[PATCH] drivers/acorn/char/pcf8583.[hc] vs. RTC subsystem
authorG. Liakhovetski <gl@dsa-ac.de>
Sun, 25 Jun 2006 12:48:18 +0000 (05:48 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sun, 25 Jun 2006 17:01:13 +0000 (10:01 -0700)
A port of the driver for the pcf8583 i2c rtc controller to the generic RTC
framework by Alessandro Zummo.  Based on
drivers/acorn/char/{pcf8583.[hc],i2c.c}.  Hopefully, acorn can be converted
too to use this driver in the future.

Signed-off-by: G. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jean Delvare <khali@linux-fr.org>
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-pcf8583.c [new file with mode: 0644]

index 725d6b6..37ee69f 100644 (file)
@@ -132,6 +132,16 @@ config RTC_DRV_PCF8563
          This driver can also be built as a module. If so, the module
          will be called rtc-pcf8563.
 
+config RTC_DRV_PCF8583
+       tristate "Philips PCF8583"
+       depends on RTC_CLASS && I2C
+       help
+         If you say yes here you get support for the
+         Philips PCF8583 RTC chip.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-pcf8583.
+
 config RTC_DRV_RS5C372
        tristate "Ricoh RS5C372A/B"
        depends on RTC_CLASS && I2C
index ca8bed5..090f197 100644 (file)
@@ -16,6 +16,7 @@ obj-$(CONFIG_RTC_DRV_TEST)    += rtc-test.o
 obj-$(CONFIG_RTC_DRV_DS1307)   += rtc-ds1307.o
 obj-$(CONFIG_RTC_DRV_DS1672)   += rtc-ds1672.o
 obj-$(CONFIG_RTC_DRV_PCF8563)  += rtc-pcf8563.o
+obj-$(CONFIG_RTC_DRV_PCF8583)  += rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_RS5C372)  += rtc-rs5c372.o
 obj-$(CONFIG_RTC_DRV_M48T86)   += rtc-m48t86.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
diff --git a/drivers/rtc/rtc-pcf8583.c b/drivers/rtc/rtc-pcf8583.c
new file mode 100644 (file)
index 0000000..b235a30
--- /dev/null
@@ -0,0 +1,394 @@
+/*
+ *  drivers/rtc/rtc-pcf8583.c
+ *
+ *  Copyright (C) 2000 Russell King
+ *
+ * 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.
+ *
+ *  Driver for PCF8583 RTC & RAM chip
+ *
+ *  Converted to the generic RTC susbsystem by G. Liakhovetski (2006)
+ */
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/mc146818rtc.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/bcd.h>
+
+struct rtc_mem {
+       unsigned int    loc;
+       unsigned int    nr;
+       unsigned char   *data;
+};
+
+struct pcf8583 {
+       struct i2c_client client;
+       struct rtc_device *rtc;
+       unsigned char ctrl;
+};
+
+#define CTRL_STOP      0x80
+#define CTRL_HOLD      0x40
+#define CTRL_32KHZ     0x00
+#define CTRL_MASK      0x08
+#define CTRL_ALARMEN   0x04
+#define CTRL_ALARM     0x02
+#define CTRL_TIMER     0x01
+
+static unsigned short normal_i2c[] = { I2C_CLIENT_END };
+
+/* Module parameters */
+I2C_CLIENT_INSMOD;
+
+static struct i2c_driver pcf8583_driver;
+
+#define get_ctrl(x)    ((struct pcf8583 *)i2c_get_clientdata(x))->ctrl
+#define set_ctrl(x, v) get_ctrl(x) = v
+
+#define CMOS_YEAR      (64 + 128)
+#define CMOS_CHECKSUM  (63)
+
+static int pcf8583_get_datetime(struct i2c_client *client, struct rtc_time *dt)
+{
+       unsigned char buf[8], addr[1] = { 1 };
+       struct i2c_msg msgs[2] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = 1,
+                       .buf = addr,
+               }, {
+                       .addr = client->addr,
+                       .flags = I2C_M_RD,
+                       .len = 6,
+                       .buf = buf,
+               }
+       };
+       int ret;
+
+       memset(buf, 0, sizeof(buf));
+
+       ret = i2c_transfer(client->adapter, msgs, 2);
+       if (ret == 2) {
+               dt->tm_year = buf[4] >> 6;
+               dt->tm_wday = buf[5] >> 5;
+
+               buf[4] &= 0x3f;
+               buf[5] &= 0x1f;
+
+               dt->tm_sec = BCD_TO_BIN(buf[1]);
+               dt->tm_min = BCD_TO_BIN(buf[2]);
+               dt->tm_hour = BCD_TO_BIN(buf[3]);
