rtc-ds1307: SMBus compatibility

Change i2c access functions to SMBus access functions in order to use the
ds1307 with SMBus adapter.

Signed-off-by: Sebastien Barre <sbarre@sdelcc.com>
Acked-by: David Brownell <david-b@pacbell.net>
Tested-by: David Brownell <david-b@pacbell.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Tested-by: Sebastien Barre <sbarre@sdelcc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 35 insertions, 88 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 162330b9d1dc..fec13e7d48ef 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -86,13 +86,11 @@ enum ds_type {
 
 
 struct ds1307 {
-        u8                      reg_addr;
         u8                      regs[11];
         enum ds_type            type;
         unsigned long           flags;
 #define HAS_NVRAM       0               /* bit 0 == sysfs file active */
 #define HAS_ALARM       1               /* bit 1 == irq claimed */
-        struct i2c_msg          msg[2];
         struct i2c_client       *client;
         struct rtc_device       *rtc;
         struct work_struct      work;
@@ -204,13 +202,9 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
         int             tmp;
 
         /* read the RTC date and time registers all at once */
-        ds1307->reg_addr = 0;
-        ds1307->msg[1].flags = I2C_M_RD;
-        ds1307->msg[1].len = 7;
-
-        tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
-                        ds1307->msg, 2);
-        if (tmp != 2) {
+        tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+                DS1307_REG_SECS, 7, ds1307->regs);
+        if (tmp != 7) {
                 dev_err(dev, "%s error %d\n", "read", tmp);
                 return -EIO;
         }
@@ -257,7 +251,6 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
                 t->tm_hour, t->tm_mday,
                 t->tm_mon, t->tm_year, t->tm_wday);
 
-        *buf++ = 0;             /* first register addr */
         buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
         buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
         buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
@@ -282,18 +275,14 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
                 break;
         }
 
-        ds1307->msg[1].flags = 0;
-        ds1307->msg[1].len = 8;
-
         dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
                 "write", buf[0], buf[1], buf[2], buf[3],
                 buf[4], buf[5], buf[6]);
 
-        result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
-                        &ds1307->msg[1], 1);
-        if (result != 1) {
-                dev_err(dev, "%s error %d\n", "write", tmp);
-                return -EIO;
+        result = i2c_smbus_write_i2c_block_data(ds1307->client, 0, 7, buf);
+        if (result < 0) {
+                dev_err(dev, "%s error %d\n", "write", result);
+                return result;
         }
         return 0;
 }
@@ -308,13 +297,9 @@ static int ds1307_read_alarm(struct device *dev, struct rtc_wkalrm *t)
                 return -EINVAL;
 
         /* read all ALARM1, ALARM2, and status registers at once */
-        ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
-        ds1307->msg[1].flags = I2C_M_RD;
-        ds1307->msg[1].len = 9;
-
-        ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-                        ds1307->msg, 2);
-        if (ret != 2) {
+        ret = i2c_smbus_read_i2c_block_data(client,
+                        DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
+        if (ret != 9) {
                 dev_err(dev, "%s error %d\n", "alarm read", ret);
                 return -EIO;
         }
@@ -371,13 +356,9 @@ static int ds1307_set_alarm(struct device *dev, struct rtc_wkalrm *t)
                 t->enabled, t->pending);
 
         /* read current status of both alarms and the chip */
-        ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
-        ds1307->msg[1].flags = I2C_M_RD;
-        ds1307->msg[1].len = 9;
-
-        ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-                        ds1307->msg, 2);
-        if (ret != 2) {
+        ret = i2c_smbus_read_i2c_block_data(client,
+                        DS1339_REG_ALARM1_SECS, 9, buf);
+        if (ret != 9) {
                 dev_err(dev, "%s error %d\n", "alarm write", ret);
                 return -EIO;
         }
@@ -392,7 +373,6 @@ static int ds1307_set_alarm(struct device *dev, struct rtc_wkalrm *t)
                         ds1307->regs[6], control, status);
 
         /* set ALARM1, using 24 hour and day-of-month modes */
-        *buf++ = DS1339_REG_ALARM1_SECS;        /* first register addr */
         buf[0] = bin2bcd(t->time.tm_sec);
         buf[1] = bin2bcd(t->time.tm_min);
         buf[2] = bin2bcd(t->time.tm_hour);
@@ -411,14 +391,11 @@ static int ds1307_set_alarm(struct device *dev, struct rtc_wkalrm *t)
         }
         buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
 
