rtc: ds1307: add support for mcp7940x chips

MCP7940x is same RTC as MCP7941x.  The difference is that MCP7941x chips
contain additional EEPROM on a different i2c address.

DS1307 driver already supports MCP7941x, so just add a new i2c device id
and rename functions and defines accordingly.

Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 64 insertions, 63 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index bb43cf703efc..4ffabb322a9a 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -35,7 +35,7 @@ enum ds_type {
         ds_1388,
         ds_3231,
         m41t00,
-        mcp7941x,
+        mcp794xx,
         rx_8025,
         last_ds_type /* always last */
         /* rs5c372 too?  different address... */
@@ -46,7 +46,7 @@ enum ds_type {
 #define DS1307_REG_SECS         0x00    /* 00-59 */
 #       define DS1307_BIT_CH            0x80
 #       define DS1340_BIT_nEOSC         0x80
-#       define MCP7941X_BIT_ST          0x80
+#       define MCP794XX_BIT_ST          0x80
 #define DS1307_REG_MIN          0x01    /* 00-59 */
 #define DS1307_REG_HOUR         0x02    /* 00-23, or 1-12{am,pm} */
 #       define DS1307_BIT_12HR          0x40    /* in REG_HOUR */
@@ -54,7 +54,7 @@ enum ds_type {
 #       define DS1340_BIT_CENTURY_EN    0x80    /* in REG_HOUR */
 #       define DS1340_BIT_CENTURY       0x40    /* in REG_HOUR */
 #define DS1307_REG_WDAY         0x03    /* 01-07 */
-#       define MCP7941X_BIT_VBATEN      0x08
+#       define MCP794XX_BIT_VBATEN      0x08
 #define DS1307_REG_MDAY         0x04    /* 01-31 */
 #define DS1307_REG_MONTH        0x05    /* 01-12 */
 #       define DS1337_BIT_CENTURY       0x80    /* in REG_MONTH */
@@ -159,7 +159,7 @@ static struct chip_desc chips[last_ds_type] = {
         [ds_3231] = {
                 .alarm          = 1,
         },
-        [mcp7941x] = {
+        [mcp794xx] = {
                 .alarm          = 1,
                 /* this is battery backed SRAM */
                 .nvram_offset   = 0x20,
@@ -176,7 +176,8 @@ static const struct i2c_device_id ds1307_id[] = {
         { "ds1340", ds_1340 },
         { "ds3231", ds_3231 },
         { "m41t00", m41t00 },
-        { "mcp7941x", mcp7941x },
+        { "mcp7940x", mcp794xx },
+        { "mcp7941x", mcp794xx },
         { "pt7c4338", ds_1307 },
         { "rx8025", rx_8025 },
         { }
@@ -439,14 +440,14 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
                 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
                                 | DS1340_BIT_CENTURY;
                 break;
-        case mcp7941x:
+        case mcp794xx:
                 /*
                  * these bits were cleared when preparing the date/time
                  * values and need to be set again before writing the
                  * buffer out to the device.
                  */
-                buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
-                buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
+                buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
+                buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
                 break;
         default:
                 break;
@@ -614,26 +615,26 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
 /*----------------------------------------------------------------------*/
 
 /*
- * Alarm support for mcp7941x devices.
+ * Alarm support for mcp794xx devices.
  */
 