+               dt->tm_mday = BCD_TO_BIN(buf[4]);
+               dt->tm_mon = BCD_TO_BIN(buf[5]);
+       }
+
+       return ret == 2 ? 0 : -EIO;
+}
+
+static int pcf8583_set_datetime(struct i2c_client *client, struct rtc_time *dt, int datetoo)
+{
+       unsigned char buf[8];
+       int ret, len = 6;
+
+       buf[0] = 0;
+       buf[1] = get_ctrl(client) | 0x80;
+       buf[2] = 0;
+       buf[3] = BIN_TO_BCD(dt->tm_sec);
+       buf[4] = BIN_TO_BCD(dt->tm_min);
+       buf[5] = BIN_TO_BCD(dt->tm_hour);
+
+       if (datetoo) {
+               len = 8;
+               buf[6] = BIN_TO_BCD(dt->tm_mday) | (dt->tm_year << 6);
+               buf[7] = BIN_TO_BCD(dt->tm_mon)  | (dt->tm_wday << 5);
+       }
+
+       ret = i2c_master_send(client, (char *)buf, len);
+       if (ret != len)
+               return -EIO;
+
+       buf[1] = get_ctrl(client);
+       ret = i2c_master_send(client, (char *)buf, 2);
+
+       return ret == 2 ? 0 : -EIO;
+}
+
+static int pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
+{
+       *ctrl = get_ctrl(client);
+       return 0;
+}
+
+static int pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
+{
+       unsigned char buf[2];
+
+       buf[0] = 0;
+       buf[1] = *ctrl;
+       set_ctrl(client, *ctrl);
+
+       return i2c_master_send(client, (char *)buf, 2);
+}
+
+static int pcf8583_read_mem(struct i2c_client *client, struct rtc_mem *mem)
+{
+       unsigned char addr[1];
+       struct i2c_msg msgs[2] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = 1,
+                       .buf = addr,
+               }, {
+                       .addr = client->addr,
+                       .flags = I2C_M_RD,
+                       .len = mem->nr,
+                       .buf = mem->data,
+               }
+       };
+
+       if (mem->loc < 8)
+               return -EINVAL;
+
+       addr[0] = mem->loc;
+
+       return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
+}
+
+static int pcf8583_write_mem(struct i2c_client *client, struct rtc_mem *mem)
+{
+       unsigned char addr[1];
+       struct i2c_msg msgs[2] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = 1,
+                       .buf = addr,
+               }, {
+                       .addr = client->addr,
+                       .flags = I2C_M_NOSTART,
+                       .len = mem->nr,
+                       .buf = mem->data,
+               }
+       };
+
+       if (mem->loc < 8)
+               return -EINVAL;
+
+       addr[0] = mem->loc;
+
+       return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
+}
+
+static int pcf8583_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       unsigned char ctrl, year[2];
+       struct rtc_mem mem = { CMOS_YEAR, sizeof(year), year };
+       int real_year, year_offset, err;
+
+       /*
+        * Ensure that the RTC is running.
+        */
+       pcf8583_get_ctrl(client, &ctrl);
+       if (ctrl & (CTRL_STOP | CTRL_HOLD)) {
+               unsigned char new_ctrl = ctrl & ~(CTRL_STOP | CTRL_HOLD);
+
+               printk(KERN_WARNING "RTC: resetting control %02x -> %02x\n",
+                      ctrl, new_ctrl);
+
+               if ((err = pcf8583_set_ctrl(client, &new_ctrl)) < 0)
+                       return err;
+       }
+
+       if (pcf8583_get_datetime(client, tm) ||
+           pcf8583_read_mem(client, &mem))
+               return -EIO;
+
+       real_year = year[0];
+
+       /*
+        * The RTC year holds the LSB two bits of the current
+        * year, which should reflect the LSB two bits of the
+        * CMOS copy of the year.  Any difference indicates
+        * that we have to correct the CMOS version.
+        */
+       year_offset = tm->tm_year - (real_year & 3);
+       if (year_offset < 0)
+               /*
+                * RTC year wrapped.  Adjust it appropriately.
