@@ -264,6 +264,17 @@ config RTC_DRV_PCF8583
This driver can also be built as a module. If so, the module
will be called rtc-pcf8583.
+config RTC_DRV_PCF2127A
+ tristate "Philips PCF2127A (only I2C)"
+ help
+ If you say yes here you get support for the Philips PCF2127A
+ RTC. This driver implements only the i2c-interface to the chip.
+ It may work with pcf2127, but is tested only against
+ the pcf2127a.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-pcf2127a.
+
config RTC_DRV_M41T80
tristate "ST M41T62/65/M41T80/81/82/83/84/85/87"
help
@@ -69,6 +69,7 @@ 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_PCF2123) += rtc-pcf2123.o
+obj-$(CONFIG_RTC_DRV_PCF2127A) += rtc-pcf2127a.o
obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o
new file mode 100644
@@ -0,0 +1,307 @@
+/*
+ * Driver the the NXP/Philips PCF2127A RTC (only I2C)
+ *
+ * Copyright (c) 2011 ECKELMANN AG.
+ *
+ * Authors: Matthias Wolf <m.wolf@eckelmann.de>
+ * Torsten Mehnert <t.mehnert@eckelmann.de>
+ *
+ * RTC-Datasheet: http://www.nxp.com/documents/data_sheet/PCF2127A.pdf
+ *
+ * NOTE: This driver only implements the i2c-interface to the RTC.
+ * This driver is based on rtc-pcf8363 from Alessandro Zummo.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+/* PCF2127A Registers */
+#define PCF2127A_REG_CTL1 0x00 /* Control 1 */
+#define PCF2127A_REG_CTL2 0x01 /* Control 2 */
+#define PCF2127A_REG_CTL3 0x02 /* Control 3 */
+
+#define PCF2127A_REG_SC 0x03 /* second value */
+#define PCF2127A_REG_MN 0x04 /* minute value */
+#define PCF2127A_REG_HR 0x05 /* hour value */
+#define PCF2127A_REG_DM 0x06 /* day value */
+#define PCF2127A_REG_DW 0x07 /* weekday value */
+#define PCF2127A_REG_MO 0x08 /* month value */
+#define PCF2127A_REG_YR 0x09 /* year value */
+
+#define PCF2127A_REG_SC_ALARM 0x0A /* second alarm */
+#define PCF2127A_REG_MN_ALARM 0x0B /* minute alarm */
+#define PCF2127A_REG_HR_ALARM 0x0C /* hour alarm */
+#define PCF2127A_REG_DM_ALARM 0x0D /* day alarm */
+#define PCF2127A_REG_DW_ALARM 0x0E /* weekday alarm */
+
+#define PCF2127A_REG_CLKO 0x0F /* clock out */
+#define PCF2127A_REG_WD_TMRC 0x10 /* watchdog timer control */
+#define PCF2127A_REG_WD_TMVAL 0x11 /* watchdog timer value */
+
+#define PCF2127A_REG_TSCTL 0x12 /* timestamp control */
+#define PCF2127A_REG_SC_TS 0x13 /* second timestamp */
+#define PCF2127A_REG_MN_TS 0x14 /* minute timestamp */
+#define PCF2127A_REG_HR_TS 0x15 /* hour timestamp */
+#define PCF2127A_REG_DM_TS 0x16 /* day timestamp */
+#define PCF2127A_REG_MO_TS 0x17 /* month timestamp */
+#define PCF2127A_REG_YR_TS 0x18 /* year timestamp */
+#define PCF2127A_REG_AGI_OFF 0x19 /* aging offset */
+#define PCF2127A_REG_RAM_MSB 0x1A /* RAM address MSB */
+#define PCF2127A_REG_RAM_LSB 0x1B /* RAM address LSB */
+#define PCF2127A_REG_RAM_WCMD 0x1C /* RAM write command */
+#define PCF2127A_REG_RAM_RCMD 0x1D /* RAM read command */
+
+/* Bits in PCF2127A_REG_CTL1 */
+#define PCF2127A_BIT_SI 0x01 /* second interrupt */
+#define PCF2127A_BIT_MI 0x02 /* minute interrupt */
+#define PCF2127A_BIT_H_24_12 0x04 /* 12/24 hour mode */
+#define PCF2127A_BIT_POR_OVRD 0x08 /* POR override */
+#define PCF2127A_BIT_TSF1 0x10 /* timestamp flag 1 */
+#define PCF2127A_BIT_STOP 0x20 /* stop bit */
+#define PCF2127A_BIT_EXTTEST 0x80 /* external clock test mode*/
+
+/* Bits in PCF2127A_REG_CTL2 */
+#define PCF2127A_BIT_CDTIE 0x01 /* countdown timer flag */
+#define PCF2127A_BIT_AIE 0x02 /* alarm interrupt enable */
+#define PCF2127A_BIT_TSIE 0x04 /* timestamp int. enable */
+#define PCF2127A_BIT_CDTF 0x08 /* countdown timer flag */
+#define PCF2127A_BIT_AF 0x10 /* alarm flag */
+#define PCF2127A_BIT_TSF2 0x20 /* timestamp flag 2 */
+#define PCF2127A_BIT_WDTF 0x40 /* watchdog timer flag */
+#define PCF2127A_BIT_MSF 0x80 /* minute/second flag */