-#define MCP7941X_REG_CONTROL            0x07
-#       define MCP7941X_BIT_ALM0_EN     0x10
-#       define MCP7941X_BIT_ALM1_EN     0x20
-#define MCP7941X_REG_ALARM0_BASE        0x0a
-#define MCP7941X_REG_ALARM0_CTRL        0x0d
-#define MCP7941X_REG_ALARM1_BASE        0x11
-#define MCP7941X_REG_ALARM1_CTRL        0x14
-#       define MCP7941X_BIT_ALMX_IF     (1 << 3)
-#       define MCP7941X_BIT_ALMX_C0     (1 << 4)
-#       define MCP7941X_BIT_ALMX_C1     (1 << 5)
-#       define MCP7941X_BIT_ALMX_C2     (1 << 6)
-#       define MCP7941X_BIT_ALMX_POL    (1 << 7)
-#       define MCP7941X_MSK_ALMX_MATCH  (MCP7941X_BIT_ALMX_C0 | \
-                                         MCP7941X_BIT_ALMX_C1 | \
-                                         MCP7941X_BIT_ALMX_C2)
-
-static void mcp7941x_work(struct work_struct *work)
+#define MCP794XX_REG_CONTROL            0x07
+#       define MCP794XX_BIT_ALM0_EN     0x10
+#       define MCP794XX_BIT_ALM1_EN     0x20
+#define MCP794XX_REG_ALARM0_BASE        0x0a
+#define MCP794XX_REG_ALARM0_CTRL        0x0d
+#define MCP794XX_REG_ALARM1_BASE        0x11
+#define MCP794XX_REG_ALARM1_CTRL        0x14
+#       define MCP794XX_BIT_ALMX_IF     (1 << 3)
+#       define MCP794XX_BIT_ALMX_C0     (1 << 4)
+#       define MCP794XX_BIT_ALMX_C1     (1 << 5)
+#       define MCP794XX_BIT_ALMX_C2     (1 << 6)
+#       define MCP794XX_BIT_ALMX_POL    (1 << 7)
+#       define MCP794XX_MSK_ALMX_MATCH  (MCP794XX_BIT_ALMX_C0 | \
+                                         MCP794XX_BIT_ALMX_C1 | \
+                                         MCP794XX_BIT_ALMX_C2)
+
+static void mcp794xx_work(struct work_struct *work)
 {
         struct ds1307 *ds1307 = container_of(work, struct ds1307, work);
         struct i2c_client *client = ds1307->client;
@@ -642,22 +643,22 @@ static void mcp7941x_work(struct work_struct *work)
         mutex_lock(&ds1307->rtc->ops_lock);
 
         /* Check and clear alarm 0 interrupt flag. */
-        reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_ALARM0_CTRL);
+        reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
         if (reg < 0)
                 goto out;
-        if (!(reg & MCP7941X_BIT_ALMX_IF))
+        if (!(reg & MCP794XX_BIT_ALMX_IF))
                 goto out;
-        reg &= ~MCP7941X_BIT_ALMX_IF;
-        ret = i2c_smbus_write_byte_data(client, MCP7941X_REG_ALARM0_CTRL, reg);
+        reg &= ~MCP794XX_BIT_ALMX_IF;
+        ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
         if (ret < 0)
                 goto out;
 
         /* Disable alarm 0. */
-        reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_CONTROL);
+        reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
         if (reg < 0)
                 goto out;
-        reg &= ~MCP7941X_BIT_ALM0_EN;
-        ret = i2c_smbus_write_byte_data(client, MCP7941X_REG_CONTROL, reg);
+        reg &= ~MCP794XX_BIT_ALM0_EN;
+        ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
         if (ret < 0)
                 goto out;
 
@@ -669,7 +670,7 @@ out:
         mutex_unlock(&ds1307->rtc->ops_lock);
 }
 
-static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
         struct i2c_client *client = to_i2c_client(dev);
         struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -680,11 +681,11 @@ static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
                 return -EINVAL;
 
         /* Read control and alarm 0 registers. */
-        ret = ds1307->read_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+        ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
         if (ret < 0)
                 return ret;
 
-        t->enabled = !!(regs[0] & MCP7941X_BIT_ALM0_EN);
+        t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
 
         /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
         t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
@@ -701,14 +702,14 @@ static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
                 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
-                !!(ds1307->regs[6] & MCP7941X_BIT_ALMX_POL),
-                !!(ds1307->regs[6] & MCP7941X_BIT_ALMX_IF),
-                (ds1307->regs[6] & MCP7941X_MSK_ALMX_MATCH) >> 4);
+                !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
+                !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
+                (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
 
         return 0;
 }
 
-static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
         struct i2c_client *client = to_i2c_client(dev);
         struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -725,7 +726,7 @@ static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
                 t->enabled, t->pending);
 
         /* Read control and alarm 0 registers. */
-        ret = ds1307->read_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+        ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
         if (ret < 0)
                 return ret;
 
@@ -738,23 +739,23 @@ static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
         regs[8] = bin2bcd(t->time.tm_mon) + 1;
 
