1 files changed, 246 insertions, 0 deletions

diff --git a/drivers/i2c/chips/m41t00.c b/drivers/i2c/chips/m41t00.c
new file mode 100644
index 000000000000..e771566dffa8
--- /dev/null
+++ b/drivers/i2c/chips/m41t00.c
@@ -0,0 +1,246 @@
+/*
+ * drivers/i2c/chips/m41t00.c
+ *
+ * I2C client/driver for the ST M41T00 Real-Time Clock chip.
+ *
+ * Author: Mark A. Greer <mgreer@mvista.com>
+ *
+ * 2005 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+/*
+ * This i2c client/driver wedges between the drivers/char/genrtc.c RTC
+ * interface and the SMBus interface of the i2c subsystem.
+ * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
+ * recommened in .../Documentation/i2c/writing-clients section
+ * "Sending and receiving", using SMBus level communication is preferred.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+#include <asm/time.h>
+#include <asm/rtc.h>
+
+#define M41T00_DRV_NAME         "m41t00"
+
+static DECLARE_MUTEX(m41t00_mutex);
+
+static struct i2c_driver m41t00_driver;
+static struct i2c_client *save_client;
+
+static unsigned short ignore[] = { I2C_CLIENT_END };
+static unsigned short normal_addr[] = { 0x68, I2C_CLIENT_END };
+
+static struct i2c_client_address_data addr_data = {
+        .normal_i2c             = normal_addr,
+        .normal_i2c_range       = ignore,
+        .probe                  = ignore,
+        .probe_range            = ignore,
+        .ignore                 = ignore,
+        .ignore_range           = ignore,
+        .force                  = ignore,
+};
+
+ulong
+m41t00_get_rtc_time(void)
+{
+        s32     sec, min, hour, day, mon, year;
+        s32     sec1, min1, hour1, day1, mon1, year1;
+        ulong   limit = 10;
+
+        sec = min = hour = day = mon = year = 0;
+        sec1 = min1 = hour1 = day1 = mon1 = year1 = 0;
+
+        down(&m41t00_mutex);
+        do {
+                if (((sec = i2c_smbus_read_byte_data(save_client, 0)) >= 0)
+                        && ((min = i2c_smbus_read_byte_data(save_client, 1))
+                                >= 0)
+                        && ((hour = i2c_smbus_read_byte_data(save_client, 2))
+                                >= 0)
+                        && ((day = i2c_smbus_read_byte_data(save_client, 4))
+                                >= 0)
+                        && ((mon = i2c_smbus_read_byte_data(save_client, 5))
+                                >= 0)
+                        && ((year = i2c_smbus_read_byte_data(save_client, 6))
+                                >= 0)
+                        && ((sec == sec1) && (min == min1) && (hour == hour1)
+                                && (day == day1) && (mon == mon1)
+                                && (year == year1)))
+
+                                break;
+
+                sec1 = sec;
+                min1 = min;
+                hour1 = hour;
+                day1 = day;
+                mon1 = mon;
+                year1 = year;
+        } while (--limit > 0);
+        up(&m41t00_mutex);
+
+        if (limit == 0) {
+                dev_warn(&save_client->dev,
+                        "m41t00: can't read rtc chip\n");
+                sec = min = hour = day = mon = year = 0;
+        }
+
+        sec &= 0x7f;
+        min &= 0x7f;
+        hour &= 0x3f;
+        day &= 0x3f;
+        mon &= 0x1f;
+        year &= 0xff;
+
+        BCD_TO_BIN(sec);
+        BCD_TO_BIN(min);
+        BCD_TO_BIN(hour);
+        BCD_TO_BIN(day);
+        BCD_TO_BIN(mon);
+        BCD_TO_BIN(year);
+
+        year += 1900;
+        if (year < 1970)
+                year += 100;
+
