rtc: m41t80: replace i2c functions for smbus ones

The driver used i2c_transfer methods to read and set date/time.
The smbus methods should be used.

This commit replaces i2c_transfer functions by i2c_smbus_XX_i2c_block_data
for reading and setting the datetime.

Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index cc8b93d2edf5fc6520f102b65b264c60063a66d9..1a769275ab9d87ca39d22d53325ebae84876b910 100644 (file)
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -32,21 +32,21 @@
 #include <linux/watchdog.h>
 #endif
 
-#define M41T80_REG_SSEC        0
-#define M41T80_REG_SEC 1
-#define M41T80_REG_MIN 2
-#define M41T80_REG_HOUR        3
-#define M41T80_REG_WDAY        4
-#define M41T80_REG_DAY 5
-#define M41T80_REG_MON 6
-#define M41T80_REG_YEAR        7
-#define M41T80_REG_ALARM_MON   0xa
-#define M41T80_REG_ALARM_DAY   0xb
-#define M41T80_REG_ALARM_HOUR  0xc
-#define M41T80_REG_ALARM_MIN   0xd
-#define M41T80_REG_ALARM_SEC   0xe
-#define M41T80_REG_FLAGS       0xf
-#define M41T80_REG_SQW 0x13
+#define M41T80_REG_SSEC                0x00
+#define M41T80_REG_SEC         0x01
+#define M41T80_REG_MIN         0x02
+#define M41T80_REG_HOUR                0x03
+#define M41T80_REG_WDAY                0x04
+#define M41T80_REG_DAY         0x05
+#define M41T80_REG_MON         0x06
+#define M41T80_REG_YEAR                0x07
+#define M41T80_REG_ALARM_MON   0x0a
+#define M41T80_REG_ALARM_DAY   0x0b
+#define M41T80_REG_ALARM_HOUR  0x0c
+#define M41T80_REG_ALARM_MIN   0x0d
+#define M41T80_REG_ALARM_SEC   0x0e
+#define M41T80_REG_FLAGS       0x0f
+#define M41T80_REG_SQW         0x13
 
 #define M41T80_DATETIME_REG_SIZE       (M41T80_REG_YEAR + 1)
 #define M41T80_ALARM_REG_SIZE  \
@@ -93,24 +93,13 @@ struct m41t80_data {
 static int m41t80_get_datetime(struct i2c_client *client,
                               struct rtc_time *tm)
 {
-       u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
-       struct i2c_msg msgs[] = {
-               {
-                       .addr   = client->addr,
-                       .flags  = 0,
-                       .len    = 1,
-                       .buf    = dt_addr,
-               },
-               {
-                       .addr   = client->addr,
-                       .flags  = I2C_M_RD,
-                       .len    = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
-                       .buf    = buf + M41T80_REG_SEC,
-               },
-       };
+       unsigned char buf[8];
+       int err;
 
-       if (i2c_transfer(client->adapter, msgs, 2) < 0) {
-               dev_err(&client->dev, "read error\n");
+       err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC,
+                                           sizeof(buf), buf);
+       if (err < 0) {
+               dev_err(&client->dev, "Unable to read date\n");
                return -EIO;
        }
 
@@ -129,67 +118,29 @@ static int m41t80_get_datetime(struct i2c_client *client,
 /* Sets the given date and time to the real time clock. */
 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
-       u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
-       u8 *buf = &wbuf[1];
-       u8 dt_addr[1] = { M41T80_REG_SEC };
-       struct i2c_msg msgs_in[] = {
-               {
-                       .addr   = client->addr,
-                       .flags  = 0,
-                       .len    = 1,
-                       .buf    = dt_addr,
-               },
-               {
-                       .addr   = client->addr,
-                       .flags  = I2C_M_RD,
-                       .len    = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
-                       .buf    = buf + M41T80_REG_SEC,
-               },
-       };
-       struct i2c_msg msgs[] = {
-               {
-                       .addr   = client->addr,
-                       .flags  = 0,
-                       .len    = 1 + M41T80_DATETIME_REG_SIZE,
-                       .buf    = wbuf,
-                },
-       };
+       unsigned char buf[8];
+       int err;
 
-       /* Read current reg values into buf[1..7] */
-       if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
-               dev_err(&client->dev, "read error\n");
-               return -EIO;
-       }
+       if (tm->tm_year < 100 || tm->tm_year > 199)
+               return -EINVAL;
 
-       wbuf[0] = 0; /* offset into rtc's regs */
-       /* Merge time-data and register flags into buf[0..7] */
        buf[M41T80_REG_SSEC] = 0;
-       buf[M41T80_REG_SEC] =
-               bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
-       buf[M41T80_REG_MIN] =
-               bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
-       buf[M41T80_REG_HOUR] =
-               bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f);
-       buf[M41T80_REG_WDAY] =
-               (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
-       buf[M41T80_REG_DAY] =
-               bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
-       buf[M41T80_REG_MON] =
-               bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
-
-       /* assume 20YY not 19YY */
-       if (tm->tm_year < 100 || tm->tm_year > 199) {
-               dev_err(&client->dev, "Year must be between 2000 and 2099. It's %d.\n",
-                       tm->tm_year + 1900);
-               return -EINVAL;
+       buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec);
+       buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min);
+       buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour);
+       buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday);
+       buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1);
+       buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
+       buf[M41T80_REG_WDAY] = tm->tm_wday;
+
+       err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
+                                            sizeof(buf), buf);
+       if (err < 0) {
+               dev_err(&client->dev, "Unable to write to date registers\n");
+               return err;
        }
-       buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
 
-       if (i2c_transfer(client->adapter, msgs, 1) != 1) {
-               dev_err(&client->dev, "write error\n");
-               return -EIO;
-       }
-       return 0;
+       return err;
 }
 
 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
@@ -631,14 +582,17 @@ static void m41t80_remove_sysfs_group(void *_dev)
 static int m41t80_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
+       struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
        int rc = 0;
        struct rtc_device *rtc = NULL;
        struct rtc_time tm;
        struct m41t80_data *clientdata = NULL;
 
-       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
-                                    | I2C_FUNC_SMBUS_BYTE_DATA))
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
+                                    I2C_FUNC_SMBUS_BYTE_DATA)) {
+               dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
                return -ENODEV;
+       }
 
        clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata),
                                GFP_KERNEL);