         /* Clear the alarm 0 interrupt flag. */
-        regs[6] &= ~MCP7941X_BIT_ALMX_IF;
+        regs[6] &= ~MCP794XX_BIT_ALMX_IF;
         /* Set alarm match: second, minute, hour, day, date, month. */
-        regs[6] |= MCP7941X_MSK_ALMX_MATCH;
+        regs[6] |= MCP794XX_MSK_ALMX_MATCH;
 
         if (t->enabled)
-                regs[0] |= MCP7941X_BIT_ALM0_EN;
+                regs[0] |= MCP794XX_BIT_ALM0_EN;
         else
-                regs[0] &= ~MCP7941X_BIT_ALM0_EN;
+                regs[0] &= ~MCP794XX_BIT_ALM0_EN;
 
-        ret = ds1307->write_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+        ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
         if (ret < 0)
                 return ret;
 
         return 0;
 }
 
-static int mcp7941x_alarm_irq_enable(struct device *dev, unsigned int enabled)
+static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
 {
         struct i2c_client *client = to_i2c_client(dev);
         struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -763,24 +764,24 @@ static int mcp7941x_alarm_irq_enable(struct device *dev, unsigned int enabled)
         if (!test_bit(HAS_ALARM, &ds1307->flags))
                 return -EINVAL;
 
-        reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_CONTROL);
+        reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
         if (reg < 0)
                 return reg;
 
         if (enabled)
-                reg |= MCP7941X_BIT_ALM0_EN;
+                reg |= MCP794XX_BIT_ALM0_EN;
         else
-                reg &= ~MCP7941X_BIT_ALM0_EN;
+                reg &= ~MCP794XX_BIT_ALM0_EN;
 
-        return i2c_smbus_write_byte_data(client, MCP7941X_REG_CONTROL, reg);
+        return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
 }
 
-static const struct rtc_class_ops mcp7941x_rtc_ops = {
+static const struct rtc_class_ops mcp794xx_rtc_ops = {
         .read_time      = ds1307_get_time,
         .set_time       = ds1307_set_time,
-        .read_alarm     = mcp7941x_read_alarm,
-        .set_alarm      = mcp7941x_set_alarm,
-        .alarm_irq_enable = mcp7941x_alarm_irq_enable,
+        .read_alarm     = mcp794xx_read_alarm,
+        .set_alarm      = mcp794xx_set_alarm,
+        .alarm_irq_enable = mcp794xx_alarm_irq_enable,
 };
 
 /*----------------------------------------------------------------------*/
@@ -1049,10 +1050,10 @@ static int ds1307_probe(struct i2c_client *client,
         case ds_1388:
                 ds1307->offset = 1; /* Seconds starts at 1 */
                 break;
-        case mcp7941x:
-                rtc_ops = &mcp7941x_rtc_ops;
+        case mcp794xx:
+                rtc_ops = &mcp794xx_rtc_ops;
                 if (ds1307->client->irq > 0 && chip->alarm) {
-                        INIT_WORK(&ds1307->work, mcp7941x_work);
+                        INIT_WORK(&ds1307->work, mcp794xx_work);
                         want_irq = true;
                 }
                 break;
@@ -1117,18 +1118,18 @@ read_rtc:
                         dev_warn(&client->dev, "SET TIME!\n");
                 }
                 break;
-        case mcp7941x:
+        case mcp794xx:
                 /* make sure that the backup battery is enabled */
-                if (!(ds1307->regs[DS1307_REG_WDAY] & MCP7941X_BIT_VBATEN)) {
+                if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
                         i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
                                         ds1307->regs[DS1307_REG_WDAY]
-                                        | MCP7941X_BIT_VBATEN);
+                                        | MCP794XX_BIT_VBATEN);
                 }
 
                 /* clock halted?  turn it on, so clock can tick. */
-                if (!(tmp & MCP7941X_BIT_ST)) {
+                if (!(tmp & MCP794XX_BIT_ST)) {
                         i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
-                                        MCP7941X_BIT_ST);
+                                        MCP794XX_BIT_ST);
                         dev_warn(&client->dev, "SET TIME!\n");
                         goto read_rtc;
                 }