+        return mktime(year, mon, day, hour, min, sec);
+}
+
+static void
+m41t00_set_tlet(ulong arg)
+{
+        struct rtc_time tm;
+        ulong   nowtime = *(ulong *)arg;
+
+        to_tm(nowtime, &tm);
+        tm.tm_year = (tm.tm_year - 1900) % 100;
+
+        BIN_TO_BCD(tm.tm_sec);
+        BIN_TO_BCD(tm.tm_min);
+        BIN_TO_BCD(tm.tm_hour);
+        BIN_TO_BCD(tm.tm_mon);
+        BIN_TO_BCD(tm.tm_mday);
+        BIN_TO_BCD(tm.tm_year);
+
+        down(&m41t00_mutex);
+        if ((i2c_smbus_write_byte_data(save_client, 0, tm.tm_sec & 0x7f) < 0)
+                || (i2c_smbus_write_byte_data(save_client, 1, tm.tm_min & 0x7f)
+                        < 0)
+                || (i2c_smbus_write_byte_data(save_client, 2, tm.tm_hour & 0x7f)
+                        < 0)
+                || (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x7f)
+                        < 0)
+                || (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x7f)
+                        < 0)
+                || (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0x7f)
+                        < 0))
+
+                dev_warn(&save_client->dev,"m41t00: can't write to rtc chip\n");
+
+        up(&m41t00_mutex);
+        return;
+}
+
+ulong   new_time;
+
+DECLARE_TASKLET_DISABLED(m41t00_tasklet, m41t00_set_tlet, (ulong)&new_time);
+
+int
+m41t00_set_rtc_time(ulong nowtime)
+{
+        new_time = nowtime;
+
+        if (in_interrupt())
+                tasklet_schedule(&m41t00_tasklet);
+        else
+                m41t00_set_tlet((ulong)&new_time);
+
+        return 0;
+}
+
+/*
+ *****************************************************************************
+ *
+ *      Driver Interface
+ *
+ *****************************************************************************
+ */
+static int
+m41t00_probe(struct i2c_adapter *adap, int addr, int kind)
+{
+        struct i2c_client *client;
+        int rc;
+
+        client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
+        if (!client)
+                return -ENOMEM;
+
+        memset(client, 0, sizeof(struct i2c_client));
+        strncpy(client->name, M41T00_DRV_NAME, I2C_NAME_SIZE);
+        client->flags = I2C_DF_NOTIFY;
+        client->addr = addr;
+        client->adapter = adap;
+        client->driver = &m41t00_driver;
+
+        if ((rc = i2c_attach_client(client)) != 0) {
+                kfree(client);
+                return rc;
+        }
+
+        save_client = client;
+        return 0;
+}
+
+static int
+m41t00_attach(struct i2c_adapter *adap)
+{
+        return i2c_probe(adap, &addr_data, m41t00_probe);
+}
+
+static int
+m41t00_detach(struct i2c_client *client)
+{
+        int     rc;
+
+        if ((rc = i2c_detach_client(client)) == 0) {
+                kfree(i2c_get_clientdata(client));
+                tasklet_kill(&m41t00_tasklet);
+        }
+        return rc;
+}
+
+static struct i2c_driver m41t00_driver = {
+        .owner          = THIS_MODULE,
+        .name           = M41T00_DRV_NAME,
+        .id             = I2C_DRIVERID_STM41T00,
+        .flags          = I2C_DF_NOTIFY,
+        .attach_adapter = m41t00_attach,
+        .detach_client  = m41t00_detach,
+};
+
+static int __init
+m41t00_init(void)
+{
+        return i2c_add_driver(&m41t00_driver);
+}
+
+static void __exit
+m41t00_exit(void)
+{
+        i2c_del_driver(&m41t00_driver);
+        return;
+}
+
+module_init(m41t00_init);
+module_exit(m41t00_exit);
+
+MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
+MODULE_DESCRIPTION("ST Microelectronics M41T00 RTC I2C Client Driver");
+MODULE_LICENSE("GPL");