-        ds1307->msg[1].flags = 0;
-        ds1307->msg[1].len = 10;
-
-        ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-                        &ds1307->msg[1], 1);
-        if (ret != 1) {
+        ret = i2c_smbus_write_i2c_block_data(client,
+                        DS1339_REG_ALARM1_SECS, 9, buf);
+        if (ret < 0) {
                 dev_err(dev, "can't set alarm time\n");
-                return -EIO;
+                return ret;
         }
 
         return 0;
@@ -490,7 +467,6 @@ ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
 {
         struct i2c_client       *client;
         struct ds1307           *ds1307;
-        struct i2c_msg          msg[2];
         int                     result;
 
         client = kobj_to_i2c_client(kobj);
@@ -503,24 +479,10 @@ ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
         if (unlikely(!count))
                 return count;
 
-        msg[0].addr = client->addr;
-        msg[0].flags = 0;
-        msg[0].len = 1;
-        msg[0].buf = buf;
-
-        buf[0] = 8 + off;
-
-        msg[1].addr = client->addr;
-        msg[1].flags = I2C_M_RD;
-        msg[1].len = count;
-        msg[1].buf = buf;
-
-        result = i2c_transfer(to_i2c_adapter(client->dev.parent), msg, 2);
-        if (result != 2) {
+        result = i2c_smbus_read_i2c_block_data(client, 8 + off, count, buf);
+        if (result < 0)
                 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
-                return -EIO;
-        }
-        return count;
+        return result;
 }
 
 static ssize_t
@@ -528,8 +490,7 @@ ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
                 char *buf, loff_t off, size_t count)
 {
         struct i2c_client       *client;
-        u8                      buffer[NVRAM_SIZE + 1];
-        int                     ret;
+        int                     result;
 
         client = kobj_to_i2c_client(kobj);
 
@@ -540,11 +501,12 @@ ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
         if (unlikely(!count))
                 return count;
 
-        buffer[0] = 8 + off;
-        memcpy(buffer + 1, buf, count);
-
-        ret = i2c_master_send(client, buffer, count + 1);
-        return (ret < 0) ? ret : (ret - 1);
+        result = i2c_smbus_write_i2c_block_data(client, 8 + off, count, buf);
+        if (result < 0) {
+                dev_err(&client->dev, "%s error %d\n", "nvram write", result);
+                return result;
+        }
+        return count;
 }
 
 static struct bin_attribute nvram = {
@@ -571,9 +533,11 @@ static int __devinit ds1307_probe(struct i2c_client *client,
         const struct chip_desc  *chip = &chips[id->driver_data];
         struct i2c_adapter      *adapter = to_i2c_adapter(client->dev.parent);
         int                     want_irq = false;
+        unsigned char           *buf;
 
         if (!i2c_check_functionality(adapter,
-                        I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+                        I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+                        I2C_FUNC_SMBUS_I2C_BLOCK))
                 return -EIO;
 
         if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
@@ -581,18 +545,8 @@ static int __devinit ds1307_probe(struct i2c_client *client,
 
         ds1307->client = client;
         i2c_set_clientdata(client, ds1307);
-
-        ds1307->msg[0].addr = client->addr;
-        ds1307->msg[0].flags = 0;
-        ds1307->msg[0].len = 1;
-        ds1307->msg[0].buf = &ds1307->reg_addr;
-
-        ds1307->msg[1].addr = client->addr;
-        ds1307->msg[1].flags = I2C_M_RD;
-        ds1307->msg[1].len = sizeof(ds1307->regs);
-        ds1307->msg[1].buf = ds1307->regs;
-
         ds1307->type = id->driver_data;
+        buf = ds1307->regs;
 
         switch (ds1307->type) {
         case ds_1337:
@@ -602,21 +556,15 @@ static int __devinit ds1307_probe(struct i2c_client *client,
                         INIT_WORK(&ds1307->work, ds1307_work);
                         want_irq = true;
                 }
-
-                ds1307->reg_addr = DS1337_REG_CONTROL;
-                ds1307->msg[1].len = 2;
-
                 /* get registers that the "rtc" read below won't read... */
-                tmp = i2c_transfer(adapter, ds1307->msg, 2);
+                tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+                                DS1337_REG_CONTROL, 2, buf);
                 if (tmp != 2) {
                         pr_debug("read error %d\n", tmp);
                         err = -EIO;
                         goto exit_free;
                 }
 
-                ds1307->reg_addr = 0;
-                ds1307->msg[1].len = sizeof(ds1307->regs);
-
                 /* oscillator off?  turn it on, so clock can tick. */
                 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
                         ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
@@ -647,9 +595,8 @@ static int __devinit ds1307_probe(struct i2c_client *client,
 
 read_rtc:
         /* read RTC registers */
-
-        tmp = i2c_transfer(adapter, ds1307->msg, 2);
-        if (tmp != 2) {
+        tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 0, 8, buf);
+        if (tmp != 8) {
                 pr_debug("read error %d\n", tmp);
                 err = -EIO;
                 goto exit_free;