+                */
+               year_offset += 4;
+
+       tm->tm_year = real_year + year_offset + year[1] * 100;
+
+       return 0;
+}
+
+static int pcf8583_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       unsigned char year[2], chk;
+       struct rtc_mem cmos_year  = { CMOS_YEAR, sizeof(year), year };
+       struct rtc_mem cmos_check = { CMOS_CHECKSUM, 1, &chk };
+       int ret;
+
+       /*
+        * The RTC's own 2-bit year must reflect the least
+        * significant two bits of the CMOS year.
+        */
+
+       ret = pcf8583_set_datetime(client, tm, 1);
+       if (ret)
+               return ret;
+
+       ret = pcf8583_read_mem(client, &cmos_check);
+       if (ret)
+               return ret;
+
+       ret = pcf8583_read_mem(client, &cmos_year);
+       if (ret)
+               return ret;
+
+       chk -= year[1] + year[0];
+
+       year[1] = tm->tm_year / 100;
+       year[0] = tm->tm_year % 100;
+
+       chk += year[1] + year[0];
+
+       ret = pcf8583_write_mem(client, &cmos_year);
+
+       if (ret)
+               return ret;
+
+       ret = pcf8583_write_mem(client, &cmos_check);
+
+       return ret;
+}
+
+static struct rtc_class_ops pcf8583_rtc_ops = {
+       .read_time      = pcf8583_rtc_read_time,
+       .set_time       = pcf8583_rtc_set_time,
+};
+
+static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind);
+
+static int pcf8583_attach(struct i2c_adapter *adap)
+{
+       return i2c_probe(adap, &addr_data, pcf8583_probe);
+}
+
+static int pcf8583_detach(struct i2c_client *client)
+{
+       int err;
+       struct pcf8583 *pcf = i2c_get_clientdata(client);
+       struct rtc_device *rtc = pcf->rtc;
+
+       if (rtc)
+               rtc_device_unregister(rtc);
+
+       if ((err = i2c_detach_client(client)))
+               return err;
+
+       kfree(pcf);
+       return 0;
+}
+
+static struct i2c_driver pcf8583_driver = {
+       .driver = {
+               .name   = "pcf8583",
+       },
+       .id             = I2C_DRIVERID_PCF8583,
+       .attach_adapter = pcf8583_attach,
+       .detach_client  = pcf8583_detach,
+};
+
+static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind)
+{
+       struct pcf8583 *pcf;
+       struct i2c_client *client;
+       struct rtc_device *rtc;
+       unsigned char buf[1], ad[1] = { 0 };
+       int err;
+       struct i2c_msg msgs[2] = {
+               {
+                       .addr = addr,
+                       .flags = 0,
+                       .len = 1,
+                       .buf = ad,
+               }, {
+                       .addr = addr,
+                       .flags = I2C_M_RD,
+                       .len = 1,
+                       .buf = buf,
+               }
+       };
+
+       pcf = kzalloc(sizeof(*pcf), GFP_KERNEL);
+       if (!pcf)
+               return -ENOMEM;
+
+       client = &pcf->client;
+
+       client->addr            = addr;
+       client->adapter = adap;
+       client->driver  = &pcf8583_driver;
+
+       strlcpy(client->name, pcf8583_driver.driver.name, I2C_NAME_SIZE);
+
+       if (i2c_transfer(client->adapter, msgs, 2) != 2) {
+               err = -EIO;
+               goto exit_kfree;
+       }
+
+       err = i2c_attach_client(client);
+
+       if (err)
+               goto exit_kfree;
+
+       rtc = rtc_device_register(pcf8583_driver.driver.name, &client->dev,
+                                 &pcf8583_rtc_ops, THIS_MODULE);
+
+       if (IS_ERR(rtc)) {
+               err = PTR_ERR(rtc);
+               goto exit_detach;
+       }
+
+       pcf->rtc = rtc;
+       i2c_set_clientdata(client, pcf);
+       set_ctrl(client, buf[0]);
+
+       return 0;
+
+exit_detach:
+       i2c_detach_client(client);
+
+exit_kfree:
+       kfree(pcf);
+
+       return err;
+}
+
+static __init int pcf8583_init(void)
+{
+       return i2c_add_driver(&pcf8583_driver);
+}
+
+static __exit void pcf8583_exit(void)
+{
+       i2c_del_driver(&pcf8583_driver);
+}
+
+module_init(pcf8583_init);
+module_exit(pcf8583_exit);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("PCF8583 I2C RTC driver");
+MODULE_LICENSE("GPL");