| Message ID | 1317815823-27297-1-git-send-email-yauhen.kharuzhy@promwad.com |
|---|---|
| State | Rejected |
| Headers | show |
(sorry, catching up on rtc things whcih I wasn't cc'ed on) On Wed, 5 Oct 2011 14:57:03 +0300 Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> wrote: > This driver is based on PCF8563 driver and supports only base functions > now: read/write date & time. > > > ... > > --- /dev/null > +++ b/drivers/rtc/rtc-pcf8523.c > @@ -0,0 +1,246 @@ > +/* > + * An I2C driver for the NXP PCF8523 RTC > + * Copyright 2011 Promwad Innovation Company > + * > + * Author: Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> > + * Promwad Innovation Company, http://promwad.com/ > + * > + * based on the pcf8563 driver > + * > + * 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> Should this driver have a "depends on I2C" in Kconfig? > > ... > > +/* > + * In the routines that deal directly with the pcf8523 hardware, we use > + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. > + */ > +static int pcf8523_get_datetime(struct i2c_client *client, struct rtc_time *tm) > +{ > + struct pcf8523 *pcf8523 = i2c_get_clientdata(client); > + unsigned char buf[14] = { PCF8523_REG_CTL1 }; Please try to make local arrays such as the above "static const". Because the above code can needlessly cause the kernel to assemble and evaluate the array on the stack each time this function is called. > + struct i2c_msg msgs[] = { > + { client->addr, 0, 1, buf }, /* setup read ptr */ > + { client->addr, I2C_M_RD, 14, 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[PCF8523_REG_CTL3] & PCF8523_CTL3_BLF) "buf" wasn't a very good choice of name. Is there something more descriptive whcih we can use? > + dev_info(&client->dev, > + "low voltage detected, date/time is not reliable.\n"); > + > + dev_dbg(&client->dev, > + "%s: raw data is ctl1=%02x, ctl2=%02x, ctl3=%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], buf[9]); > + > + > + tm->tm_sec = bcd2bin(buf[PCF8523_REG_SC] & 0x7F); > + tm->tm_min = bcd2bin(buf[PCF8523_REG_MN] & 0x7F); > + tm->tm_hour = bcd2bin(buf[PCF8523_REG_HR] & 0x3F); /* rtc hr 0-23 */ > + tm->tm_mday = bcd2bin(buf[PCF8523_REG_DM] & 0x3F); > + tm->tm_wday = buf[PCF8523_REG_DW] & 0x07; > + tm->tm_mon = bcd2bin(buf[PCF8523_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ > + tm->tm_year = bcd2bin(buf[PCF8523_REG_YR]); > + if (tm->tm_year < 70) > + tm->tm_year += 100; /* assume we are in 1970...2069 */ > + > + 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. > + */ This comment seems to imply that the driver allows hwclock to set the time to something which we know is incorrect? If so, wouldn't it be better to leave the time at something obviously wrong, such as 1 Jan 1970? > + if (rtc_valid_tm(tm) < 0) > + dev_err(&client->dev, "retrieved date/time is not valid.\n"); > + > + return 0; > +} > + > > ... >
> > +/* > > + * In the routines that deal directly with the pcf8523 hardware, we use > > + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. Do we really need to limit year w.r.t. epoch? Instead why don't you define a macro for base year in your driver itself? With this, the same driver may be usable forever, without any modifications except for this macro (which also need to change once in a century). If you use year w.r.t. epoch, this driver definitely need modification before year 2070. > > + */ > > +static int pcf8523_get_datetime(struct i2c_client *client, struct rtc_time > *tm) > > +{ > > + struct pcf8523 *pcf8523 = i2c_get_clientdata(client); > > + unsigned char