7cf874201eb882beea406013bb38a8fcdd980782 Mon Sep 17 00:00:00 2001
    > From: Roman Fietze <roman.fietze@telemotive.de>
    > Date: Thu, 17 Jun 2010 10:57:13 +0200
    > Subject: [PATCH] isl12022: added Intersil ISL12022 RTC
    >
    > - derived from rtc-pcf8563
    > - no SRAM driver
    >
    > Signed-off-by: Roman Fietze <roman.fietze@telemotive.de>
    > ---
    >  drivers/rtc/Kconfig        |    9 ++
    >  drivers/rtc/Makefile       |    1 +
    >  drivers/rtc/rtc-isl12022.c |  312 ++++++++++++++++++++++++++++++++++++++++++++
    >  3 files changed, 322 insertions(+), 0 deletions(-)
    >  create mode 100644 drivers/rtc/rtc-isl12022.c
    >
    > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
    > index 6a13037..ade6427 100644
    > --- a/drivers/rtc/Kconfig
    > +++ b/drivers/rtc/Kconfig
    > @@ -203,6 +203,15 @@ config RTC_DRV_ISL1208
    >          This driver can also be built as a module. If so, the module
    >          will be called rtc-isl1208.
    >
    > +config RTC_DRV_ISL12022
    > +       tristate "Intersil ISL12022"
    > +       help
    > +         If you say yes here you get support for the
    > +         Intersil ISL12022 RTC chip.
    > +
    > +         This driver can also be built as a module. If so, the module
    > +         will be called rtc-isl12022.
    > +
    >  config RTC_DRV_X1205
    >        tristate "Xicor/Intersil X1205"
    >        help
    > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
    > index 44ef194..782d516 100644
    > --- a/drivers/rtc/Makefile
    > +++ b/drivers/rtc/Makefile
    > @@ -45,6 +45,7 @@ obj-$(CONFIG_RTC_DRV_EP93XX)  += rtc-ep93xx.o
    >  obj-$(CONFIG_RTC_DRV_FM3130)   += rtc-fm3130.o
    >  obj-$(CONFIG_RTC_DRV_GENERIC)  += rtc-generic.o
    >  obj-$(CONFIG_RTC_DRV_ISL1208)  += rtc-isl1208.o
    > +obj-$(CONFIG_RTC_DRV_ISL12022) += rtc-isl12022.o
    >  obj-$(CONFIG_RTC_DRV_M41T80)   += rtc-m41t80.o
    >  obj-$(CONFIG_RTC_DRV_M41T94)   += rtc-m41t94.o
    >  obj-$(CONFIG_RTC_DRV_M48T35)   += rtc-m48t35.o
    > diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c
    > new file mode 100644
    > index 0000000..e0a340f
    > --- /dev/null
    > +++ b/drivers/rtc/rtc-isl12022.c
    > @@ -0,0 +1,312 @@
    > +/*
    > + * An I2C driver for the Intersil ISL 12022
    > + *
    > + * Author: Roman Fietze <roman.fietze@telemotive.de>
    > + *
    > + * Based on the Philips PCF8563 RTC
    > + * by Alessandro Zummo <a.zummo@towertech.it>.
    > + *
    > + * 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.
    > + */
    > +
    > +#include <linux/i2c.h>
    > +#include <linux/bcd.h>
    > +#include <linux/rtc.h>
    > +#include <linux/slab.h>
    > +
    > +#define DRV_VERSION "0.1"
    > +
    > +/* ISL register offsets */
    > +#define ISL12022_REG_SC                0x00
    > +#define ISL12022_REG_MN                0x01
    > +#define ISL12022_REG_HR                0x02
    > +#define ISL12022_REG_DT                0x03
    > +#define ISL12022_REG_MO                0x04
    > +#define ISL12022_REG_YR                0x05
    > +#define ISL12022_REG_DW                0x06
    > +
    > +#define ISL12022_REG_SR                0x07
    > +#define ISL12022_REG_INT       0x08
    > +
    > +/* ISL register bits */
    > +#define ISL12022_HR_MIL                (1 << 7)        /* military or 24 hour time */
    > +
    > +#define ISL12022_SR_LBAT85     (1 << 2)
    > +#define ISL12022_SR_LBAT75     (1 << 1)
    > +
    > +#define ISL12022_INT_WRTC      (1 << 6)
    > +
    > +
    > +static struct i2c_driver isl12022_driver;
    > +
    > +struct isl12022 {
    > +       struct rtc_device *rtc;
    > +
    > +       bool write_enabled;     /* true if write enable is set */
    > +};
    > +
    > +
    > +static int isl12022_read_regs(struct i2c_client *client, uint8_t reg, uint8_t *data, size_t n)
    > +{
    > +       struct i2c_msg msgs[] = {
    > +               {
    > +                       .addr   = client->addr,
    > +                       .flags  = 0,
    > +                       .len    = 1,
    > +                       .buf    = data
    > +               },              /* setup read ptr */
    > +               {
    > +                       .addr   = client->addr,
    > +                       .flags  = I2C_M_RD,
    > +                       .len    = n,
    > +                       .buf    = data
    > +               }
    > +       };
    > +
    > +       int ret;
    > +
    > +       data[0] = reg;
    > +       ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
    > +       if (ret != ARRAY_SIZE(msgs)) {
    > +               dev_err(&client->dev, "%s: read error, ret=%d\n", __func__, ret);
    > +               return -EIO;
    > +       }
    > +
    > +       return 0;
    > +}
    > +
    > +
    > +static int isl12022_write_reg(struct i2c_client *client, uint8_t reg, uint8_t val)
    > +{
    > +       uint8_t data[2] = { reg, val };
    > +       int err;
    > +
    > +       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;
    > +}
    > +
    > +
    > +/*
    > + * In the routines that deal directly with the isl12022 hardware, we use
    > + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
    > + */
    > +static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
    > +{
    > +       uint8_t buf[ISL12022_REG_INT + 1];
    > +       int ret;
    > +
    > +       ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
    > +       if (ret)
