[PATCH 12/13] RTC subsystem, PCF8563 driver

Alessandro Zummo
2006-03-04T16:44:20Z

[-- Attachment #1: rtc-drv-pcf8563.patch --]
[-- Type: text/plain, Size: 10893 bytes --]

An RTC class aware driver for the Philips
PCF8563 RTC and Epson RTC8564 chips.

This chip is used on the Iomega NAS100D.

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
--
drivers/rtc/Kconfig | 11 +
drivers/rtc/Makefile | 1
drivers/rtc/rtc-pcf8563.c | 355 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 367 insertions(+)

--- linux-rtc.orig/drivers/rtc/Kconfig 2006-03-04 16:17:17.000000000 +0100
+++ linux-rtc/drivers/rtc/Kconfig 2006-03-04 16:17:18.000000000 +0100
@@ -95,6 +95,17 @@ config RTC_DRV_DS1672
This driver can also be built as a module. If so, the module
will be called rtc-ds1672.

+config RTC_DRV_PCF8563
+ tristate "Philips PCF8563/Epson RTC8564"
+ depends on RTC_CLASS && I2C
+ help
+ If you say yes here you get support for the
+ Philips PCF8563 RTC chip. The Epson RTC8564
+ should work as well.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-pcf8563.
+
config RTC_DRV_TEST
tristate "Test driver/device"
depends on RTC_CLASS
--- linux-rtc.orig/drivers/rtc/Makefile 2006-03-04 16:17:17.000000000 +0100
+++ linux-rtc/drivers/rtc/Makefile 2006-03-04 16:17:18.000000000 +0100
@@ -15,4 +15,5 @@ obj-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o
obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o
obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
+obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-rtc/drivers/rtc/rtc-pcf8563.c 2006-03-04 16:17:18.000000000 +0100
@@ -0,0 +1,355 @@
+/*
+ * An I2C driver for the Philips PCF8563 RTC
+ * Copyright 2005-06 Tower Technologies
+ *
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ * Maintainers: http://www.nslu2-linux.org/
+ *
+ * based on the other drivers in this same directory.
+ *
+ * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
+ *
+ * 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.
+ */
+
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+
+#define DRV_VERSION "0.4.2"
+
+/* Addresses to scan: none
+ * This chip cannot be reliably autodetected. An empty eeprom
+ * located at 0x51 will pass the validation routine due to
+ * the way the registers are implemented.
+ */
+static unsigned short normal_i2c[] = { I2C_CLIENT_END };
+
+/* Module parameters */
+I2C_CLIENT_INSMOD;
+
+#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 */
+
+/* Prototypes */
+static int pcf8563_attach(struct i2c_adapter *adapter);
+static int pcf8563_detach(struct i2c_client *client);
+static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind);
+
+static struct i2c_driver pcf8563_driver = {
+ .driver = {
+ .name = "pcf8563",
+ },
+ .attach_adapter = &pcf8563_attach,
+ .detach_client = &pcf8563_detach,
+};
+
+/*
+ * 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)
+{
+ 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", __FUNCTION__);
+ 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",
+ __FUNCTION__,
+ 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])
+ + (buf[PCF8563_REG_MO] & PCF8563_MO_C ? 100 : 0);
+
+ dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+ "mday=%d, mon=%d, year=%d, wday=%d\n",
+ __FUNCTION__,
+ 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)
+{
+ 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",
+ __FUNCTION__,
+ 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 (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",
+ __FUNCTION__, err, data[0], data[1]);
+ return -EIO;
+ }
+ };
+
+ return 0;
+}
+
+struct pcf8563_limit
+{
+ unsigned char reg;
+ unsigned char mask;
+ unsigned char min;
+ unsigned char max;
+};
+
+static int pcf8563_validate_client(struct i2c_client *client)
+{
+ int i;
+
+ static const struct pcf8563_limit pattern[] = {
+ /* register, mask, min, max */
+ { PCF8563_REG_SC, 0x7F, 0, 59 },
+ { PCF8563_REG_MN, 0x7F, 0, 59 },
+ { PCF8563_REG_HR, 0x3F, 0, 23 },
+ { PCF8563_REG_DM, 0x3F, 0, 31 },
+ { PCF8563_REG_MO, 0x1F, 0, 12 },
+ };
+
+ /* check limits (only registers with bcd values) */
+ for (i = 0; i < ARRAY_SIZE(pattern); i++) {
+ int xfer;
+ unsigned char value;
+ unsigned char buf = pattern[i].reg;
+
+ struct i2c_msg msgs[] = {
+ { client->addr, 0, 1, &buf },
+ { client->addr, I2C_M_RD, 1, &buf },
+ };
+
+ xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+
+ if (xfer != ARRAY_SIZE(msgs)) {
+ dev_err(&client->adapter->dev,
+ "%s: could not read register 0x%02X\n",
+ __FUNCTION__, pattern[i].reg);
+
+ return -EIO;
+ }
+
+ value = BCD2BIN(buf & pattern[i].mask);
+
+ if (value > pattern[i].max ||
+ value < pattern[i].min) {
+ dev_dbg(&client->adapter->dev,
+ "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, "
+ "max=%d, value=%d, raw=0x%02X\n",
+ __FUNCTION__, i, pattern[i].reg, pattern[i].mask,
+ pattern[i].min, pattern[i].max,
+ value, buf);
+
+ return -ENODEV;
+ }
+ }
+
+ 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 int pcf8563_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+ seq_printf(seq, "24hr\t\t: yes\n");
+ return 0;
+}
+
+static struct rtc_class_ops pcf8563_rtc_ops = {
+ .proc = pcf8563_rtc_proc,
+ .read_time = pcf8563_rtc_read_time,
+ .set_time = pcf8563_rtc_set_time,
+};
+
+static int pcf8563_attach(struct i2c_adapter *adapter)
+{
+ return i2c_probe(adapter, &addr_data, pcf8563_probe);
+}
+
+static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind)
+{
+ struct i2c_client *client;
+ struct rtc_device *rtc;
+
+ int err = 0;
+
+ dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
+ err = -ENODEV;
+ goto exit;
+ }
+
+ if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ client->addr = address;
+ client->driver = &pcf8563_driver;
+ client->adapter = adapter;
+
+ strlcpy(client->name, pcf8563_driver.driver.name, I2C_NAME_SIZE);
+
+ /* Verify the chip is really an PCF8563 */
+ if (kind < 0) {
+ if (pcf8563_validate_client(client) < 0) {
+ err = -ENODEV;
+ goto exit_kfree;
+ }
+ }
+
+ /* Inform the i2c layer */
+ if ((err = i2c_attach_client(client)))
+ goto exit_kfree;
+
+ dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
+
+ rtc = rtc_device_register(pcf8563_driver.driver.name, &client->dev,
+ &pcf8563_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(rtc)) {
+ err = PTR_ERR(rtc);
+ dev_err(&client->dev,
+ "unable to register the class device\n");
+ goto exit_detach;
+ }
+
+ i2c_set_clientdata(client, rtc);
+
+ return 0;
+
+exit_detach:
+ i2c_detach_client(client);
+
+exit_kfree:
+ kfree(client);
+
+exit:
+ return err;
+}
+
+static int pcf8563_detach(struct i2c_client *client)
+{
+ int err;
+ struct rtc_device *rtc = i2c_get_clientdata(client);
+
+ dev_dbg(&client->dev, "%s\n", __FUNCTION__);
+
+ if (rtc)
+ rtc_device_unregister(rtc);
+
+ if ((err = i2c_detach_client(client)))
+ return err;
+
+ kfree(client);
+
+ return 0;
+}
+
+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);

--