buf[14] = { PCF8523_REG_CTL1 }; > > + /* the clock can give out invalid datetime, but we cannot return > > + * -EINVAL otherwise hwclock will refuse to set the time on bootup. > > + */ Somehow I feel to set the RTC to a known time, probably the BASE year, in such error cases. > > This comment seems to imply that the driver allows hwclock to set the > time to something which we know is incorrect? If so, wouldn't it be > better to leave the time at something obviously wrong, such as 1 Jan > 1970? > > > + if (rtc_valid_tm(tm) < 0) > > + dev_err(&client->dev, "retrieved date/time is not valid.\n"); > > + > > + return 0; > > +}
On Wed, 5 Oct 2011 14:57:03 +0300 Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> wrote: > This driver is based on PCF8563 driver and supports only base functions > now: read/write date & time. This patch breaks my x86_64 allmodconfig build. drivers/rtc/rtc-pcf8523.c: In function 'pcf8523_get_datetime': drivers/rtc/rtc-pcf8523.c:55: warning: unused variable 'pcf8523' drivers/rtc/rtc-pcf8523.c: In function 'pcf8523_set_datetime': drivers/rtc/rtc-pcf8523.c:110: warning: unused variable 'pcf8523' drivers/rtc/rtc-pcf8523.c: In function 'pcf8523_probe': drivers/rtc/rtc-pcf8523.c:179: error: invalid application of 'sizeof' to incomplete type 'struct pcf8523' drivers/rtc/rtc-pcf8523.c:187: error: dereferencing pointer to incomplete type drivers/rtc/rtc-pcf8523.c:188: error: 'THIS_MODULE' undeclared (first use in this function) drivers/rtc/rtc-pcf8523.c:188: error: (Each undeclared identifier is reported only once drivers/rtc/rtc-pcf8523.c:188: error: for each function it appears in.) drivers/rtc/rtc-pcf8523.c:190: error: dereferencing pointer to incomplete type drivers/rtc/rtc-pcf8523.c:191: error: dereferencing pointer to incomplete type drivers/rtc/rtc-pcf8523.c: In function 'pcf8523_remove': drivers/rtc/rtc-pcf8523.c:207: error: dereferencing pointer to incomplete type drivers/rtc/rtc-pcf8523.c:208: error: dereferencing pointer to incomplete type drivers/rtc/rtc-pcf8523.c: At top level: drivers/rtc/rtc-pcf8523.c:219: warning: data definition has no type or storage class drivers/rtc/rtc-pcf8523.c:219: warning: type defaults to 'int' in declaration of 'MODULE_DEVICE_TABLE' drivers/rtc/rtc-pcf8523.c:219: warning: parameter names (without types) in function declaration drivers/rtc/rtc-pcf8523.c: In function 'pcf8523_init': drivers/rtc/rtc-pcf8523.c:232: error: 'THIS_MODULE' undeclared (first use in this function) drivers/rtc/rtc-pcf8523.c: At top level: drivers/rtc/rtc-pcf8523.c:240: error: expected declaration specifiers or '...' before string constant drivers/rtc/rtc-pcf8523.c:240: warning: data definition has no type or storage class drivers/rtc/rtc-pcf8523.c:240: warning: type defaults to 'int' in declaration of 'MODULE_AUTHOR' drivers/rtc/rtc-pcf8523.c:240: warning: function declaration isn't a prototype drivers/rtc/rtc-pcf8523.c:241: error: expected declaration specifiers or '...' before string constant drivers/rtc/rtc-pcf8523.c:241: warning: data definition has no type or storage class drivers/rtc/rtc-pcf8523.c:241: warning: type defaults to 'int' in declaration of 'MODULE_DESCRIPTION' drivers/rtc/rtc-pcf8523.c:241: warning: function declaration isn't a prototype drivers/rtc/rtc-pcf8523.c:242: error: expected declaration specifiers or '...' before string constant drivers/rtc/rtc-pcf8523.c:242: warning: data definition has no type or storage class drivers/rtc/rtc-pcf8523.c:242: warning: type defaults to 'int' in declaration of 'MODULE_LICENSE' drivers/rtc/rtc-pcf8523.c:242: warning: function declaration isn't a prototype drivers/rtc/rtc-pcf8523.c:243: error: expected declaration specifiers or '...' before string constant drivers/rtc/rtc-pcf8523.c:243: warning: data definition has no type or storage class drivers/rtc/rtc-pcf8523.c:243: warning: type defaults to 'int' in declaration of 'MODULE_VERSION' drivers/rtc/rtc-pcf8523.c:243: warning: function declaration isn't a prototype