    > +               return ret;
    > +
    > +       if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
    > +               dev_warn(&client->dev,
    > +                        "voltage dropped below %u%%, date and time is not reliable.\n",
    > +                        buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
    > +       }
    > +
    > +       dev_dbg(&client->dev,
    > +               "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
    > +               "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
    > +               "sr=%02x, int=%02x",
    > +               __func__,
    > +               buf[ISL12022_REG_SC], buf[ISL12022_REG_MN], buf[ISL12022_REG_HR],
    > +               buf[ISL12022_REG_DT], buf[ISL12022_REG_MO], buf[ISL12022_REG_YR],
    > +               buf[ISL12022_REG_DW],
    > +               buf[ISL12022_REG_SR], buf[ISL12022_REG_INT]);
    > +
    > +       tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
    > +       tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
    > +       tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
    > +       tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
    > +       tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
    > +       tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
    > +       tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
    > +
    > +       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);
    > +
    > +       /* 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 and time is invalid.\n");
    > +
    > +       return 0;
    > +}
    > +
    > +static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
    > +{
    > +       struct isl12022 *isl12022 = i2c_get_clientdata(client);
    > +       size_t i;
    > +       int ret;
    > +       uint8_t buf[ISL12022_REG_DW + 1];
    > +
    > +       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);
    > +
    > +       if (!isl12022->write_enabled) {
    > +
    > +               ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
    > +               if (ret)
    > +                       return ret;
    > +
    > +               /* Check if WRTC (write rtc enable) is set factory default is 0 (not set) */
    > +               if (!(buf[0] & ISL12022_INT_WRTC))
    > +               {
    > +                       dev_info(&client->dev, "init write enable and 24 hour format\n");
    > +
    > +                       /* Set the write enable bit. */
    > +                       ret = isl12022_write_reg(client, ISL12022_REG_INT, buf[0] | ISL12022_INT_WRTC);
    > +                       if (ret)
    > +                               return ret;
    > +
    > +                       /* Write to any RTC register to start RTC, we use the HR register, setting
    > +                        * the MIL bit to use the 24 hour format. */
    > +                       ret = isl12022_read_regs(client, ISL12022_REG_HR, buf, 1);
    > +                       if (ret)
    > +                               return ret;
    > +                       ret = isl12022_write_reg(client, ISL12022_REG_HR, buf[0] | ISL12022_HR_MIL);
    > +                       if (ret)
    > +                               return ret;
    > +               }
    > +
    > +               isl12022->write_enabled = 1;
    > +       }
    > +
    > +       /* hours, minutes and seconds */
    > +       buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
    > +       buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
    > +       buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour);
    > +
    > +       buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
    > +
    > +       /* month, 1 - 12 */
    > +       buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
    > +
    > +       /* year and century */
    > +       buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
    > +
    > +       buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
    > +
    > +       /* write register's data */
    > +       for (i = 0; i < ARRAY_SIZE(buf); i++) {
    > +               ret = isl12022_write_reg(client, ISL12022_REG_SC + i, buf[ISL12022_REG_SC + i]);
    > +               if (ret)
    > +                       return -EIO;
    > +       };
    > +
    > +       return 0;
    > +}
    > +
    > +static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
    > +{
    > +       return isl12022_get_datetime(to_i2c_client(dev), tm);
    > +}
    > +
    > +static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
    > +{
    > +       return isl12022_set_datetime(to_i2c_client(dev), tm);
    > +}
    > +
    > +static const struct rtc_class_ops isl12022_rtc_ops = {
    > +       .read_time      = isl12022_rtc_read_time,
    > +       .set_time       = isl12022_rtc_set_time,
    > +};
    > +
    > +static int isl12022_probe(struct i2c_client *client,
    > +                         const struct i2c_device_id *id)
    > +{
    > +       struct isl12022 *isl12022;
    > +
    > +       int ret = 0;
    > +
    > +       dev_dbg(&client->dev, "%s\n", __func__);
    > +
    > +       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
    > +               return -ENODEV;
    > +
    > +       isl12022 = kzalloc(sizeof(struct isl12022), GFP_KERNEL);
    > +       if (!isl12022)
    > +               return -ENOMEM;
    > +
    > +       dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
    > +