+
+/* Bits in PCF2127A_REG_CTL3 */
+#define PCF2127A_BIT_BLIE 0x01 /* battery low Interrupt enable */
+#define PCF2127A_BIT_BIE 0x02 /* battery Switch int. enable */
+#define PCF2127A_BIT_BLF 0x04 /* battery low flag */
+#define PCF2127A_BIT_BF 0x08 /* battery switch flag */
+#define PCF2127A_BIT_BTSE 0x10 /* battery timestamp enable */
+#define PCF2127A_BIT_BLDOFF 0x20 /* battery low detection off */
+#define PCF2127A_BIT_BSM 0x40 /* battery switch mode */
+#define PCF2127A_BIT_BSOFF 0x80 /* battery switch off */
+
+static struct i2c_driver pcf2127a_driver;
+
+/*
+ * In the routines that deal directly with the pcf2127a hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static
+int pcf2127a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+ unsigned char buf[10] = { PCF2127A_REG_CTL1 };
+
+ /*
+ * Note: We can't use i2c_transfer to send/recv multiple i2c_msg's
+ * to/from pcf2127a at once. The reason is that the pcf2127a doesn't
+ * handle (repeated START)-Conditions correctly.
+ *
+ * PCF2127A Manual, Section 9.2.2 START and STOP conditions:
+ * "Remark: For the PCF2127A a repeated START is not allowed. Therefore
+ * a STOP has to be released before the next START."
+ */
+
+ /* setup read ptr */
+ if (!i2c_master_send(client, buf, 1)) {
+ dev_err(&client->dev, "%s: write error\n", __func__);
+ return -EIO;
+ }
+
+ /* read status + date */
+ if (!i2c_master_recv(client, buf, 10)) {
+ dev_err(&client->dev, "%s: read error\n", __func__);
+ return -EIO;
+ }
+
+ if (buf[PCF2127A_REG_CTL3] & PCF2127A_BIT_BLF)
+ dev_info(&client->dev,
+ "low battery detected, date/time is not reliable.\n");
+
+#ifdef DEBUG
+ unsigned char bf_buf[2];
+ if (buf[PCF2127A_REG_CTL3] & PCF2127A_BIT_BF) {
+ dev_info(&client->dev,
+ "battery switch-over detected - reset BF flag.\n");
+
+ bf_buf[0] = PCF2127A_REG_CTL3;
+ bf_buf[1] = buf[PCF2127A_REG_CTL3] & ~PCF2127A_BIT_BF;
+ if (!i2c_master_send(client, bf_buf, 2)) {
+ dev_err(&client->dev,
+ "%s: write error\n", __func__);
+ return -EIO;
+ }
+ }
+#endif
+
+ dev_dbg(&client->dev,
+ "%s: raw data is ctl1=%02x, ctl2=%02x, ctl3=%02x, sec=%02x, "
+ "min=%02x, hour=%02x, day=%02x, wday=%02x, month=%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[PCF2127A_REG_SC] & 0x7F);
+ tm->tm_min = bcd2bin(buf[PCF2127A_REG_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[PCF2127A_REG_HR] & 0x3F); /* rtc hr 0-23 */
+ tm->tm_mday = bcd2bin(buf[PCF2127A_REG_DM] & 0x3F);
+ tm->tm_wday = buf[PCF2127A_REG_DW] & 0x07;
+ tm->tm_mon = bcd2bin(buf[PCF2127A_REG_MO] & 0x1F) - 1; /* rtc m 1-12 */
+ tm->tm_year = bcd2bin(buf[PCF2127A_REG_YR]);
+
+ if (tm->tm_year < 70)
+ tm->tm_year += 100; /* assume we are in 1970...2069 */
+
+ /*
+ * 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 pcf2127a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+ int i, err;
+ unsigned char msgdata[2]; /* send data*/
+ unsigned char buf[10]; /* Index 0 - 9 */
+
+ /* hours, minutes and seconds */
+ buf[PCF2127A_REG_SC] = bin2bcd(tm->tm_sec);
+ buf[PCF2127A_REG_MN] = bin2bcd(tm->tm_min);
+ buf[PCF2127A_REG_HR] = bin2bcd(tm->tm_hour);
+
+ /* day of month */
+ buf[PCF2127A_REG_DM] = bin2bcd(tm->tm_mday);
+
+ /* weekday */
+ buf[PCF2127A_REG_DW] = tm->tm_wday & 0x07;
+
+ /* month, 1 - 12 */
+ buf[PCF2127A_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+ /* year */
+ buf[PCF2127A_REG_YR] = bin2bcd(tm->tm_year % 100);
+
+ /* write register's data */
+ for (i = 0; i < 7; i++) {
+ msgdata[0] = PCF2127A_REG_SC + i;
+ msgdata[1] = buf[PCF2127A_REG_SC + i];
+ err = i2c_master_send(client, msgdata, sizeof(msgdata));
+ if (err != sizeof(msgdata)) {
+ dev_err(&client->dev,
+ "%s: err=%d addr=%02x, data=%02x\n",
+ __func__, err, msgdata[0], msgdata[1]);
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
