rtc: rx8025: don't reset the time
[cascardo/linux.git] / drivers / rtc / rtc-rx8025.c
index 6fe8770..d158a64 100644 (file)
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/bcd.h>
+#include <linux/bitops.h>
 #include <linux/i2c.h>
-#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/rtc.h>
 
 /* Register definitions */
 #define RX8025_BIT_CTRL1_CT    (7 << 0)
 /* 1 Hz periodic level irq */
 #define RX8025_BIT_CTRL1_CT_1HZ        4
-#define RX8025_BIT_CTRL1_TEST  (1 << 3)
-#define RX8025_BIT_CTRL1_1224  (1 << 5)
-#define RX8025_BIT_CTRL1_DALE  (1 << 6)
-#define RX8025_BIT_CTRL1_WALE  (1 << 7)
-
-#define RX8025_BIT_CTRL2_DAFG  (1 << 0)
-#define RX8025_BIT_CTRL2_WAFG  (1 << 1)
-#define RX8025_BIT_CTRL2_CTFG  (1 << 2)
-#define RX8025_BIT_CTRL2_PON   (1 << 4)
-#define RX8025_BIT_CTRL2_XST   (1 << 5)
-#define RX8025_BIT_CTRL2_VDET  (1 << 6)
+#define RX8025_BIT_CTRL1_TEST  BIT(3)
+#define RX8025_BIT_CTRL1_1224  BIT(5)
+#define RX8025_BIT_CTRL1_DALE  BIT(6)
+#define RX8025_BIT_CTRL1_WALE  BIT(7)
+
+#define RX8025_BIT_CTRL2_DAFG  BIT(0)
+#define RX8025_BIT_CTRL2_WAFG  BIT(1)
+#define RX8025_BIT_CTRL2_CTFG  BIT(2)
+#define RX8025_BIT_CTRL2_PON   BIT(4)
+#define RX8025_BIT_CTRL2_XST   BIT(5)
+#define RX8025_BIT_CTRL2_VDET  BIT(6)
 
 /* Clock precision adjustment */
 #define RX8025_ADJ_RESOLUTION  3050 /* in ppb */
@@ -74,14 +72,12 @@ MODULE_DEVICE_TABLE(i2c, rx8025_id);
 struct rx8025_data {
        struct i2c_client *client;
        struct rtc_device *rtc;
-       struct work_struct work;
        u8 ctrl1;
-       unsigned exiting:1;
 };
 
 static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
 {
-       int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
+       int ret = i2c_smbus_read_byte_data(client, number << 4);
 
        if (ret < 0) {
                dev_err(&client->dev, "Unable to read register #%d\n", number);
@@ -95,7 +91,7 @@ static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
 static int rx8025_read_regs(struct i2c_client *client,
                            int number, u8 length, u8 *values)
 {
-       int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
+       int ret = i2c_smbus_read_i2c_block_data(client, number << 4,
                                                length, values);
 
        if (ret != length) {
@@ -121,7 +117,7 @@ static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
 static int rx8025_write_regs(struct i2c_client *client,
                             int number, u8 length, u8 *values)
 {
-       int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
+       int ret = i2c_smbus_write_i2c_block_data(client, number << 4,
                                                 length, values);
 
        if (ret)
@@ -131,26 +127,12 @@ static int rx8025_write_regs(struct i2c_client *client,
        return ret;
 }
 
-static irqreturn_t rx8025_irq(int irq, void *dev_id)
+static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
 {
        struct i2c_client *client = dev_id;
        struct rx8025_data *rx8025 = i2c_get_clientdata(client);
-
-       disable_irq_nosync(irq);
-       schedule_work(&rx8025->work);
-       return IRQ_HANDLED;
-}
-
-static void rx8025_work(struct work_struct *work)
-{
-       struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
-                                                 work);
-       struct i2c_client *client = rx8025->client;
-       struct mutex *lock = &rx8025->rtc->ops_lock;
        u8 status;
 
-       mutex_lock(lock);
-
        if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
                goto out;
 
@@ -178,18 +160,29 @@ static void rx8025_work(struct work_struct *work)
                         status | RX8025_BIT_CTRL2_XST);
 
 out:
-       if (!rx8025->exiting)
-               enable_irq(client->irq);
-
-       mutex_unlock(lock);
+       return IRQ_HANDLED;
 }
 
 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 {
        struct rx8025_data *rx8025 = dev_get_drvdata(dev);
-       u8 date[7];
+       u8 date[7], ctrl;
        int err;
 
+       err = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2, &ctrl);
+       if (err)
+               return err;
+
+       if (ctrl & RX8025_BIT_CTRL2_PON) {
+               dev_warn(dev, "power-on reset detected, date is invalid\n");
+               return -EINVAL;
+       }
+
+       if (!(ctrl & RX8025_BIT_CTRL2_XST)) {
+               dev_warn(dev, "crystal stopped, date is invalid\n");
+               return -EINVAL;
+       }
+
        err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
        if (err)
                return err;
@@ -209,10 +202,7 @@ static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 
        dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
        dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
-       dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
-
-       if (dt->tm_year < 70)
-               dt->tm_year += 100;
+       dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
 
        dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
                dt->tm_sec, dt->tm_min, dt->tm_hour,
@@ -226,11 +216,8 @@ static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
        struct rx8025_data *rx8025 = dev_get_drvdata(dev);
        u8 date[7];
 