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 5a538fc..ace0259a 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -249,6 +249,15 @@ config RTC_DRV_X1205 This driver can also be built as a module. If so, the module will be called rtc-x1205. +config RTC_DRV_PCF8523 + tristate "NXP PCF8523" + help + If you say yes here you get support for the + NXP PCF8523 RTC chip. + + This driver can also be built as a module. If so, the module + will be called rtc-pcf8523. + config RTC_DRV_PCF8563 tristate "Philips PCF8563/Epson RTC8564" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 6e69823..7812730 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -71,6 +71,7 @@ obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o obj-$(CONFIG_RTC_DRV_NUC900) += rtc-nuc900.o obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o obj-$(CONFIG_RTC_DRV_PCAP) += rtc-pcap.o +obj-$(CONFIG_RTC_DRV_PCF8523) += rtc-pcf8523.o obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o obj-$(CONFIG_RTC_DRV_PCF2123) += rtc-pcf2123.o diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c new file mode 100644 index 0000000..06a6679 --- /dev/null +++ b/drivers/rtc/rtc-pcf8523.c @@ -0,0 +1,246 @@ +/* + * An I2C driver for the NXP PCF8523 RTC + * Copyright 2011 Promwad Innovation Company + * + * Author: Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> + * Promwad Innovation Company, http://promwad.com/ + * + * based on the pcf8563 driver + * + * 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 "1.0" + +#define PCF8523_REG_CTL1 0x00 /* control and status registers */ +#define PCF8523_REG_CTL2 0x01 +#define PCF8523_REG_CTL3 0x02 + +#define PCF8523_REG_SC 0x03 /* datetime */ +#define PCF8523_REG_MN 0x04 +#define PCF8523_REG_HR 0x05 +#define PCF8523_REG_DM 0x06 +#define PCF8523_REG_DW 0x07 +#define PCF8523_REG_MO 0x08 +#define PCF8523_REG_YR 0x09 + +#define PCF8523_REG_AMN 0x0A /* alarm */ +#define PCF8523_REG_AHR 0x0B +#define PCF8523_REG_ADM 0x0C +#define PCF8523_REG_ADW 0x0D + +#define PCF8523_REG_CLKO 0x0F /* clock out */ +#define PCF8523_REG_TMRAC 0x10 /* timer control */ +#define PCF8523_REG_TMRA 0x11 /* timer */ +#define PCF8523_REG_TMRBC 0x12 /* timer control */ +#define PCF8523_REG_TMRB 0x13 /* timer */ + +#define PCF8523_CTL3_BLF (1 << 2) + +static struct i2c_driver pcf8523_driver; + +/* + * In the routines that deal directly with the pcf8523 hardware, we use + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. + */ +static int pcf8523_get_datetime(struct i2c_client *client, struct rtc_time *tm) +{ + struct pcf8523 *pcf8523 = i2c_get_clientdata(client); + unsigned char buf[14] = { PCF8523_REG_CTL1 }; + + struct i2c_msg msgs[] = { + { client->addr, 0, 1, buf }, /* setup read ptr */ + { client->addr, I2C_M_RD, 14, 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[PCF8523_REG_CTL3] & PCF8523_CTL3_BLF) + dev_info(&client->dev, + "low voltage detected, date/time is not reliable.