    There is no need to print your private driver info in Kernel, please
    get rid of it.

    > +       i2c_set_clientdata(client, isl12022);
    > +
    > +       isl12022->rtc = rtc_device_register(isl12022_driver.driver.name,
    > +                                           &client->dev, &isl12022_rtc_ops, THIS_MODULE);
    > +
    > +       if (IS_ERR(isl12022->rtc)) {
    > +               ret = PTR_ERR(isl12022->rtc);
    > +               goto exit_kfree;
    > +       }
    > +
    > +       return 0;
    > +
    > +exit_kfree:
    > +       kfree(isl12022);
    > +
    > +       return ret;
    > +}
    > +
    > +static int isl12022_remove(struct i2c_client *client)
    > +{
    > +       struct isl12022 *isl12022 = i2c_get_clientdata(client);
    > +
    > +       if (isl12022->rtc)
    > +               rtc_device_unregister(isl12022->rtc);

    'isl12022->rtc' can't be NULL in remove(), there is no need to check it.

    > +
    > +       kfree(isl12022);
    > +
    > +       return 0;
    > +}
    > +
    > +static const struct i2c_device_id isl12022_id[] = {
    > +       { "isl12022", 0 },
    > +       { "rtc8564", 0 },
    > +       { }
    > +};
    > +MODULE_DEVICE_TABLE(i2c, isl12022_id);
    > +
    > +static struct i2c_driver isl12022_driver = {
    > +       .driver         = {
    > +               .name   = "rtc-isl12022",
    > +       },
    > +       .probe          = isl12022_probe,
    > +       .remove         = isl12022_remove,
    > +       .id_table       = isl12022_id,
    > +};
    > +
    > +static int __init isl12022_init(void)
    > +{
    > +       return i2c_add_driver(&isl12022_driver);
    > +}
    > +
    > +static void __exit isl12022_exit(void)
    > +{
    > +       i2c_del_driver(&isl12022_driver);
    > +}
    > +
    > +MODULE_AUTHOR("roman.fietze@telemotive.de");
    > +MODULE_DESCRIPTION("ISL 12022 RTC driver");
    > +MODULE_LICENSE("GPL");
    > +MODULE_VERSION(DRV_VERSION);
    > +

    Please put MODULE_XXX at the end.

    > +module_init(isl12022_init);
    > +module_exit(isl12022_exit);
    > --
    > 1.7.1
    >
    >
    >
    > --
    > Roman Fietze                Telemotive AG Büro Mühlhausen
    > Breitwiesen                              73347 Mühlhausen
    > Tel.: +49(0)7335/18493-45        http://www.telemotive.de
    >
    > --
    > You received this message because you are subscribed to "rtc-linux".
    > Membership options at http://groups.google.com/group/rtc-linux .
    > Please read http://groups.google.com/group/rtc-linux/web/checklist
    > before submitting a driver.



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