]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
[PATCH] RTC subsystem: PCF8563 driver
authorAlessandro Zummo <a.zummo@towertech.it>
Mon, 27 Mar 2006 09:16:44 +0000 (01:16 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Mon, 27 Mar 2006 16:44:52 +0000 (08:44 -0800)
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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-pcf8563.c [new file with mode: 0644]

index de335265865452795a5e1f30d4be5ff1710be933..0309fb36875831319348a86d96c0945d7097c85d 100644 (file)
@@ -96,6 +96,17 @@ 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
index f3fd5b0cd735262de470c1b94fe7426a337191dc..bdf7e491d5ac4b2114eb2ee6766e6c7659f74a58 100644 (file)
@@ -14,4 +14,5 @@ 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
 
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
new file mode 100644 (file)
index 0000000..d857d45
--- /dev/null
@@ -0,0 +1,353 @@
+/*
+ * 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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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 */
+
+static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind);
+static int pcf8563_detach(struct i2c_client *client);
+
+/*
+ * 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 struct i2c_driver pcf8563_driver = {
+       .driver         = {
+               .name   = "pcf8563",
+       },
+       .id             = I2C_DRIVERID_PCF8563,
+       .attach_adapter = &pcf8563_attach,
+       .detach_client  = &pcf8563_detach,
+};
+
+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);