-       /*
-        * BUG: The HW assumes every year that is a multiple of 4 to be a leap
-        * year.  Next time this is wrong is 2100, which will not be a leap
-        * year.
-        */
+       if ((dt->tm_year < 100) || (dt->tm_year > 199))
+               return -EINVAL;
 
        /*
         * Here the read-only bits are written as "0".  I'm not sure if that
@@ -247,7 +234,7 @@ static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
        date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
        date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
        date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
-       date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
+       date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
 
        dev_dbg(dev,
                "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
@@ -257,7 +244,7 @@ static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
        return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 }
 
-static int rx8025_init_client(struct i2c_client *client, int *need_reset)
+static int rx8025_init_client(struct i2c_client *client)
 {
        struct rx8025_data *rx8025 = i2c_get_clientdata(client);
        u8 ctrl[2], ctrl2;
@@ -274,19 +261,19 @@ static int rx8025_init_client(struct i2c_client *client, int *need_reset)
        if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
                dev_warn(&client->dev, "power-on reset was detected, "
                         "you may have to readjust the clock\n");
-               *need_reset = 1;
+               need_clear = 1;
        }
 
        if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
                dev_warn(&client->dev, "a power voltage drop was detected, "
                         "you may have to readjust the clock\n");
-               *need_reset = 1;
+               need_clear = 1;
        }
 
        if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
                dev_warn(&client->dev, "Oscillation stop was detected,"
                         "you may have to readjust the clock\n");
-               *need_reset = 1;
+               need_clear = 1;
        }
 
        if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
@@ -297,7 +284,7 @@ static int rx8025_init_client(struct i2c_client *client, int *need_reset)
        if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
                need_clear = 1;
 
-       if (*need_reset || need_clear) {
+       if (need_clear) {
                ctrl2 = ctrl[0];
                ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
                           RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
@@ -535,53 +522,42 @@ static int rx8025_probe(struct i2c_client *client,
 {
        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
        struct rx8025_data *rx8025;
-       int err, need_reset = 0;
+       int err = 0;
 
        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
                                     | I2C_FUNC_SMBUS_I2C_BLOCK)) {
                dev_err(&adapter->dev,
                        "doesn't support required functionality\n");
-               err = -EIO;
-               goto errout;
+               return -EIO;
        }
 
        rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
        if (!rx8025) {
-               err = -ENOMEM;
-               goto errout;
+               return -ENOMEM;
        }
 
        rx8025->client = client;
        i2c_set_clientdata(client, rx8025);
-       INIT_WORK(&rx8025->work, rx8025_work);
 
-       err = rx8025_init_client(client, &need_reset);
+       err = rx8025_init_client(client);
        if (err)
-               goto errout;
-
-       if (need_reset) {
-               struct rtc_time tm;
-               dev_info(&client->dev,
-                        "bad conditions detected, resetting date\n");
-               rtc_time_to_tm(0, &tm); /* 1970/1/1 */
-               rx8025_set_time(&client->dev, &tm);
-       }
+               return err;
 
        rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
                                          &rx8025_rtc_ops, THIS_MODULE);
        if (IS_ERR(rx8025->rtc)) {
-               err = PTR_ERR(rx8025->rtc);
                dev_err(&client->dev, "unable to register the class device\n");
-               goto errout;
+               return PTR_ERR(rx8025->rtc);
        }
 
        if (client->irq > 0) {
                dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
-               err = request_irq(client->irq, rx8025_irq,
-                                 0, "rx8025", client);
+               err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+                                               rx8025_handle_irq, 0, "rx8025",
+                                               client);
                if (err) {
                        dev_err(&client->dev, "unable to request IRQ\n");
-                       goto errout;
+                       return err;
                }
        }
 
@@ -589,34 +565,11 @@ static int rx8025_probe(struct i2c_client *client,
        rx8025->rtc->max_user_freq = 1;
 
        err = rx8025_sysfs_register(&client->dev);
-       if (err)
-               goto errout_irq;
-
-       return 0;
-
-errout_irq:
-       if (client->irq > 0)
-               free_irq(client->irq, client);
-
-errout:
-       dev_err(&adapter->dev, "probing for rx8025 failed\n");
        return err;
 }
 
 static int rx8025_remove(struct i2c_client *client)
 {
-       struct rx8025_data *rx8025 = i2c_get_clientdata(client);
-       struct mutex *lock = &rx8025->rtc->ops_lock;
-
-       if (client->irq > 0) {
-               mutex_lock(lock);
-               rx8025->exiting = 1;
-               mutex_unlock(lock);
-
-               free_irq(client->irq, client);
-               cancel_work_sync(&rx8025->work);
-       }
-
        rx8025_sysfs_unregister(&client->dev);
        return 0;
 }