\n"); + + dev_dbg(&client->dev, + "%s: raw data is ctl1=%02x, ctl2=%02x, ctl3=%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], buf[9]); + + + tm->tm_sec = bcd2bin(buf[PCF8523_REG_SC] & 0x7F); + tm->tm_min = bcd2bin(buf[PCF8523_REG_MN] & 0x7F); + tm->tm_hour = bcd2bin(buf[PCF8523_REG_HR] & 0x3F); /* rtc hr 0-23 */ + tm->tm_mday = bcd2bin(buf[PCF8523_REG_DM] & 0x3F); + tm->tm_wday = buf[PCF8523_REG_DW] & 0x07; + tm->tm_mon = bcd2bin(buf[PCF8523_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ + tm->tm_year = bcd2bin(buf[PCF8523_REG_YR]); + if (tm->tm_year < 70) + tm->tm_year += 100; /* assume we are in 1970...2069 */ + + 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 pcf8523_set_datetime(struct i2c_client *client, struct rtc_time *tm) +{ + struct pcf8523 *pcf8523 = i2c_get_clientdata(client); + int i, err; + unsigned char buf[10]; + + 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[PCF8523_REG_SC] = bin2bcd(tm->tm_sec); + buf[PCF8523_REG_MN] = bin2bcd(tm->tm_min); + buf[PCF8523_REG_HR] = bin2bcd(tm->tm_hour); + + buf[PCF8523_REG_DM] = bin2bcd(tm->tm_mday); + + /* month, 1 - 12 */ + buf[PCF8523_REG_MO] = bin2bcd(tm->tm_mon + 1); + + /* year and century */ + buf[PCF8523_REG_YR] = bin2bcd(tm->tm_year % 100); + + buf[PCF8523_REG_DW] = tm->tm_wday & 0x07; + + /* write register's data */ + for (i = 0; i < 7; i++) { + unsigned char data[2] = { PCF8523_REG_SC + i, + buf[PCF8523_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 pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + return pcf8523_get_datetime(to_i2c_client(dev), tm); +} + +static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + return pcf8523_set_datetime(to_i2c_client(dev), tm); +} + +static const struct rtc_class_ops pcf8523_rtc_ops = { + .read_time = pcf8523_rtc_read_time, + .set_time = pcf8523_rtc_set_time, +}; + +static int pcf8523_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pcf8523 *pcf8523; + + int err = 0; + + dev_dbg(&client->dev, "%s\n", __func__); + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + pcf8523 = kzalloc(sizeof(struct pcf8523), GFP_KERNEL); + if (!pcf8523) + return -ENOMEM; + + dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); + + i2c_set_clientdata(client, pcf8523); + + pcf8523->rtc = rtc_device_register(pcf8523_driver.driver.name, + &client->dev, &pcf8523_rtc_ops, THIS_MODULE); + + if (IS_ERR(pcf8523->rtc)) { + err = PTR_ERR(pcf8523->rtc); + goto exit_kfree; + } + + return 0; + +exit_kfree: + kfree(pcf8523); + + return err; +} + +static int pcf8523_remove(struct i2c_client *client) +{ + struct pcf8523 *pcf8523 = i2c_get_clientdata(client); + + if (pcf8523->rtc) + rtc_device_unregister(pcf8523->rtc); + + kfree(pcf8523); + + return 0; +} + +static const struct i2c_device_id pcf8523_id[] = { + { "pcf8523", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pcf8523_id); + +static struct i2c_driver pcf8523_driver = { + .driver = { + .name = "rtc-pcf8523", + }, + .probe = pcf8523_probe, + .remove = pcf8523_remove, + .id_table = pcf8523_id, +}; + +static int __init pcf8523_init(void) +{ + return i2c_add_driver(&pcf8523_driver); +} + +static void __exit pcf8523_exit(void) +{ + i2c_del_driver(&pcf8523_driver); +} + +MODULE_AUTHOR("Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com>"); +MODULE_DESCRIPTION("NXP PCF8523"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); + +module_init(pcf8523_init); +module_exit(pcf8523_exit);
This driver is based on PCF8563 driver and supports only base functions now: read/write date & time. Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> --- drivers/rtc/Kconfig | 9 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-pcf8523.c | 246 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 256 insertions(+), 0 deletions(-) create mode 100644 drivers/rtc/rtc-pcf8523.c