+/*---------------------------------------------------------------------------*/
+
+static int pcf2127a_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ return pcf2127a_get_datetime(to_i2c_client(dev), tm);
+}
+
+static int pcf2127a_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ return pcf2127a_set_datetime(to_i2c_client(dev), tm);
+}
+
+static const struct rtc_class_ops pcf2127a_rtc_ops = {
+ .read_time = pcf2127a_rtc_read_time,
+ .set_time = pcf2127a_rtc_set_time,
+};
+
+/*---------------------------------------------------------------------------*/
+
+static int pcf2127a_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct rtc_device *pcf2127a_device;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ dev_info(&client->dev, "chip found\n");
+
+ pcf2127a_device = rtc_device_register(pcf2127a_driver.driver.name,
+ &client->dev, &pcf2127a_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(pcf2127a_device))
+ return PTR_ERR(pcf2127a_device);
+
+ i2c_set_clientdata(client, pcf2127a_device);
+
+ return 0;
+}
+
+/*---------------------------------------------------------------------------*/
+
+static int pcf2127a_remove(struct i2c_client *client)
+{
+ struct rtc_device *pcf2127a_device = i2c_get_clientdata(client);
+
+ if (pcf2127a_device)
+ rtc_device_unregister(pcf2127a_device);
+
+ return 0;
+}
+
+static const struct i2c_device_id pcf2127a_id[] = {
+ /*
+ * This driver should also work with the pcf2127, but
+ * I can't prove it.
+ */
+ { "pcf2127a", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pcf2127a_id);
+
+static struct i2c_driver pcf2127a_driver = {
+ .driver = {
+ .name = "rtc-pcf2127a",
+ },
+ .probe = pcf2127a_probe,
+ .remove = pcf2127a_remove,
+ .id_table = pcf2127a_id,
+};
+
+static int __init pcf2127a_init(void)
+{
+ return i2c_add_driver(&pcf2127a_driver);
+}
+module_init(pcf2127a_init);
+
+static void __exit pcf2127a_exit(void)
+{
+ i2c_del_driver(&pcf2127a_driver);
+}
+module_exit(pcf2127a_exit);
+
+MODULE_AUTHOR("ECKELMANN AG");
+MODULE_DESCRIPTION("NXP/Philips PCF2127A RTC (I2C) driver");
+MODULE_LICENSE("GPL");
Hi, thanks again for your review. There is no chip named "rtc2127a", this time it's clear ;-) And the "checkpatch" script is worth gold. Changes v3: - Signed-off-by added - Coding-Style issues removed (like whitespaces) - "checkpatch" confirmed - Removed compatiblity with"rtc2127a", because no such chip exists - Fixed an error in probe that cause an unnecessary/doubled memory allocation - Removed global static rtc_device pointer, using i2c_get_clientdata instead - Fixed MODULE_AUTHOR macro Changes v2: - Fixed spelling mistakes in Kconfig and header - <linux/module.h> included - DRV_VERSION / MODULE_VERSION removed - struct pcf2127a removed, because it has only one member - Some unnecessary debug outputs removed - Fixed comments to match kernel style guidelines - module_init/_exit makros are now placed under the respective function Thanks for your patience, Torsten From: T. Mehnert <t.mehnert@eckelmann.de> Date: Mon, 27 Jun 2011 16:29:08 +0200 Subject: [PATCH] RTC pcf2127a i2c implementation This patch adds the device driver for the RTC NXP PCF2127A. It only implement the i2c interface to the RTC. rtc_class_ops: read_time, set_time Signed-off-by: Torsten Mehnert <t.mehnert@eckelmann.de> --- drivers/rtc/Kconfig | 11 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-pcf2127a.c | 307 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 319 insertions(+), 0 deletions(-) create mode 100644 drivers/rtc/rtc-pcf2127a.c -- 1.7.0.4 ECKELMANN AG Vorstand: Dr.-Ing. Gerd Eckelmann (Vorsitzender), Dr.-Ing. Peter Cordes, Dr.-Ing. Frank-Thomas Mellert Vorsitzender des Aufsichtsrats: Hubertus G. Krossa Sitz der Gesellschaft: Wiesbaden Amtsgericht Wiesbaden, HRB 12636