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Date: Wed, 5 Oct 2011 14:57:03 +0300
From: Yauhen Kharuzhy <yauhen.kharuzhy@...mwad.com>
To: Alessandro Zummo <a.zummo@...ertech.it>
Cc: rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org,
Ivan Kuten <ivan.kuten@...mwad.com>,
Yauhen Kharuzhy <yauhen.kharuzhy@...mwad.com>
Subject: [PATCH] RTC: Add driver for NXP PCF8523 RTC chip
This driver is based on PCF8563 driver and supports only base functions
now: read/write date & time.
Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@...mwad.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
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@...mwad.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@...mwad.com>");
+MODULE_DESCRIPTION("NXP PCF8523");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(pcf8523_init);
+module_exit(pcf8523_exit);
--
1.7.6.3
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